1 المقدمة

يعدد هذا المستند المتطلبات التي يجب استيفاؤها حتى تكون الأجهزة متوافقة مع Android 7.1.

إن استخدام "يجب" و"يجب ألا" و"مطلوب" و"يجب" و"لا يجوز" و"ينبغي" و"ينبغي ألا" و"موصى به" و"قد" و"اختياري" هو وفقًا لـ IETF المعيار المحدد في RFC2119 .

كما هو مستخدم في هذا المستند، فإن "منفذ الجهاز" أو "المنفذ" هو شخص أو مؤسسة تقوم بتطوير حل أجهزة/برنامج يعمل بنظام التشغيل Android 7.1. "تنفيذ الجهاز" أو "التنفيذ هو حل الأجهزة/البرمجيات الذي تم تطويره على هذا النحو.

لكي يتم اعتبارها متوافقة مع Android 7.1، يجب أن تستوفي تطبيقات الجهاز المتطلبات الواردة في تعريف التوافق هذا، بما في ذلك أي مستندات مدمجة عبر مرجع.

عندما يكون هذا التعريف أو اختبارات البرامج الموضحة في القسم 10 صامتة أو غامضة أو غير كاملة، تقع على عاتق منفذ الجهاز مسؤولية ضمان التوافق مع التطبيقات الحالية.

لهذا السبب، يعد مشروع Android مفتوح المصدر هو المرجع والتطبيق المفضل لنظام Android. يوصى بشدة بمنفذي الأجهزة أن يبنوا عملياتهم إلى أقصى حد ممكن على كود المصدر "المنبع" المتوفر من مشروع Android مفتوح المصدر. في حين أنه يمكن استبدال بعض المكونات افتراضيًا بتطبيقات بديلة، إلا أنه يوصى بشدة بعدم اتباع هذه الممارسة، لأن اجتياز اختبارات البرامج سيصبح أكثر صعوبة إلى حد كبير. تقع على عاتق المُنفِّذ مسؤولية ضمان التوافق السلوكي الكامل مع تطبيق Android القياسي، بما في ذلك مجموعة اختبار التوافق وما بعدها. أخيرًا، لاحظ أن بعض بدائل وتعديلات المكونات محظورة صراحةً بموجب هذه الوثيقة.

العديد من الموارد المرتبطة بهذا المستند مستمدة بشكل مباشر أو غير مباشر من Android SDK وستكون متطابقة وظيفيًا مع المعلومات الموجودة في وثائق SDK تلك. في أي حالة لا يتفق فيها تعريف التوافق هذا أو مجموعة اختبار التوافق مع وثائق SDK، تعتبر وثائق SDK موثوقة. أي تفاصيل فنية مقدمة في الموارد المرتبطة في هذه الوثيقة تعتبر من خلال تضمينها جزءًا من تعريف التوافق هذا.

2. أنواع الأجهزة

في حين تم استخدام مشروع Android مفتوح المصدر في تنفيذ مجموعة متنوعة من أنواع الأجهزة وعوامل الشكل، فقد تم تحسين العديد من جوانب البنية ومتطلبات التوافق للأجهزة المحمولة. بدءًا من Android 5.0، يهدف مشروع Android Open Source Project إلى احتضان مجموعة واسعة من أنواع الأجهزة كما هو موضح في هذا القسم.

يشير جهاز Android المحمول إلى تطبيق جهاز Android الذي يتم استخدامه عادةً عن طريق الإمساك به في اليد، مثل مشغلات mp3 والهواتف والأجهزة اللوحية. تطبيقات الأجهزة المحمولة التي تعمل بنظام Android:

• يجب أن يكون لديك شاشة تعمل باللمس مدمجة في الجهاز.
• يجب أن يكون لديك مصدر طاقة يوفر إمكانية التنقل، مثل البطارية.

يشير جهاز Android Television إلى تطبيق جهاز Android الذي يمثل واجهة ترفيهية لاستهلاك الوسائط الرقمية و/أو الأفلام و/أو الألعاب و/أو التطبيقات و/أو البث التلفزيوني المباشر للمستخدمين الذين يجلسون على بعد حوالي عشرة أقدام (واجهة مستخدم "متكئة" أو "واجهة مستخدم بطول 10 أقدام" "). أجهزة التلفاز التي تعمل بنظام أندرويد:

• يجب أن يحتوي على شاشة مدمجة أو يتضمن منفذ إخراج فيديو، مثل VGA أو HDMI أو منفذ لاسلكي للعرض.
• يجب الإعلان عن الميزات android.software.leanback وandroid.hardware.type.television.

يشير جهاز Android Watch إلى تطبيق جهاز Android المصمم ليتم ارتداؤه على الجسم، وربما على المعصم، و:

• يجب أن يكون لديك شاشة ذات طول قطري فعلي يتراوح من 1.1 إلى 2.5 بوصة.
• يجب الإعلان عن الميزة android.hardware.type.watch.
• يجب أن يدعم uiMode = UI_MODE_TYPE_WATCH .

يشير تطبيق Android Automotive إلى الوحدة الرئيسية للمركبة التي تعمل بنظام Android كنظام تشغيل لجزء أو كل النظام و/أو وظائف المعلومات والترفيه. تطبيقات Android للسيارات:

• يجب أن يكون لديك شاشة بطول قطري فعلي يساوي أو يزيد عن 6 بوصات.
• يجب أن تعلن عن الميزة android.hardware.type.automotive.
• يجب أن يدعم uiMode = UI_MODE_TYPE_CAR .
• يجب أن تدعم تطبيقات Android Automotive جميع واجهات برمجة التطبيقات العامة في مساحة الاسم android.car.* .

يجب أن تستوفي جميع تطبيقات أجهزة Android التي لا تتناسب مع أي من أنواع الأجهزة المذكورة أعلاه جميع المتطلبات الواردة في هذا المستند لتكون متوافقة مع Android 7.1، ما لم يتم وصف المتطلبات صراحةً على أنها تنطبق فقط على نوع جهاز Android محدد من الأعلى.

2.1 تكوينات الجهاز

هذا ملخص للاختلافات الرئيسية في تكوين الأجهزة حسب نوع الجهاز. (تشير الخلايا الفارغة إلى "مايو"). لا يتم تغطية كافة التكوينات في هذا الجدول؛ راجع أقسام الأجهزة ذات الصلة لمزيد من التفاصيل.

3. البرمجيات

3.1. توافق واجهة برمجة التطبيقات المُدارة

تعد بيئة تنفيذ Dalvik bytecode المُدارة هي الوسيلة الأساسية لتطبيقات Android. واجهة برمجة تطبيقات Android (API) هي مجموعة واجهات نظام Android الأساسية المعرضة للتطبيقات التي تعمل في بيئة التشغيل المُدارة. يجب أن توفر تطبيقات الأجهزة تطبيقات كاملة، بما في ذلك جميع السلوكيات الموثقة، لأي واجهة برمجة تطبيقات موثقة تم الكشف عنها بواسطة Android SDK أو أي واجهة برمجة تطبيقات مزينة بعلامة "@SystemApi" في كود مصدر Android الأساسي.

يجب أن تدعم/تحافظ تطبيقات الجهاز على جميع الفئات والأساليب والعناصر المرتبطة بها والتي تم وضع علامة عليها بواسطة التعليق التوضيحي TestApi (@TestApi).

يجب ألا تحذف تطبيقات الأجهزة أي واجهات برمجة تطبيقات مُدارة، أو تغير واجهات واجهة برمجة التطبيقات أو التوقيعات، أو تحيد عن السلوك الموثق، أو تتضمن عدم العمليات، باستثناء ما يسمح به تعريف التوافق هذا على وجه التحديد.

يسمح تعريف التوافق هذا بحذف بعض أنواع الأجهزة التي يتضمن Android واجهات برمجة التطبيقات (APIs) لها من خلال عمليات تنفيذ الجهاز. في مثل هذه الحالات، يجب أن تظل واجهات برمجة التطبيقات موجودة وتتصرف بطريقة معقولة. راجع القسم 7 للتعرف على المتطلبات المحددة لهذا السيناريو.

3.1.1. ملحقات أندرويد

يتضمن Android دعمًا لتوسيع واجهات برمجة التطبيقات المُدارة مع الاحتفاظ بنفس إصدار مستوى واجهة برمجة التطبيقات. يجب أن تقوم تطبيقات أجهزة Android بتحميل تطبيق AOSP مسبقًا لكل من المكتبة المشتركة ExtShared والخدمات ExtServices بإصدارات أعلى من أو تساوي الحد الأدنى من الإصدارات المسموح بها لكل مستوى من مستويات واجهة برمجة التطبيقات. على سبيل المثال، يجب أن تتضمن تطبيقات الأجهزة التي تعمل بنظام التشغيل Android 7.0، والتي تعمل بمستوى API 24، الإصدار 1 على الأقل.

3.2. توافق واجهة برمجة التطبيقات الناعمة

بالإضافة إلى واجهات برمجة التطبيقات المُدارة من القسم 3.1 ، يشتمل Android أيضًا على واجهة برمجة تطبيقات "ناعمة" مهمة لوقت التشغيل فقط، في شكل أشياء مثل المقاصد والأذونات والجوانب المماثلة لتطبيقات Android التي لا يمكن تنفيذها في وقت ترجمة التطبيق.

3.2.1. الأذونات

يجب على منفذي الأجهزة دعم وتنفيذ كافة ثوابت الأذونات كما هو موثق في الصفحة المرجعية للأذونات . لاحظ أن القسم 9 يسرد المتطلبات الإضافية المتعلقة بنموذج أمان Android.

3.2.2. بناء المعلمات

تشتمل واجهات برمجة تطبيقات Android على عدد من الثوابت في فئة android.os.Build والتي تهدف إلى وصف الجهاز الحالي. لتوفير قيم متسقة وذات معنى عبر تطبيقات الأجهزة، يتضمن الجدول أدناه قيودًا إضافية على تنسيقات هذه القيم التي يجب أن تتوافق معها تطبيقات الأجهزة.

3.2.3. توافق النية

3.2.3.1. نوايا التطبيق الأساسية

تسمح أهداف Android لمكونات التطبيق بطلب الوظائف من مكونات Android الأخرى. يتضمن مشروع Android الأولي قائمة بالتطبيقات التي تعتبر تطبيقات Android الأساسية، والتي تنفذ العديد من أنماط الأغراض لتنفيذ الإجراءات الشائعة. تطبيقات أندرويد الأساسية هي:

• ساعة مكتب
• المتصفح
• تقويم
• جهات الاتصال
• صالة عرض
• البحث العالمي
• منصة الإطلاق
• موسيقى
• إعدادات

يجب أن تتضمن تطبيقات الأجهزة تطبيقات Android الأساسية حسب الاقتضاء أو مكونًا ينفذ نفس أنماط النوايا المحددة بواسطة جميع مكونات النشاط أو الخدمة لتطبيقات Android الأساسية هذه المعرضة لتطبيقات أخرى، ضمنيًا أو صراحةً، من خلال السمة android:exported .

3.2.3.2. قرار النية

نظرًا لأن Android هو نظام أساسي قابل للتوسيع، يجب أن تسمح تطبيقات الأجهزة بتجاوز كل نمط غرض مشار إليه في القسم 3.2.3.1 بواسطة تطبيقات الطرف الثالث. يسمح تطبيق Android مفتوح المصدر بذلك افتراضيًا؛ يجب على منفذي الأجهزة عدم إرفاق امتيازات خاصة لاستخدام تطبيقات النظام لأنماط الأغراض هذه، أو منع تطبيقات الطرف الثالث من الارتباط بهذه الأنماط والسيطرة عليها. يتضمن هذا الحظر على وجه التحديد، على سبيل المثال لا الحصر، تعطيل واجهة المستخدم "المختار" التي تسمح للمستخدم بالاختيار بين تطبيقات متعددة تتعامل جميعها مع نفس نمط الهدف.

يجب أن توفر تطبيقات الجهاز واجهة مستخدم للمستخدمين لتعديل النشاط الافتراضي للأهداف.

ومع ذلك، قد توفر تطبيقات الجهاز أنشطة افتراضية لأنماط URI محددة (على سبيل المثال http://play.google.com) عندما يوفر النشاط الافتراضي سمة أكثر تحديدًا لـ URI للبيانات. على سبيل المثال، يعد نمط مرشح الغرض الذي يحدد URI للبيانات "http://www.android.com" أكثر تحديدًا من نمط الهدف الأساسي للمتصفح لـ "http://".

يتضمن Android أيضًا آلية لتطبيقات الجهات الخارجية للإعلان عن سلوك ربط التطبيق الافتراضي الرسمي لأنواع معينة من أهداف URI على الويب. عندما يتم تحديد مثل هذه التصريحات الرسمية في أنماط مرشح غرض التطبيق، فإن تطبيقات الجهاز:

• يجب محاولة التحقق من صحة أي مرشحات نوايا عن طريق تنفيذ خطوات التحقق المحددة في مواصفات روابط الأصول الرقمية كما تم تنفيذها بواسطة مدير الحزم في مشروع Android مفتوح المصدر.
• يجب محاولة التحقق من صحة مرشحات الهدف أثناء تثبيت التطبيق وتعيين جميع مرشحات هدف UIR التي تم التحقق من صحتها بنجاح كمعالجات التطبيق الافتراضية لمعرفات UIR الخاصة بهم.
• يجوز تعيين مرشحات هدف URI محددة كمعالجات التطبيق الافتراضية لعناوين URI الخاصة بهم، إذا تم التحقق منها بنجاح ولكن مرشحات URI المرشحة الأخرى تفشل في التحقق. إذا كان تطبيق الجهاز يقوم بذلك، فيجب أن يوفر للمستخدم تجاوزات نمط URI المناسبة في قائمة الإعدادات.
• يجب تزويد المستخدم بعناصر التحكم في روابط التطبيقات لكل تطبيق في الإعدادات على النحو التالي:
  • يجب أن يكون المستخدم قادرًا على تجاوز سلوك روابط التطبيق الافتراضي بشكل كلي ليكون التطبيق: مفتوح دائمًا، أو يسأل دائمًا، أو لا يفتح أبدًا، والذي يجب أن ينطبق على جميع مرشحات غرض URI المرشحة بالتساوي.
  • يجب أن يكون المستخدم قادرًا على رؤية قائمة بمرشحات غرض URI المرشحة.
  • قد يوفر تطبيق الجهاز للمستخدم القدرة على تجاوز مرشحات غرض URI المرشحة التي تم التحقق منها بنجاح، على أساس عامل التصفية لكل غرض.
  • يجب أن يوفر تطبيق الجهاز للمستخدمين القدرة على عرض وتجاوز مرشحات غرض URI المرشحة المحددة إذا كان تطبيق الجهاز يسمح لبعض مرشحات غرض URI المرشحة بالنجاح في التحقق بينما قد يفشل البعض الآخر.

3.2.3.3. مساحات الأسماء النية

يجب ألا تتضمن تطبيقات الجهاز أي مكون Android يحترم أي نية جديدة أو أنماط نية البث باستخدام ACTION أو CATEGORY أو سلسلة مفاتيح أخرى في android. أو com.android. مساحة الاسم. يجب ألا يقوم منفذو الأجهزة بتضمين أي مكونات Android تحترم أي نية جديدة أو أنماط نية للبث باستخدام ACTION أو CATEGORY أو سلسلة مفاتيح أخرى في مساحة الحزمة التابعة لمؤسسة أخرى. يجب على منفذي الأجهزة عدم تغيير أو توسيع أي من أنماط الأغراض التي تستخدمها التطبيقات الأساسية المدرجة في القسم 3.2.3.1 . قد تتضمن تطبيقات الأجهزة أنماط غرض تستخدم مساحات الأسماء المرتبطة بشكل واضح وواضح بمؤسستها الخاصة. يشبه هذا الحظر الحظر المحدد لفئات لغة Java في القسم 3.6 .

3.2.3.4. نوايا البث

تعتمد تطبيقات الطرف الثالث على النظام الأساسي لبث نوايا معينة لإعلامها بالتغييرات في بيئة الأجهزة أو البرامج. يجب أن تقوم الأجهزة المتوافقة مع Android ببث أهداف البث العامة استجابةً لأحداث النظام المناسبة. يتم وصف أهداف البث في وثائق SDK.

3.2.3.5. إعدادات التطبيق الافتراضية

يتضمن Android إعدادات توفر للمستخدمين طريقة سهلة لتحديد تطبيقاتهم الافتراضية، على سبيل المثال، للشاشة الرئيسية أو الرسائل النصية القصيرة. عندما يكون ذلك منطقيًا، يجب أن توفر تطبيقات الجهاز قائمة إعدادات مماثلة وأن تكون متوافقة مع نمط مرشح الهدف وطرق واجهة برمجة التطبيقات الموضحة في وثائق SDK على النحو التالي.

تطبيقات الجهاز:

• يجب احترام نية android.settings.HOME_SETTINGS لإظهار قائمة إعدادات التطبيق الافتراضية للشاشة الرئيسية، إذا أبلغ تنفيذ الجهاز عن android.software.home_screen.
• يجب توفير قائمة الإعدادات التي ستستدعي غرض android.provider.Telephony.ACTION_CHANGE_DEFAULT لإظهار مربع حوار لتغيير تطبيق الرسائل القصيرة الافتراضي، إذا أبلغ تنفيذ الجهاز عن android.hardware.telephony.
• يجب احترام نية android.settings.NFC_PAYMENT_SETTINGS لإظهار قائمة إعدادات التطبيق الافتراضية للنقر والدفع، إذا كان تنفيذ الجهاز يُبلغ عن android.hardware.nfc.hce.
• يجب احترام نية android.telecom.action.CHANGE_DEFAULT_DIALER لإظهار مربع حوار للسماح للمستخدم بتغيير تطبيق الهاتف الافتراضي، إذا أبلغ تنفيذ الجهاز عن android.hardware.telephony .
• يجب احترام غرض android.settings.ACTION_VOICE_INPUT_SETTINGS عندما يدعم الجهاز خدمة VoiceInteractionService وإظهار قائمة إعدادات التطبيق الافتراضية للإدخال الصوتي والمساعدة.

3.3. توافق واجهة برمجة التطبيقات الأصلية

يعد توافق التعليمات البرمجية الأصلية أمرًا صعبًا. لهذا السبب، يُنصح بشدة منفذي الأجهزة باستخدام تطبيقات المكتبات المدرجة أدناه من مشروع Android مفتوح المصدر الأساسي.

3.3.1. واجهات التطبيق الثنائية

يمكن لرمز Dalvik bytecode المُدار استدعاء التعليمات البرمجية الأصلية المتوفرة في ملف التطبيق .apk كملف ELF .so تم تجميعه لبنية أجهزة الجهاز المناسبة. نظرًا لأن الكود الأصلي يعتمد بشكل كبير على تقنية المعالج الأساسية، فإن Android يحدد عددًا من الواجهات الثنائية للتطبيقات (ABIs) في Android NDK. يجب أن تكون تطبيقات الأجهزة متوافقة مع واحد أو أكثر من واجهات برمجة التطبيقات (ABIs) المحددة، ويجب أن تنفذ التوافق مع Android NDK، كما هو موضح أدناه.

إذا كان تنفيذ الجهاز يتضمن دعمًا لـ Android ABI، فإنه:

• يجب أن يتضمن دعمًا للتعليمات البرمجية التي يتم تشغيلها في البيئة المُدارة لاستدعاء التعليمات البرمجية الأصلية، باستخدام دلالات واجهة Java الأصلية (JNI) القياسية.
• يجب أن يكون متوافقًا مع المصدر (أي متوافق مع الرأس) ومتوافقًا مع الثنائي (لـ ABI) مع كل مكتبة مطلوبة في القائمة أدناه.
• يجب أن يدعم واجهة برمجة تطبيقات 32 بت المكافئة في حالة دعم أي واجهة برمجة تطبيقات 64 بت.
• يجب الإبلاغ بدقة عن الواجهة الثنائية للتطبيقات الأصلية (ABI) التي يدعمها الجهاز، عبر معلمات android.os.Build.SUPPORTED_ABIS وandroid.os.Build.SUPPORTED_32_BIT_ABIS وandroid.os.Build.SUPPORTED_64_BIT_ABIS، كل قائمة مفصولة بفواصل من يتم ترتيب واجهات ABI من الأكثر إلى الأقل تفضيلاً.
• يجب الإبلاغ، من خلال المعلمات المذكورة أعلاه، فقط عن واجهات ABI الموثقة والموصوفة في الإصدار الأحدث من وثائق إدارة Android NDK ABI ، ويجب أن تتضمن دعمًا لامتداد SIMD المتقدم (المعروف أيضًا باسم NEON).
• يجب أن يتم إنشاؤه باستخدام الكود المصدري وملفات الرأس المتوفرة في مشروع Android مفتوح المصدر

لاحظ أن الإصدارات المستقبلية من Android NDK قد تقدم دعمًا لواجهات ABI الإضافية. إذا كان تنفيذ الجهاز غير متوافق مع واجهة برمجة التطبيقات (ABI) المحددة مسبقًا، فيجب ألا يبلغ عن دعم أي واجهات برمجة التطبيقات (ABI) على الإطلاق.

يجب أن تكون واجهات برمجة تطبيقات التعليمات البرمجية الأصلية التالية متاحة للتطبيقات التي تتضمن تعليمات برمجية أصلية:

• libandroid.so (دعم نشاط Android الأصلي)
• ليبك (مكتبة C)
• libcamera2ndk.so
• libdl (رابط ديناميكي)
• libEGL.so (إدارة سطح OpenGL الأصلية)
• libGLESv1_CM.so (OpenGL ES 1.x)
• libGLESv2.so (OpenGL ES 2.0)
• libGLESv3.so (OpenGL ES 3.x)
• libicui18n.so
• libicuuc.so
• libjnigraphics.so
• liblog (تسجيل Android)
• libmediandk.so (دعم واجهات برمجة التطبيقات للوسائط الأصلية)
• ليب (مكتبة الرياضيات)
• libOpenMAXAL.so (دعم OpenMAX AL 1.0.1)
• libOpenSLES.so (دعم الصوت OpenSL ES 1.0.1)
• libRS.so
• libstdc++ (الحد الأدنى من الدعم لـ C++)
• libvulkan.so (فولكان)
• libz (ضغط Zlib)
• واجهة جي ان اي
• دعم OpenGL، كما هو موضح أدناه

بالنسبة للمكتبات الأصلية المذكورة أعلاه، يجب ألا يقوم تنفيذ الجهاز بإضافة أو إزالة الوظائف العامة.

المكتبات الأصلية غير المذكورة أعلاه ولكن تم تنفيذها وتوفيرها في AOSP حيث أن مكتبات النظام محجوزة ويجب ألا تتعرض لتطبيقات الجهات الخارجية التي تستهدف مستوى واجهة برمجة التطبيقات (API) 24 أو أعلى.

قد تضيف تطبيقات الأجهزة مكتبات غير تابعة لـ AOSP وتعرضها مباشرة كواجهة برمجة تطبيقات لتطبيقات الطرف الثالث ولكن يجب أن تكون المكتبات الإضافية في /vendor/lib أو /vendor/lib64 ويجب أن تكون مدرجة في /vendor/etc/public.libraries.txt .

لاحظ أن تطبيقات الجهاز يجب أن تتضمن libGLESv3.so، وبالتالي، يجب تصدير جميع رموز وظائف OpenGL ES 3.1 و Android Extension Pack كما هو محدد في إصدار NDK android-24. على الرغم من أنه يجب أن تكون جميع الرموز موجودة، إلا أنه يجب تنفيذ الوظائف المقابلة لإصدارات OpenGL ES وامتداداتها التي يدعمها الجهاز بشكل كامل.

3.3.1.1. المكتبات الرسومية

Vulkan عبارة عن واجهة برمجة تطبيقات منخفضة التكلفة ومتعددة المنصات للرسومات ثلاثية الأبعاد عالية الأداء. يجب أن تستوفي تطبيقات الأجهزة، حتى لو لم تتضمن دعم واجهات برمجة تطبيقات Vulkan، المتطلبات التالية:

• يجب أن توفر دائمًا مكتبة أصلية باسم libvulkan.so والتي تصدر رموز الوظائف لواجهة برمجة تطبيقات Vulkan 1.0 الأساسية بالإضافة إلى ملحقات VK_KHR_surface و VK_KHR_android_surface و VK_KHR_swapchain .

تطبيقات الأجهزة، إذا كانت تتضمن دعم واجهات برمجة تطبيقات Vulkan:

• يجب الإبلاغ عن واحد أو أكثر VkPhysicalDevices من خلال استدعاء vkEnumeratePhysicalDevices .
• يجب على كل VkPhysicalDevices المذكور تنفيذ واجهة برمجة تطبيقات Vulkan 1.0 بشكل كامل.
• يجب الإبلاغ عن علامات ميزات PackageManager#FEATURE_VULKAN_HARDWARE_LEVEL و PackageManager#FEATURE_VULKAN_HARDWARE_VERSION الصحيحة.
• يجب تعداد الطبقات الموجودة في المكتبات الأصلية المسماة libVkLayer*.so في دليل المكتبة الأصلية لحزمة التطبيق، من خلال وظائف vkEnumerateInstanceLayerProperties و vkEnumerateDeviceLayerProperties في libvulkan.so
• يجب عدم تعداد الطبقات التي توفرها المكتبات خارج حزمة التطبيق، أو توفير طرق أخرى لتتبع أو اعتراض واجهة برمجة تطبيقات Vulkan، ما لم يكن التطبيق يحتوي على السمة android:debuggable=”true” .

