Android 2.3 兼容性定義

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目錄

一、簡介
2. 資源
3. 軟件
4. 應用打包兼容性
5. 多媒體兼容性
6. 開發者工具兼容性
7. 硬件兼容性
8. 性能兼容性
9. 安全模型兼容性
10. 軟件兼容性測試
11. 可更新軟件
12. 聯繫我們
附錄 A - 藍牙測試程序

一、簡介

本文檔列舉了為使手機與 Android 2.3 兼容而必須滿足的要求。

“必須”、“不得”、“要求”、“應”、“不應”、“應該”、“不應”、“推薦”、“可能”和“可選”的使用符合 IETF 標準在 RFC2119 [資源,1 ] 中定義。

本文檔中使用的“設備實施者”或“實施者”是指開發運行 Android 2.3 的硬件/軟件解決方案的個人或組織。 “設備實現”或“實現”是這樣開發的硬件/軟件解決方案。

要被視為與 Android 2.3 兼容,設備實現必須滿足本兼容性定義中提出的要求,包括通過引用併入的任何文檔。

如果此定義或第 10 節中描述的軟件測試是沉默的、模棱兩可的或不完整的,則設備實現者有責任確保與現有實現的兼容性。出於這個原因,Android 開源項目 [ Resources, 3 ] 既是 Android 的參考實現,也是首選實現。強烈建議設備實施者盡可能將其實施基於 Android 開源項目提供的“上游”源代碼。雖然假設某些組件可以替換為替代實現,但強烈建議不要這樣做,因為通過軟件測試將變得更加困難。實施者有責任確保與標準 Android 實施的行為完全兼容,包括和超越兼容性測試套件。最後,請注意,本文檔明確禁止某些組件替換和修改。

請注意,發布此兼容性定義是為了與 Android 的 2.3.3 更新相對應,即 API 級別 10。此定義已過時並替換了 2.3.3 之前的 Android 2.3 版本的兼容性定義。 (也就是說,版本 2.3.1 和 2.3.2 已過時。)未來運行 Android 2.3 的 Android 兼容設備必須隨附 2.3.3 或更高版本。

2. 資源

  1. IETF RFC2119 要求級別: http ://www.ietf.org/rfc/rfc2119.txt
  2. Android 兼容性計劃概述:http: //source.android.com/compatibility/index.html
  3. Android 開源項目:http: //source.android.com/
  4. API 定義和文檔:http: //developer.android.com/reference/packages.html
  5. Android 權限參考:http: //developer.android.com/reference/android/Manifest.permission.html
  6. android.os.Build 參考:http: //developer.android.com/reference/android/os/Build.html
  7. Android 2.3 允許的版本字符串:http: //source.android.com/compatibility/2.3/versions.html
  8. android.webkit.WebView 類:http: //developer.android.com/reference/android/webkit/WebView.html
  9. HTML5:http: //www.whatwg.org/specs/web-apps/current-work/multipage/
  10. HTML5 離線功能: http ://dev.w3.org/html5/spec/Overview.html#offline
  11. HTML5 視頻標籤: http ://dev.w3.org/html5/spec/Overview.html#video
  12. HTML5/W3C 地理定位 API: http ://www.w3.org/TR/geolocation-API/
  13. HTML5/W3C 網絡數據庫 API: http ://www.w3.org/TR/webdatabase/
  14. HTML5/W3C IndexedDB API: http ://www.w3.org/TR/IndexedDB/
  15. Dalvik 虛擬機規範:可在 Android 源代碼中找到,位於 dalvik/docs
  16. AppWidgets:http: //developer.android.com/guide/practices/ui_guidelines/widget_design.html
  17. 通知:http: //developer.android.com/guide/topics/ui/notifiers/notifications.html
  18. 應用資源: http ://code.google.com/android/reference/available-resources.html
  19. 狀態欄圖標樣式指南:http: //developer.android.com/guide/practices/ui_guideline/icon_design.html#statusbarstructure
  20. 搜索管理器:http: //developer.android.com/reference/android/app/SearchManager.html
  21. 祝酒詞:http: //developer.android.com/reference/android/widget/Toast.html
  22. 動態壁紙:http: //developer.android.com/resources/articles/live-wallpapers.html
  23. 參考工具文檔(用於 adb、aapt、ddms):http: //developer.android.com/guide/developing/tools/index.html
  24. Android apk 文件說明:http: //developer.android.com/guide/topics/fundamentals.html
  25. 清單文件:http: //developer.android.com/guide/topics/manifest/manifest-intro.html
  26. 猴子測試工具:http: //developer.android.com/guide/developing/tools/monkey.html
  27. Android 硬件功能列表:http: //developer.android.com/reference/android/content/pm/PackageManager.html
  28. 支持多屏:http: //developer.android.com/guide/practices/screens_support.html
  29. android.util.DisplayMetrics:http: //developer.android.com/reference/android/util/DisplayMetrics.html
  30. android.content.res.Configuration:http: //developer.android.com/reference/android/content/res/Configuration.html
  31. 傳感器坐標空間:http: //developer.android.com/reference/android/hardware/SensorEvent.html
  32. 藍牙 API:http: //developer.android.com/reference/android/bluetooth/package-summary.html
  33. NDEF 推送協議:http: //source.android.com/compatibility/ndef-push-protocol.pdf
  34. MIFARE MF1S503X: http ://www.nxp.com/documents/data_sheet/MF1S503x.pdf
  35. MIFARE MF1S703X: http ://www.nxp.com/documents/data_sheet/MF1S703x.pdf
  36. MIFARE MF0ICU1: http ://www.nxp.com/documents/data_sheet/MF0ICU1.pdf
  37. MIFARE MF0ICU2: http ://www.nxp.com/documents/short_data_sheet/MF0ICU2_SDS.pdf
  38. MIFARE AN130511: http ://www.nxp.com/documents/application_note/AN130511.pdf
  39. MIFARE AN130411: http ://www.nxp.com/documents/application_note/AN130411.pdf
  40. 相機方向 API:http: //developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)
  41. android.hardware.Camera:http://developer.android.com/reference/android/hardware/Camera.html
  42. Android 安全和權限參考:http: //developer.android.com/guide/topics/security/security.html
  43. 適用於 Android 的應用程序: http ://code.google.com/p/apps-for-android

其中許多資源直接或間接源自 Android 2.3 SDK,並且在功能上與該 SDK 文檔中的信息相同。在此兼容性定義或兼容性測試套件與 SDK 文檔不一致的任何情況下,SDK 文檔被視為權威。上述參考文獻中提供的任何技術細節都被視為包含在本兼容性定義中。

3. 軟件

Android 平台包括一組託管 API、一組原生 API 和一組所謂的“軟”API,例如 Intent 系統和 Web 應用程序 API。本節詳細介紹了兼容性不可或缺的硬 API 和軟 API,以及某些其他相關的技術和用戶界面行為。設備實現必須符合本節中的所有要求。

3.1。託管 API 兼容性

託管(基於 Dalvik)的執行環境是 Android 應用程序的主要工具。 Android 應用程序編程接口 (API) 是向在託管 VM 環境中運行的應用程序公開的一組 Android 平台接口。設備實現必須提供 Android 2.3 SDK [參考資料,4 ] 公開的任何記錄在案的 API 的完整實施,包括所有記錄在案的行為。

設備實現不得省略任何託管 API、更改 API 接口或簽名、偏離記錄的行為或包含無操作,除非此兼容性定義特別允許。

此兼容性定義允許設備實現忽略 Android 包含 API 的某些類型的硬件。在這種情況下,API 必須仍然存在並以合理的方式運行。有關此場景的具體要求,請參見第 7 節。

3.2.軟 API 兼容性

除了第 3.1 節中的託管 API 之外,Android 還包括一個重要的僅運行時“軟”API,其形式為諸如 Intent、權限和 Android 應用程序的類似方面等無法在應用程序編譯時強制執行的方面。本節詳細介紹了與 Android 2.3 兼容所需的“軟”API 和系統行為。設備實現必須滿足本節中提出的所有要求。

3.2.1。權限

設備實現者必須支持並強制執行權限參考頁 [資源,5 ] 中記錄的所有權限常量。請注意,第 10 節列出了與 Android 安全模型相關的其他要求。

3.2.2.構建參數

Android API 在android.os.Build類 [ Resources, 6 ] 上包含許多常量,用於描述當前設備。為了在設備實現中提供一致、有意義的值,下表包含了對設備實現必須遵守的這些值的格式的額外限制。

範圍註釋
android.os.Build.VERSION.RELEASE當前執行的 Android 系統的版本,採用人類可讀的格式。該字段必須具有 [ Resources, 7 ] 中定義的字符串值之一。
android.os.Build.VERSION.SDK當前執行的 Android 系統的版本,採用第三方應用程序代碼可訪問的格式。對於 Android 2.3,此字段必須具有整數值 9。
android.os.Build.VERSION.INCREMENTAL設備實現者選擇的值,以人類可讀的格式指定當前執行的 Android 系統的特定構建。此值不得重新用於最終用戶可用的不同構建。此字段的典型用途是指示使用哪個構建號或源代碼控制更改標識符來生成構建。該字段的具體格式沒有要求,但不能為空或空字符串(“”)。
android.os.Build.BOARD設備實現者選擇的一個值,用於標識設備使用的特定內部硬件,採用人類可讀的格式。該字段的一個可能用途是指示為設備供電的電路板的特定版本。此字段的值必須可編碼為 7 位 ASCII 並匹配正則表達式"^[a-zA-Z0-9.,_-]+$"
android.os.Build.BRAND由設備實施者選擇的值,以人類可讀的格式標識生產設備的公司、組織、個人等的名稱。此字段的一種可能用途是指明銷售設備的 OEM 和/或運營商。此字段的值必須可編碼為 7 位 ASCII 並匹配正則表達式"^[a-zA-Z0-9.,_-]+$"
android.os.Build.DEVICE由設備實施者選擇的一個值,用於標識設備主體的特定配置或修訂(有時稱為“工業設計”)。此字段的值必須可編碼為 7 位 ASCII 並匹配正則表達式"^[a-zA-Z0-9.,_-]+$"
android.os.Build.FINGERPRINT唯一標識此構建的字符串。它應該是合理的人類可讀的。它必須遵循這個模板:
$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)
例如:
acme/mydevice/generic/generic:2.3/ERC77/3359:userdebug/test-keys
指紋不得包含空格字符。如果上面模板中包含的其他字段包含空格字符,則必須在構建指紋中將它們替換為另一個字符,例如下劃線(“_”)字符。該字段的值必須可編碼為 7 位 ASCII。
android.os.Build.HOST一個字符串,以人類可讀的格式唯一標識構建所基於的主機。該字段的具體格式沒有要求,但不能為空或空字符串(“”)。
android.os.Build.ID設備實現者選擇的標識符,用於引用特定版本,採用人類可讀的格式。此字段可以與 android.os.Build.VERSION.INCREMENTAL 相同,但應該是一個足以讓最終用戶區分軟件構建的值。此字段的值必須可編碼為 7 位 ASCII 並匹配正則表達式"^[a-zA-Z0-9.,_-]+$"
android.os.Build.MODEL由設備實現者選擇的一個值,其中包含最終用戶已知的設備名稱。這應該與設備銷售和銷售給最終用戶的名稱相同。該字段的具體格式沒有要求,但不能為空或空字符串(“”)。
android.os.Build.PRODUCT設備實現者選擇的一個值,包含設備的開發名稱或代碼名稱。必須是人類可讀的,但不一定供最終用戶查看。此字段的值必須可編碼為 7 位 ASCII 並匹配正則表達式"^[a-zA-Z0-9.,_-]+$"
android.os.Build.TAGS由設備實現者選擇的以逗號分隔的標籤列表,用於進一步區分構建。例如,“未簽名,調試”。此字段的值必須可編碼為 7 位 ASCII 並匹配正則表達式"^[a-zA-Z0-9.,_-]+$"
android.os.Build.TIME表示構建發生時間的時間戳的值。
android.os.Build.TYPE設備實現者選擇的值,指定構建的運行時配置。該字段應該具有對應於三個典型 Android 運行時配置的值之一:“user”、“userdebug”或“eng”。此字段的值必須可編碼為 7 位 ASCII 並匹配正則表達式"^[a-zA-Z0-9.,_-]+$"
android.os.Build.USER生成構建的用戶(或自動用戶)的名稱或用戶 ID。該字段的具體格式沒有要求,但不能為空或空字符串(“”)。