تطبيقات الأجهزة، إن لم تكن تتضمن دعم واجهات برمجة تطبيقات Vulkan:

• يجب الإبلاغ عن 0 VkPhysicalDevices من خلال استدعاء vkEnumeratePhysicalDevices .
• يجب عدم الإعلان عن أي من علامتي ميزات Vulkan PackageManager#FEATURE_VULKAN_HARDWARE_LEVEL و PackageManager#FEATURE_VULKAN_HARDWARE_VERSION .

3.3.2. توافق الكود الأصلي ARM 32 بت

تتجاهل بنية ARMv8 العديد من عمليات وحدة المعالجة المركزية، بما في ذلك بعض العمليات المستخدمة في التعليمات البرمجية الأصلية الموجودة. في أجهزة ARM 64 بت، يجب أن تظل العمليات المهملة التالية متاحة لرمز ARM الأصلي 32 بت، إما من خلال دعم وحدة المعالجة المركزية الأصلية أو من خلال محاكاة البرنامج:

• تعليمات SWP وSWPB
• تعليمات الإعداد
• عمليات الحاجز CP15ISB، CP15DSB، وCP15DMB

استخدمت الإصدارات القديمة من Android NDK /proc/cpuinfo لاكتشاف ميزات وحدة المعالجة المركزية من كود ARM الأصلي 32 بت. للتوافق مع التطبيقات التي تم إنشاؤها باستخدام NDK، يجب أن تتضمن الأجهزة الأسطر التالية في /proc/cpuinfo عند قراءتها بواسطة تطبيقات ARM 32 بت:

• "الميزات: "، متبوعة بقائمة بأي ميزات اختيارية لوحدة المعالجة المركزية ARMv7 التي يدعمها الجهاز.
• "بنية وحدة المعالجة المركزية: "، متبوعة بعدد صحيح يصف أعلى بنية ARM مدعومة بالجهاز (على سبيل المثال، "8" لأجهزة ARMv8).

تنطبق هذه المتطلبات فقط عند قراءة /proc/cpuinfo بواسطة تطبيقات ARM 32 بت. يجب ألا تقوم الأجهزة بتغيير /proc/cpuinfo عند قراءتها بواسطة تطبيقات ARM 64 بت أو تطبيقات غير ARM.

3.4. التوافق مع الويب

3.4.1. التوافق مع عرض الويب

يجب الإبلاغ عن ميزة النظام الأساسي android.software.webview على أي جهاز يوفر تنفيذًا كاملاً لواجهة برمجة تطبيقات android.webkit.WebView، ويجب عدم الإبلاغ عنها على الأجهزة التي لا تحتوي على تنفيذ كامل لواجهة برمجة التطبيقات. يستخدم تطبيق Android Open Source تعليمات برمجية من مشروع Chromium لتنفيذ android.webkit.WebView . نظرًا لأنه ليس من الممكن تطوير مجموعة اختبار شاملة لنظام عرض الويب، يجب على منفذي الأجهزة استخدام البنية الأولية المحددة لـ Chromium في تطبيق WebView. خاصة:

• يجب أن تعتمد تطبيقات android.webkit.WebView للجهاز على إصدار Chromium من مشروع Android مفتوح المصدر لنظام Android 7.1. يتضمن هذا الإصدار مجموعة محددة من إصلاحات الوظائف والأمان لـ WebView.

• يجب أن تكون سلسلة وكيل المستخدم التي أبلغ عنها WebView بهذا التنسيق:

  Mozilla/5.0 (Linux; Android $(VERSION); $(MODEL) Build/$(BUILD); wv) AppleWebKit/537.36 (KHTML، مثل Gecko) الإصدار/4.0 $(CHROMIUM_VER) Mobile Safari/537.36

  • يجب أن تكون قيمة سلسلة $(VERSION) هي نفس قيمة android.os.Build.VERSION.RELEASE.
  • يجب أن تكون قيمة السلسلة $(MODEL) هي نفس قيمة android.os.Build.MODEL.
  • يجب أن تكون قيمة السلسلة $(BUILD) هي نفس قيمة android.os.Build.ID.
  • يجب أن تكون قيمة السلسلة $(CHROMIUM_VER) هي إصدار Chromium في مشروع Android مفتوح المصدر.
  • قد تحذف تطبيقات الجهاز الهاتف المحمول في سلسلة وكيل المستخدم.

يجب أن يتضمن مكون WebView دعمًا لأكبر عدد ممكن من ميزات HTML5، وإذا كان يدعم الميزة فيجب أن يتوافق مع مواصفات HTML5 .

3.4.2. التوافق المتصفح

قد يعتمد المتصفح المستقل على تقنية المتصفح بخلاف WebKit. ومع ذلك ، حتى إذا تم استخدام تطبيق متصفح بديل ، فيجب أن يعتمد مكون Android.webkit.webview المقدم لتطبيقات الطرف الثالث على WebKit ، كما هو موضح في القسم 3.4.1 .

قد تشحن التطبيقات سلسلة وكيل مستخدم مخصصة في تطبيق المتصفح المستقل.

يجب أن يتضمن تطبيق المتصفح المستقل (سواء استنادًا إلى تطبيق متصفح WebKit في المنبع أو بديل من طرف ثالث) دعمًا لأكبر قدر ممكن من HTML5 . الحد الأدنى ، يجب أن تدعم تطبيقات الأجهزة كل من واجهات برمجة التطبيقات هذه المرتبطة بـ HTML5:

• ذاكرة التخزين المؤقت للتطبيق/العملية غير المتصلة بالإنترنت
• <vide> علامة
• تحديد الموقع الجغرافي

بالإضافة إلى ذلك ، يجب أن تدعم تطبيقات الأجهزة واجهة برمجة تطبيقات HTML5/W3C WebStorage ويجب أن تدعم واجهة برمجة تطبيقات HTML5/W3C INSTINGEDDB . لاحظ أنه مع انتقال أجسام معايير تطوير الويب لصالح indexedDB عبر WebStorage ، من المتوقع أن تصبح IndexedDB مكونًا مطلوبًا في إصدار مستقبلي من Android.

3.5. API التوافق السلوكي

يجب أن تكون سلوكيات كل نوع من أنواع API (المدارة ، الناعمة ، الأصلية ، والويب) متسقة مع التنفيذ المفضل لمشروع المصدر المفتوح في Android . بعض مجالات التوافق المحددة هي:

• يجب ألا تغير الأجهزة سلوك أو دلالات النية القياسية.
• يجب ألا تغير الأجهزة دلالات دورة الحياة أو دورة الحياة لنوع معين من مكونات النظام (مثل الخدمة ، النشاط ، ContentProvider ، إلخ).
• يجب ألا تغير الأجهزة دلالات الإذن القياسي.

القائمة أعلاه ليست شاملة. يختبر مجموعة اختبار التوافق (CTS) أجزاء كبيرة من النظام الأساسي للتوافق السلوكي ، ولكن ليس كل شيء. تقع على عاتق المنفذ مسؤولية ضمان التوافق السلوكي مع مشروع Android Open Source. لهذا السبب ، يجب على منفذي الأجهزة استخدام التعليمات البرمجية المصدر المتاحة عبر مشروع Android Open Source حيثما أمكن ، بدلاً من إعادة تنفيذ أجزاء كبيرة من النظام.

3.6. مساحات أسماء API

يتبع Android اتفاقيات مساحة اسم الحزمة والفئة المحددة بواسطة لغة برمجة Java. لضمان التوافق مع تطبيقات الطرف الثالث ، يجب ألا يقوم منفذي الأجهزة بإجراء أي تعديلات محظورة (انظر أدناه) على مساحات أسماء الحزمة هذه:

• جافا.*
• جافاكس.*
• شمس.*
• ذكري المظهر.*
• com.android.*

تشمل التعديلات المحظورة :

• يجب ألا تعدل تطبيقات الأجهزة واجهات برمجة التطبيقات المكشوفة للجمهور على منصة Android عن طريق تغيير أي طريقة أو توقيعات فئة ، أو عن طريق إزالة الفئات أو حقول الفصول الدراسية.
• يجوز لمنفذي الأجهزة تعديل التنفيذ الأساسي لواجهة برمجة التطبيقات ، ولكن يجب ألا تؤثر مثل هذه التعديلات على السلوك المعلن وتوقيع اللغة Java لأي واجهات برمجة التطبيقات المكشوفة للجمهور.
• يجب على منفذي الأجهزة عدم إضافة أي عناصر مكشوفة علنًا (مثل الفئات أو الواجهات ، أو الحقول أو الطرق إلى الفئات أو الواجهات الموجودة) إلى واجهات برمجة التطبيقات أعلاه.

"العنصر المكشوف علنًا" هو أي بناء غير مزين بعلامة "Hide" كما هو مستخدم في رمز مصدر Android في المنبع. بمعنى آخر ، يجب ألا يعرض منفذو الأجهزة واجهات برمجة التطبيقات الجديدة أو تغيير واجهات برمجة التطبيقات الموجودة في مساحات الأسماء المذكورة أعلاه. قد يقوم منفذو الأجهزة بإجراء تعديلات داخلية فقط ، ولكن يجب عدم الإعلان عن هذه التعديلات أو تعرضها للمطورين.

قد يضيف منفذو الأجهزة واجهات برمجة التطبيقات المخصصة ، ولكن يجب ألا يكون أي واجهات برمجة التطبيقات في مساحة اسم مملوكة أو تشير إلى مؤسسة أخرى. على سبيل المثال ، يجب على منفذي الأجهزة عدم إضافة واجهات برمجة التطبيقات إلى com.google.* أو مساحة الاسم المماثلة: قد تقوم Google بذلك فقط. وبالمثل ، يجب ألا تضيف Google واجهات برمجة التطبيقات إلى مساحات أسماء الشركات الأخرى. بالإضافة إلى ذلك ، إذا كان تطبيق الجهاز يتضمن واجهات برمجة التطبيقات المخصصة خارج مساحة اسم Android القياسية ، فيجب تعبئة واجهات برمجة التطبيقات هذه في مكتبة مشتركة Android بحيث تتأثر التطبيقات التي تستخدمها بشكل صريح (عبر آلية <Septire-Library>) بزيادة استخدام الذاكرة من واجهات برمجة التطبيقات هذه.

إذا اقترح تطبيق الجهاز تحسين أحد مساحات أسماء الحزمة أعلاه (مثل إضافة وظائف جديدة مفيدة إلى واجهة برمجة تطبيقات موجودة ، أو إضافة واجهة برمجة تطبيقات جديدة) ، يجب على المنفذ زيارة Source.android.com وبدء العملية للمساهمة في التغييرات و رمز ، وفقا للمعلومات الواردة في هذا الموقع.

لاحظ أن القيود المذكورة أعلاه تتوافق مع الاتفاقيات القياسية لتسمية واجهات برمجة التطبيقات في لغة برمجة Java ؛ يهدف هذا القسم ببساطة إلى تعزيز تلك الاتفاقيات وجعلها ملزمة من خلال التضمين في تعريف التوافق هذا.

3.7. توافق وقت التشغيل

يجب أن تدعم تطبيقات الأجهزة تنسيق Dalvik القابل للتنفيذ (DEX) الكامل ومواصفات Dalvik bytecode ودلالاتها . يجب على منفذي الأجهزة استخدام ART ، والتنفيذ المرجعي للتنسيق القابل للتنفيذ Dalvik ، ونظام إدارة الحزم للتطبيق المرجعي.

يجب أن تقوم تطبيقات الجهاز بتكوين Dalvik Runtimes لتخصيص الذاكرة وفقًا لمنصة Android المنبع ، وكما هو محدد في الجدول التالي. (انظر القسم 7.1.1 للحصول على تعريفات شاشة الشاشة وتعريفات كثافة الشاشة.) لاحظ أن قيم الذاكرة المحددة أدناه تعتبر الحد الأدنى للقيم وقد تخصيص تطبيقات الجهاز المزيد من الذاكرة لكل تطبيق.

3.8. توافق واجهة المستخدم

3.8.1. مشغل (الشاشة الرئيسية)

يتضمن Android تطبيق قاذفة (الشاشة الرئيسية) ودعم تطبيقات الطرف الثالث لاستبدال قاذفة الجهاز (الشاشة الرئيسية). يجب أن تعلن تطبيقات الجهاز التي تسمح لتطبيقات الطرف الثالث باستبدال الشاشة الرئيسية للجهاز ميزة النظام الأساسي Android.software.home_screen.

3.8.2. الحاجيات

يحدد Android نوع المكون و API ودورة الحياة المقابلة التي تسمح للتطبيقات بفضح "AppWidget" للمستخدم النهائي ، وهي ميزة موصى بها بشدة لدعمها في تطبيقات الأجهزة المحمولة. يجب أن تلبي تطبيقات الأجهزة التي تدعم أجهزة تدمير الشاشة الرئيسية المتطلبات التالية وإعلان الدعم لميزة النظام الأساسي Android.software.app_widgets.

• يجب أن تتضمن قاذفات الأجهزة دعمًا مدمجًا لـ AppWidgets وفضح معطفات واجهة المستخدم لإضافة وتكوين وعرض وإزالة AppWidgets مباشرة داخل المشغل.
• يجب أن تكون تطبيقات الأجهزة قادرة على تقديم أجهزة واجهة مستخدم 4 × 4 في حجم الشبكة القياسي. راجع إرشادات تصميم عنصر واجهة المستخدم في وثائق Android SDK للحصول على التفاصيل.
• قد تدعم تطبيقات الجهاز التي تتضمن دعم شاشة القفل عناصر تطبيق التطبيق على شاشة القفل.

3.8.3. إشعارات

يتضمن Android واجهات برمجة التطبيقات التي تسمح للمطورين بإخطار المستخدمين بالأحداث البارزة باستخدام ميزات الأجهزة والبرامج للجهاز.

تتيح بعض واجهات برمجة التطبيقات للتطبيقات إجراء الإخطارات أو جذب الانتباه باستخدام الأجهزة - على وجه التحديد الصوت والاهتزاز والضوء. يجب أن تدعم تطبيقات الأجهزة الإخطارات التي تستخدم ميزات الأجهزة ، كما هو موضح في وثائق SDK ، وإلى حد ممكن مع أجهزة تنفيذ الجهاز. على سبيل المثال ، إذا كان تطبيق الجهاز يتضمن هزازًا ، فيجب عليه تطبيق واجهات برمجة تطبيقات الاهتزاز بشكل صحيح. إذا كان تطبيق الجهاز يفتقر إلى الأجهزة ، فيجب تنفيذ واجهات برمجة التطبيقات المقابلة على أنه لا يوجد. تم تفصيل هذا السلوك في القسم 7 .

بالإضافة إلى ذلك ، يجب أن يؤدي التنفيذ بشكل صحيح إلى تقديم جميع الموارد (الرموز ، وملفات الرسوم المتحركة وما إلى ذلك) المنصوص عليها في واجهات برمجة التطبيقات ، أو في دليل نمط شريط الحالة/النظام ، والذي يتضمن في حالة جهاز تلفزيون Android إمكانية عدم عرض إشعارات. قد يوفر منفذ الأجهزة تجربة مستخدم بديلة للإخطارات من تلك التي يوفرها تطبيق Android Open Source المرجعي ؛ ومع ذلك ، يجب أن تدعم أنظمة الإخطار البديلة موارد الإخطار الحالية ، على النحو الوارد أعلاه.

يتضمن Android دعمًا لمختلف الإخطارات ، مثل:

• الإخطارات الغنية . وجهات نظر تفاعلية للإشعارات المستمرة.
• الإخطارات . طرق عرض تفاعلية يمكن للمستخدمين التصرف عليها أو رفضها دون مغادرة التطبيق الحالي.
• قفل إشعارات الشاشة . الإخطارات التي تظهر على شاشة القفل مع تحكم حبيبتي على الرؤية.

يجب أن تنفذ تطبيقات أجهزة Android ، عند إقرار هذه الإخطارات ، الإشعارات الغنية والرؤوس بشكل صحيح وتشمل العنوان/الاسم ، أيقونة ، نص كما هو موثق في واجهات برمجة التطبيقات Android .

يتضمن Android واجهات برمجة تطبيقات خدمة مستمع الإخطار التي تسمح للتطبيقات (بمجرد تمكين المستخدم بشكل صريح) لتلقي نسخة من جميع الإخطارات عند نشرها أو تحديثها. يجب أن ترسل تطبيقات الجهاز بشكل صحيح وسرقة الإخطارات بالكامل إلى جميع خدمات المستمع المثبتة والمستخدمة ، بما في ذلك أي وجميع البيانات الوصفية المرتبطة بكائن الإخطار.

يجب أن تدعم تطبيقات الأجهزة المحمولة سلوكيات التحديث والإزالة والرد على الإخطارات وتجميعها كما هو موضح في هذا القسم .

أيضا ، يجب أن توفر تطبيقات الأجهزة المحمولة:

• القدرة على التحكم في الإخطارات مباشرة في ظل الإخطار.
• التكاليف البصرية لتشغيل لوحة التحكم في ظل الإخطار.
• القدرة على حظر وتفضيل الإخطار وإعادة تعيينه من الحزمة ، سواء في لوحة التحكم المضمنة وكذلك في تطبيق الإعدادات.

يجب دعم جميع الفئات الفرعية المباشرة الستة من Notification.Style class كما هو موضح في مستندات SDK .

يجب أن تلبي تطبيقات الأجهزة التي تدعم ميزة DND (لا تزعج) المتطلبات التالية:

• يجب تنفيذ نشاط يستجيب لـ Action_notification_policy_access_settings ، وهو بالنسبة للتطبيقات باستخدام ui_mode_type_normal ، يجب أن يكون نشاطًا حيث يمكن للمستخدم منح أو رفض الوصول إلى تكوينات سياسة DND.
• يجب ، عندما يكون تطبيق الجهاز قد وفر وسيلة للمستخدم لمنح أو رفض تطبيقات الطرف الثالث للوصول إلى تكوين سياسة DND ، وعرض قواعد DND التلقائية التي تم إنشاؤها بواسطة التطبيقات إلى جانب القواعد التي تم إنشاؤها قبل المستخدم.
• يجب أن يكرم قيم suppressedVisualEffects التي تم تمريرها على طول NotificationManager.Policy .

3.8.4. يبحث

يشتمل Android على واجهات برمجة التطبيقات التي تسمح للمطورين بدمج البحث في تطبيقاتهم وفضح بيانات تطبيقهم في بحث النظام العالمي. بشكل عام ، تتكون هذه الوظيفة من واجهة مستخدم واحدة على مستوى النظام تتيح للمستخدمين إدخال استعلامات ، وتعرض الاقتراحات كنوع المستخدمين ، ويعرض النتائج. تتيح واجهات برمجة تطبيقات Android للمطورين إعادة استخدام هذه الواجهة لتوفير البحث داخل تطبيقاتهم الخاصة والسماح للمطورين بتوفير النتائج لواجهة مستخدم البحث العالمية الشائعة.

يجب أن تتضمن تطبيقات أجهزة Android البحث العالمي ، واجهة مستخدم بحثية واحدة ، مشتركة ، على مستوى النظام ، قادرة على اقتراحات الوقت الفعلي استجابةً لإدخال المستخدم. يجب أن تنفذ تطبيقات الأجهزة واجهات برمجة التطبيقات التي تسمح للمطورين بإعادة استخدام واجهة المستخدم هذه لتوفير البحث داخل تطبيقاتهم الخاصة. يجب أن تنفذ تطبيقات الأجهزة التي تنفذ واجهة البحث العالمية واجهات برمجة التطبيقات التي تسمح لتطبيقات الطرف الثالث بإضافة اقتراحات إلى مربع البحث عند تشغيلها في وضع البحث العالمي. إذا لم يتم تثبيت تطبيقات طرف ثالث تستفيد من هذه الوظيفة ، فيجب أن يكون السلوك الافتراضي هو عرض نتائج واقتراحات محرك بحث الويب.

يجب أن تنفذ تطبيقات أجهزة Android ، ويجب أن تنفذ تطبيقات السيارات Android مساعدًا على الجهاز للتعامل مع إجراء المساعدة .

يتضمن Android أيضًا واجهات برمجة تطبيقات Assist للسماح للتطبيقات بانتخاب مقدار المعلومات التي يتم مشاركتها مع المساعد على المساعد على الجهاز. يجب أن تشير تطبيقات الجهاز التي تدعم إجراء المساعدة بوضوح إلى المستخدم النهائي عندما تتم مشاركة السياق من خلال عرض ضوء أبيض حول حواف الشاشة. لضمان رؤية واضحة للمستخدم النهائي ، يجب أن تفي المؤشر أو يتجاوز مدة وسطوع تطبيق مشروع Android Open Source.

قد يتم تعطيل هذا المؤشر افتراضيًا للتطبيقات التي تم تثبيتها مسبقًا باستخدام API Assist و VoiceInterCtionService ، إذا تم استيفاء جميع المتطلبات التالية:

• يجب أن يطلب التطبيق الذي تم تثبيته مسبقًا من مشاركة السياق فقط عندما يستدعي المستخدم التطبيق من خلال إحدى الوسائل التالية ، ويعمل التطبيق في المقدمة:

  • الكلمة الساخنة الاحتجاج
  • إدخال مفتاح/زر/زر

• يجب أن يوفر تطبيق الجهاز تكاليف لتمكين الإشارة ، أقل من تنقلتين بعيدًا عن (قائمة إعدادات الصوت الافتراضية وإعدادات التطبيق المساعد) 3.2.3.5 .

3.8.5. الخبز المحمص

يمكن للتطبيقات استخدام واجهة برمجة تطبيقات "Toast" لعرض سلاسل قصيرة غير وسيطة للمستخدم النهائي الذي يختفي بعد فترة قصيرة من الزمن. يجب أن تعرض تطبيقات الأجهزة الخبز المحمص من التطبيقات إلى المستخدمين النهائيين بطريقة عالية الوضوح.

3.8.6. المواضيع

يوفر Android "موضوعات" كآلية للتطبيقات لتطبيق الأنماط عبر نشاط أو تطبيق كامل.

يتضمن Android عائلة "Holo" لمجموعة من الأساليب المحددة لمطوري التطبيقات لاستخدامها إذا كانوا يرغبون في مطابقة مظهر Holo ومظهره كما هو محدد من قبل Android SDK. يجب ألا تغير تطبيقات الجهاز أي من سمات موضوع Holo المعرضة للتطبيقات.

يتضمن Android عائلة موضوع "المواد" كمجموعة من الأساليب المحددة لمطوري التطبيقات لاستخدامها إذا كانوا يريدون مطابقة مظهر موضوع التصميم ومشعره عبر مجموعة واسعة من أنواع أجهزة Android المختلفة. يجب أن تدعم تطبيقات الجهاز عائلة السمة "المادية" ويجب ألا تغير أي من سمات موضوع المادة أو أصولها المعرضة للتطبيقات.

يشتمل Android أيضًا على عائلة سمة "Device Default" كمجموعة من الأساليب المحددة لمطوري التطبيقات لاستخدامها إذا كانوا يريدون مطابقة مظهر ومظهر الجهاز كما هو محدد من قبل تطبيق الجهاز. قد تعدل تطبيقات الجهاز سمات السمة الافتراضية للجهاز المعرضة للتطبيقات.

يدعم Android سمة متغيرة مع أشرطة نظام شفافة ، والتي تتيح لمطوري التطبيقات ملء المنطقة خلف شريط الحالة والملاحة بمحتوى التطبيق الخاص بهم. لتمكين تجربة مطور متسقة في هذا التكوين ، من المهم الحفاظ على نمط رمز شريط الحالة عبر تطبيقات الأجهزة المختلفة. لذلك ، يجب أن تستخدم تطبيقات أجهزة Android White لأيقونات حالة النظام (مثل قوة الإشارة ومستوى البطارية) والإشعارات الصادرة عن النظام ، ما لم يشير الرمز إلى حالة إشكالية أو يطلب تطبيق شريط ضوء باستخدام System_UI_FLAG_LAIVE_STATUS_BAR. عندما يطلب التطبيق شريط حالة الضوء ، يجب أن تغير تطبيقات جهاز Android لون أيقونات حالة النظام إلى الأسود (للحصول على التفاصيل ، راجع R.Style ).

3.8.7. خلفيات حية

يحدد Android نوع المكون و API ودورة الحياة المقابلة التي تسمح للتطبيقات بفضح "خلفيات حية" واحدة أو أكثر للمستخدم النهائي. خلفيات الحية هي رسوم متحركة أو أنماط أو صور مماثلة مع إمكانات إدخال محدودة تعرض كخلفية ، وراء التطبيقات الأخرى.

تعتبر الأجهزة قادرة على تشغيل خلفيات حية بشكل موثوق إذا كان بإمكانها تشغيل جميع خلفيات حية ، مع عدم وجود قيود على الوظيفة ، بمعدل إطار معقول دون أي آثار سلبية على التطبيقات الأخرى. إذا تسبب القيود في الأجهزة في خلفيات و/أو تطبيقات إلى تعطل ، أو عطل ، أو تستهلك وحدة المعالجة المركزية المفرطة أو طاقة البطارية ، أو تعمل بمعدلات إطار منخفضة بشكل غير مقبول ، فإن الأجهزة تعتبر غير قادرة على تشغيل خلفية حية. على سبيل المثال ، قد تستخدم بعض الخلفيات الحية سياق OpenGL 2.0 أو 3.x لتقديم محتواها. لن يتم تشغيل خلفية حية بشكل موثوق على الأجهزة التي لا تدعم سياقات OpenGL متعددة لأن استخدام خلفية الحجرة المباشرة لسياق OpenGL قد يتعارض مع التطبيقات الأخرى التي تستخدم أيضًا سياق OpenGL.