3.2.3。意圖兼容性

Android 使用 Intents 來實現應用程序之間的松耦合集成。本節描述了與設備實現必須遵守的 Intent 模式相關的要求。 “尊敬”是指設備實現者必須提供一個 Android 活動或服務,該活動或服務指定一個匹配的 Intent 過濾器,並綁定到每個指定的 Intent 模式並實現正確的行為。

3.2.3.1。核心應用意圖

Android 上游項目定義了一些核心應用,例如電話撥號器、日曆、通訊錄、音樂播放器等。設備實施者可以用替代版本替換這些應用程序。

但是,任何此類替代版本都必須遵循上游項目提供的相同 Intent 模式。例如,如果設備包含替代音樂播放器,它仍必須遵循第三方應用程序發布的 Intent 模式來挑選歌曲。

以下應用程序被視為核心 Android 系統應用程序:

  • 台鐘
  • 瀏覽器
  • 日曆
  • 計算器
  • 聯繫人
  • 電子郵件
  • 畫廊
  • 全球搜索
  • 啟動器
  • 音樂
  • 設置

核心 Android 系統應用程序包括各種被視為“公共”的 Activity 或 Service 組件。也就是說,屬性“android:exported”可能不存在,或者可能具有值“true”。

對於在核心 Android 系統應用之一中定義的每個 Activity 或 Service 未通過值為“false”的 android:exported 屬性標記為非公共,設備實現必須包含實現相同 Intent 過濾器的相同類型的組件模式作為核心的Android系統應用程序。

換句話說,設備實現可能會取代核心的 Android 系統應用程序;但是,如果支持,設備實現必須支持每個被替換的核心 Android 系統應用程序定義的所有 Intent 模式。

3.2.3.2。意圖覆蓋

由於 Android 是一個可擴展的平台,設備實現者必須允許第 3.2.3.1 節中引用的每個 Intent 模式被第三方應用程序覆蓋。上游 Android 開源項目默認允許這樣做;設備實現者不得將特殊權限附加到系統應用程序對這些 Intent 模式的使用,或阻止第三方應用程序綁定並控制這些模式。該禁止具體包括但不限於禁用“選擇器”用戶界面,該界面允許用戶在所有處理相同意圖模式的多個應用程序之間進行選擇。

3.2.3.3。意圖命名空間

設備實現者不得包含任何使用 android.* 命名空間中的 ACTION、CATEGORY 或其他鍵字符串來支持任何新 Intent 或 Broadcast Intent 模式的 Android 組件。設備實施者不得在屬於另一個組織的包空間中包含任何使用 ACTION、CATEGORY 或其他鍵字符串來尊重任何新 Intent 或 Broadcast Intent 模式的 Android 組件。設備實現者不得更改或擴展第 3.2.3.1 節中列出的核心應用程序使用的任何 Intent 模式。

這種禁止類似於第 3.6 節中為 Java 語言類指定的禁止。

3.2.3.4。廣播意圖

第三方應用程序依靠平台廣播某些 Intent 來通知他們硬件或軟件環境的變化。 Android 兼容設備必須廣播公共廣播 Intent 以響應適當的系統事件。廣播意圖在 SDK 文檔中進行了描述。

3.3.原生 API 兼容性

在 Dalvik 中運行的託管代碼可以調用應用程序 .apk 文件中提供的本機代碼,作為為適當的設備硬件架構編譯的 ELF .so 文件。由於本機代碼高度依賴於底層處理器技術,Android 在 Android NDK 中的docs/CPU-ARCH-ABIS.txt文件中定義了許多應用程序二進制接口 (ABI)。如果設備實現與一個或多個定義的 ABI 兼容,它應該實現與 Android NDK 的兼容性,如下所示。

如果設備實現包括對 Android ABI 的支持,它:

  • 必須包括對在託管環境中運行的代碼的支持,以使用標準 Java 本機接口 (JNI) 語義調用本機代碼。
  • 必須與以下列表中的每個所需庫兼容源代碼(即標頭兼容)和二進制兼容(對於 ABI)
  • 必須通過android.os.Build.CPU_ABI API 準確報告設備支持的本機應用程序二進制接口 (ABI)
  • 必須僅在文件docs/CPU-ARCH-ABIS.txt中報告最新版本的 Android NDK 中記錄的 ABI
  • 應該使用上游 Android 開源項目中可用的源代碼和頭文件構建

以下本機代碼 API 必須可用於包含本機代碼的應用程序:

  • libc(C 庫)
  • libm(數學庫)
  • 對 C++ 的最低支持
  • JNI接口
  • liblog(Android 日誌記錄)
  • libz(Zlib 壓縮)
  • libdl(動態鏈接器)
  • libGLESv1_CM.so (OpenGL ES 1.0)
  • libGLESv2.so (OpenGL ES 2.0)
  • libEGL.so(原生 OpenGL 表面管理)
  • libjnigraphics.so
  • libOpenSLES.so(開放聲音庫音頻支持)
  • libandroid.so(原生 Android 活動支持)
  • 支持 OpenGL,如下所述