يجب أن تنفذ تطبيقات الأجهزة القادرة على تشغيل خلفيات حية بشكل موثوق كما هو موضح أعلاه ، وعندما يتم تنفيذها ، يجب الإبلاغ عن ميزة النظام الأساسي Android.software.live_wallpaper.

3.8.8. تبديل النشاط

يتضمن رمز مصدر Android Opstream شاشة النظرة العامة ، وواجهة مستخدم على مستوى النظام لتبديل المهام وعرض الأنشطة والمهام التي تم الوصول إليها مؤخرًا باستخدام صورة مصغرة لحالة الرسوم البيانية للتطبيق في اللحظة التي غادر فيها المستخدم آخر التطبيق. تطبيقات الجهاز بما في ذلك مفتاح التنقل في دالة Recents كما هو مفصل في القسم 7.2.3 قد يغير الواجهة ولكن يجب أن تفي بالمتطلبات التالية:

• يجب أن تدعم ما يصل إلى 20 نشاطًا معروضًا على الأقل.
• يجب على الأقل عرض عنوان 4 أنشطة في وقت واحد.
• يجب تنفيذ سلوك تثبيت الشاشة وتزويد المستخدم بقائمة إعدادات لتبديل الميزة.
• يجب عرض تسليط الضوء على اللون ، أيقونة ، عنوان الشاشة في Recents.
• يجب أن تعرض تكاليف إغلاق ("X") ولكن قد يؤخر ذلك حتى يتفاعل المستخدم مع الشاشات.
• يجب تنفيذ اختصار للتبديل بسهولة إلى النشاط السابق
• قد تعرض عمليات الاسترداد التابعة كمجموعة تتحرك معًا.
• يجب أن تؤدي إلى إجراء التبديل السريع بين التطبيقين الذين تم استخدامهما مؤخرًا ، عندما يتم استغلال مفتاح وظيفة Recents مرتين.
• يجب أن تؤدي إلى ظهور وضع MultiWindow Multiwindow ، إذا تم دعمه ، عندما يتم الضغط على مفتاح وظائف Recents منذ فترة طويلة.

يوصى بشدة بتطبيقات الجهاز لاستخدام واجهة مستخدم Android المنبع (أو واجهة مماثلة قائمة على الصورة المصغرة) لشاشة نظرة عامة.

3.8.9. إدارة المدخلات

يتضمن Android دعمًا لإدارة المدخلات ودعم محرري طريقة إدخال الطرف الثالث. يجب أن تعلن تطبيقات الأجهزة التي تسمح للمستخدمين باستخدام طرق إدخال الطرف الثالث على الجهاز أن ميزة النظام الأساسي Android.software.input_methods ودعم واجهات برمجة تطبيقات IME على النحو المحدد في وثائق Android SDK.

يجب أن توفر تطبيقات الأجهزة التي تعلن عن ميزة Android.software.input_methods آلية يمكن الوصول إليها من قبل المستخدم لإضافة وتكوين طرق إدخال الطرف الثالث. يجب أن تعرض تطبيقات الجهاز واجهة الإعدادات استجابةً لـ Android.settings.input_method_settings النية.

3.8.10. قفل التحكم في وسائط الشاشة

يتم إهمال واجهة برمجة تطبيقات عميل التحكم عن بُعد من Android 5.0 لصالح قالب إعلام الوسائط الذي يسمح لتطبيقات الوسائط بالاندماج مع عناصر التحكم في التشغيل التي يتم عرضها على شاشة القفل. تطبيقات الجهاز التي تدعم شاشة القفل ، ما لم يكن على تنفيذ سيارة Android أو تطبيق المشاهدة ، عرض إشعارات شاشة القفل بما في ذلك قالب إعلام الوسائط.

3.8.11. مدخرات الشاشة (الأحلام السابقة)

يتضمن Android دعمًا لـ InterctivesCreensavers ، يشار إليه سابقًا باسم الأحلام. يتيح مدخرات الشاشة للمستخدمين التفاعل مع التطبيقات عندما يكون الجهاز المتصل بمصدر طاقة خاملاً أو مرسومة في رصيف مكتب. قد تقوم أجهزة Watch Android بتطبيق توفر الشاشة ، ولكن يجب أن تتضمن أنواع أخرى من تطبيقات الأجهزة دعمًا لزواحف الشاشة وتوفير خيار إعدادات للمستخدمين لتشكيل شاشة Savers استجابةً لـ android.settings.DREAM_SETTINGS .

3.8.12. موقع

عندما يحتوي الجهاز على مستشعر للأجهزة (EG GPS) قادر على توفير إحداثيات الموقع ، يجب عرض أوضاع الموقع في قائمة الموقع داخل الإعدادات.

3.8.13. يونيكود وخط

يتضمن Android دعمًا لشخصيات الرموز التعبيرية المحددة في Unicode 9.0 . يجب أن تكون جميع تطبيقات الأجهزة قادرة على تقديم هذه الأحرف الرموز التعبيرية في أرجوحة اللون وعندما تتضمن تطبيقات جهاز Android IME ، يجب أن توفر طريقة إدخال للمستخدم لهذه الأحرف الرموز التعبيرية.

يجب أن تدعم أجهزة Android Handheld لون البشرة والرموز التعبيرية للأسرة المتنوعة كما هو محدد في التقرير الفني Unicode #51 .

يتضمن Android دعمًا لخط Roboto 2 مع أوزان مختلفة-Sans-serif-shin ، sans-serif-light ، sans-serifium ، sans-sans-serif-black ، sans-sans-condensed ، light-sans-serif-condensive-light-الذي يضيء الخلاص- يجب أن يتم تضمين جميع اللغات المتوفرة على الجهاز وتغطية Unicode 7.0 الكاملة لللاتينية واليونانية والسيريلية ، بما في ذلك النطاقات اللاتينية الممتدة A و B و C و D ، وجميع الحروف الرسومية في كتلة رموز العملة من Unicode 7.0.

3.8.14. نوافذ متعددة

قد يختار تطبيق الجهاز عدم تنفيذ أي أوضاع متعددة النوافذ ، ولكن إذا كان لديه القدرة على عرض أنشطة متعددة في نفس الوقت ، فيجب عليه تنفيذ هذه الوضع (الوضع) متعدد النوافذ وفقًا لسلوكيات التطبيق وواجهات برمجة التطبيقات الموصوفة في دعم الوثائق التي تعمل بنافذة Multi-Window Android SDK وتلبية المتطلبات التالية:

• يمكن للتطبيقات أن تشير إلى ما إذا كانت قادرة على العمل في وضع النافذ متعدد النافذة في ملف AndroidManifest.xml ، إما بشكل صريح عبر السمة الناتجة android:resizeableActivity أو ضمنيًا عن طريق وجود TargetSdKversion> 24. التطبيقات التي تعيد هذه السمة بشكل صريح إلى خطأ في واضحة. لا يتم إطلاقها في وضع النوافذ المتعددة. يمكن تشغيل التطبيقات التي لا تضع السمة في ملفها البياني (TargetSdKversion <24) في وضع النوافذ متعدد النافذ ، ولكن يجب أن يوفر النظام تحذيرًا من أن التطبيق قد لا يعمل كما هو متوقع في وضع النوافذ المتعدد.
• يجب ألا تقدم تطبيقات الأجهزة وضعًا منقسمًا أو Freeform إذا كان ارتفاع الشاشة وعرضها أقل من 440 DP.
• يجب أن تدعم تطبيقات الجهاز مع حجم الشاشة xlarge وضع Freeform.
• يجب أن تدعم تطبيقات جهاز تلفزيون Android وضع Multi-Window multi-window ووضع النافذة Multi-Window في الزاوية اليمنى العليا عند تشغيل PIP.
• يجب أن تخصص تطبيقات الجهاز مع وضع PIP MODE Multi-Window ما لا يقل عن 240 × 135 DP لنافذة PIP.
• إذا تم دعم وضع PIP Multi-Window ، فيجب استخدام مفتاح KeyEvent.KEYCODE_WINDOW للتحكم في نافذة PIP ؛ خلاف ذلك ، يجب أن يكون المفتاح متاحًا للنشاط الأمامي.

3.9. إدارة الجهاز

يشتمل Android على ميزات تسمح لتطبيقات الأمن التي تدرك الأمن بتنفيذ وظائف إدارة الجهاز على مستوى النظام ، مثل فرض سياسات كلمة المرور أو إجراء مسح عن بُعد ، من خلال واجهة برمجة تطبيقات أجهزة Android ]. يجب أن توفر تطبيقات الأجهزة تنفيذ فئة DevicePolicyManager . يجب أن تنفذ تطبيقات الجهاز التي تدعم شاشة قفل آمنة النطاق الكامل لسياسات إدارة الجهاز المحددة في وثائق Android SDK والإبلاغ عن ميزة النظام الأساسي Android.software.device_admin.

3.9.1 توفير الجهاز

3.9.1.1 توفير مالك الجهاز

إذا أعلن تطبيق الجهاز عن ميزة android.software.device_admin ، فيجب عليه تنفيذ توفير تطبيق مالك الجهاز لتطبيق عميل سياسة الجهاز (DPC) كما هو موضح أدناه:

• عندما لا يكون لتطبيق الجهاز تكوين بيانات مستخدم حتى الآن ، فإنه:
  • يجب الإبلاغ true DevicePolicyManager.isProvisioningAllowed(ACTION_PROVISION_MANAGED_DEVICE) .
  • يجب تسجيل تطبيق DPC كتطبيق مالك الجهاز استجابةً لـ ACTION ACTION android.app.action.PROVISION_MANAGED_DEVICE .
  • يجب تسجيل تطبيق DPC كمالك للجهاز إذا أعلن الجهاز دعم الاتصالات القريبة (NFC) عبر علامة الميزة android.hardware.nfc ويتلقى رسالة NFC تحتوي على سجل مع نوع MIME_TYPE_PROVISIONING_NFC .
• عندما يكون لتطبيق الجهاز بيانات المستخدم ، فإنه:
  • يجب الإبلاغ false عن DevicePolicyManager.isProvisioningAllowed(ACTION_PROVISION_MANAGED_DEVICE) .
  • يجب ألا تسجل أي تطبيق DPC كتطبيق مالك الجهاز بعد الآن.

قد يكون لتطبيقات الجهاز وظائف تطبيق الجهاز التي يتم تثبيتها مسبقًا ولكن يجب ألا يتم تعيين هذا التطبيق كتطبيق مالك الجهاز دون موافقة أو إجراء صريح من المستخدم أو مسؤول الجهاز.

3.9.1.2 توفير الملف الشخصي المدارة

إذا أعلن تطبيق الجهاز عن Android.software.managed_users ، فيجب أن يكون من الممكن تسجيل تطبيق وحدة تحكم سياسة الجهاز (DPC) كمالك لملف تعريف جديد مُدار .

يجب أن تتماشى عملية توفير ملف التعريف المدارة (التدفق الذي بدأته Android.App.Action.provision_managed_profile ) مع تطبيق AOSP.

يجب أن توفر تطبيقات الجهاز معارف المستخدم التالية ضمن واجهة مستخدم الإعدادات للإشارة إلى المستخدم عندما يتم تعطيل وظيفة نظام معينة بواسطة وحدة تحكم سياسة الجهاز (DPC):

• أيقونة ثابتة أو غيرها من تحمل تكاليف المستخدم (على سبيل المثال رمز معلومات AOSP المنبع) لتمثيله عندما يتم تقييد إعداد معين بواسطة مسؤول الجهاز.
• رسالة شرح قصيرة ، كما هو موضح من قبل مسؤول الجهاز عبر setShortSupportMessage .
• أيقونة تطبيق DPC.

3.9.2 دعم الملف الشخصي المدارة

الأجهزة التي تتم إدارتها قادرة على الأجهزة هي تلك الأجهزة التي:

• إعلان Android.software.device_admin (انظر القسم 3.9 إدارة الجهاز ).
• ليست أجهزة RAM منخفضة (انظر القسم 7.6.1 ).
• تخصيص سعة التخزين الداخلية (غير القابلة للإزالة) كتخزين مشترك (انظر القسم 7.6.2 ).

يجب أن تكون الأجهزة القادرة على ملف التعريف المدارة:

• إعلان أن منصة ميزة علامة android.software.managed_users .
• دعم الملامح المدارة عبر android.app.admin.DevicePolicyManager APIs.
• السماح بإنشاء ملف تعريف واحد مُدار واحد فقط.
• استخدم شارة أيقونة (على غرار شارة العمل AOSP Upstream) لتمثيل التطبيقات المدارة والعناصر واجهة المستخدم وعناصر واجهة المستخدم الأخرى مثل التكرار والإشعارات.
• عرض رمز الإخطار (على غرار شارة العمل AOSP Opstream) للإشارة إلى متى يكون المستخدم ضمن تطبيق ملف تعريف مُدار.
• عرض نخبًا يشير إلى أن المستخدم موجود في الملف الشخصي المُدار إذا كان الجهاز يستيقظ (Action_user_present) وعندما يكون الجهاز (Action_user_present) ، وأن يكون تطبيق المقدمة ضمن ملف التعريف المدارة.
• في حالة وجود ملف تعريف مُدار ، أظهر تكاليفًا مرئية في نية "المختار" للسماح للمستخدم بإعادة توجيه النية من الملف الشخصي المدار إلى المستخدم الأساسي أو العكس ، إذا تم تمكينه بواسطة وحدة تحكم سياسة الجهاز.
• في حالة وجود ملف تعريف مُدار ، كشف معارف المستخدم التالية لكل من المستخدم الأساسي والملف الشخصي المدار:
  • منفصل عن المحاسبة للبطارية والموقع وبيانات الهاتف المحمول واستخدام التخزين للمستخدم الأساسي والملف الشخصي المدار.
  • الإدارة المستقلة لتطبيقات VPN المثبتة داخل المستخدم الأساسي أو الملف الشخصي المدار.
  • الإدارة المستقلة للتطبيقات المثبتة داخل المستخدم الأساسي أو الملف الشخصي المدار.
  • الإدارة المستقلة للحسابات داخل المستخدم الأساسي أو الملف الشخصي المدارة.
• تأكد من أن الاتصالات المُثبتة مسبقًا وجهات الاتصال وتطبيقات المراسلة يمكنها البحث عن معلومات المتصل والبحث عنها من ملف التعريف المدار (إذا كان هناك واحد) جنبًا إلى جنب مع تلك الموجودة في الملف الشخصي الأساسي ، إذا سمحت وحدة تحكم سياسة الجهاز بذلك. عندما يتم عرض جهات الاتصال من ملف التعريف المدارة في سجل المكالمات المُثبت مسبقًا ، واتصالات IN IN ، وإخطارات قيد التنفيذ والمكالمات الفائتة ، وجهات الاتصال وتطبيقات المراسلة ، يجب أن تكون خافتة مع نفس الشارة المستخدمة للإشارة إلى تطبيقات الملف الشخصي المدارة.
• يجب التأكد من أنه يفي بجميع متطلبات الأمان المطبقة على الجهاز مع تمكين العديد من المستخدمين (انظر القسم 9.5 ) ، على الرغم من أن الملف الشخصي المدار لا يتم حسابه كمستخدم آخر بالإضافة إلى المستخدم الأساسي.
• دعم القدرة على تحديد شاشة قفل منفصلة تلبية المتطلبات التالية لمنح الوصول إلى التطبيقات التي تعمل في ملف تعريف مُدار.
  • يجب أن تكرم تطبيقات الجهاز جهاز DevicePolicyManager.ACTION_SET_NEW_PASSWORD واعرض واجهة لتكوين بيانات اعتماد شاشة قفل منفصلة للملف الشخصي المدار.
  • يجب أن تستخدم بيانات اعتماد شاشة القفل الخاصة بالملف الشخصي المدار نفس آليات تخزين وإدارة بيانات الاعتماد مثل ملف تعريف الوالدين ، كما هو موثق في موقع مشروع Android Open Source
  • يجب أن تنطبق سياسات كلمة مرور DPC على بيانات اعتماد شاشة قفل الملف الشخصي فقط ما لم يتم استدعاء مثيل DevicePolicyManager الذي تم إرجاعه بواسطة GetParentProfileInstance .

3.10. إمكانية الوصول

يوفر Android طبقة إمكانية الوصول التي تساعد المستخدمين على إعاقة للتنقل في أجهزتهم بسهولة أكبر. بالإضافة إلى ذلك ، يوفر Android واجهات برمجة تطبيقات النظام الأساسي التي تتيح تطبيقات خدمة الوصول من تلقي عمليات الاسترجاعات لأحداث المستخدم والنظام وإنشاء آليات ردود فعل بديلة ، مثل النص إلى الكلام ، والتعليقات haptic ، والملاحة التربوية/D-PAD.

تتضمن تطبيقات الأجهزة المتطلبات التالية:

• يجب أن توفر تطبيقات Android Automotive تنفيذًا لإطار وصول Android بما يتوافق مع تطبيق Android الافتراضي.
• يجب أن توفر تطبيقات الأجهزة (ANDROIT Automotive) تنفيذ إطار إمكانية الوصول إلى Android بما يتوافق مع تطبيق Android الافتراضي.
• يجب أن تدعم تطبيقات الأجهزة (Android Automotive) تطبيقات خدمة الوصول إلى الطرف الثالث من خلال Android.AccessibelationService APIs .
• يجب أن تنشئ تطبيقات الأجهزة (ANDROID Automotive) توليد إمكانية الوصول وتقديم هذه الأحداث إلى جميع تطبيقات خدمة Accessiblectibility بطريقة تتسق مع تطبيق Android الافتراضي

• يجب أن توفر تطبيقات الأجهزة (أجهزة Android Automotive و Android Watch التي لا يتم استبعادها لمخرجات صوتية) آلية يمكن الوصول إليها من قبل المستخدم لتمكين خدمات الوصول وتعطيلها ، ويجب أن تعرض هذه الواجهة استجابةً لـ Android.provider.settings.action_accessibility_settings.

• يوصى بشدة بتطبيقات أجهزة Android مع إخراج الصوت لتوفير تطبيقات خدمات الوصول على الجهاز قابلة للمقارنة في أو تجاوز وظائف Talkback ** وخدمات إمكانية الوصول إلى التبديل (https://github.com/google/talkback).

• Android Watch devices with audio output SHOULD provide implementations of an accessibility service on the device comparable in or exceeding functionality of the TalkBack accessibility service (https://github.com/google/talkback).
• Device implementations SHOULD provide a mechanism in the out-of-box setup flow for users to enable relevant accessibility services, as well as options to adjust the font size, display size and magnification gestures.

** For languages supported by Text-to-speech.

Also, note that if there is a preloaded accessibility service, it MUST be a Direct Boot aware {directBootAware} app if the device has encrypted storage using File Based Encryption (FBE).

3.11. النص إلى الكلام

Android includes APIs that allow applications to make use of text-to-speech (TTS) services and allows service providers to provide implementations of TTS services. Device implementations reporting the feature android.hardware.audio.output MUST meet these requirements related to the Android TTS framework .

Android Automotive implementations:

• MUST support the Android TTS framework APIs.
• MAY support installation of third-party TTS engines. If supported, partners MUST provide a user-accessible interface that allows the user to select a TTS engine for use at system level.

All other device implementations:

• MUST support the Android TTS framework APIs and SHOULD include a TTS engine supporting the languages available on the device. Note that the upstream Android open source software includes a full-featured TTS engine implementation.
• MUST support installation of third-party TTS engines.
• MUST provide a user-accessible interface that allows users to select a TTS engine for use at the system level.

3.12. TV Input Framework

The Android Television Input Framework (TIF) simplifies the delivery of live content to Android Television devices. TIF provides a standard API to create input modules that control Android Television devices. Android Television device implementations MUST support TV Input Framework.

Device implementations that support TIF MUST declare the platform feature android.software.live_tv.

3.12.1. تطبيق التلفزيون

Any device implementation that declares support for Live TV MUST have an installed TV application (TV App). The Android Open Source Project provides an implementation of the TV App.

The TV App MUST provide facilities to install and use TV Channels and meet the following requirements:

• Device implementations MUST allow third-party TIF-based inputs ( third-party inputs ) to be installed and managed.
• Device implementations MAY provide visual separation between pre-installed TIF-based inputs (installed inputs) and third-party inputs.
• Device implementations MUST NOT display the third-party inputs more than a single navigation action away from the TV App (ie expanding a list of third-party inputs from the TV App).

3.12.1.1. دليل البرامج الالكتروني

Android Television device implementations MUST show an informational and interactive overlay, which MUST include an electronic program guide (EPG) generated from the values in the TvContract.Programs fields. The EPG MUST meet the following requirements:

• The EPG MUST display information from all installed inputs and third-party inputs.
• The EPG MAY provide visual separation between the installed inputs and third-party inputs.
• The EPG is STRONGLY RECOMMENDED to display installed inputs and third-party inputs with equal prominence. The EPG MUST NOT display the third-party inputs more than a single navigation action away from the installed inputs on the EPG.
• On channel change, device implementations MUST display EPG data for the currently playing program.

3.12.1.2. ملاحة

The TV App MUST allow navigation for the following functions via the D-pad, Back, and Home keys on the Android Television device's input device(s) (ie remote control, remote control application, or game controller):

• Changing TV channels
• Opening EPG
• Configuring and tuning to third-party TIF-based inputs
• Opening Settings menu

The TV App SHOULD pass key events to HDMI inputs through CEC.

3.12.1.3. TV input app linking

Android Television device implementations MUST support TV input app linking , which allows all inputs to provide activity links from the current activity to another activity (ie a link from live programming to related content). The TV App MUST show TV input app linking when it is provided.

3.12.1.4. تغيير الوقت

Android Television device implementations MUST support time shifting, which allows the user to pause and resume live content. Device implementations MUST provide the user a way to pause and resume the currently playing program, if time shifting for that program is available .

3.12.1.5. TV recording

Android Television device implementations are STRONGLY RECOMMENDED to support TV recording. If the TV input supports recording, the EPG MAY provide a way to record a program if the recording of such a program is not prohibited . Device implementations SHOULD provide a user interface to play recorded programs.

3.13. الإعدادات السريعة

Android device implementations SHOULD include a Quick Settings UI component that allow quick access to frequently used or urgently needed actions.

Android includes the quicksettings API allowing third party apps to implement tiles that can be added by the user alongside the system-provided tiles in the Quick Settings UI component. If a device implementation has a Quick Settings UI component, it:

• MUST allow the user to add or remove tiles from a third-party app to Quick Settings.
• MUST NOT automatically add a tile from a third-party app directly to Quick Settings.
• MUST display all the user-added tiles from third-party apps alongside the system-provided quick setting tiles.

3.14. Vehicle UI APIs

3.14.1. Vehicle Media UI

Any device implementation that declares automotive support MUST include a UI framework to support third-party apps consuming the MediaBrowser and MediaSession APIs.

The UI framework supporting third-party apps that depend on MediaBrowser and MediaSession has the following visual requirements:

• MUST display MediaItem icons and notification icons unaltered.
• MUST display those items as described by MediaSession, eg, metadata, icons, imagery.
• MUST show app title.
• MUST have drawer to present MediaBrowser hierarchy.

4. Application Packaging Compatibility

Device implementations MUST install and run Android “.apk” files as generated by the “aapt” tool included in the official Android SDK . For this reason device implementations SHOULD use the reference implementation's package management system.

The package manager MUST support verifying “.apk” files using the APK Signature Scheme v2 and JAR signing .

Devices implementations MUST NOT extend either the .apk , Android Manifest , Dalvik bytecode , or RenderScript bytecode formats in such a way that would prevent those files from installing and running correctly on other compatible devices.

Device implementations MUST NOT allow apps other than the current "installer of record" for the package to silently uninstall the app without any prompt, as documented in the SDK for the DELETE_PACKAGE permission. The only exceptions are the system package verifier app handling PACKAGE_NEEDS_VERIFICATION intent and the storage manager app handling ACTION_MANAGE_STORAGE intent.

5. Multimedia Compatibility

5.1. برامج ترميز الوسائط

Device implementations—

• MUST support the core media formats specified in the Android SDK documentation, except where explicitly permitted in this document.

• MUST support the media formats, encoders, decoders, file types, and container formats defined in the tables below and reported via MediaCodecList .

• MUST also be able to decode all profiles reported in its CamcorderProfile

• MUST be able to decode all formats it can encode. This includes all bitstreams that its encoders generate.

Codecs SHOULD aim for minimum codec latency, in other words, codecs—

• SHOULD NOT consume and store input buffers and return input buffers only once processed
• SHOULD NOT hold onto decoded buffers for longer than as specified by the standard (eg SPS).
• SHOULD NOT hold onto encoded buffers longer than required by the GOP structure.

All of the codecs listed in the table below are provided as software implementations in the preferred Android implementation from the Android Open Source Project.

Please note that neither Google nor the Open Handset Alliance make any representation that these codecs are free from third-party patents. Those intending to use this source code in hardware or software products are advised that implementations of this code, including in open source software or shareware, may require patent licenses from the relevant patent holders.

5.1.1. برامج ترميز الصوت

1 Required for device implementations that define android.hardware.microphone but optional for Android Watch device implementations.