請注意,Android NDK 的未來版本可能會引入對其他 ABI 的支持。如果設備實現與現有的預定義 ABI 不兼容,則它絕不能報告對任何 ABI 的支持。

本機代碼兼容性具有挑戰性。出於這個原因,應該重申的是,強烈鼓勵設備實現者使用上面列出的庫的上游實現,以幫助確保兼容性。

3.4.網絡兼容性

許多開發人員和應用程序的用戶界面依賴於android.webkit.WebView類 [資源,8 ] 的行為,因此 WebView 實現必須在 Android 實現之間兼容。同樣,一個完整的現代網絡瀏覽器是 Android 用戶體驗的核心。設備實現必須包含與上游 Android 軟件一致的android.webkit.WebView版本,並且必須包含支持 HTML5 的現代瀏覽器,如下所述。

3.4.1。 Web 視圖兼容性

Android 開源實現使用 WebKit 渲染引擎來實現android.webkit.WebView 。因為為 Web 渲染系統開發一個全面的測試套件是不可行的,設備實現者必須在 WebView 實現中使用特定的上游構建的 WebKit。具體來說:

  • 設備實現的android.webkit.WebView實現必須基於來自 Android 2.3 的上游 Android 開源樹的 533.1 WebKit 構建。此版本包括一組特定的 WebView 功能和安全修復程序。設備實現者可以包括對 WebKit 實現的定制;但是,任何此類自定義都不得改變 WebView 的行為,包括呈現行為。
  • WebView 報告的用戶代理字符串必須採用以下格式:
    Mozilla/5.0 (Linux; U; Android $(VERSION); $(LOCALE); $(MODEL) Build/$(BUILD)) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1
    • $(VERSION) 字符串的值必須與android.os.Build.VERSION.RELEASE的值相同
    • $(LOCALE) 字符串的值應該遵循國家代碼和語言的 ISO 約定,並且應該參考設備當前配置的區域設置
    • $(MODEL) 字符串的值必須與android.os.Build.MODEL的值相同
    • $(BUILD) 字符串的值必須與android.os.Build.ID的值相同

WebView 組件應該盡可能多地支持 HTML5 [資源,9 ]。最低限度,設備實現必須支持與 WebView 中的 HTML5 關聯的這些 API:

此外,設備實現必須支持 HTML5/W3C webstorage API [資源,13 ],並且應該支持 HTML5/W3C IndexedDB API [資源,14 ]。請注意,隨著 Web 開發標準機構正在轉變為偏愛 IndexedDB 而不是 webstorage,IndexedDB 有望成為未來版本 Android 的必需組件。

HTML5 API 與所有 JavaScript API 一樣,必須在 WebView 中默認禁用,除非開發人員通過通常的 Android API 明確啟用它們。

3.4.2.瀏覽器兼容性

設備實現必須包含用於一般用戶網頁瀏覽的獨立瀏覽器應用程序。獨立瀏覽器可能基於 WebKit 以外的瀏覽器技術。但是,即使使用備用瀏覽器應用程序,提供給第三方應用程序的android.webkit.WebView組件也必須基於 WebKit,如第 3.4.1 節所述。

實現可以在獨立的瀏覽器應用程序中提供自定義用戶代理字符串。

獨立的瀏覽器應用程序(無論是基於上游 WebKit 瀏覽器應用程序還是第三方替代品)應該盡可能多地支持 HTML5 [參考資料,9 ]。最低限度,設備實現必須支持與 HTML5 相關的這些 API:

此外,設備實現必須支持 HTML5/W3C webstorage API [資源,13 ],並且應該支持 HTML5/W3C IndexedDB API [資源,14 ]。請注意,隨著 Web 開發標準機構正在轉變為偏愛 IndexedDB 而不是 webstorage,IndexedDB 有望成為未來版本 Android 的必需組件。

3.5. API 行為兼容性

每種 API 類型(託管、軟、本機和 Web)的行為必須與上游 Android 開源項目 [參考資料,3 ] 的首選實現一致。一些特定的兼容性領域是:

  • 設備不得更改標準 Intent 的行為或語義
  • 設備不得改變特定類型的系統組件(如服務、活動、內容提供者等)的生命週期或生命週期語義
  • 設備不得更改標準權限的語義

上面的列表並不全面。兼容性測試套件 (CTS) 測試平台的重要部分的行為兼容性,但不是全部。實施者有責任確保與 Android 開源項目的行為兼容性。出於這個原因,設備實現者應該盡可能使用通過 Android 開源項目提供的源代碼,而不是重新實現系統的重要部分。

3.6. API 命名空間

Android 遵循 Java 編程語言定義的包和類命名空間約定。為確保與第三方應用程序的兼容性,設備實施者不得對這些包命名空間進行任何禁止的修改(見下文):

  • 爪哇。*
  • javax.*
  • 太陽。*
  • 安卓。*
  • com.android.*

禁止的修改包括:

  • 設備實現不得通過更改任何方法或類簽名或刪除類或類字段來修改 Android 平台上公開的 API。
  • 設備實現者可以修改 API 的底層實現,但此類修改不得影響任何公開公開的 API 的聲明行為和 Java 語言簽名。
  • 設備實現者不得將任何公開暴露的元素(例如類或接口,或現有類或接口的字段或方法)添加到上述 API。

“公開暴露的元素”是任何未使用上游 Android 源代碼中使用的“@hide”標記修飾的構造。換句話說,設備實現者不得公開新的 API 或更改上述命名空間中的現有 API。設備實施者可以進行僅限內部的修改,但不得向開發人員宣傳或以其他方式公開這些修改。

設備實現者可以添加自定義 API,但任何此類 API 不得位於其他組織擁有或引用的命名空間中。例如,設備實現者不得將 API 添加到 com.google.* 或類似命名空間;只有谷歌可以這樣做。同樣,Google 不得將 API 添加到其他公司的命名空間。此外,如果設備實現包含標準 Android 命名空間之外的自定義 API,則這些 API 必須打包在 Android 共享庫中,以便只有顯式使用它們(通過<uses-library>機制)的應用程序才會受到內存使用量增加的影響此類 API。

如果設備實現者提議改進上述包命名空間之一(例如通過向現有 API 添加有用的新功能,或添加新 API),則實現者應該訪問 source.android.com 並開始貢獻更改和代碼,根據該網站上的信息。