2 Recording or playback MAY be performed in mono or stereo, but the decoding of AAC input buffers of multichannel streams (ie more than two channels) to PCM through the default AAC audio decoder in the android.media.MediaCodec API, the following MUST be أيد:

• decoding is performed without downmixing (eg a 5.0 AAC stream must be decoded to five channels of PCM, a 5.1 AAC stream must be decoded to six channels of PCM),
• dynamic range metadata, as defined in "Dynamic Range Control (DRC)" in ISO/IEC 14496-3, and the android.media.MediaFormat DRC keys to configure the dynamic range-related behaviors of the audio decoder. The AAC DRC keys were introduced in API 21,and are: KEY_AAC_DRC_ATTENUATION_FACTOR, KEY_AAC_DRC_BOOST_FACTOR, KEY_AAC_DRC_HEAVY_COMPRESSION, KEY_AAC_DRC_TARGET_REFERENCE_LEVEL and KEY_AAC_ENCODED_TARGET_LEVEL

3 Required for Android Handheld device implementations.

4 Required for device implementations that define android.hardware.microphone, including Android Watch device implementations.

5.1.2. Image Codecs

5.1.3. برامج ترميز الفيديو

• Codecs advertising HDR profile support MUST support HDR static metadata parsing and handling.

• If a media codec advertises intra refresh support, then it MUST support the refresh periods in the range of 10 - 60 frames and accurately operate within 20% of configured refresh period.

• Video codecs MUST support output and input bytebuffer sizes that accommodate the largest feasible compressed and uncompressed frame as dictated by the standard and configuration but also not overallocate.

• Video encoders and decoders MUST support YUV420 flexible color format (COLOR_FormatYUV420Flexible).

1 Required for device implementations that include camera hardware and define android.hardware.camera or android.hardware.camera.front.

2 Required for device implementations except Android Watch devices.

3 For acceptable quality of web video streaming and video-conference services, device implementations SHOULD use a hardware VP8 codec that meets the requirements .

4 Device implementations SHOULD support writing Matroska WebM files.

5 STRONGLY RECOMMENDED for Android Automotive, optional for Android Watch, and required for all other device types.

6 Applies only to Android Television device implementations.

5.2. ترميز الفيديو

H.264, VP8, VP9 and HEVC video encoders—

• MUST support dynamically configurable bitrates.
• SHOULD support variable frame rates, where video encoder SHOULD determine instantaneous frame duration based on the timestamps of input buffers, and allocate its bit bucket based on that frame duration.

H.263 and MPEG-4 video encoder SHOULD support dynamically configurable bitrates.

All video encoders SHOULD meet the following bitrate targets over two sliding windows:

• It SHOULD be not more than ~15% over the bitrate between intraframe (I-frame) intervals.
• It SHOULD be not more than ~100% over the bitrate over a sliding window of 1 second.

5.2.1. H.263

Android device implementations with H.263 encoders MUST support Baseline Profile Level 45.

5.2.2. ح-264

Android device implementations with H.264 codec support:

• MUST support Baseline Profile Level 3.
  However, support for ASO (Arbitrary Slice Ordering), FMO (Flexible Macroblock Ordering) and RS (Redundant Slices) is OPTIONAL. Moreover, to maintain compatibility with other Android devices, it is RECOMMENDED that ASO, FMO and RS are not used for Baseline Profile by encoders.
• MUST support the SD (Standard Definition) video encoding profiles in the following table.
• SHOULD support Main Profile Level 4.
• SHOULD support the HD (High Definition) video encoding profiles as indicated in the following table.
• In addition, Android Television devices are STRONGLY RECOMMENDED to encode HD 1080p video at 30 fps.

1 When supported by hardware, but STRONGLY RECOMMENDED for Android Television devices.

5.2.3. VP8

Android device implementations with VP8 codec support MUST support the SD video encoding profiles and SHOULD support the following HD (High Definition) video encoding profiles.

1 When supported by hardware.

5.3. فك تشفير الفيديو

Device implementations—

• MUST support dynamic video resolution and frame rate switching through the standard Android APIs within the same stream for all VP8, VP9, H.264, and H.265 codecs in real time and up to the maximum resolution supported by each codec on the device.

• Implementations that support the Dolby Vision decoder—

• MUST provide a Dolby Vision-capable extractor.

• MUST properly display Dolby Vision content on the device screen or on a standard video output port (eg, HDMI).

• Implementations that provide a Dolby Vision-capable extractor MUST set the track index of backward-compatible base-layer(s) (if present) to be the same as the combined Dolby Vision layer's track index.

5.3.1. مبيغ-2

Android device implementations with MPEG-2 decoders must support the Main Profile High Level.

5.3.2. H.263

Android device implementations with H.263 decoders MUST support Baseline Profile Level 30 and Level 45.

5.3.3. مبيغ-4

Android device implementations with MPEG-4 decoders MUST support Simple Profile Level 3.

5.3.4. ح.264

Android device implementations with H.264 decoders:

• MUST support Main Profile Level 3.1 and Baseline Profile.
  Support for ASO (Arbitrary Slice Ordering), FMO (Flexible Macroblock Ordering) and RS (Redundant Slices) is OPTIONAL.
• MUST be capable of decoding videos with the SD (Standard Definition) profiles listed in the following table and encoded with the Baseline Profile and Main Profile Level 3.1 (including 720p30).
• SHOULD be capable of decoding videos with the HD (High Definition) profiles as indicated in the following table.
• In addition, Android Television devices—
  • MUST support High Profile Level 4.2 and the HD 1080p60 decoding profile.
  • MUST be capable of decoding videos with both HD profiles as indicated in the following table and encoded with either the Baseline Profile, Main Profile, or the High Profile Level 4.2

1 REQUIRED for when the height as reported by the Display.getSupportedModes() method is equal or greater than the video resolution.

2 REQUIRED for Android Television device implementations.

5.3.5. H.265 (HEVC)

Android device implementations, when supporting H.265 codec as described in section 5.1.3 :

• MUST support the Main Profile Level 3 Main tier and the SD video decoding profiles as indicated in the following table.
• SHOULD support the HD decoding profiles as indicated in the following table.
• MUST support the HD decoding profiles as indicated in the following table if there is a hardware decoder.
• In addition, Android Television devices:
• MUST support the HD 720p decoding profile.
• STRONGLY RECOMMENDED to support the HD 1080p decoding profile. If the HD 1080p decoding profile is supported, it MUST support the Main Profile Level 4.1 Main tier.
• SHOULD support the UHD decoding profile. If the UHD decoding profile is supported the codec MUST support Main10 Level 5 Main Tier profile.

1 REQUIRED for Android Television device implementations with H.265 hardware decoding.

5.3.6. VP8

Android device implementations, when supporting VP8 codec as described in section 5.1.3 :

• MUST support the SD decoding profiles in the following table.
• SHOULD support the HD decoding profiles in the following table.
• Android Television devices MUST support the HD 1080p60 decoding profile.

1 REQUIRED for when the height as reported by the Display.getSupportedModes() method is equal or greater than the video resolution.

2 REQUIRED for Android Television device implementations.

5.3.7. VP9

Android device implementations, when supporting VP9 codec as described in section 5.1.3 :

• MUST support the SD video decoding profiles as indicated in the following table.
• SHOULD support the HD decoding profiles as indicated in the following table.
• MUST support the HD decoding profiles as indicated in the following table, if there is a hardware decoder.

• In addition, Android Television devices:

  • MUST support the HD 720p decoding profile.
  • STRONGLY RECOMMENDED to support the HD 1080p decoding profile.
  • SHOULD support the UHD decoding profile. If the UHD video decoding profile is supported, it MUST support 8-bit color depth and SHOULD support VP9 Profile 2 (10-bit).

1 REQUIRED for Android Television device implementations with VP9 hardware decoding.

5.4. تسجيل الصوت

While some of the requirements outlined in this section are stated as SHOULD since Android 4.3, the Compatibility Definition for a future version is planned to change these to MUST. Existing and new Android devices are STRONGLY RECOMMENDED to meet these requirements that are stated as SHOULD, or they will not be able to attain Android compatibility when upgraded to the future version.

5.4.1. Raw Audio Capture

Device implementations that declare android.hardware.microphone MUST allow capture of raw audio content with the following characteristics:

• Format : Linear PCM, 16-bit
• Sampling rates : 8000, 11025, 16000, 44100
• Channels : Mono

The capture for the above sample rates MUST be done without up-sampling, and any down-sampling MUST include an appropriate anti-aliasing filter.

Device implementations that declare android.hardware.microphone SHOULD allow capture of raw audio content with the following characteristics:

• Format : Linear PCM, 16-bit
• Sampling rates : 22050, 48000
• Channels : Stereo

If capture for the above sample rates is supported, then the capture MUST be done without up-sampling at any ratio higher than 16000:22050 or 44100:48000. Any up-sampling or down-sampling MUST include an appropriate anti-aliasing filter.

5.4.2. Capture for Voice Recognition

The android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source MUST support capture at one of the sampling rates, 44100 and 48000.

In addition to the above recording specifications, when an application has started recording an audio stream using the android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source:

• The device SHOULD exhibit approximately flat amplitude versus frequency characteristics: specifically, ±3 dB, from 100 Hz to 4000 Hz.
• Audio input sensitivity SHOULD be set such that a 90 dB sound power level (SPL) source at 1000 Hz yields RMS of 2500 for 16-bit samples.
• PCM amplitude levels SHOULD linearly track input SPL changes over at least a 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.
• Total harmonic distortion SHOULD be less than 1% for 1 kHz at 90 dB SPL input level at the microphone.
• Noise reduction processing, if present, MUST be disabled.
• Automatic gain control, if present, MUST be disabled.

If the platform supports noise suppression technologies tuned for speech recognition, the effect MUST be controllable from the android.media.audiofx.NoiseSuppressor API. Moreover, the UUID field for the noise suppressor's effect descriptor MUST uniquely identify each implementation of the noise suppression technology.

5.4.3. Capture for Rerouting of Playback

The android.media.MediaRecorder.AudioSource class includes the REMOTE_SUBMIX audio source. Devices that declare android.hardware.audio.output MUST properly implement the REMOTE_SUBMIX audio source so that when an application uses the android.media.AudioRecord API to record from this audio source, it can capture a mix of all audio streams except for the following :

• STREAM_RING
• STREAM_ALARM
• STREAM_NOTIFICATION

5.5. تشغيل الصوت

Device implementations that declare android.hardware.audio.output MUST conform to the requirements in this section.

5.5.1. Raw Audio Playback

The device MUST allow playback of raw audio content with the following characteristics:

• Format : Linear PCM, 16-bit
• Sampling rates : 8000, 11025, 16000, 22050, 32000, 44100
• Channels : Mono, Stereo

The device SHOULD allow playback of raw audio content with the following characteristics:

• Sampling rates : 24000, 48000

5.5.2. تأثيرات صوتية

Android provides an API for audio effects for device implementations. Device implementations that declare the feature android.hardware.audio.output:

• MUST support the EFFECT_TYPE_EQUALIZER and EFFECT_TYPE_LOUDNESS_ENHANCER implementations controllable through the AudioEffect subclasses Equalizer, LoudnessEnhancer.
• MUST support the visualizer API implementation, controllable through the Visualizer class.
• SHOULD support the EFFECT_TYPE_BASS_BOOST, EFFECT_TYPE_ENV_REVERB, EFFECT_TYPE_PRESET_REVERB, and EFFECT_TYPE_VIRTUALIZER implementations controllable through the AudioEffect sub-classes BassBoost, EnvironmentalReverb, PresetReverb, and Virtualizer.

5.5.3. Audio Output Volume

Android Television device implementations MUST include support for system Master Volume and digital audio output volume attenuation on supported outputs, except for compressed audio passthrough output (where no audio decoding is done on the device).

Android Automotive device implementations SHOULD allow adjusting audio volume separately per each audio stream using the content type or usage as defined by AudioAttributes and car audio usage as publicly defined in android.car.CarAudioManager .

5.6. Audio Latency

Audio latency is the time delay as an audio signal passes through a system. Many classes of applications rely on short latencies, to achieve real-time sound effects.

For the purposes of this section, use the following definitions:

• output latency . The interval between when an application writes a frame of PCM-coded data and when the corresponding sound is presented to environment at an on-device transducer or signal leaves the device via a port and can be observed externally.
• cold output latency . The output latency for the first frame, when the audio output system has been idle and powered down prior to the request.
• continuous output latency . The output latency for subsequent frames, after the device is playing audio.
• input latency . The interval between when a sound is presented by environment to device at an on-device transducer or signal enters the device via a port and when an application reads the corresponding frame of PCM-coded data.
• lost input . The initial portion of an input signal that is unusable or unavailable.
• cold input latency . The sum of lost input time and the input latency for the first frame, when the audio input system has been idle and powered down prior to the request.
• continuous input latency . The input latency for subsequent frames, while the device is capturing audio.
• cold output jitter . The variability among separate measurements of cold output latency values.
• cold input jitter . The variability among separate measurements of cold input latency values.
• continuous round-trip latency . The sum of continuous input latency plus continuous output latency plus one buffer period. The buffer period allows time for the app to process the signal and time for the app to mitigate phase difference between input and output streams.
• OpenSL ES PCM buffer queue API . The set of PCM-related OpenSL ES APIs within Android NDK .

Device implementations that declare android.hardware.audio.output are STRONGLY RECOMMENDED to meet or exceed these audio output requirements:

• cold output latency of 100 milliseconds or less
• continuous output latency of 45 milliseconds or less
• minimize the cold output jitter

If a device implementation meets the requirements of this section after any initial calibration when using the OpenSL ES PCM buffer queue API, for continuous output latency and cold output latency over at least one supported audio output device, it is STRONGLY RECOMMENDED to report support for low-latency audio, by reporting the feature android.hardware.audio.low_latency via the android.content.pm.PackageManager class. Conversely, if the device implementation does not meet these requirements it MUST NOT report support for low-latency audio.

Device implementations that include android.hardware.microphone are STRONGLY RECOMMENDED to meet these input audio requirements:

• cold input latency of 100 milliseconds or less
• continuous input latency of 30 milliseconds or less
• continuous round-trip latency of 50 milliseconds or less
• minimize the cold input jitter

5.7. بروتوكولات الشبكة

Devices MUST support the media network protocols for audio and video playback as specified in the Android SDK documentation. Specifically, devices MUST support the following media network protocols:

• HTTP(S) progressive streaming
  All required codecs and container formats in section 5.1 MUST be supported over HTTP(S)

• HTTP Live Streaming draft protocol, Version 7
  The following media segment formats MUST be supported:

• RTSP (RTP, SDP)

  The following RTP audio video profile and related codecs MUST be supported. For exceptions please see the table footnotes in section 5.1 .

5.8. Secure Media

Device implementations that support secure video output and are capable of supporting secure surfaces MUST declare support for Display.FLAG_SECURE. Device implementations that declare support for Display.FLAG_SECURE, if they support a wireless display protocol, MUST secure the link with a cryptographically strong mechanism such as HDCP 2.x or higher for Miracast wireless displays. Similarly if they support a wired external display, the device implementations MUST support HDCP 1.2 or higher. Android Television device implementations MUST support HDCP 2.2 for devices supporting 4K resolution and HDCP 1.4 or above for lower resolutions. The upstream Android open source implementation includes support for wireless (Miracast) and wired (HDMI) displays that satisfies this requirement.

5.9. Musical Instrument Digital Interface (MIDI)

If a device implementation supports the inter-app MIDI software transport (virtual MIDI devices), and it supports MIDI over all of the following MIDI-capable hardware transports for which it provides generic non-MIDI connectivity, it is STRONGLY RECOMMENDED to report support for feature android.software.midi via the android.content.pm.PackageManager class.

The MIDI-capable hardware transports are:

• USB host mode (section 7.7 USB)
• USB peripheral mode (section 7.7 USB)
• MIDI over Bluetooth LE acting in central role (section 7.4.3 Bluetooth)

Conversely, if the device implementation provides generic non-MIDI connectivity over a particular MIDI-capable hardware transport listed above, but does not support MIDI over that hardware transport, it MUST NOT report support for feature android.software.midi.

5.10. Professional Audio

If a device implementation meets all of the following requirements, it is STRONGLY RECOMMENDED to report support for feature android.hardware.audio.pro via the android.content.pm.PackageManager class.

• The device implementation MUST report support for feature android.hardware.audio.low_latency.
• The continuous round-trip audio latency, as defined in section 5.6 Audio Latency, MUST be 20 milliseconds or less and SHOULD be 10 milliseconds or less over at least one supported path.
• If the device includes a 4 conductor 3.5mm audio jack, the continuous round-trip audio latency MUST be 20 milliseconds or less over the audio jack path, and SHOULD be 10 milliseconds or less over at the audio jack path.
• The device implementation MUST include a USB port(s) supporting USB host mode and USB peripheral mode.
• The USB host mode MUST implement the USB audio class.
• If the device includes an HDMI port, the device implementation MUST support output in stereo and eight channels at 20-bit or 24-bit depth and 192 kHz without bit-depth loss or resampling.
• The device implementation MUST report support for feature android.software.midi.
• If the device includes a 4 conductor 3.5mm audio jack, the device implementation is STRONGLY RECOMMENDED to comply with section Mobile device (jack) specifications of the Wired Audio Headset Specification (v1.1) .

Latencies and USB audio requirements MUST be met using the OpenSL ES PCM buffer queue API.

In addition, a device implementation that reports support for this feature SHOULD:

• Provide a sustainable level of CPU performance while audio is active.
• Minimize audio clock inaccuracy and drift relative to standard time.
• Minimize audio clock drift relative to the CPU CLOCK_MONOTONIC when both are active.
• Minimize audio latency over on-device transducers.
• Minimize audio latency over USB digital audio.
• Document audio latency measurements over all paths.
• Minimize jitter in audio buffer completion callback entry times, as this affects usable percentage of full CPU bandwidth by the callback.
• Provide zero audio underruns (output) or overruns (input) under normal use at reported latency.
• Provide zero inter-channel latency difference.
• Minimize MIDI mean latency over all transports.
• Minimize MIDI latency variability under load (jitter) over all transports.
• Provide accurate MIDI timestamps over all transports.
• Minimize audio signal noise over on-device transducers, including the period immediately after cold start.
• Provide zero audio clock difference between the input and output sides of corresponding end-points, when both are active. Examples of corresponding end-points include the on-device microphone and speaker, or the audio jack input and output.
• Handle audio buffer completion callbacks for the input and output sides of corresponding end-points on the same thread when both are active, and enter the output callback immediately after the return from the input callback. Or if it is not feasible to handle the callbacks on the same thread, then enter the output callback shortly after entering the input callback to permit the application to have a consistent timing of the input and output sides.
• Minimize the phase difference between HAL audio buffering for the input and output sides of corresponding end-points.
• Minimize touch latency.
• Minimize touch latency variability under load (jitter).

5.11. Capture for Unprocessed

Starting from Android 7.0, a new recording source has been added. It can be accessed using the android.media.MediaRecorder.AudioSource.UNPROCESSED audio source. In OpenSL ES, it can be accessed with the record preset SL_ANDROID_RECORDING_PRESET_UNPROCESSED .

A device MUST satisfy all of the following requirements to report support of the unprocessed audio source via the android.media.AudioManager property PROPERTY_SUPPORT_AUDIO_SOURCE_UNPROCESSED :

• The device MUST exhibit approximately flat amplitude-versus-frequency characteristics in the mid-frequency range: specifically ±10dB from 100 Hz to 7000 Hz.

• The device MUST exhibit amplitude levels in the low frequency range: specifically from ±20 dB from 5 Hz to 100 Hz compared to the mid-frequency range.

• The device MUST exhibit amplitude levels in the high frequency range: specifically from ±30 dB from 7000 Hz to 22 KHz compared to the mid-frequency range.

• Audio input sensitivity MUST be set such that a 1000 Hz sinusoidal tone source played at 94 dB Sound Pressure Level (SPL) yields a response with RMS of 520 for 16 bit-samples (or -36 dB Full Scale for floating point/double precision samples ).

• SNR > 60 dB (difference between 94 dB SPL and equivalent SPL of self noise, A-weighted).

• Total harmonic distortion MUST be less than 1% for 1 kHZ at 90 dB SPL input level at the microphone.

• The only signal processing allowed in the path is a level multiplier to bring the level to desired range. This level multiplier MUST NOT introduce delay or latency to the signal path.

• No other signal processing is allowed in the path, such as Automatic Gain Control, High Pass Filter, or Echo Cancellation. If any signal processing is present in the architecture for any reason, it MUST be disabled and effectively introduce zero delay or extra latency to the signal path.

All SPL measurements are made directly next to the microphone under test.

For multiple microphone configurations, these requirements apply to each microphone.

It is STRONGLY RECOMMENDED that a device satisfy as many of the requirements for the signal path for the unprocessed recording source; however, a device must satisfy all of these requirements, listed above, if it claims to support the unprocessed audio source.

6. Developer Tools and Options Compatibility

6.1. ادوات المطورين

Device implementations MUST support the Android Developer Tools provided in the Android SDK. Android compatible devices MUST be compatible with:

• جسر تصحيح أندرويد (adb)
  • Device implementations MUST support all adb functions as documented in the Android SDK including dumpsys .
  • The device-side adb daemon MUST be inactive by default and there MUST be a user-accessible mechanism to turn on the Android Debug Bridge. If a device implementation omits USB peripheral mode, it MUST implement the Android Debug Bridge via local-area network (such as Ethernet or 802.11).
  • Android includes support for secure adb. Secure adb enables adb on known authenticated hosts. Device implementations MUST support secure adb.
• Dalvik Debug Monitor Service (ddms)
  • Device implementations MUST support all ddms features as documented in the Android SDK.
  • As ddms uses adb, support for ddms SHOULD be inactive by default, but MUST be supported whenever the user has activated the Android Debug Bridge, as above.
• Monkey Device implementations MUST include the Monkey framework, and make it available for applications to use.
• SysTrace
  • Device implementations MUST support systrace tool as documented in the Android SDK. Systrace must be inactive by default, and there MUST be a user-accessible mechanism to turn on Systrace.
  • Most Linux-based systems and Apple Macintosh systems recognize Android devices using the standard Android SDK tools, without additional support; however Microsoft Windows systems typically require a driver for new Android devices. (For instance, new vendor IDs and sometimes new device IDs require custom USB drivers for Windows systems.)
  • If a device implementation is unrecognized by the adb tool as provided in the standard Android SDK, device implementers MUST provide Windows drivers allowing developers to connect to the device using the adb protocol. These drivers MUST be provided for Windows XP, Windows Vista, Windows 7, Windows 8, and Windows 10 in both 32-bit and 64-bit versions.

6.2. خيارات للمطور

Android includes support for developers to configure application development-related settings. Device implementations MUST honor the android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show application development-related settings The upstream Android implementation hides the Developer Options menu by default and enables users to launch Developer Options after pressing seven (7) times on the Settings > About Device > Build Number menu item. Device implementations MUST provide a consistent experience for Developer Options. Specifically, device implementations MUST hide Developer Options by default and MUST provide a mechanism to enable Developer Options that is consistent with the upstream Android implementation.

7. Hardware Compatibility

If a device includes a particular hardware component that has a corresponding API for third-party developers, the device implementation MUST implement that API as described in the Android SDK documentation. If an API in the SDK interacts with a hardware component that is stated to be optional and the device implementation does not possess that component:

• Complete class definitions (as documented by the SDK) for the component APIs MUST still be presented.
• The API's behaviors MUST be implemented as no-ops in some reasonable fashion.
• API methods MUST return null values where permitted by the SDK documentation.
• API methods MUST return no-op implementations of classes where null values are not permitted by the SDK documentation.
• API methods MUST NOT throw exceptions not documented by the SDK documentation.

A typical example of a scenario where these requirements apply is the telephony API: Even on non-phone devices, these APIs must be implemented as reasonable no-ops.

Device implementations MUST consistently report accurate hardware configuration information via the getSystemAvailableFeatures() and hasSystemFeature(String) methods on the android.content.pm.PackageManager class for the same build fingerprint.

7.1. العرض والرسومات

Android includes facilities that automatically adjust application assets and UI layouts appropriately for the device to ensure that third-party applications run well on a variety of hardware configurations . Devices MUST properly implement these APIs and behaviors, as detailed in this section.

The units referenced by the requirements in this section are defined as follows:

• physical diagonal size . The distance in inches between two opposing corners of the illuminated portion of the display.
• dots per inch (dpi) . The number of pixels encompassed by a linear horizontal or vertical span of 1”. Where dpi values are listed, both horizontal and vertical dpi must fall within the range.
• ابعاد متزنة . The ratio of the pixels of the longer dimension to the shorter dimension of the screen. For example, a display of 480x854 pixels would be 854/480 = 1.779, or roughly “16:9”.
• density-independent pixel (dp) . The virtual pixel unit normalized to a 160 dpi screen, calculated as: pixels = dps * (density/160).

7.1.1. Screen Configuration

7.1.1.1. حجم الشاشة

The Android UI framework supports a variety of different screen sizes, and allows applications to query the device screen size (aka “screen layout") via android.content.res.Configuration.screenLayout with the SCREENLAYOUT_SIZE_MASK. Device implementations MUST report the correct screen size as defined in the Android SDK documentation and determined by the upstream Android platform. Specifically, device implementations MUST report the correct screen size according to the following logical density-independent pixel (dp) screen dimensions.

• Devices MUST have screen sizes of at least 426 dp x 320 dp ('small'), unless it is an Android Watch device.
• Devices that report screen size 'normal' MUST have screen sizes of at least 480 dp x 320 dp.
• Devices that report screen size 'large' MUST have screen sizes of at least 640 dp x 480 dp.
• Devices that report screen size 'xlarge' MUST have screen sizes of at least 960 dp x 720 dp.

فضلاً عن ذلك:

• Android Watch devices MUST have a screen with the physical diagonal size in the range from 1.1 to 2.5 inches.
• Android Automotive devices MUST have a screen with the physical diagonal size greater than or equal to 6 inches.
• Android Automotive devices MUST have a screen size of at least 750 dp x 480 dp.
• Other types of Android device implementations, with a physically integrated screen, MUST have a screen at least 2.5 inches in physical diagonal size.

Devices MUST NOT change their reported screen size at any time.

Applications optionally indicate which screen sizes they support via the <supports-screens> attribute in the AndroidManifest.xml file. Device implementations MUST correctly honor applications' stated support for small, normal, large, and xlarge screens, as described in the Android SDK documentation.

7.1.1.2. Screen Aspect Ratio

While there is no restriction to the screen aspect ratio value of the physical screen display, the screen aspect ratio of the surface that third-party apps are rendered on and which can be derived from the values reported via the DisplayMetrics MUST meet the following requirements:

• If the uiMode is configured as UI_MODE_TYPE_WATCH, the aspect ratio value MAY be set as 1.0 (1:1).
• If the third-party app indicates that it is resizeable via the android:resizeableActivity attribute, there are no restrictions to the aspect ratio value.
• For all other cases, the aspect ratio MUST be a value between 1.3333 (4:3) and 1.86 (roughly 16:9) unless the app has indicated explicitly that it supports a higher screen aspect ratio through the maxAspectRatio metadata value.

7.1.1.3. كثافة الشاشة

The Android UI framework defines a set of standard logical densities to help application developers target application resources. By default, device implementations MUST report only one of the following logical Android framework densities through the DENSITY_DEVICE_STABLE API and this value MUST NOT change at any time; however, the device MAY report a different arbitrary density according to the display configuration changes made by the user (for example, display size) set after initial boot.

• 120 dpi (ldpi)
• 160 dpi (mdpi)
• 213 dpi (tvdpi)
• 240 dpi (hdpi)
• 260 dpi (260dpi)
• 280 dpi (280dpi)
• 300 dpi (300dpi)
• 320 dpi (xhdpi)
• 340 dpi (340dpi)
• 360 dpi (360dpi)
• 400 dpi (400dpi)
• 420 dpi (420dpi)
• 480 dpi (xxhdpi)
• 560 dpi (560dpi)
• 640 dpi (xxxhdpi)

Device implementations SHOULD define the standard Android framework density that is numerically closest to the physical density of the screen, unless that logical density pushes the reported screen size below the minimum supported. If the standard Android framework density that is numerically closest to the physical density results in a screen size that is smaller than the smallest supported compatible screen size (320 dp width), device implementations SHOULD report the next lowest standard Android framework density.

Device implementations are STRONGLY RECOMMENDED to provide users a setting to change the display size. If there is an implementation to change the display size of the device, it MUST align with the AOSP implementation as indicated below:

• The display size MUST NOT be scaled any larger than 1.5 times the native density or produce an effective minimum screen dimension smaller than 320dp (equivalent to resource qualifier sw320dp), whichever comes first.
• Display size MUST NOT be scaled any smaller than 0.85 times the native density.
• To ensure good usability and consistent font sizes, it is RECOMMENDED that the following scaling of Native Display options be provided (while complying with the limits specified above)
• Small: 0.85x
• Default: 1x (Native display scale)
• Large: 1.15x
• Larger: 1.3x
• Largest 1.45x

7.1.2. Display Metrics

Device implementations MUST report correct values for all display metrics defined in android.util.DisplayMetrics and MUST report the same values regardless of whether the embedded or external screen is used as the default display.

7.1.3. اتجاه الشاشة

Devices MUST report which screen orientations they support (android.hardware.screen.portrait and/or android.hardware.screen.landscape) and MUST report at least one supported orientation. For example, a device with a fixed orientation landscape screen, such as a television or laptop, SHOULD only report android.hardware.screen.landscape.

Devices that report both screen orientations MUST support dynamic orientation by applications to either portrait or landscape screen orientation. That is, the device must respect the application's request for a specific screen orientation. Device implementations MAY select either portrait or landscape orientation as the default.

Devices MUST report the correct value for the device's current orientation, whenever queried via the android.content.res.Configuration.orientation, android.view.Display.getOrientation(), or other APIs.

Devices MUST NOT change the reported screen size or density when changing orientation.

7.1.4. 2D and 3D Graphics Acceleration

Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied and detailed in the Android SDK documentations. Device implementations SHOULD support OpenGL ES 3.0, 3.1, or 3.2 on devices capable of supporting it. Device implementations MUST also support Android RenderScript , as detailed in the Android SDK documentation.

Device implementations MUST also correctly identify themselves as supporting OpenGL ES 1.0, OpenGL ES 2.0, OpenGL ES 3.0, OpenGL 3.1, or OpenGL 3.2. إنه:

• The managed APIs (such as via the GLES10.getString() method) MUST report support for OpenGL ES 1.0 and OpenGL ES 2.0.
• The native C/C++ OpenGL APIs (APIs available to apps via libGLES_v1CM.so, libGLES_v2.so, or libEGL.so) MUST report support for OpenGL ES 1.0 and OpenGL ES 2.0.
• Device implementations that declare support for OpenGL ES 3.0, 3.1, or 3.2 MUST support the corresponding managed APIs and include support for native C/C++ APIs. On device implementations that declare support for OpenGL ES 3.0, 3.1, or 3.2 libGLESv2.so MUST export the corresponding function symbols in addition to the OpenGL ES 2.0 function symbols.

Android provides an OpenGL ES extension pack with Java interfaces and native support for advanced graphics functionality such as tessellation and the ASTC texture compression format. Android device implementations MUST support the extension pack if the device supports OpenGL ES 3.2 and MAY support it otherwise. If the extension pack is supported in its entirety, the device MUST identify the support through the android.hardware.opengles.aep feature flag.

Also, device implementations MAY implement any desired OpenGL ES extensions. However, device implementations MUST report via the OpenGL ES managed and native APIs all extension strings that they do support, and conversely MUST NOT report extension strings that they do not support.

Note that Android includes support for applications to optionally specify that they require specific OpenGL texture compression formats. These formats are typically vendor-specific. Device implementations are not required by Android to implement any specific texture compression format. However, they SHOULD accurately report any texture compression formats that they do support, via the getString() method in the OpenGL API.

Android includes a mechanism for applications to declare that they want to enable hardware acceleration for 2D graphics at the Application, Activity, Window, or View level through the use of a manifest tag android:hardwareAccelerated or direct API calls.

Device implementations MUST enable hardware acceleration by default, and MUST disable hardware acceleration if the developer so requests by setting android:hardwareAccelerated="false” or disabling hardware acceleration directly through the Android View APIs.

In addition, device implementations MUST exhibit behavior consistent with the Android SDK documentation on hardware acceleration .

Android includes a TextureView object that lets developers directly integrate hardware-accelerated OpenGL ES textures as rendering targets in a UI hierarchy. Device implementations MUST support the TextureView API, and MUST exhibit consistent behavior with the upstream Android implementation.

Android includes support for EGL_ANDROID_RECORDABLE, an EGLConfig attribute that indicates whether the EGLConfig supports rendering to an ANativeWindow that records images to a video. Device implementations MUST support EGL_ANDROID_RECORDABLE extension.

7.1.5. Legacy Application Compatibility Mode

Android specifies a “compatibility mode” in which the framework operates in a 'normal' screen size equivalent (320dp width) mode for the benefit of legacy applications not developed for old versions of Android that pre-date screen-size independence.

• Android Automotive does not support legacy compatibility mode.
• All other device implementations MUST include support for legacy application compatibility mode as implemented by the upstream Android open source code. That is, device implementations MUST NOT alter the triggers or thresholds at which compatibility mode is activated, and MUST NOT alter the behavior of the compatibility mode itself.

7.1.6. Screen Technology

The Android platform includes APIs that allow applications to render rich graphics to the display. Devices MUST support all of these APIs as defined by the Android SDK unless specifically allowed in this document.

• Devices MUST support displays capable of rendering 16-bit color graphics and SHOULD support displays capable of 24-bit color graphics.
• Devices MUST support displays capable of rendering animations.
• The display technology used MUST have a pixel aspect ratio (PAR) between 0.9 and 1.15. That is, the pixel aspect ratio MUST be near square (1.0) with a 10 ~ 15% tolerance.

7.1.7. Secondary Displays

Android includes support for secondary display to enable media sharing capabilities and developer APIs for accessing external displays. If a device supports an external display either via a wired, wireless, or an embedded additional display connection then the device implementation MUST implement the display manager API as described in the Android SDK documentation.

7.2. أجهزة إدخال

Devices MUST support a touchscreen or meet the requirements listed in 7.2.2 for non-touch navigation.

7.2.1. لوحة المفاتيح

Device implementations:

• MUST include support for the Input Management Framework (which allows third-party developers to create Input Method Editors—ie soft keyboard) as detailed at http://developer.android.com .
• MUST provide at least one soft keyboard implementation (regardless of whether a hard keyboard is present) except for Android Watch devices where the screen size makes it less reasonable to have a soft keyboard.
• MAY include additional soft keyboard implementations.
• MAY include a hardware keyboard.
• MUST NOT include a hardware keyboard that does not match one of the formats specified in android.content.res.Configuration.keyboard (QWERTY or 12-key).

7.2.2. Non-touch Navigation

Device implementations:

• MAY omit a non-touch navigation option (trackball, d-pad, or wheel) if the device implementation is not an Android Television device.
• MUST report the correct value for android.content.res.Configuration.navigation .
• MUST provide a reasonable alternative user interface mechanism for the selection and editing of text, compatible with Input Management Engines. The upstream Android open source implementation includes a selection mechanism suitable for use with devices that lack non-touch navigation inputs.

7.2.3. مفاتيح التنقل

The Home, Recents, and Back functions (mapped to the key events KEYCODE_HOME, KEYCODE_APP_SWITCH, KEYCODE_BACK, respectively) are essential to the Android navigation paradigm and therefore:

• Android Handheld device implementations MUST provide the Home, Recents, and Back functions.
• Android Television device implementations MUST provide the Home and Back functions.
• Android Watch device implementations MUST have the Home function available to the user, and the Back function except for when it is in UI_MODE_TYPE_WATCH .
• Android Watch device implementations, and no other Android device types, MAY consume the long press event on the key event KEYCODE_BACK and omit it from being sent to the foreground application.
• Android Automotive implementations MUST provide the Home function and MAY provide Back and Recent functions.
• All other types of device implementations MUST provide the Home and Back functions.

These functions MAY be implemented via dedicated physical buttons (such as mechanical or capacitive touch buttons), or MAY be implemented using dedicated software keys on a distinct portion of the screen, gestures, touch panel, etc. Android supports both implementations. All of these functions MUST be accessible with a single action (eg tap, double-click or gesture) when visible.

Recents function, if provided, MUST have a visible button or icon unless hidden together with other navigation functions in full-screen mode. This does not apply to devices upgrading from earlier Android versions that have physical buttons for navigation and no recents key.

The Home and Back functions, if provided, MUST each have a visible button or icon unless hidden together with other navigation functions in full-screen mode or when the uiMode UI_MODE_TYPE_MASK is set to UI_MODE_TYPE_WATCH.

The Menu function is deprecated in favor of action bar since Android 4.0. Therefore the new device implementations shipping with Android 7.1 and later MUST NOT implement a dedicated physical button for the Menu function. Older device implementations SHOULD NOT implement a dedicated physical button for the Menu function, but if the physical Menu button is implemented and the device is running applications with targetSdkVersion > 10, the device implementation:

• MUST display the action overflow button on the action bar when it is visible and the resulting action overflow menu popup is not empty. For a device implementation launched before Android 4.4 but upgrading to Android 7.1, this is RECOMMENDED.
• MUST NOT modify the position of the action overflow popup displayed by selecting the overflow button in the action bar.
• MAY render the action overflow popup at a modified position on the screen when it is displayed by selecting the physical menu button.

For backwards compatibility, device implementations MUST make the Menu function available to applications when targetSdkVersion is less than 10, either by a physical button, a software key, or gestures. This Menu function should be presented unless hidden together with other navigation functions.

Android device implementations supporting the Assist action and/or VoiceInteractionService MUST be able to launch an assist app with a single interaction (eg tap, double-click, or gesture) when other navigation keys are visible. It is STRONGLY RECOMMENDED to use long press on home as this interaction. The designated interaction MUST launch the user-selected assist app, in other words the app that implements a VoiceInteractionService, or an activity handling the ACTION_ASSIST intent.

Device implementations MAY use a distinct portion of the screen to display the navigation keys, but if so, MUST meet these requirements:

• Device implementation navigation keys MUST use a distinct portion of the screen, not available to applications, and MUST NOT obscure or otherwise interfere with the portion of the screen available to applications.
• Device implementations MUST make available a portion of the display to applications that meets the requirements defined in section 7.1.1 .
• Device implementations MUST display the navigation keys when applications do not specify a system UI mode, or specify SYSTEM_UI_FLAG_VISIBLE.
• Device implementations MUST present the navigation keys in an unobtrusive “low profile” (eg. dimmed) mode when applications specify SYSTEM_UI_FLAG_LOW_PROFILE.
• Device implementations MUST hide the navigation keys when applications specify SYSTEM_UI_FLAG_HIDE_NAVIGATION.

7.2.4. Touchscreen Input

Device implementations SHOULD have a pointer input system of some kind (either mouse-like or touch). However, if a device implementation does not support a pointer input system, it MUST NOT report the android.hardware.touchscreen or android.hardware.faketouch feature constant. Device implementations that do include a pointer input system:

• SHOULD support fully independently tracked pointers, if the device input system supports multiple pointers.
• MUST report the value of android.content.res.Configuration.touchscreen corresponding to the type of the specific touchscreen on the device.

Android includes support for a variety of touchscreens, touch pads, and fake touch input devices. Touchscreen-based device implementations are associated with a display such that the user has the impression of directly manipulating items on screen. Since the user is directly touching the screen, the system does not require any additional affordances to indicate the objects being manipulated. In contrast, a fake touch interface provides a user input system that approximates a subset of touchscreen capabilities. For example, a mouse or remote control that drives an on-screen cursor approximates touch, but requires the user to first point or focus then click. Numerous input devices like the mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, and multi-touch trackpad can support fake touch interactions. Android includes the feature constant android.hardware.faketouch, which corresponds to a high-fidelity non-touch (pointer-based) input device such as a mouse or trackpad that can adequately emulate touch-based input (including basic gesture support), and indicates that the device supports an emulated subset of touchscreen functionality. Device implementations that declare the fake touch feature MUST meet the fake touch requirements in section 7.2.5 .

Device implementations MUST report the correct feature corresponding to the type of input used. Device implementations that include a touchscreen (single-touch or better) MUST report the platform feature constant android.hardware.touchscreen. Device implementations that report the platform feature constant android.hardware.touchscreen MUST also report the platform feature constant android.hardware.faketouch. Device implementations that do not include a touchscreen (and rely on a pointer device only) MUST NOT report any touchscreen feature, and MUST report only android.hardware.faketouch if they meet the fake touch requirements in section 7.2.5 .

7.2.5. Fake Touch Input

Device implementations that declare support for android.hardware.faketouch:

• MUST report the absolute X and Y screen positions of the pointer location and display a visual pointer on the screen.
• MUST report touch event with the action code that specifies the state change that occurs on the pointer going down or up on the screen .
• MUST support pointer down and up on an object on the screen, which allows users to emulate tap on an object on the screen.
• MUST support pointer down, pointer up, pointer down then pointer up in the same place on an object on the screen within a time threshold, which allows users to emulate double tap on an object on the screen.
• MUST support pointer down on an arbitrary point on the screen, pointer move to any other arbitrary point on the screen, followed by a pointer up, which allows users to emulate a touch drag.
• MUST support pointer down then allow users to quickly move the object to a different position on the screen and then pointer up on the screen, which allows users to fling an object on the screen.

Devices that declare support for android.hardware.faketouch.multitouch.distinct MUST meet the requirements for faketouch above, and MUST also support distinct tracking of two or more independent pointer inputs.

7.2.6. Game Controller Support

Android Television device implementations MUST support button mappings for game controllers as listed below. The upstream Android implementation includes implementation for game controllers that satisfies this requirement.

7.2.6.1. Button Mappings

Android Television device implementations MUST support the following key mappings:

1 KeyEvent

2 The above HID usages must be declared within a Game pad CA (0x01 0x0005).

3 This usage must have a Logical Minimum of 0, a Logical Maximum of 7, a Physical Minimum of 0, a Physical Maximum of 315, Units in Degrees, and a Report Size of 4. The logical value is defined to be the clockwise rotation away from the vertical axis; for example, a logical value of 0 represents no rotation and the up button being pressed, while a logical value of 1 represents a rotation of 45 degrees and both the up and left keys being pressed.

4 MotionEvent

1 MotionEvent

7.2.7. جهاز التحكم

Android Television device implementations SHOULD provide a remote control to allow users to access the TV interface. The remote control MAY be a physical remote or can be a software-based remote that is accessible from a mobile phone or tablet. The remote control MUST meet the requirements defined below.

• Search affordance . Device implementations MUST fire KEYCODE_SEARCH (or KEYCODE_ASSIST if the device supports an assistant) when the user invokes voice search on either the physical or software-based remote.
• ملاحة . All Android Television remotes MUST include Back, Home, and Select buttons and support for D-pad events .

7.3. أجهزة الاستشعار

Android includes APIs for accessing a variety of sensor types. Devices implementations generally MAY omit these sensors, as provided for in the following subsections. If a device includes a particular sensor type that has a corresponding API for third-party developers, the device implementation MUST implement that API as described in the Android SDK documentation and the Android Open Source documentation on sensors . For example, device implementations:

• MUST accurately report the presence or absence of sensors per the android.content.pm.PackageManager class.
• MUST return an accurate list of supported sensors via the SensorManager.getSensorList() and similar methods.
• MUST behave reasonably for all other sensor APIs (for example, by returning true or false as appropriate when applications attempt to register listeners, not calling sensor listeners when the corresponding sensors are not present; etc.).
• MUST report all sensor measurements using the relevant International System of Units (metric) values for each sensor type as defined in the Android SDK documentation.
• SHOULD report the event time in nanoseconds as defined in the Android SDK documentation, representing the time the event happened and synchronized with the SystemClock.elapsedRealtimeNano() clock. Existing and new Android devices are STRONGLY RECOMMENDED to meet these requirements so they will be able to upgrade to the future platform releases where this might become a REQUIRED component. The synchronization error SHOULD be below 100 milliseconds.
• MUST report sensor data with a maximum latency of 100 milliseconds + 2 * sample_time for the case of a sensor streamed with a minimum required latency of 5 ms + 2 * sample_time when the application processor is active. This delay does not include any filtering delays.
• MUST report the first sensor sample within 400 milliseconds + 2 * sample_time of the sensor being activated. It is acceptable for this sample to have an accuracy of 0.

The list above is not comprehensive; the documented behavior of the Android SDK and the Android Open Source Documentations on sensors is to be considered authoritative.

Some sensor types are composite, meaning they can be derived from data provided by one or more other sensors. (Examples include the orientation sensor and the linear acceleration sensor.) Device implementations SHOULD implement these sensor types, when they include the prerequisite physical sensors as described in sensor types . If a device implementation includes a composite sensor it MUST implement the sensor as described in the Android Open Source documentation on composite sensors .

Some Android sensors support a “continuous” trigger mode , which returns data continuously. For any API indicated by the Android SDK documentation to be a continuous sensor, device implementations MUST continuously provide periodic data samples that SHOULD have a jitter below 3%, where jitter is defined as the standard deviation of the difference of the reported timestamp values between consecutive الأحداث.

Note that the device implementations MUST ensure that the sensor event stream MUST NOT prevent the device CPU from entering a suspend state or waking up from a suspend state.

Finally, when several sensors are activated, the power consumption SHOULD NOT exceed the sum of the individual sensor's reported power consumption.

7.3.1. مقياس التسارع

Device implementations SHOULD include a 3-axis accelerometer. Android Handheld devices, Android Automotive implementations, and Android Watch devices are STRONGLY RECOMMENDED to include this sensor. If a device implementation does include a 3-axis accelerometer, it:

• MUST implement and report TYPE_ACCELEROMETER sensor .
• MUST be able to report events up to a frequency of at least 50 Hz for Android Watch devices as such devices have a stricter power constraint and 100 Hz for all other device types.
• SHOULD report events up to at least 200 Hz.
• MUST comply with the Android sensor coordinate system as detailed in the Android APIs. Android Automotive implementations MUST comply with the Android car sensor coordinate system .
• MUST be capable of measuring from freefall up to four times the gravity (4g) or more on any axis.
• MUST have a resolution of at least 12-bits and SHOULD have a resolution of at least 16-bits.
• SHOULD be calibrated while in use if the characteristics changes over the life cycle and compensated, and preserve the compensation parameters between device reboots.
• SHOULD be temperature compensated.
• MUST have a standard deviation no greater than 0.05 m/s^, where the standard deviation should be calculated on a per axis basis on samples collected over a period of at least 3 seconds at the fastest sampling rate.
• SHOULD implement the TYPE_SIGNIFICANT_MOTION, TYPE_TILT_DETECTOR, TYPE_STEP_DETECTOR, TYPE_STEP_COUNTER composite sensors as described in the Android SDK document. Existing and new Android devices are STRONGLY RECOMMENDED to implement the TYPE_SIGNIFICANT_MOTION composite sensor. If any of these sensors are implemented, the sum of their power consumption MUST always be less than 4 mW and SHOULD each be below 2 mW and 0.5 mW for when the device is in a dynamic or static condition.
• If a gyroscope sensor is included, MUST implement the TYPE_GRAVITY and TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR sensor.
• MUST implement a TYPE_ROTATION_VECTOR composite sensor, if a gyroscope sensor and a magnetometer sensor is also included.

7.3.2. مقياس المغناطيسية

Device implementations SHOULD include a 3-axis magnetometer (compass). If a device does include a 3-axis magnetometer, it:

• MUST implement the TYPE_MAGNETIC_FIELD sensor and SHOULD also implement TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor. Existing and new Android devices are STRONGLY RECOMMENDED to implement the TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor.
• MUST be able to report events up to a frequency of at least 10 Hz and SHOULD report events up to at least 50 Hz.
• MUST comply with the Android sensor coordinate system as detailed in the Android APIs.
• MUST be capable of measuring between -900 µT and +900 µT on each axis before saturating.
• MUST have a hard iron offset value less than 700 µT and SHOULD have a value below 200 µT, by placing the magnetometer far from dynamic (current-induced) and static (magnet-induced) magnetic fields.
• MUST have a resolution equal or denser than 0.6 µT and SHOULD have a resolution equal or denser than 0.2 µT.
• SHOULD be temperature compensated.
• MUST support online calibration and compensation of the hard iron bias, and preserve the compensation parameters between device reboots.
• MUST have the soft iron compensation applied—the calibration can be done either while in use or during the production of the device.
• SHOULD have a standard deviation, calculated on a per axis basis on samples collected over a period of at least 3 seconds at the fastest sampling rate, no greater than 0.5 µT.
• MUST implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer sensor and a gyroscope sensor is also included.
• MAY implement the TYPE_GEOMAGNETIC_ROTATION_VECTOR sensor if an accelerometer sensor is also implemented. However if implemented, it MUST consume less than 10 mW and SHOULD consume less than 3 mW when the sensor is registered for batch mode at 10 Hz.

7.3.3. نظام تحديد المواقع

Device implementations SHOULD include a GPS/GNSS receiver. If a device implementation does include a GPS/GNSS receiver and reports the capability to applications through the android.hardware.location.gps feature flag:

• It is STRONGLY RECOMMENDED that the device continue to deliver normal GPS/GNSS outputs to applications during an emergency phone call and that location output not be blocked during an emergency phone call.
• It MUST support location outputs at a rate of at least 1 Hz when requested via LocationManager#requestLocationUpdate .
• It MUST be able to determine the location in open-sky conditions (strong signals, negligible multipath, HDOP < 2) within 10 seconds (fast time to first fix), when connected to a 0.5 Mbps or faster data speed internet connection. This requirement is typically met by the use of some form of Assisted or Predicted GPS/GNSS technique to minimize GPS/GNSS lock-on time (Assistance data includes Reference Time, Reference Location and Satellite Ephemeris/Clock).
  • After making such a location calculation, it is STRONGLY RECOMMENDED for the device to be able to determine its location, in open sky, within 10 seconds, when location requests are restarted, up to an hour after the initial location calculation, even when the subsequent request is made without a data connection, and/or after a power cycle.
• In open sky conditions after determining the location, while stationary or moving with less than 1 meter per second squared of acceleration:
  • It MUST be able to determine location within 20 meters, and speed within 0.5 meters per second, at least 95% of the time.
  • It MUST simultaneously track and report via GnssStatus.Callback at least 8 satellites from one constellation.
  • It SHOULD be able to simultaneously track at least 24 satellites, from multiple constellations (eg GPS + at least one of Glonass, Beidou, Galileo).
• It MUST report the GNSS technology generation through the test API 'getGnssYearOfHardware'.
• It is STRONGLY RECOMMENDED to meet and MUST meet all requirements below if the GNSS technology generation is reported as the year "2016" or newer.
  • It MUST report GPS measurements, as soon as they are found, even if a location calculated from GPS/GNSS is not yet reported.
  • It MUST report GPS pseudoranges and pseudorange rates, that, in open-sky conditions after determining the location, while stationary or moving with less than 0.2 meter per second squared of acceleration, are sufficient to calculate position within 20 meters, and speed within 0.2 meters per second, at least 95% of the time.