請注意,上述限制對應於 Java 編程語言中命名 API 的標準約定;本節旨在通過包含在此兼容性定義中來加強這些約定並使其具有約束力。

3.7.虛擬機兼容性

設備實現必須支持完整的 Dalvik 可執行文件 (DEX) 字節碼規範和 Dalvik 虛擬機語義 [資源,15 ]。

屏幕分類為中密度或低密度的設備實現必須配置 Dalvik 為每個應用程序分配至少 16MB 的內存。屏幕分類為高密度或超高密度的設備實現必須配置 Dalvik 為每個應用程序分配至少 24MB 的內存。請注意,設備實現可能分配比這些數字更多的內存。

3.8.用戶界面兼容性

Android 平台包含一些開發人員 API,允許開發人員連接到系統用戶界面。設備實現必須將這些標準 UI API 合併到他們開發的自定義用戶界面中,如下所述。

3.8.1.小部件

Android 定義了一個組件類型和相應的 API 和生命週期,允許應用程序向最終用戶公開一個“AppWidget”[參考資料,16 ]。 Android 開源參考版本包括一個 Launcher 應用程序,該應用程序包含用戶界面元素,允許用戶從主屏幕添加、查看和刪除 AppWidget。

設備實施者可以替代參考啟動器(即主屏幕)的替代方案。替代啟動器應該包含對 AppWidgets 的內置支持,並公開用戶界面元素以直接在啟動器中添加、配置、查看和刪除 AppWidgets。替代啟動器可以省略這些用戶界面元素;但是,如果它們被省略,設備實現者必須提供一個可從 Launcher 訪問的單獨應用程序,允許用戶添加、配置、查看和刪除 AppWidget。

3.8.2.通知

Android 包含允許開發人員通知用戶重要事件的 API [參考資料,17 ]。設備實現者必須為如此定義的每一類通知提供支持;具體來說:聲音、振動、燈光和狀態欄。

此外,實現必須正確呈現 API [資源,18 ] 或狀態欄圖標樣式指南 [資源,19 ] 中提供的所有資源(圖標、聲音文件等)。設備實現者可以為通知提供一種替代的用戶體驗,而不是參考 Android 開源實現提供的體驗;然而,這樣的替代通知系統必須支持現有的通知資源,如上所述。

Android 包括 API [參考資料,20 ],允許開發人員將搜索合併到他們的應用程序中,並將他們的應用程序數據公開到全局系統搜索中。一般而言,此功能由一個單一的、系統範圍的用戶界面組成,允許用戶輸入查詢、在用戶鍵入時顯示建議並顯示結果。 Android API 允許開發人員重用此接口以在他們自己的應用程序中提供搜索,並允許開發人員將結果提供給通用的全局搜索用戶界面。

設備實現必須包括一個單一的、共享的、系統範圍的搜索用戶界面,該界面能夠響應用戶輸入提供實時建議。設備實現必須實現允許開發人員重用此用戶界面以在他們自己的應用程序中提供搜索的 API。設備實現必須實現允許第三方應用程序在全局搜索模式下運行時向搜索框添加建議的 API。如果沒有安裝使用此功能的第三方應用程序,則默認行為應該是顯示網絡搜索引擎結果和建議。

設備實現可以提供替代的搜索用戶界面,但應該包括一個硬或軟專用搜索按鈕,可以在任何應用程序中隨時使用它來調用搜索框架,其行為在 API 文檔中提供。

3.8.4.敬酒

應用程序可以使用“Toast”API(在 [參考資料,21 ] 中定義)向最終用戶顯示簡短的非模態字符串,這些字符串會在短暫的一段時間後消失。設備實現必須以某種高可見度的方式從應用程序向最終用戶顯示 Toast。

3.8.5。動態壁紙

Android 定義了一種組件類型和相應的 API 和生命週期,允許應用程序向最終用戶公開一個或多個“動態壁紙”[參考資料,22 ]。動態壁紙是具有有限輸入功能的動畫、圖案或類似圖像,在其他應用程序後面顯示為壁紙。

如果硬件能夠以合理的幀速率運行所有動態壁紙,並且沒有功能限制,並且對其他應用程序沒有不利影響,則認為硬件能夠可靠地運行動態壁紙。如果硬件限制導致壁紙和/或應用程序崩潰、故障、消耗過多的 CPU 或電池電量,或以不可接受的低幀速率運行,則認為硬件無法運行動態壁紙。例如,一些動態壁紙可能使用 Open GL 1.0 或 2.0 上下文來呈現其內容。動態壁紙無法在不支持多個 OpenGL 上下文的硬件上可靠運行,因為使用 OpenGL 上下文的動態壁紙可能會與也使用 OpenGL 上下文的其他應用程序發生衝突。

如上所述,能夠可靠運行動態壁紙的設備實現應該實現動態壁紙。如上所述確定不能可靠運行動態壁紙的設備實現不得實現動態壁紙。

4. 應用打包兼容性

設備實現必須安裝並運行由官方 Android SDK [資源,23 ] 中包含的“aapt”工俱生成的 Android“.apk”文件。

設備實現不得以阻止這些文件在其他兼容設備上正確安裝和運行的方式擴展 .apk [ Resources, 24 ]、Android Manifest [ Resources, 25 ] 或 Dalvik 字節碼 [ Resources, 15 ] 格式.設備實現者應該使用 Dalvik 的參考上游實現,以及參考實現的包管理系統。

5. 多媒體兼容性

設備實現必須完全實現所有多媒體 API。設備實現必須包括對下文所述的所有多媒體編解碼器的支持,並且應符合下文所述的聲音處理指南。設備實現必須包括至少一種形式的音頻輸出,例如揚聲器、耳機插孔、外部揚聲器連接等。

5.1。媒體編解碼器

設備實現必須支持以下部分中詳述的多媒體編解碼器。所有這些編解碼器都作為軟件實現在 Android 開源項目的首選 Android 實現中提供。

請注意,Google 和開放手機聯盟均未聲明這些編解碼器不受第三方專利的約束。建議那些打算在硬件或軟件產品中使用此源代碼的人,此代碼的實現(包括在開源軟件或共享軟件中)可能需要相關專利持有人的專利許可。