Note that while some of the GPS requirements above are stated as STRONGLY RECOMMENDED, the Compatibility Definition for the next major version is expected to change these to a MUST.

7.3.4. جيروسكوب

Device implementations SHOULD include a gyroscope (angular change sensor). Devices SHOULD NOT include a gyroscope sensor unless a 3-axis accelerometer is also included. If a device implementation includes a gyroscope, it:

• MUST implement the TYPE_GYROSCOPE sensor and SHOULD also implement TYPE_GYROSCOPE_UNCALIBRATED sensor. Existing and new Android devices are STRONGLY RECOMMENDED to implement the SENSOR_TYPE_GYROSCOPE_UNCALIBRATED sensor.
• MUST be capable of measuring orientation changes up to 1,000 degrees per second.
• MUST be able to report events up to a frequency of at least 50 Hz for Android Watch devices as such devices have a stricter power constraint and 100 Hz for all other device types.
• SHOULD report events up to at least 200 Hz.
• MUST have a resolution of 12-bits or more and SHOULD have a resolution of 16-bits or more.
• MUST be temperature compensated.
• MUST be calibrated and compensated while in use, and preserve the compensation parameters between device reboots.
• MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, or rad^2 / s). The variance is allowed to vary with the sampling rate, but must be constrained by this value. In other words, if you measure the variance of the gyro at 1 Hz sampling rate it should be no greater than 1e-7 rad^2/s^2.
• MUST implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer sensor and a magnetometer sensor is also included.
• If an accelerometer sensor is included, MUST implement the TYPE_GRAVITY and TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices are STRONGLY RECOMMENDED to implement the TYPE_GAME_ROTATION_VECTOR sensor.

7.3.5. بارومتر

Device implementations SHOULD include a barometer (ambient air pressure sensor). If a device implementation includes a barometer, it:

• MUST implement and report TYPE_PRESSURE sensor.
• MUST be able to deliver events at 5 Hz or greater.
• MUST have adequate precision to enable estimating altitude.
• MUST be temperature compensated.

7.3.6. ميزان الحرارة

Device implementations MAY include an ambient thermometer (temperature sensor). If present, it MUST be defined as SENSOR_TYPE_AMBIENT_TEMPERATURE and it MUST measure the ambient (room) temperature in degrees Celsius.

Device implementations MAY but SHOULD NOT include a CPU temperature sensor. If present, it MUST be defined as SENSOR_TYPE_TEMPERATURE, it MUST measure the temperature of the device CPU, and it MUST NOT measure any other temperature. Note the SENSOR_TYPE_TEMPERATURE sensor type was deprecated in Android 4.0.

7.3.7. مضواء

Device implementations MAY include a photometer (ambient light sensor).

7.3.8. مستشعر القرب

Device implementations MAY include a proximity sensor. Devices that can make a voice call and indicate any value other than PHONE_TYPE_NONE in getPhoneType SHOULD include a proximity sensor. If a device implementation does include a proximity sensor, it:

• MUST measure the proximity of an object in the same direction as the screen. That is, the proximity sensor MUST be oriented to detect objects close to the screen, as the primary intent of this sensor type is to detect a phone in use by the user. If a device implementation includes a proximity sensor with any other orientation, it MUST NOT be accessible through this API.
• MUST have 1-bit of accuracy or more.

7.3.9. High Fidelity Sensors

Device implementations supporting a set of higher quality sensors that can meet all the requirements listed in this section MUST identify the support through the android.hardware.sensor.hifi_sensors feature flag.

A device declaring android.hardware.sensor.hifi_sensors MUST support all of the following sensor types meeting the quality requirements as below:

• SENSOR_TYPE_ACCELEROMETER
  • MUST have a measurement range between at least -8g and +8g.
  • MUST have a measurement resolution of at least 1024 LSB/G.
  • MUST have a minimum measurement frequency of 12.5 Hz or lower.
  • MUST have a maximum measurement frequency of 400 Hz or higher.
  • MUST have a measurement noise not above 400 uG/√Hz.
  • MUST implement a non-wake-up form of this sensor with a buffering capability of at least 3000 sensor events.
  • MUST have a batching power consumption not worse than 3 mW.
  • SHOULD have a stationary noise bias stability of \<15 μg √Hz from 24hr static dataset.
  • SHOULD have a bias change vs. temperature of ≤ +/- 1mg / °C.
  • SHOULD have a best-fit line non-linearity of ≤ 0.5%, and sensitivity change vs. temperature of ≤ 0.03%/C°.

• SENSOR_TYPE_GYROSCOPE

  • MUST have a measurement range between at least -1000 and +1000 dps.
  • MUST have a measurement resolution of at least 16 LSB/dps.
  • MUST have a minimum measurement frequency of 12.5 Hz or lower.
  • MUST have a maximum measurement frequency of 400 Hz or higher.
  • MUST have a measurement noise not above 0.014°/s/√Hz.
  • SHOULD have a stationary bias stability of < 0.0002 °/s √Hz from 24-hour static dataset.
  • SHOULD have a bias change vs. temperature of ≤ +/- 0.05 °/ s / °C.
  • SHOULD have a sensitivity change vs. temperature of ≤ 0.02% / °C.
  • SHOULD have a best-fit line non-linearity of ≤ 0.2%.
  • SHOULD have a noise density of ≤ 0.007 °/s/√Hz.

• SENSOR_TYPE_GYROSCOPE_UNCALIBRATED with the same quality requirements as SENSOR_TYPE_GYROSCOPE.

• SENSOR_TYPE_GEOMAGNETIC_FIELD
  • MUST have a measurement range between at least -900 and +900 uT.
  • MUST have a measurement resolution of at least 5 LSB/uT.
  • MUST have a minimum measurement frequency of 5 Hz or lower.
  • MUST have a maximum measurement frequency of 50 Hz or higher.
  • MUST have a measurement noise not above 0.5 uT.
• SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED with the same quality requirements as SENSOR_TYPE_GEOMAGNETIC_FIELD and in addition:
  • MUST implement a non-wake-up form of this sensor with a buffering capability of at least 600 sensor events.
• SENSOR_TYPE_PRESSURE
  • MUST have a measurement range between at least 300 and 1100 hPa.
  • MUST have a measurement resolution of at least 80 LSB/hPa.
  • MUST have a minimum measurement frequency of 1 Hz or lower.
  • MUST have a maximum measurement frequency of 10 Hz or higher.
  • MUST have a measurement noise not above 2 Pa/√Hz.
  • MUST implement a non-wake-up form of this sensor with a buffering capability of at least 300 sensor events.
  • MUST have a batching power consumption not worse than 2 mW.
• SENSOR_TYPE_GAME_ROTATION_VECTOR
  • MUST implement a non-wake-up form of this sensor with a buffering capability of at least 300 sensor events.
  • MUST have a batching power consumption not worse than 4 mW.
• SENSOR_TYPE_SIGNIFICANT_MOTION
  • MUST have a power consumption not worse than 0.5 mW when device is static and 1.5 mW when device is moving.
• SENSOR_TYPE_STEP_DETECTOR
  • MUST implement a non-wake-up form of this sensor with a buffering capability of at least 100 sensor events.
  • MUST have a power consumption not worse than 0.5 mW when device is static and 1.5 mW when device is moving.
  • MUST have a batching power consumption not worse than 4 mW.
• SENSOR_TYPE_STEP_COUNTER
  • MUST have a power consumption not worse than 0.5 mW when device is static and 1.5 mW when device is moving.
• SENSOR_TILT_DETECTOR
  • MUST have a power consumption not worse than 0.5 mW when device is static and 1.5 mW when device is moving.

Also such a device MUST meet the following sensor subsystem requirements:

• The event timestamp of the same physical event reported by the Accelerometer, Gyroscope sensor and Magnetometer MUST be within 2.5 milliseconds of each other.
• The Gyroscope sensor event timestamps MUST be on the same time base as the camera subsystem and within 1 milliseconds of error.
• High Fidelity sensors MUST deliver samples to applications within 5 milliseconds from the time when the data is available on the physical sensor to the application.
• The power consumption MUST not be higher than 0.5 mW when device is static and 2.0 mW when device is moving when any combination of the following sensors are enabled:
  • SENSOR_TYPE_SIGNIFICANT_MOTION
  • SENSOR_TYPE_STEP_DETECTOR
  • SENSOR_TYPE_STEP_COUNTER
  • SENSOR_TILT_DETECTORS

Note that all power consumption requirements in this section do not include the power consumption of the Application Processor. It is inclusive of the power drawn by the entire sensor chain—the sensor, any supporting circuitry, any dedicated sensor processing system, etc.

The following sensor types MAY also be supported on a device implementation declaring android.hardware.sensor.hifi_sensors, but if these sensor types are present they MUST meet the following minimum buffering capability requirement:

• SENSOR_TYPE_PROXIMITY: 100 sensor events

7.3.10. ماسح البصمات

Device implementations with a secure lock screen SHOULD include a fingerprint sensor. If a device implementation includes a fingerprint sensor and has a corresponding API for third-party developers, it:

• MUST declare support for the android.hardware.fingerprint feature.
• MUST fully implement the corresponding API as described in the Android SDK documentation.
• MUST have a false acceptance rate not higher than 0.002%.
• Is STRONGLY RECOMMENDED to have a false rejection rate of less than 10%, as measured on the device
• Is STRONGLY RECOMMENDED to have a latency below 1 second, measured from when the fingerprint sensor is touched until the screen is unlocked, for one enrolled finger.
• MUST rate limit attempts for at least 30 seconds after five false trials for fingerprint verification.
• MUST have a hardware-backed keystore implementation, and perform the fingerprint matching in a Trusted Execution Environment (TEE) or on a chip with a secure channel to the TEE.
• MUST have all identifiable fingerprint data encrypted and cryptographically authenticated such that they cannot be acquired, read or altered outside of the Trusted Execution Environment (TEE) as documented in the implementation guidelines on the Android Open Source Project site.
• MUST prevent adding a fingerprint without first establishing a chain of trust by having the user confirm existing or add a new device credential (PIN/pattern/password) that's secured by TEE; the Android Open Source Project implementation provides the mechanism in the framework to do so.
• MUST NOT enable 3rd-party applications to distinguish between individual fingerprints.
• MUST honor the DevicePolicyManager.KEYGUARD_DISABLE_FINGERPRINT flag.
• MUST, when upgraded from a version earlier than Android 6.0, have the fingerprint data securely migrated to meet the above requirements or removed.
• SHOULD use the Android Fingerprint icon provided in the Android Open Source Project.

7.3.11. Android Automotive-only sensors

Automotive-specific sensors are defined in the android.car.CarSensorManager API .

7.3.11.1. العتاد الحالي

Android Automotive implementations SHOULD provide current gear as SENSOR_TYPE_GEAR.

7.3.11.2. وضع الليل والنهار

Android Automotive implementations MUST support day/night mode defined as SENSOR_TYPE_NIGHT. The value of this flag MUST be consistent with dashboard day/night mode and SHOULD be based on ambient light sensor input. The underlying ambient light sensor MAY be the same as Photometer .

7.3.11.3. Driving Status

Android Automotive implementations MUST support driving status defined as SENSOR_TYPE_DRIVING_STATUS, with a default value of DRIVE_STATUS_UNRESTRICTED when the vehicle is fully stopped and parked. It is the responsibility of device manufacturers to configure SENSOR_TYPE_DRIVING_STATUS in compliance with all laws and regulations that apply to markets where the product is shipping.

7.3.11.4. سرعة العجلة

Android Automotive implementations MUST provide vehicle speed defined as SENSOR_TYPE_CAR_SPEED.

7.3.12. Pose Sensor

Device implementations MAY support pose sensor with 6 degrees of freedom. Android Handheld devices are RECOMMENDED to support this sensor. If a device implementation does support pose sensor with 6 degrees of freedom, it:

• MUST implement and report TYPE_POSE_6DOF sensor.
• MUST be more accurate than the rotation vector alone.

7.4. اتصال البيانات

7.4.1. الاتصالات الهاتفية

“Telephony” as used by the Android APIs and this document refers specifically to hardware related to placing voice calls and sending SMS messages via a GSM or CDMA network. While these voice calls may or may not be packet-switched, they are for the purposes of Android considered independent of any data connectivity that may be implemented using the same network. In other words, the Android “telephony” functionality and APIs refer specifically to voice calls and SMS. For instance, device implementations that cannot place calls or send/receive SMS messages MUST NOT report the android.hardware.telephony feature or any subfeatures, regardless of whether they use a cellular network for data connectivity.

Android MAY be used on devices that do not include telephony hardware. That is, Android is compatible with devices that are not phones. However, if a device implementation does include GSM or CDMA telephony, it MUST implement full support for the API for that technology. Device implementations that do not include telephony hardware MUST implement the full APIs as no-ops.

7.4.1.1. Number Blocking Compatibility

Android Telephony device implementations MUST include number blocking support and:

• MUST fully implement BlockedNumberContract and the corresponding API as described in the SDK documentation.
• MUST block all calls and messages from a phone number in 'BlockedNumberProvider' without any interaction with apps. The only exception is when number blocking is temporarily lifted as described in the SDK documentation.
• MUST NOT write to the platform call log provider for a blocked call.
• MUST NOT write to the Telephony provider for a blocked message.
• MUST implement a blocked numbers management UI, which is opened with the intent returned by TelecomManager.createManageBlockedNumbersIntent() method.
• MUST NOT allow secondary users to view or edit the blocked numbers on the device as the Android platform assumes the primary user to have full control of the telephony services, a single instance, on the device. All blocking related UI MUST be hidden for secondary users and the blocked list MUST still be respected.
• SHOULD migrate the blocked numbers into the provider when a device updates to Android 7.0.

7.4.2. IEEE 802.11 (Wi-Fi)

All Android device implementations SHOULD include support for one or more forms of 802.11. If a device implementation does include support for 802.11 and exposes the functionality to a third-party application, it MUST implement the corresponding Android API and:

• MUST report the hardware feature flag android.hardware.wifi.
• MUST implement the multicast API as described in the SDK documentation.
• MUST support multicast DNS (mDNS) and MUST NOT filter mDNS packets (224.0.0.251) at any time of operation including:
  • Even when the screen is not in an active state.
  • For Android Television device implementations, even when in standby power states.

7.4.2.1. واي فاي مباشر

Device implementations SHOULD include support for Wi-Fi Direct (Wi-Fi peer-to-peer). If a device implementation does include support for Wi-Fi Direct, it MUST implement the corresponding Android API as described in the SDK documentation. If a device implementation includes support for Wi-Fi Direct, then it:

• MUST report the hardware feature android.hardware.wifi.direct.
• MUST support regular Wi-Fi operation.
• SHOULD support concurrent Wi-Fi and Wi-Fi Direct operation.

7.4.2.2. Wi-Fi Tunneled Direct Link Setup

Device implementations SHOULD include support for Wi-Fi Tunneled Direct Link Setup (TDLS) as described in the Android SDK Documentation. If a device implementation does include support for TDLS and TDLS is enabled by the WiFiManager API, the device:

• SHOULD use TDLS only when it is possible AND beneficial.
• SHOULD have some heuristic and NOT use TDLS when its performance might be worse than going through the Wi-Fi access point.

7.4.3. بلوتوث

Device implementations that support android.hardware.vr.high_performance feature MUST support Bluetooth 4.2 and Bluetooth LE Data Length Extension.

Android includes support for Bluetooth and Bluetooth Low Energy . Device implementations that include support for Bluetooth and Bluetooth Low Energy MUST declare the relevant platform features (android.hardware.bluetooth and android.hardware.bluetooth_le respectively) and implement the platform APIs. Device implementations SHOULD implement relevant Bluetooth profiles such as A2DP, AVCP, OBEX, etc. as appropriate for the device.

Android Automotive implementations SHOULD support Message Access Profile (MAP). Android Automotive implementations MUST support the following Bluetooth profiles:

• Phone calling over Hands-Free Profile (HFP).
• Media playback over Audio Distribution Profile (A2DP).
• Media playback control over Remote Control Profile (AVRCP).
• Contact sharing using the Phone Book Access Profile (PBAP).

Device implementations including support for Bluetooth Low Energy:

• MUST declare the hardware feature android.hardware.bluetooth_le.
• MUST enable the GATT (generic attribute profile) based Bluetooth APIs as described in the SDK documentation and android.bluetooth .
• are STRONGLY RECOMMENDED to implement a Resolvable Private Address (RPA) timeout no longer than 15 minutes and rotate the address at timeout to protect user privacy.
• SHOULD support offloading of the filtering logic to the bluetooth chipset when implementing the ScanFilter API , and MUST report the correct value of where the filtering logic is implemented whenever queried via the android.bluetooth.BluetoothAdapter.isOffloadedFilteringSupported() method.
• SHOULD support offloading of the batched scanning to the bluetooth chipset, but if not supported, MUST report 'false' whenever queried via the android.bluetooth.BluetoothAdapter.isOffloadedScanBatchingSupported() method.
• SHOULD support multi advertisement with at least 4 slots, but if not supported, MUST report 'false' whenever queried via the android.bluetooth.BluetoothAdapter.isMultipleAdvertisementSupported() method.

7.4.4. بالقرب اتصالات الميدان

Device implementations SHOULD include a transceiver and related hardware for Near-Field Communications (NFC). If a device implementation does include NFC hardware and plans to make it available to third-party apps, then it:

• MUST report the android.hardware.nfc feature from the android.content.pm.PackageManager.hasSystemFeature() method .
• MUST be capable of reading and writing NDEF messages via the following NFC standards:
  • MUST be capable of acting as an NFC Forum reader/writer (as defined by the NFC Forum technical specification NFCForum-TS-DigitalProtocol-1.0) via the following NFC standards:
    • NfcA (ISO14443-3A)
    • NfcB (ISO14443-3B)
    • NfcF (JIS X 6319-4)
    • IsoDep (ISO 14443-4)
    • NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)
  • STRONGLY RECOMMENDED to be capable of reading and writing NDEF messages as well as raw data via the following NFC standards. Note that while the NFC standards below are stated as STRONGLY RECOMMENDED, the Compatibility Definition for a future version is planned to change these to MUST. These standards are optional in this version but will be required in future versions. Existing and new devices that run this version of Android are very strongly encouraged to meet these requirements now so they will be able to upgrade to the future platform releases.
    • NfcV (ISO 15693)
  • SHOULD be capable of reading the barcode and URL (if encoded) of Thinfilm NFC Barcode products.
  • MUST be capable of transmitting and receiving data via the following peer-to-peer standards and protocols:
    • ISO 18092
    • LLCP 1.2 (defined by the NFC Forum)
    • SDP 1.0 (defined by the NFC Forum)
    • NDEF Push Protocol
    • SNEP 1.0 (defined by the NFC Forum)
  • MUST include support for Android Beam .
  • MUST implement the SNEP default server. Valid NDEF messages received by the default SNEP server MUST be dispatched to applications using the android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam in settings MUST NOT disable dispatch of incoming NDEF message.
  • MUST honor the android.settings.NFCSHARING_SETTINGS intent to show NFC sharing settings .
  • MUST implement the NPP server. Messages received by the NPP server MUST be processed the same way as the SNEP default server.
  • MUST implement a SNEP client and attempt to send outbound P2P NDEF to the default SNEP server when Android Beam is enabled. If no default SNEP server is found then the client MUST attempt to send to an NPP server.
  • MUST allow foreground activities to set the outbound P2P NDEF message using android.nfc.NfcAdapter.setNdefPushMessage, and android.nfc.NfcAdapter.setNdefPushMessageCallback, and android.nfc.NfcAdapter.enableForegroundNdefPush.
  • SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', before sending outbound P2P NDEF messages.
  • SHOULD enable Android Beam by default and MUST be able to send and receive using Android Beam, even when another proprietary NFC P2p mode is turned on.
  • MUST support NFC Connection handover to Bluetooth when the device supports Bluetooth Object Push Profile. Device implementations MUST support connection handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, by implementing the “ Connection Handover version 1.2 ” and “ Bluetooth Secure Simple Pairing Using NFC version 1.0 ” specs from the NFC Forum. Such an implementation MUST implement the handover LLCP service with service name “urn:nfc:sn:handover” for exchanging the handover request/select records over NFC, and it MUST use the Bluetooth Object Push Profile for the actual Bluetooth data transfer. For legacy reasons (to remain compatible with Android 4.1 devices), the implementation SHOULD still accept SNEP GET requests for exchanging the handover request/select records over NFC. However an implementation itself SHOULD NOT send SNEP GET requests for performing connection handover.
  • MUST poll for all supported technologies while in NFC discovery mode.
  • SHOULD be in NFC discovery mode while the device is awake with the screen active and the lock-screen unlocked.

(Note that publicly available links are not available for the JIS, ISO, and NFC Forum specifications cited above.)

Android includes support for NFC Host Card Emulation (HCE) mode. If a device implementation does include an NFC controller chipset capable of HCE (for NfcA and/or NfcB) and it supports Application ID (AID) routing, then it:

• MUST report the android.hardware.nfc.hce feature constant.
• MUST support NFC HCE APIs as defined in the Android SDK.

If a device implementation does include an NFC controller chipset capable of HCE for NfcF, and it implements the feature for third-party applications, then it:

• MUST report the android.hardware.nfc.hcef feature constant.
• MUST implement the NfcF Card Emulation APIs as defined in the Android SDK.

Additionally, device implementations MAY include reader/writer support for the following MIFARE technologies.

• MIFARE Classic
• MIFARE Ultralight
• NDEF on MIFARE Classic

Note that Android includes APIs for these MIFARE types. If a device implementation supports MIFARE in the reader/writer role, it:

• MUST implement the corresponding Android APIs as documented by the Android SDK.
• MUST report the feature com.nxp.mifare from the android.content.pm.PackageManager.hasSystemFeature() method. Note that this is not a standard Android feature and as such does not appear as a constant in the android.content.pm.PackageManager class.
• MUST NOT implement the corresponding Android APIs nor report the com.nxp.mifare feature unless it also implements general NFC support as described in this section.

If a device implementation does not include NFC hardware, it MUST NOT declare the android.hardware.nfc feature from the android.content.pm.PackageManager.hasSystemFeature() method, and MUST implement the Android NFC API as a no-op.

As the classes android.nfc.NdefMessage and android.nfc.NdefRecord represent a protocol-independent data representation format, device implementations MUST implement these APIs even if they do not include support for NFC or declare the android.hardware.nfc feature.

7.4.5. Minimum Network Capability

Device implementations MUST include support for one or more forms of data networking. Specifically, device implementations MUST include support for at least one data standard capable of 200Kbit/sec or greater. Examples of technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, Ethernet, Bluetooth PAN, etc.

Device implementations where a physical networking standard (such as Ethernet) is the primary data connection SHOULD also include support for at least one common wireless data standard, such as 802.11 (Wi-Fi).

Devices MAY implement more than one form of data connectivity.

Devices MUST include an IPv6 networking stack and support IPv6 communication using the managed APIs, such as java.net.Socket and java.net.URLConnection , as well as the native APIs, such as AF_INET6 sockets. The required level of IPv6 support depends on the network type, as follows:

• Devices that support Wi-Fi networks MUST support dual-stack and IPv6-only operation on Wi-Fi.
• Devices that support Ethernet networks MUST support dual-stack operation on Ethernet.
• Devices that support cellular data SHOULD support IPv6 operation (IPv6-only and possibly dual-stack) on cellular data.
• When a device is simultaneously connected to more than one network (eg, Wi-Fi and cellular data), it MUST simultaneously meet these requirements on each network to which it is connected.

IPv6 MUST be enabled by default.

In order to ensure that IPv6 communication is as reliable as IPv4, unicast IPv6 packets sent to the device MUST NOT be dropped, even when the screen is not in an active state. Redundant multicast IPv6 packets, such as repeated identical Router Advertisements, MAY be rate-limited in hardware or firmware if doing so is necessary to save power. In such cases, rate-limiting MUST NOT cause the device to lose IPv6 connectivity on any IPv6-compliant network that uses RA lifetimes of at least 180 seconds.

IPv6 connectivity MUST be maintained in doze mode.

7.4.6. إعدادات المزامنة

Device implementations MUST have the master auto-sync setting on by default so that the method getMasterSyncAutomatically() returns “true”.

7.4.7. توفير البيانات

Device implementations with a metered connection are STRONGLY RECOMMENDED to provide the data saver mode.

If a device implementation provides the data saver mode, it:

• MUST support all the APIs in the ConnectivityManager class as described in the SDK documentation

• MUST provide a user interface in the settings, allowing users to add applications to or remove applications from the allowlist.

Conversely if a device implementation does not provide the data saver mode, it:

• MUST return the value RESTRICT_BACKGROUND_STATUS_DISABLED for ConnectivityManager.getRestrictBackgroundStatus()

• MUST not broadcast ConnectivityManager.ACTION_RESTRICT_BACKGROUND_CHANGED

• MUST have an activity that handles the Settings.ACTION_IGNORE_BACKGROUND_DATA_RESTRICTIONS_SETTINGS intent but MAY implement it as a no-op.

7.5. الكاميرات

Device implementations SHOULD include a rear-facing camera and MAY include a front-facing camera. A rear-facing camera is a camera located on the side of the device opposite the display; that is, it images scenes on the far side of the device, like a traditional camera. A front-facing camera is a camera located on the same side of the device as the display; that is, a camera typically used to image the user, such as for video conferencing and similar applications.

If a device implementation includes at least one camera, it MUST be possible for an application to simultaneously allocate 3 RGBA_8888 bitmaps equal to the size of the images produced by the largest-resolution camera sensor on the device, while camera is open for the purpose of basic preview and still capture.

7.5.1. الكاميرا الخلفية المواجهة

Device implementations SHOULD include a rear-facing camera. If a device implementation includes at least one rear-facing camera, it:

• MUST report the feature flag android.hardware.camera and android.hardware.camera.any.
• MUST have a resolution of at least 2 megapixels.
• SHOULD have either hardware auto-focus or software auto-focus implemented in the camera driver (transparent to application software).
• MAY have fixed-focus or EDOF (extended depth of field) hardware.
• MAY include a flash. If the Camera includes a flash, the flash lamp MUST NOT be lit while an android.hardware.Camera.PreviewCallback instance has been registered on a Camera preview surface, unless the application has explicitly enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes of a Camera.Parameters object. Note that this constraint does not apply to the device's built-in system camera application, but only to third-party applications using Camera.PreviewCallback.

7.5.2. الكاميرا الأمامية

Device implementations MAY include a front-facing camera. If a device implementation includes at least one front-facing camera, it:

• MUST report the feature flag android.hardware.camera.any and android.hardware.camera.front.
• MUST have a resolution of at least VGA (640x480 pixels).
• MUST NOT use a front-facing camera as the default for the Camera API. The camera API in Android has specific support for front-facing cameras and device implementations MUST NOT configure the API to to treat a front-facing camera as the default rear-facing camera, even if it is the only camera on the device.
• MAY include features (such as auto-focus, flash, etc.) available to rear-facing cameras as described in section 7.5.1 .
• MUST horizontally reflect (ie mirror) the stream displayed by an app in a CameraPreview, as follows:
  • If the device implementation is capable of being rotated by user (such as automatically via an accelerometer or manually via user input), the camera preview MUST be mirrored horizontally relative to the device's current orientation.
  • If the current application has explicitly requested that the Camera display be rotated via a call to the android.hardware.Camera.setDisplayOrientation() method, the camera preview MUST be mirrored horizontally relative to the orientation specified by the application.
  • Otherwise, the preview MUST be mirrored along the device's default horizontal axis.
• MUST mirror the image displayed by the postview in the same manner as the camera preview image stream. If the device implementation does not support postview, this requirement obviously does not apply.
• MUST NOT mirror the final captured still image or video streams returned to application callbacks or committed to media storage.

7.5.3. كاميرا خارجية

Device implementations MAY include support for an external camera that is not necessarily always connected. If a device includes support for an external camera, it:

• MUST declare the platform feature flag android.hardware.camera.external and android.hardware camera.any .
• MAY support multiple cameras.
• MUST support USB Video Class (UVC 1.0 or higher) if the external camera connects through the USB port.
• SHOULD support video compressions such as MJPEG to enable transfer of high-quality unencoded streams (ie raw or independently compressed picture streams).
• MAY support camera-based video encoding. If supported, a simultaneous unencoded / MJPEG stream (QVGA or greater resolution) MUST be accessible to the device implementation.

7.5.4. Camera API Behavior

Android includes two API packages to access the camera, the newer android.hardware.camera2 API expose lower-level camera control to the app, including efficient zero-copy burst/streaming flows and per-frame controls of exposure, gain, white balance gains, color conversion, denoising, sharpening, and more.

The older API package, android.hardware.Camera, is marked as deprecated in Android 5.0 but as it should still be available for apps to use Android device implementations MUST ensure the continued support of the API as described in this section and in the Android SDK .

Device implementations MUST implement the following behaviors for the camera-related APIs, for all available cameras:

• If an application has never called android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to application callbacks.
• If an application registers an android.hardware.Camera.PreviewCallback instance and the system calls the onPreviewFrame() method when the preview format is YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() must further be in the NV21 encoding format. That is, NV21 MUST be the default.
• For android.hardware.Camera, device implementations MUST support the YV12 format (as denoted by the android.graphics.ImageFormat.YV12 constant) for camera previews for both front- and rear-facing cameras. (The hardware video encoder and camera may use any native pixel format, but the device implementation MUST support conversion to YV12.)
• For android.hardware.camera2, device implementations must support the android.hardware.ImageFormat.YUV_420_888 and android.hardware.ImageFormat.JPEG formats as outputs through the android.media.ImageReader API.

Device implementations MUST still implement the full Camera API included in the Android SDK documentation, regardless of whether the device includes hardware autofocus or other capabilities. For instance, cameras that lack autofocus MUST still call any registered android.hardware.Camera.AutoFocusCallback instances (even though this has no relevance to a non-autofocus camera.) Note that this does apply to front-facing cameras; for instance, even though most front-facing cameras do not support autofocus, the API callbacks must still be “faked” as described.

Device implementations MUST recognize and honor each parameter name defined as a constant on the android.hardware.Camera.Parameters class, if the underlying hardware supports the feature. If the device hardware does not support a feature, the API must behave as documented. Conversely, device implementations MUST NOT honor or recognize string constants passed to the android.hardware.Camera.setParameters() method other than those documented as constants on the android.hardware.Camera.Parameters. That is, device implementations MUST support all standard Camera parameters if the hardware allows, and MUST NOT support custom Camera parameter types. For instance, device implementations that support image capture using high dynamic range (HDR) imaging techniques MUST support camera parameter Camera.SCENE_MODE_HDR.

Because not all device implementations can fully support all the features of the android.hardware.camera2 API, device implementations MUST report the proper level of support with the android.info.supportedHardwareLevel property as described in the Android SDK and report the appropriate framework feature flags .

Device implementations MUST also declare its Individual camera capabilities of android.hardware.camera2 via the android.request.availableCapabilities property and declare the appropriate feature flags ; a device must define the feature flag if any of its attached camera devices supports the feature.

Device implementations MUST broadcast the Camera.ACTION_NEW_PICTURE intent whenever a new picture is taken by the camera and the entry of the picture has been added to the media store.

Device implementations MUST broadcast the Camera.ACTION_NEW_VIDEO intent whenever a new video is recorded by the camera and the entry of the picture has been added to the media store.

7.5.5. اتجاه الكاميرا

Both front- and rear-facing cameras, if present, MUST be oriented so that the long dimension of the camera aligns with the screen's long dimension. That is, when the device is held in the landscape orientation, cameras MUST capture images in the landscape orientation. This applies regardless of the device's natural orientation; that is, it applies to landscape-primary devices as well as portrait-primary devices.

7.6. الذاكرة والتخزين

7.6.1. Minimum Memory and Storage

The memory available to the kernel and userspace on device implementations MUST be at least equal or larger than the minimum values specified by the following table. (See section 7.1.1 for screen size and density definitions.)

The minimum memory values MUST be in addition to any memory space already dedicated to hardware components such as radio, video, and so on that is not under the kernel's control.

Device implementations with less than 512MB of memory available to the kernel and userspace, unless an Android Watch, MUST return the value "true" for ActivityManager.isLowRamDevice().

Android Television devices MUST have at least 4GB and other device implementations MUST have at least 3GB of non-volatile storage available for application private data. That is, the /data partition MUST be at least 4GB for Android Television devices and at least 3GB for other device implementations. Device implementations that run Android are STRONGLY RECOMMENDED to have at least 4GB of non-volatile storage for application private data so they will be able to upgrade to the future platform releases.

The Android APIs include a Download Manager that applications MAY use to download data files. The device implementation of the Download Manager MUST be capable of downloading individual files of at least 100MB in size to the default “cache” location.

7.6.2. Application Shared Storage

Device implementations MUST offer shared storage for applications also often referred as “shared external storage”.

Device implementations MUST be configured with shared storage mounted by default, “out of the box”. If the shared storage is not mounted on the Linuxpath /sdcard, then the device MUST include a Linux symbolic link from /sdcard to the actual mount point.

Device implementations MAY have hardware for user-accessible removable storage, such as a Secure Digital (SD) card slot. If this slot is used to satisfy the shared storage requirement, the device implementation:

• MUST implement a toast or pop-up user interface warning the user when there is no SD card.
• MUST include a FAT-formatted SD card 1GB in size or larger OR show on the box and other material available at time of purchase that the SD card has to be separately purchased.
• MUST mount the SD card by default.

Alternatively, device implementations MAY allocate internal (non-removable) storage as shared storage for apps as included in the upstream Android Open Source Project; device implementations SHOULD use this configuration and software implementation. If a device implementation uses internal (non-removable) storage to satisfy the shared storage requirement, while that storage MAY share space with the application private data, it MUST be at least 1GB in size and mounted on /sdcard (or /sdcard MUST be a symbolic link to the physical location if it is mounted elsewhere).

Device implementations MUST enforce as documented the android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage. Shared storage MUST otherwise be writable by any application that obtains that permission.

Device implementations that include multiple shared storage paths (such as both an SD card slot and shared internal storage) MUST allow only pre-installed & privileged Android applications with the WRITE_EXTERNAL_STORAGE permission to write to the secondary external storage, except when writing to their package-specific directories or within the URI returned by firing the ACTION_OPEN_DOCUMENT_TREE intent.

However, device implementations SHOULD expose content from both storage paths transparently through Android's media scanner service and android.provider.MediaStore.

Regardless of the form of shared storage used, if the device implementation has a USB port with USB peripheral mode support, it MUST provide some mechanism to access the contents of shared storage from a host computer. Device implementations MAY use USB mass storage, but SHOULD use Media Transfer Protocol to satisfy this requirement. If the device implementation supports Media Transfer Protocol, it:

• SHOULD be compatible with the reference Android MTP host, Android File Transfer .
• SHOULD report a USB device class of 0x00.
• SHOULD report a USB interface name of 'MTP'.

7.6.3. Adoptable Storage

Device implementations are STRONGLY RECOMMENDED to implement adoptable storage if the removable storage device port is in a long-term stable location, such as within the battery compartment or other protective cover.

Device implementations such as a television, MAY enable adoption through USB ports as the device is expected to be static and not mobile. But for other device implementations that are mobile in nature, it is STRONGLY RECOMMENDED to implement the adoptable storage in a long-term stable location, since accidentally disconnecting them can cause data loss/corruption.

7.7. USB

Device implementations SHOULD support USB peripheral mode and SHOULD support USB host mode.

7.7.1. USB peripheral mode

If a device implementation includes a USB port supporting peripheral mode:

• The port MUST be connectable to a USB host that has a standard type-A or type-C USB port.
• The port SHOULD use micro-B, micro-AB or Type-C USB form factor. Existing and new Android devices are STRONGLY RECOMMENDED to meet these requirements so they will be able to upgrade to the future platform releases.
• The port SHOULD be located on the bottom of the device (according to natural orientation) or enable software screen rotation for all apps (including home screen), so that the display draws correctly when the device is oriented with the port at bottom. Existing and new Android devices are STRONGLY RECOMMENDED to meet these requirements so they will be able to upgrade to future platform releases.
• It MUST allow a USB host connected with the Android device to access the contents of the shared storage volume using either USB mass storage or Media Transfer Protocol.
• It SHOULD implement the Android Open Accessory (AOA) API and specification as documented in the Android SDK documentation, and if it is an Android Handheld device it MUST implement the AOA API. Device implementations implementing the AOA specification:
  • MUST declare support for the hardware feature android.hardware.usb.accessory .
  • MUST implement the USB audio class as documented in the Android SDK documentation.
  • The USB mass storage class MUST include the string "android" at the end of the interface description iInterface string of the USB mass storage
• It SHOULD implement support to draw 1.5 A current during HS chirp and traffic as specified in the USB Battery Charging specification, revision 1.2 . Existing and new Android devices are STRONGLY RECOMMENDED to meet these requirements so they will be able to upgrade to the future platform releases.
• Type-C devices MUST detect 1.5A and 3.0A chargers per the Type-C resistor standard and it must detect changes in the advertisement.
• Type-C devices also supporting USB host mode are STRONGLY RECOMMENDED to support Power Delivery for data and power role swapping.
• Type-C devices SHOULD support Power Delivery for high-voltage charging and support for Alternate Modes such as display out.
• The value of iSerialNumber in USB standard device descriptor MUST be equal to the value of android.os.Build.SERIAL.
• Type-C devices are STRONGLY RECOMMENDED to not support proprietary charging methods that modify Vbus voltage beyond default levels, or alter sink/source roles as such may result in interoperability issues with the chargers or devices that support the standard USB Power Delivery methods. While this is called out as "STRONGLY RECOMMENDED", in future Android versions we might REQUIRE all type-C devices to support full interoperability with standard type-C chargers.

7.7.2. USB host mode

If a device implementation includes a USB port supporting host mode, it:

• SHOULD use a type-C USB port, if the device implementation supports USB 3.1.
• MAY use a non-standard port form factor, but if so MUST ship with a cable or cables adapting the port to a standard type-A or type-C USB port.
• MAY use a micro-AB USB port, but if so SHOULD ship with a cable or cables adapting the port to a standard type-A or type-C USB port.
• is STRONGLY RECOMMENDED to implement the USB audio class as documented in the Android SDK documentation.
• MUST implement the Android USB host API as documented in the Android SDK, and MUST declare support for the hardware feature android.hardware.usb.host .
• SHOULD support device charging while in host mode; advertising a source current of at least 1.5A as specified in the Termination Parameters section of the [USB Type-C Cable and Connector Specification Revision 1.2] (http://www.usb.org/developers/docs/usb_31_021517.zip) for USB Type-C connectors or using Charging Downstream Port(CDP) output current range as specified in the USB Battery Charging specifications, revision 1.2 for Micro-AB connectors.
• USB Type-C devices are STRONGLY RECOMMENDED to support DisplayPort, SHOULD support USB SuperSpeed Data Rates, and are STRONGLY RECOMMENDED to support Power Delivery for data and power role swapping.
• Devices with any type-A or type-AB ports MUST NOT ship with an adapter converting from this port to a type-C receptacle.
• MUST recognize any remotely connected MTP (Media Transfer Protocol) devices and make their contents accessible through the ACTION_GET_CONTENT , ACTION_OPEN_DOCUMENT , and ACTION_CREATE_DOCUMENT intents, if the Storage Access Framework (SAF) is supported.
• MUST, if using a Type-C USB port and including support for peripheral mode, implement Dual Role Port functionality as defined by the USB Type-C specification (section 4.5.1.3.3).
• SHOULD, if the Dual Role Port functionality is supported, implement the Try.* model that is most appropriate for the device form factor. For example a handheld device SHOULD implement the Try.SNK model.

7.8. صوتي

7.8.1. ميكروفون

Device implementations MAY omit a microphone. However, if a device implementation omits a microphone, it MUST NOT report the android.hardware.microphone feature constant, and MUST implement the audio recording API at least as no-ops, per section 7 . Conversely, device implementations that do possess a microphone:

• MUST report the android.hardware.microphone feature constant.
• MUST meet the audio recording requirements in section 5.4 .
• MUST meet the audio latency requirements in section 5.6 .
• STRONGLY RECOMMENDED to support near-ultrasound recording as described in section 7.8.3 .

7.8.2. مخرج الصوت

Device implementations including a speaker or with an audio/multimedia output port for an audio output peripheral as a headset or an external speaker:

• MUST report the android.hardware.audio.output feature constant.
• MUST meet the audio playback requirements in section 5.5 .
• MUST meet the audio latency requirements in section 5.6 .
• STRONGLY RECOMMENDED to support near-ultrasound playback as described in section 7.8.3 .

Conversely, if a device implementation does not include a speaker or audio output port, it MUST NOT report the android.hardware.audio output feature, and MUST implement the Audio Output related APIs as no-ops at least.

Android Watch device implementation MAY but SHOULD NOT have audio output, but other types of Android device implementations MUST have an audio output and declare android.hardware.audio.output.

7.8.2.1. Analog Audio Ports

In order to be compatible with the headsets and other audio accessories using the 3.5mm audio plug across the Android ecosystem, if a device implementation includes one or more analog audio ports, at least one of the audio port(s) SHOULD be a 4 conductor 3.5mm audio jack. If a device implementation has a 4 conductor 3.5mm audio jack, it:

• MUST support audio playback to stereo headphones and stereo headsets with a microphone, and SHOULD support audio recording from stereo headsets with a microphone.
• MUST support TRRS audio plugs with the CTIA pin-out order, and SHOULD support audio plugs with the OMTP pin-out order.
• MUST support the detection of microphone on the plugged in audio accessory, if the device implementation supports a microphone, and broadcast the android.intent.action.HEADSET_PLUG with the extra value microphone set as 1.
• MUST support the detection and mapping to the keycodes for the following 3 ranges of equivalent impedance between the microphone and ground conductors on the audio plug:
  • 70 ohm or less : KEYCODE_HEADSETHOOK
  • 210-290 Ohm : KEYCODE_VOLUME_UP
  • 360-680 Ohm : KEYCODE_VOLUME_DOWN
• STRONGLY RECOMMENDED to detect and map to the keycode for the following range of equivalent impedance between the microphone and ground conductors on the audio plug:
  • 110-180 Ohm: KEYCODE_VOICE_ASSIST
• MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all contacts on plug are touching their relevant segments on the jack.
• MUST be capable of driving at least 150mV ± 10% of output voltage on a 32 Ohm speaker impedance.
• MUST have a microphone bias voltage between 1.8V ~ 2.9V.

7.8.3. Near-Ultrasound

Near-Ultrasound audio is the 18.5 kHz to 20 kHz band. Device implementations MUST correctly report the support of near-ultrasound audio capability via the AudioManager.getProperty API as follows:

• If PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND is "true", then the following requirements must be met by the VOICE_RECOGNITION and UNPROCESSED audio sources:
  • The microphone's mean power response in the 18.5 kHz to 20 kHz band MUST be no more than 15 dB below the response at 2 kHz.
  • The microphone's unweighted signal to noise ratio over 18.5 kHz to 20 kHz for a 19 kHz tone at -26 dBFS MUST be no lower than 50 dB.
• If PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND is "true", then the speaker's mean response in 18.5 kHz - 20 kHz MUST be no lower than 40 dB below the response at 2 kHz.

7.9. الواقع الافتراضي

Android includes APIs and facilities to build "Virtual Reality" (VR) applications including high quality mobile VR experiences. Device implementations MUST properly implement these APIs and behaviors, as detailed in this section.

7.9.1. Virtual Reality Mode

Android handheld device implementations that support a mode for VR applications that handles stereoscopic rendering of notifications and disable monocular system UI components while a VR application has user focus MUST declare android.software.vr.mode feature. Devices declaring this feature MUST include an application implementing android.service.vr.VrListenerService that can be enabled by VR applications via android.app.Activity#setVrModeEnabled .

7.9.2. Virtual Reality High Performance

Android handheld device implementations MUST identify the support of high performance virtual reality for longer user periods through the android.hardware.vr.high_performance feature flag and meet the following requirements.

• Device implementations MUST have at least 2 physical cores.
• Device implementations MUST declare android.software.vr.mode feature.
• Device implementations MAY provide an exclusive core to the foreground application and MAY support the Process.getExclusiveCores API to return the numbers of the cpu cores that are exclusive to the top foreground application. If exclusive core is supported then the core MUST not allow any other userspace processes to run on it (except device drivers used by the application), but MAY allow some kernel processes to run as necessary.
• Device implementations MUST support sustained performance mode.
• Device implementations MUST support OpenGL ES 3.2.
• Device implementations MUST support Vulkan Hardware Level 0 and SHOULD support Vulkan Hardware Level 1.
• Device implementations MUST implement EGL_KHR_mutable_render_buffer and EGL_ANDROID_front_buffer_auto_refresh, EGL_ANDROID_create_native_client_buffer, EGL_KHR_fence_sync and EGL_KHR_wait_sync so that they may be used for Shared Buffer Mode, and expose the extensions in the list of available EGL extensions.
• The GPU and display MUST be able to synchronize access to the shared front buffer such that alternating-eye rendering of VR content at 60fps with two render contexts will be displayed with no visible tearing artifacts.
• Device implementations MUST implement EGL_IMG_context_priority, and expose the extension in the list of available EGL extensions.
• Device implementations MUST implement GL_EXT_multisampled_render_to_texture, GL_OVR_multiview, GL_OVR_multiview2 and GL_OVR_multiview_multisampled_render_to_texture, and expose the extensions in the list of available GL extensions.
• Device implementations MUST implement EGL_EXT_protected_content and GL_EXT_protected_textures so that it may be used for Secure Texture Video Playback, and expose the extensions in the list of available EGL and GL extensions.
• Device implementations MUST support H.264 decoding at least 3840x2160@30fps-40Mbps (equivalent to 4 instances of 1920x1080@30fps-10Mbps or 2 instances of 1920x1080@60fps-20Mbps).
• Device implementations MUST support HEVC and VP9, MUST be capable to decode at least 1920x1080@30fps-10Mbps and SHOULD be capable to decode 3840x2160@30fps-20Mbps (equivalent to 4 instances of 1920x1080@30fps-5Mbps).
• The device implementations are STRONGLY RECOMMENDED to support android.hardware.sensor.hifi_sensors feature and MUST meet the gyroscope, accelerometer, and magnetometer related requirements for android.hardware.hifi_sensors.
• Device implementations MUST support HardwarePropertiesManager.getDeviceTemperatures API and return accurate values for skin temperature.
• The device implementation MUST have an embedded screen, and its resolution MUST be at least be FullHD(1080p) and STRONGLY RECOMMENDED TO BE be QuadHD (1440p) or higher.
• The display MUST measure between 4.7" and 6" diagonal.
• The display MUST update at least 60 Hz while in VR Mode.
• The display latency on Gray-to-Gray, White-to-Black, and Black-to-White switching time MUST be ≤ 3 ms.
• The display MUST support a low-persistence mode with ≤5 ms persistence,persistence being defined as the amount of time for which a pixel is emitting light.
• Device implementations MUST support Bluetooth 4.2 and Bluetooth LE Data Length Extension section 7.4.3 .

8. Performance and Power

Some minimum performance and power criteria are critical to the user experience and impact the baseline assumptions developers would have when developing an app. Android Watch devices SHOULD and other type of device implementations MUST meet the following criteria.

8.1. اتساق تجربة المستخدم

Device implementations MUST provide a smooth user interface by ensuring a consistent frame rate and response times for applications and games. Device implementations MUST meet the following requirements:

• Consistent frame latency . Inconsistent frame latency or a delay to render frames MUST NOT happen more often than 5 frames in a second, and SHOULD be below 1 frames in a second.
• User interface latency . Device implementations MUST ensure low latency user experience by scrolling a list of 10K list entries as defined by the Android Compatibility Test Suite (CTS) in less than 36 secs.
• تبديل المهام . When multiple applications have been launched, re-launching an already-running application after it has been launched MUST take less than 1 second.

8.2. File I/O Access Performance

Device implementations MUST ensure internal storage file access performance consistency for read and write operations.

• Sequential write . Device implementations MUST ensure a sequential write performance of at least 5MB/s for a 256MB file using 10MB write buffer.
• Random write . Device implementations MUST ensure a random write performance of at least 0.5MB/s for a 256MB file using 4KB write buffer.
• Sequential read . Device implementations MUST ensure a sequential read performance of at least 15MB/s for a 256MB file using 10MB write buffer.
• Random read . Device implementations MUST ensure a random read performance of at least 3.5MB/s for a 256MB file using 4KB write buffer.

8.3. Power-Saving Modes

Android 6.0 introduced App Standby and Doze power-saving modes to optimize battery usage. All Apps exempted from these modes MUST be made visible to the end user. Further, the triggering, maintenance, wakeup algorithms and the use of global system settings of these power-saving modes MUST not deviate from the Android Open Source Project.

In addition to the power-saving modes, Android device implementations MAY implement any or all of the 4 sleeping power states as defined by the Advanced Configuration and Power Interface (ACPI), but if it implements S3 and S4 power states, it can only enter these states when closing a lid that is physically part of the device.

8.4. Power Consumption Accounting

A more accurate accounting and reporting of the power consumption provides the app developer both the incentives and the tools to optimize the power usage pattern of the application. Therefore, device implementations:

• MUST be able to track hardware component power usage and attribute that power usage to specific applications. Specifically, implementations:
  • MUST provide a per-component power profile that defines the current consumption value for each hardware component and the approximate battery drain caused by the components over time as documented in the Android Open Source Project site.
  • MUST report all power consumption values in milliampere hours (mAh).
  • SHOULD be attributed to the hardware component itself if unable to attribute hardware component power usage to an application.
  • MUST report CPU power consumption per each process's UID. The Android Open Source Project meets the requirement through the uid_cputime kernel module implementation.
• MUST make this power usage available via the adb shell dumpsys batterystats shell command to the app developer.
• MUST honor the android.intent.action.POWER_USAGE_SUMMARY intent and display a settings menu that shows this power usage.

8.5. أداء ثابت

Performance can fluctuate dramatically for high-performance long-running apps, either because of the other apps running in the background or the CPU throttling due to temperature limits. Android includes programmatic interfaces so that when the device is capable, the top foreground application can request that the system optimize the allocation of the resources to address such fluctuations.