下表未列出大多數視頻編解碼器的特定比特率要求。這樣做的原因是,在實踐中,當前設備硬件不一定支持精確映射到相關標準指定的所需比特率的比特率。相反,設備實現應該支持硬件上實際的最高比特率,達到規範定義的限制。

5.1.1。媒體解碼器

設備實現必須包含下表中描述的每個編解碼器和格式的解碼器實現。請注意,這些媒體類型的解碼器均由上游 Android 開源項目提供。

聲音的
姓名細節文件/容器格式
AAC LC/LTP標準比特率高達 160 kbps 和採樣率介於 8 至 48 kHz 之間的任意組合的單聲道/立體聲內容3GPP (.3gp) 和 MPEG-4 (.mp4, .m4a)。不支持原始 AAC (.aac)
HE-AACv1 (AAC+)
HE-AACv2(增強型 AAC+)
AMR-NB 4.75 至 12.2 kbps 採樣率 @ 8kHz 3GPP (.3gp)
AMR-WB從 6.60 kbit/s 到 23.85 kbit/s 的 9 種速率在 16kHz 下採樣3GPP (.3gp)
MP3單聲道/立體聲 8-320Kbps 恆定 (CBR) 或可變比特率 (VBR) MP3 (.mp3)
MIDI MIDI 類型 0 和 1。DLS 版本 1 和 2。XMF 和移動 XMF。支持鈴聲格式 RTTTL/RTX、OTA 和 iMelody鍵入 0 和 1(.mid、.xmf、.mxmf)。還有 RTTTL/RTX (.rtttl, .rtx)、OTA (.ota) 和 iMelody (.imy)
奧格·沃爾比斯奧格 (.ogg)
PCM 8 位和 16 位線性 PCM(速率達到硬件限制)波 (.wav)
圖片
JPEG基礎+漸進式
動圖
PNG
BMP
視頻
H.263 3GPP (.3gp) 文件
H.264 3GPP (.3gp) 和 MPEG-4 (.mp4) 文件
MPEG4 簡單配置文件3GPP (.3gp) 文件

5.1.2.媒體編碼器

設備實現應該包括第 5.1.1 節中列出的盡可能多的媒體格式的編碼器。盡可能。但是,某些編碼器對於缺少某些可選硬件的設備沒有意義;例如,如果設備沒有任何攝像頭,H.263 視頻的編碼器就沒有意義。因此,設備實現必鬚根據下表中描述的條件實現媒體編碼器。

有關設備實現可以省略硬件的條件的詳細信息,請參見第 7 節。

聲音的
姓名細節文件/容器格式條件
AMR-NB 4.75 至 12.2 kbps 採樣率 @ 8kHz 3GPP (.3gp)包含麥克風硬件並定義android.hardware.microphone的設備實現必須包含這些音頻格式的編碼器。
AMR-WB從 6.60 kbit/s 到 23.85 kbit/s 的 9 種速率在 16kHz 下採樣3GPP (.3gp)
AAC LC/LTP標準比特率高達 160 kbps 和採樣率介於 8 至 48 kHz 之間的任意組合的單聲道/立體聲內容3GPP (.3gp) 和 MPEG-4 (.mp4, .m4a)。
圖片JPEG基礎+漸進式所有設備實現都必須包含這些圖像格式的編碼器,因為 Android 2.3 包含應用程序可用於以編程方式生成這些類型文件的 API。
PNG
視頻H.263 3GPP (.3gp) 文件包含相機硬件並定義android.hardware.cameraandroid.hardware.camera.front的設備實現必須包含這些視頻格式的編碼器。

除了上面列出的編碼器,設備實現應該包括一個 H.264 編碼器。請注意,未來版本的兼容性定義計劃將此要求更改為“必須”。也就是說,H.264 編碼在 Android 2.3 中是可選的,但在未來的版本中將需要強烈建議運行 Android 2.3 的現有設備和新設備在 Android 2.3 中滿足此要求,否則在升級到未來版本時將無法獲得 Android 兼容性。

5.2.聲音錄製

當應用程序使用android.media.AudioRecord API 開始錄製音頻流時,設備實現應該使用以下每個行為採樣和錄製音頻:

  • 降噪處理,如果存在,應該被禁用。
  • 如果存在自動增益控制,則應禁用。
  • 設備應表現出近似平坦的幅度與頻率特性;具體來說,±3 dB,從 100 Hz 到 4000 Hz
  • 應設置音頻輸入靈敏度,以使 1000 Hz 的 90 dB 聲功率級 (SPL) 源對 16 位樣本產生 5000 的 RMS。
  • PCM 幅度電平應該線性跟踪麥克風的輸入 SPL 變化,範圍從 -18 dB 到 +12 dB,再到 90 dB SPL。
  • 在 90 dB SPL 輸入電平下,從 100 Hz 到 4000 Hz 的總諧波失真應小於 1%。

注意:雖然上述要求在 Android 2.3 中被表述為“應該”,但未來版本的兼容性定義計劃將這些要求更改為“必須”。也就是說,這些要求在 Android 2.3 中是可選的,但將來的版本會要求強烈建議運行 Android 2.3 的現有設備和新設備在 Android 2.3 中滿足這些要求,否則在升級到未來版本時將無法獲得 Android 兼容性。

5.3.音頻延遲

音頻延遲廣泛定義為應用程序請求音頻播放或錄製操作與設備實現實際開始操作之間的時間間隔。許多類別的應用程序依靠短延遲來實現諸如聲音效果或 VOIP 通信等實時效果。包含麥克風硬件並聲明android.hardware.microphone的設備實現應該滿足本節中列出的所有音頻延遲要求。有關設備實現可以省略麥克風硬件的條件的詳細信息,請參見第 7 節。

為本節的目的:

  • “冷輸出延遲”被定義為應用程序請求音頻播放和聲音開始播放之間的時間間隔,音頻系統在請求之前已經空閒並斷電
  • “暖輸出延遲”定義為應用程序請求音頻播放和聲音開始播放之間的時間間隔,音頻系統最近被使用但當前處於空閒狀態(即靜音)
  • “連續輸出延遲”定義為應用程序發出要播放的樣本和揚聲器物理播放相應聲音之間的時間間隔,而設備當前正在播放音頻
  • “冷輸入延遲”定義為應用程序請求音頻錄製和第一個樣本通過其回調傳遞給應用程序之間的時間間隔,音頻系統和麥克風在請求之前已空閒並斷電
  • “連續輸入延遲”被定義為當環境聲音發生時以及當與該聲音相對應的樣本通過其回調傳遞到錄製應用程序時,而設備處於錄製模式

使用上述定義,設備實現應該展示以下每個屬性:

  • 100 毫秒或更短的冷輸出延遲
  • 10 毫秒或更短的暖輸出延遲
  • 連續輸出延遲為 45 毫秒或更短
  • 100 毫秒或更短的冷輸入延遲
  • 50毫秒或更短的連續輸入延遲

注意:雖然上述要求在 Android 2.3 中被表述為“應該”,但未來版本的兼容性定義計劃將這些要求更改為“必須”。也就是說,這些要求在 Android 2.3 中是可選的,但將來的版本會要求強烈建議運行 Android 2.3 的現有設備和新設備在 Android 2.3 中滿足這些要求,否則在升級到未來版本時將無法獲得 Android 兼容性。

如果設備實現滿足本節的要求,它可以通過android.content.pm.PackageManager類報告功能“android.hardware.audio.low-latency”來報告對低延遲音頻的支持。 [資源,27 ] 相反,如果設備實現不滿足這些要求,則不得報告對低延遲音頻的支持。

6. 開發者工具兼容性

設備實現必須支持 Android SDK 中提供的 Android 開發者工具。具體來說,Android 兼容設備必須兼容:

  • Android 調試橋(稱為 adb) [資源,23 ]
    設備實現必須支持 Android SDK 中記錄的所有adb函數。默認情況下,設備端adb守護程序應處於非活動狀態,但必須有一個用戶可訪問的機制來打開 Android 調試橋。
  • Dalvik 調試監視器服務(稱為 ddms) [資源,23 ]
    設備實現必須支持 Android SDK 中記錄的所有ddms功能。由於ddms使用adb ,因此默認情況下對ddms的支持應該是不活動的,但只要用戶激活了 Android 調試橋,就必須支持,如上所述。
  • 猴子[資源,26 ]
    設備實現必須包含 Monkey 框架,並使其可供應用程序使用。

大多數基於 Linux 的系統和 Apple Macintosh 系統使用標準 Android SDK 工具識別 Android 設備,無需額外支持;但是,Microsoft Windows 系統通常需要用於新 Android 設備的驅動程序。 (例如,新的供應商 ID 和有時新的設備 ID 需要為 Windows 系統定制 USB 驅動程序。)如果標準 Android SDK 中提供的adb工具無法識別設備實現,則設備實現者必須提供允許開發人員連接到的 Windows 驅動程序使用adb協議的設備。必須為 32 位和 64 位版本的 Windows XP、Windows Vista 和 Windows 7 提供這些驅動程序。

7. 硬件兼容性

Android 旨在使設備實施者能夠創建創新的外形和配置。同時,Android 開發人員編寫創新的應用程序,這些應用程序依賴於通過 Android API 提供的各種硬件和功能。本節中的要求在設備實施者可用的創新與開發人員的需求之間取得了平衡,以確保他們的應用程序僅適用於它們將正常運行的設備。

如果設備包含具有相應 API 的特定硬件組件供第三方開發人員使用,則設備實現必須按照 Android SDK 文檔中的說明實現該 API。如果 SDK 中的 API 與聲明為可選的硬件組件交互,並且設備實現不擁有該組件:

  • 組件 API 的完整類定義(由 SDK 記錄)必須仍然存在
  • API 的行為必須以某種合理的方式實現為無操作
  • API 方法必須在 SDK 文檔允許的情況下返回空值
  • API 方法必須返回 SDK 文檔不允許空值的類的無操作實現
  • API 方法不得拋出 SDK 文檔未記錄的異常

應用這些要求的場景的一個典型示例​​是電話 API:即使在非電話設備上,這些 API 也必須作為合理的無操作來實現。

設備實現必須通過android.content.pm.PackageManager類的getSystemAvailableFeatures()hasSystemFeature(String)方法準確報告準確的硬件配置信息。 [資源,27 ]

7.1。顯示和圖形

Android 2.3 包括自動調整應用程序資產和適合設備的 UI 佈局的工具,以確保第三方應用程序在各種硬件配置上運行良好 [參考資料,28 ]。設備必須正確實現這些 API 和行為,如本節所述。

7.1.1.屏幕配置

設備實現可以使用任何像素尺寸的屏幕,前提是它們滿足以下要求:

  • 屏幕的物理對角線尺寸必須至少為 2.5 英寸
  • 密度必須至少為 100 dpi
  • 縱橫比必須介於 1.333 (4:3) 和 1.779 (16:9) 之間
  • 使用的顯示技術由方形像素組成

屏幕滿足上述要求的設備實現被認為是兼容的,無需額外操作。 Android 框架實現自動計算顯示特徵,例如屏幕尺寸桶和密度桶。在大多數情況下,框架決策是正確的。如果使用默認框架計算,則無需額外操作。希望更改默認設置或使用不符合上述要求的屏幕的設備實施者必須按照第 12 節的規定聯繫 Android 兼容性團隊以獲得指導。

上述要求使用的單位定義如下:

  • “物理對角線尺寸”是顯示器照明部分的兩個相對角之間的距離(以英寸為單位)。
  • “dpi”(意思是“每英寸的點數”)是 1" 的線性水平或垂直跨度所包含的像素數。在列出 dpi 值的地方,水平和垂直 dpi 都必須在該範圍內。
  • “縱橫比”是屏幕的較長尺寸與較短尺寸的比率。例如,480x854 像素的顯示將是 854 / 480 = 1.779,或大致為“16:9”。