Device implementations SHOULD support Sustained Performance Mode which can provide the top foreground application a consistent level of performance for a prolonged amount of time when requested through the Window.setSustainedPerformanceMode() API method. A Device implementation MUST report the support of Sustained Performance Mode accurately through the PowerManager.isSustainedPerformanceModeSupported() API method.

Device implementations with two or more CPU cores SHOULD provide at least one exclusive core that can be reserved by the top foreground application. If provided, implementations MUST meet the following requirements:

• Implementations MUST report through the Process.getExclusiveCores() API method the id numbers of the exclusive cores that can be reserved by the top foreground application.
• Device implementations MUST not allow any user space processes except the device drivers used by the application to run on the exclusive cores, but MAY allow some kernel processes to run as necessary.

If a device implementation does not support an exclusive core, it MUST return an empty list through the Process.getExclusiveCores() API method.

9. Security Model Compatibility

Device implementations MUST implement a security model consistent with the Android platform security model as defined in Security and Permissions reference document in the APIs in the Android developer documentation. Device implementations MUST support installation of self-signed applications without requiring any additional permissions/certificates from any third parties/authorities. Specifically, compatible devices MUST support the security mechanisms described in the follow subsections.

9.1. الأذونات

Device implementations MUST support the Android permissions model as defined in the Android developer documentation. Specifically, implementations MUST enforce each permission defined as described in the SDK documentation; no permissions may be omitted, altered, or ignored. Implementations MAY add additional permissions, provided the new permission ID strings are not in the android.* namespace.

Permissions with a protectionLevel of 'PROTECTION_FLAG_PRIVILEGED' MUST only be granted to apps preloaded in the allowlisted privileged path(s) of the system image, such as the system/priv-app path in the AOSP implementation.

Permissions with a protection level of dangerous are runtime permissions. Applications with targetSdkVersion > 22 request them at runtime. Device implementations:

• MUST show a dedicated interface for the user to decide whether to grant the requested runtime permissions and also provide an interface for the user to manage runtime permissions.
• MUST have one and only one implementation of both user interfaces.
• MUST NOT grant any runtime permissions to preinstalled apps unless:
  • the user's consent can be obtained before the application uses it
  • the runtime permissions are associated with an intent pattern for which the preinstalled application is set as the default handler

9.2. UID and Process Isolation

Device implementations MUST support the Android application sandbox model, in which each application runs as a unique Unixstyle UID and in a separate process. Device implementations MUST support running multiple applications as the same Linux user ID, provided that the applications are properly signed and constructed, as defined in the Security and Permissions reference .

9.3. Filesystem Permissions

Device implementations MUST support the Android file access permissions model as defined in the Security and Permissions reference .

9.4. Alternate Execution Environments

Device implementations MAY include runtime environments that execute applications using some other software or technology than the Dalvik Executable Format or native code. However, such alternate execution environments MUST NOT compromise the Android security model or the security of installed Android applications, as described in this section.

Alternate runtimes MUST themselves be Android applications, and abide by the standard Android security model, as described elsewhere in section 9 .

Alternate runtimes MUST NOT be granted access to resources protected by permissions not requested in the runtime's AndroidManifest.xml file via the <uses-permission> mechanism.

Alternate runtimes MUST NOT permit applications to make use of features protected by Android permissions restricted to system applications.

Alternate runtimes MUST abide by the Android sandbox model. Specifically, alternate runtimes:

• SHOULD install apps via the PackageManager into separate Android sandboxes (Linux user IDs, etc.).
• MAY provide a single Android sandbox shared by all applications using the alternate runtime.
• Installed applications using an alternate runtime MUST NOT reuse the sandbox of any other app installed on the device, except through the standard Android mechanisms of shared user ID and signing certificate.
• MUST NOT launch with, grant, or be granted access to the sandboxes corresponding to other Android applications.
• MUST NOT be launched with, be granted, or grant to other applications any privileges of the superuser (root), or of any other user ID.

The .apk files of alternate runtimes MAY be included in the system image of a device implementation, but MUST be signed with a key distinct from the key used to sign other applications included with the device implementation.

When installing applications, alternate runtimes MUST obtain user consent for the Android permissions used by the application. If an application needs to make use of a device resource for which there is a corresponding Android permission (such as Camera, GPS, etc.), the alternate runtime MUST inform the user that the application will be able to access that resource. If the runtime environment does not record application capabilities in this manner, the runtime environment MUST list all permissions held by the runtime itself when installing any application using that runtime.

9.5. Multi-User Support

Android includes support for multiple users and provides support for full user isolation. Device implementations MAY enable multiple users, but when enabled MUST meet the following requirements related to multi-user support :

• Android Automotive device implementations with multi-user support enabled MUST include a guest account that allows all functions provided by the vehicle system without requiring a user to log in.
• Device implementations that do not declare the android.hardware.telephony feature flag MUST support restricted profiles, a feature that allows device owners to manage additional users and their capabilities on the device. With restricted profiles, device owners can quickly set up separate environments for additional users to work in, with the ability to manage finer-grained restrictions in the apps that are available in those environments.
• Conversely device implementations that declare the android.hardware.telephony feature flag MUST NOT support restricted profiles but MUST align with the AOSP implementation of controls to enable /disable other users from accessing the voice calls and SMS.
• Device implementations MUST, for each user, implement a security model consistent with the Android platform security model as defined in Security and Permissions reference document in the APIs.
• Each user instance on an Android device MUST have separate and isolated external storage directories. Device implementations MAY store multiple users' data on the same volume or filesystem. However, the device implementation MUST ensure that applications owned by and running on behalf a given user cannot list, read, or write to data owned by any other user. Note that removable media, such as SD card slots, can allow one user to access another's data by means of a host PC. For this reason, device implementations that use removable media for the external storage APIs MUST encrypt the contents of the SD card if multiuser is enabled using a key stored only on non-removable media accessible only to the system. As this will make the media unreadable by a host PC, device implementations will be required to switch to MTP or a similar system to provide host PCs with access to the current user's data. Accordingly, device implementations MAY but SHOULD NOT enable multi-user if they use removable media for primary external storage.

9.6. Premium SMS Warning

Android includes support for warning users of any outgoing premium SMS message . Premium SMS messages are text messages sent to a service registered with a carrier that may incur a charge to the user. Device implementations that declare support for android.hardware.telephony MUST warn users before sending a SMS message to numbers identified by regular expressions defined in /data/misc/sms/codes.xml file in the device. The upstream Android Open Source Project provides an implementation that satisfies this requirement.

9.7. Kernel Security Features

The Android Sandbox includes features that use the Security-Enhanced Linux (SELinux) mandatory access control (MAC) system, seccomp sandboxing, and other security features in the Linux kernel. SELinux or any other security features implemented below the Android framework:

• MUST maintain compatibility with existing applications.
• MUST NOT have a visible user interface when a security violation is detected and successfully blocked, but MAY have a visible user interface when an unblocked security violation occurs resulting in a successful exploit.
• SHOULD NOT be user or developer configurable.

If any API for configuration of policy is exposed to an application that can affect another application (such as a Device Administration API), the API MUST NOT allow configurations that break compatibility.

Devices MUST implement SELinux or, if using a kernel other than Linux, an equivalent mandatory access control system. Devices MUST also meet the following requirements, which are satisfied by the reference implementation in the upstream Android Open Source Project.

Device implementations:

• MUST set SELinux to global enforcing mode.
• MUST configure all domains in enforcing mode. No permissive mode domains are allowed, including domains specific to a device/vendor.
• MUST NOT modify, omit, or replace the neverallow rules present within the system/sepolicy folder provided in the upstream Android Open Source Project (AOSP) and the policy MUST compile with all neverallow rules present, for both AOSP SELinux domains as well as device/vendor specific domains.
• MUST split the media framework into multiple processes so that it is possible to more narrowly grant access for each process as described in the Android Open Source Project site.

Device implementations SHOULD retain the default SELinux policy provided in the system/sepolicy folder of the upstream Android Open Source Project and only further add to this policy for their own device-specific configuration. Device implementations MUST be compatible with the upstream Android Open Source Project.

Devices MUST implement a kernel application sandboxing mechanism which allows filtering of system calls using a configurable policy from multithreaded programs. The upstream Android Open Source Project meets this requirement through enabling the seccomp-BPF with threadgroup synchronization (TSYNC) as described in the Kernel Configuration section of source.android.com .

9.8. خصوصية

If the device implements functionality in the system that captures the contents displayed on the screen and/or records the audio stream played on the device, it MUST continuously notify the user whenever this functionality is enabled and actively capturing/recording.

If a device implementation has a mechanism that routes network data traffic through a proxy server or VPN gateway by default (for example, preloading a VPN service with android.permission.CONTROL_VPN granted), the device implementation MUST ask for the user's consent before enabling that mechanism, unless that VPN is enabled by the Device Policy Controller via the DevicePolicyManager.setAlwaysOnVpnPackage() , in which case the user does not need to provide a separate consent, but MUST only be notified.

Device implementations MUST ship with an empty user-added Certificate Authority (CA) store, and MUST preinstall the same root certificates for the system-trusted CA store as provided in the upstream Android Open Source Project.

When devices are routed through a VPN, or a user root CA is installed, the implementation MUST display a warning indicating the network traffic may be monitored to the user.

If a device implementation has a USB port with USB peripheral mode support, it MUST present a user interface asking for the user's consent before allowing access to the contents of the shared storage over the USB port.

9.9. Data Storage Encryption

If the device implementation supports a secure lock screen as described in section 9.11.1, then the device MUST support data storage encryption of the application private data (/data partition), as well as the application shared storage partition (/sdcard partition) if it is a permanent, non-removable part of the device.

For device implementations supporting data storage encryption and with Advanced Encryption Standard (AES) crypto performance above 50MiB/sec, the data storage encryption MUST be enabled by default at the time the user has completed the out-of-box setup experience. If a device implementation is already launched on an earlier Android version with encryption disabled by default, such a device cannot meet the requirement through a system software update and thus MAY be exempted.

Device implementations SHOULD meet the above data storage encryption requirement via implementing File Based Encryption (FBE).

9.9.1. Direct Boot

All devices MUST implement the Direct Boot mode APIs even if they do not support Storage Encryption. In particular, the LOCKED_BOOT_COMPLETED and ACTION_USER_UNLOCKED Intents must still be broadcast to signal Direct Boot aware applications that Device Encrypted (DE) and Credential Encrypted (CE) storage locations are available for user.

9.9.2. File Based Encryption

Device implementations supporting FBE:

• MUST boot up without challenging the user for credentials and allow Direct Boot aware apps to access to the Device Encrypted (DE) storage after the LOCKED_BOOT_COMPLETED message is broadcasted.
• MUST only allow access to Credential Encrypted (CE) storage after the user has unlocked the device by supplying their credentials (eg. passcode, pin, pattern or fingerprint) and the ACTION_USER_UNLOCKED message is broadcasted. Device implementations MUST NOT offer any method to unlock the CE protected storage without the user supplied credentials.
• MUST support Verified Boot and ensure that DE keys are cryptographically bound to the device's hardware root of trust.
• MUST support encrypting file contents using AES with a key length of 256-bits in XTS mode.
• MUST support encrypting file name using AES with a key length of 256-bits in CBC-CTS mode.
• MAY support alternative ciphers, key lengths and modes for file content and file name encryption, but MUST use the mandatorily supported ciphers, key lengths and modes by default.
• SHOULD make preloaded essential apps (eg Alarm, Phone, Messenger) Direct Boot aware.

The keys protecting CE and DE storage areas:

• MUST be cryptographically bound to a hardware-backed Keystore. CE keys must be bound to a user's lock screen credentials. If the user has specified no lock screen credentials then the CE keys MUST be bound to a default passcode.
• MUST be unique and distinct, in other words no user's CE or DE key may match any other user's CE or DE keys.

The upstream Android Open Source project provides a preferred implementation of this feature based on the Linux kernel ext4 encryption feature.

9.9.3. تشفير القرص بالكامل

Device implementations supporting full disk encryption (FDE). MUST use AES with a key of 128-bits (or greater) and a mode designed for storage (for example, AES-XTS, AES-CBC-ESSIV). The encryption key MUST NOT be written to storage at any time without being encrypted. The user MUST be provided with the possibility to AES encrypt the encryption key, except when it is in active use, with the lock screen credentials stretched using a slow stretching algorithm (eg PBKDF2 or scrypt). If the user has not specified a lock screen credentials or has disabled use of the passcode for encryption, the system SHOULD use a default passcode to wrap the encryption key. If the device provides a hardware-backed keystore, the password stretching algorithm MUST be cryptographically bound to that keystore. The encryption key MUST NOT be sent off the device (even when wrapped with the user passcode and/or hardware bound key). The upstream Android Open Source project provides a preferred implementation of this feature based on the Linux kernel feature dm-crypt.

9.10. Device Integrity

The following requirements ensures there is transparency to the status of the device integrity.

Device implementations MUST correctly report through the System API method PersistentDataBlockManager.getFlashLockState() whether their bootloader state permits flashing of the system image. The FLASH_LOCK_UNKNOWN state is reserved for device implementations upgrading from an earlier version of Android where this new system API method did not exist.

Verified boot is a feature that guarantees the integrity of the device software. If a device implementation supports the feature, it MUST:

• Declare the platform feature flag android.software.verified_boot.
• Perform verification on every boot sequence.
• Start verification from an immutable hardware key that is the root of trust and go all the way up to the system partition.
• Implement each stage of verification to check the integrity and authenticity of all the bytes in the next stage before executing the code in the next stage.
• Use verification algorithms as strong as current recommendations from NIST for hashing algorithms (SHA-256) and public key sizes (RSA-2048).
• MUST NOT allow boot to complete when system verification fails, unless the user consents to attempt booting anyway, in which case the data from any non-verified storage blocks MUST not be used.
• MUST NOT allow verified partitions on the device to be modified unless the user has explicitly unlocked the boot loader.

The upstream Android Open Source Project provides a preferred implementation of this feature based on the Linux kernel feature dm-verity.

Starting from Android 6.0, device implementations with Advanced Encryption Standard (AES) crypto performance above 50 MiB/seconds MUST support verified boot for device integrity.

If a device implementation is already launched without supporting verified boot on an earlier version of Android, such a device can not add support for this feature with a system software update and thus are exempted from the requirement.

9.11. Keys and Credentials

The Android Keystore System allows app developers to store cryptographic keys in a container and use them in cryptographic operations through the KeyChain API or the Keystore API .

All Android device implementations MUST meet the following requirements:

• SHOULD not limit the number of keys that can be generated, and MUST at least allow more than 8,192 keys to be imported.
• The lock screen authentication MUST rate limit attempts and MUST have an exponential backoff algorithm. Beyond 150 failed attempts, the delay MUST be at least 24 hours per attempt.
• When the device implementation supports a secure lock screen it MUST back up the keystore implementation with secure hardware and meet following requirements:
  • MUST have implementations of RSA, AES, ECDSA and HMAC cryptographic algorithms and MD5, SHA1, and SHA-2 family hash functions to properly support the Android Keystore system's supported algorithms in an area that is securely isolated from the code running on the kernel and above . Secure isolation MUST block all potential mechanisms by which kernel or userspace code might access the internal state of the isolated environment, including DMA. The upstream Android Open Source Project (AOSP) meets this requirement by using the Trusty implementation, but another ARM TrustZone-based solution or a third-party reviewed secure implementation of a proper hypervisor-based isolation are alternative options.
  • MUST perform the lock screen authentication in the isolated execution environment and only when successful, allow the authentication-bound keys to be used. The upstream Android Open Source Project provides the Gatekeeper Hardware Abstraction Layer (HAL) and Trusty, which can be used to satisfy this requirement.

Note that if a device implementation is already launched on an earlier Android version, such a device is exempted from the requirement to have a hardware-backed keystore, unless it declares the android.hardware.fingerprint feature which requires a hardware-backed keystore.

9.11.1. Secure Lock Screen

Device implementations MAY add or modify the authentication methods to unlock the lock screen, but MUST still meet the following requirements:

• The authentication method, if based on a known secret, MUST NOT be treated as a secure lock screen unless it meets all following requirements:
  • The entropy of the shortest allowed length of inputs MUST be greater than 10 bits.
  • The maximum entropy of all possible inputs MUST be greater than 18 bits.
  • MUST not replace any of the existing authentication methods (PIN, pattern, password) implemented and provided in AOSP.
  • MUST be disabled when the Device Policy Controller (DPC) application has set the password quality policy via the DevicePolicyManager.setPasswordQuality() method with a more restrictive quality constant than PASSWORD_QUALITY_SOMETHING .
• The authentication method, if based on a physical token or the location, MUST NOT be treated as a secure lock screen unless it meets all following requirements:
  • It MUST have a fall-back mechanism to use one of the primary authentication methods which is based on a known secret and meets the requirements to be treated as a secure lock screen.
  • It MUST be disabled and only allow the primary authentication to unlock the screen when the Device Policy Controller (DPC) application has set the policy with either the DevicePolicyManager.setKeyguardDisabledFeatures(KEYGUARD_DISABLE_TRUST_AGENTS) method or the DevicePolicyManager.setPasswordQuality() method with a more restrictive quality constant than PASSWORD_QUALITY_UNSPECIFIED .
• The authentication method, if based on biometrics, MUST NOT be treated as a secure lock screen unless it meets all following requirements:
  • It MUST have a fall-back mechanism to use one of the primary authentication methods which is based on a known secret and meets the requirements to be treated as a secure lock screen.
  • It MUST be disabled and only allow the primary authentication to unlock the screen when the Device Policy Controller (DPC) application has set the keguard feature policy by calling the method DevicePolicyManager.setKeyguardDisabledFeatures(KEYGUARD_DISABLE_FINGERPRINT) .
  • It MUST have a false acceptance rate that is equal or stronger than what is required for a fingerprint sensor as described in section 7.3.10, or otherwise MUST be disabled and only allow the primary authentication to unlock the screen when the Device Policy Controller (DPC) application has set the password quality policy via the DevicePolicyManager.setPasswordQuality() method with a more restrictive quality constant than PASSWORD_QUALITY_BIOMETRIC_WEAK .
• If the authentication method can not be treated as a secure lock screen, it:
  • MUST return false for both the KeyguardManager.isKeyguardSecure() and the KeyguardManager.isDeviceSecure() methods.
  • MUST be disabled when the Device Policy Controller (DPC) application has set the password quality policy via the DevicePolicyManager.setPasswordQuality() method with a more restrictive quality constant than PASSWORD_QUALITY_UNSPECIFIED .
  • MUST NOT reset the password expiration timers set by DevicePolicyManager.setPasswordExpirationTimeout() .
  • MUST NOT authenticate access to keystores if the application has called KeyGenParameterSpec.Builder.setUserAuthenticationRequired(true) ).
• If the authentication method is based on a physical token, the location, or biometrics that has higher false acceptance rate than what is required for fingerprint sensors as described in section 7.3.10, then it:
  • MUST NOT reset the password expiration timers set by DevicePolicyManager.setPasswordExpirationTimeout() .
  • MUST NOT authenticate access to keystores if the application has called KeyGenParameterSpec.Builder.setUserAuthenticationRequired(true) .

9.12. حذف البيانات

Devices MUST provide users with a mechanism to perform a "Factory Data Reset" that allows logical and physical deletion of all data except for the following:

• The system image
• Any operating system files required by the system image

All user-generated data MUST be deleted. This MUST satisfy relevant industry standards for data deletion such as NIST SP800-88. This MUST be used for the implementation of the wipeData() API (part of the Android Device Administration API) described in section 3.9 Device Administration .

Devices MAY provide a fast data wipe that conducts a logical data erase.

9.13. Safe Boot Mode

Android provides a mode enabling users to boot up into a mode where only preinstalled system apps are allowed to run and all third-party apps are disabled. This mode, known as "Safe Boot Mode", provides the user the capability to uninstall potentially harmful third-party apps.

Android device implementations are STRONGLY RECOMMENDED to implement Safe Boot Mode and meet following requirements:

• Device implementations SHOULD provide the user an option to enter Safe Boot Mode from the boot menu which is reachable through a workflow that is different from that of normal boot.

• Device implementations MUST provide the user an option to enter Safe Boot Mode in such a way that is uninterruptible from third-party apps installed on the device, except for when the third party app is a Device Policy Controller and has set the UserManager.DISALLOW_SAFE_BOOT flag as true.

• Device implementations MUST provide the user the capability to uninstall any third-party apps within Safe Mode.

9.14. Automotive Vehicle System Isolation

Android Automotive devices are expected to exchange data with critical vehicle subsystems, eg, by using the vehicle HAL to send and receive messages over vehicle networks such as CAN bus. Android Automotive device implementations MUST implement security features below the Android framework layers to prevent malicious or unintentional interaction between the Android framework or third-party apps and vehicle subsystems. These security features are as follows:

• Gatekeeping messages from Android framework vehicle subsystems, eg, allowlisting permitted message types and message sources.
• Watchdog against denial of service attacks from the Android framework or third-party apps. This guards against malicious software flooding the vehicle network with traffic, which may lead to malfunctioning vehicle subsystems.

10. Software Compatibility Testing

Device implementations MUST pass all tests described in this section.

However, note that no software test package is fully comprehensive. For this reason, device implementers are STRONGLY RECOMMENDED to make the minimum number of changes as possible to the reference and preferred implementation of Android available from the Android Open Source Project. This will minimize the risk of introducing bugs that create incompatibilities requiring rework and potential device updates.

10.1. Compatibility Test Suite

Device implementations MUST pass the Android Compatibility Test Suite (CTS) available from the Android Open Source Project, using the final shipping software on the device. Additionally, device implementers SHOULD use the reference implementation in the Android Open Source tree as much as possible, and MUST ensure compatibility in cases of ambiguity in CTS and for any reimplementations of parts of the reference source code.

The CTS is designed to be run on an actual device. Like any software, the CTS may itself contain bugs. The CTS will be versioned independently of this Compatibility Definition, and multiple revisions of the CTS may be released for Android 7.1. Device implementations MUST pass the latest CTS version available at the time the device software is completed.

10.2. CTS Verifier

Device implementations MUST correctly execute all applicable cases in the CTS Verifier. The CTS Verifier is included with the Compatibility Test Suite, and is intended to be run by a human operator to test functionality that cannot be tested by an automated system, such as correct functioning of a camera and sensors.

The CTS Verifier has tests for many kinds of hardware, including some hardware that is optional. Device implementations MUST pass all tests for hardware that they possess; for instance, if a device possesses an accelerometer, it MUST correctly execute the Accelerometer test case in the CTS Verifier. Test cases for features noted as optional by this Compatibility Definition Document MAY be skipped or omitted.

Every device and every build MUST correctly run the CTS Verifier, as noted above. However, since many builds are very similar, device implementers are not expected to explicitly run the CTS Verifier on builds that differ only in trivial ways. Specifically, device implementations that differ from an implementation that has passed the CTS Verifier only by the set of included locales, branding, etc. MAY omit the CTS Verifier test.

11. Updatable Software

Device implementations MUST include a mechanism to replace the entirety of the system software. The mechanism need not perform “live” upgrades—that is, a device restart MAY be required.

Any method can be used, provided that it can replace the entirety of the software preinstalled on the device. For instance, any of the following approaches will satisfy this requirement:

• “Over-the-air (OTA)” downloads with offline update via reboot.
• “Tethered” updates over USB from a host PC.
• “Offline” updates via a reboot and update from a file on removable storage.

However, if the device implementation includes support for an unmetered data connection such as 802.11 or Bluetooth PAN (Personal Area Network) profile, it MUST support OTA downloads with offline update via reboot.

The update mechanism used MUST support updates without wiping user data. That is, the update mechanism MUST preserve application private data and application shared data. Note that the upstream Android software includes an update mechanism that satisfies this requirement.

For device implementations that are launching with Android 6.0 and later, the update mechanism SHOULD support verifying that the system image is binary identical to expected result following an OTA. The block-based OTA implementation in the upstream Android Open Source Project, added since Android 5.1, satisfies this requirement.

Also, device implementations SHOULD support A/B system updates . The AOSP implements this feature using the boot control HAL.

If an error is found in a device implementation after it has been released but within its reasonable product lifetime that is determined in consultation with the Android Compatibility Team to affect the compatibility of third-party applications, the device implementer MUST correct the error via a software update available that can be applied per the mechanism just described.

Android includes features that allow the Device Owner app (if present) to control the installation of system updates. To facilitate this, the system update subsystem for devices that report android.software.device_admin MUST implement the behavior described in the SystemUpdatePolicy class.

12. Document Changelog

For a summary of changes to the Compatibility Definition in this release:

• Document changelog

For a summary of changes to individuals sections:

1. مقدمة
2. أنواع الأجهزة
3. برمجة
4. Application Packaging
5. الوسائط المتعددة
6. Developer Tools and Options
7. Hardware Compatibility
8. الأداء والقوة
9. Security Model
10. Software Compatibility Testing
11. Updatable Software
12. Document Changelog
13. اتصل بنا

12.1. Changelog Viewing Tips

Changes are marked as follows:

• العناية الواجبة
  Substantive changes to the compatibility requirements.

• المستندات
  Cosmetic or build related changes.

For best viewing, append the pretty=full and no-merges URL parameters to your changelog URLs.

13. Contact Us

You can join the android-compatibility forum and ask for clarifications or bring up any issues that you think the document does not cover.