設備實現必須僅使用具有單一靜態配置的顯示器。也就是說,設備實現不得啟用多個屏幕配置。例如,由於典型的電視支持多種分辨率,如 1080p、720p 等,因此該配置與 Android 2.3 不兼容。 (但是,對此類配置的支持正在調查中,併計劃在未來的 Android 版本中使用。)

7.1.2.顯示指標

設備實現必須為android.util.DisplayMetrics [資源,29 ] 中定義的所有顯示指標報告正確的值。

7.1.3.聲明的屏幕支持

應用程序可以通過 AndroidManifest.xml 文件中的<supports-screens>屬性選擇性地指示它們支持的屏幕尺寸。如 Android SDK 文檔中所述,設備實現必須正確遵守應用程序聲明的對小、中和大屏幕的支持。

7.1.4。屏幕方向

兼容的設備必須支持應用程序的動態方向為縱向或橫向屏幕方向。也就是說,設備必須尊重應用程序對特定屏幕方向的請求。設備實現可以選擇縱向或橫向作為默認設置。不能物理旋轉的設備可以通過請求縱向模式的“信箱”應用程序僅使用可用顯示的一部分來滿足此要求。

每當通過 android.content.res.Configuration.orientation、android.view.Display.getOrientation() 或其他 API 進行查詢時,設備必須報告設備當前方向的正確值。

7.1.5。 3D 圖形加速

根據 Android 2.3 API 的要求,設備實現必須支持 OpenGL ES 1.0。對於缺少 3D 加速硬件的設備,OpenGL ES 1.0 的軟件實現由上游 Android 開源項目提供。設備實現應該支持 OpenGL ES 2.0。

實現可以省略 Open GL ES 2.0 支持;但是,如果省略支持,則設備實現不得報告為支持 OpenGL ES 2.0。具體來說,如果設備實現缺少 OpenGL ES 2.0 支持:

  • 託管 API(例如通過GLES10.getString()方法)不得報告對 OpenGL ES 2.0 的支持
  • 本機 C/C++ OpenGL API(即那些通過 libGLES_v1CM.so、libGLES_v2.so 或 libEGL.so 可供應用程序使用的 API)不得報告對 OpenGL ES 2.0 的支持。

相反,如果設備實現確實支持 OpenGL ES 2.0,它必須通過剛剛列出的路由準確報告該支持。

Note that Android 2.3 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 2.3 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.

7.2. Input Devices

Android 2.3 supports a number of modalities for user input. Device implementations MUST support user input devices as provided for in this section.

7.2.1. Keyboard

Device implementations:

  • MUST include support for the Input Management Framework (which allows third party developers to create Input Management Engines -- ie soft keyboard) as detailed at developer.android.com
  • MUST provide at least one soft keyboard implementation (regardless of whether a hard keyboard is present)
  • 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 [ Resources, 30 ] (that is, QWERTY, or 12-key)

7.2.2. Non-touch Navigation

Device implementations:

  • MAY omit a non-touch navigation option (that is, may omit a trackball, d-pad, or wheel)
  • MUST report the correct value for android.content.res.Configuration.navigation [ Resources, 30 ]
  • 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 code includes a selection mechanism suitable for use with devices that lack non-touch navigation inputs.

7.2.3.導航鍵

The Home, Menu and Back functions are essential to the Android navigation paradigm. Device implementations MUST make these functions available to the user at all times, regardless of application state. These functions SHOULD be implemented via dedicated buttons. They MAY be implemented using software, gestures, touch panel, etc., but if so they MUST be always accessible and not obscure or interfere with the available application display area.

Device implementers SHOULD also provide a dedicated search key. Device implementers MAY also provide send and end keys for phone calls.

7.2.4.觸摸屏輸入

Device implementations:

  • MUST have a touchscreen
  • MAY have either capacitive or resistive touchscreen
  • MUST report the value of android.content.res.Configuration [ Resources, 30 ] reflecting corresponding to the type of the specific touchscreen on the device
  • SHOULD support fully independently tracked pointers, if the touchscreen supports multiple pointers

7.3.傳感器

Android 2.3 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. For example, device implementations:

  • MUST accurately report the presence or absence of sensors per the android.content.pm.PackageManager class. [ Resources, 27 ]
  • 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.)

The list above is not comprehensive; the documented behavior of the Android SDK is to be considered authoritative.

Some sensor types are synthetic, 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.

The Android 2.3 APIs introduce a notion of a "streaming" sensor, which is one that returns data continuously, rather than only when the data changes. Device implementations MUST continuously provide periodic data samples for any API indicated by the Android 2.3 SDK documentation to be a streaming sensor.

7.3.1.加速度計

Device implementations SHOULD include a 3-axis accelerometer. If a device implementation does include a 3-axis accelerometer, it:

  • MUST be able to deliver events at 50 Hz or greater
  • MUST comply with the Android sensor coordinate system as detailed in the Android APIs (see [ Resources, 31 ])
  • MUST be capable of measuring from freefall up to twice gravity (2g) or more on any three-dimensional vector
  • MUST have 8-bits of accuracy or more
  • MUST have a standard deviation no greater than 0.05 m/s^2

7.3.2. Magnetometer

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

  • MUST be able to deliver events at 10 Hz or greater
  • MUST comply with the Android sensor coordinate system as detailed in the Android APIs (see [ Resources, 31 ]).
  • MUST be capable of sampling a range of field strengths adequate to cover the geomagnetic field
  • MUST have 8-bits of accuracy or more
  • MUST have a standard deviation no greater than 0.5 µT

7.3.3. GPS

Device implementations SHOULD include a GPS receiver. If a device implementation does include a GPS receiver, it SHOULD include some form of "assisted GPS" technique to minimize GPS lock-on time.

7.3.4. Gyroscope

Device implementations SHOULD include a gyroscope (ie 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 be capable of measuring orientation changes up to 5.5*Pi radians/second (that is, approximately 1,000 degrees per second)
  • MUST be able to deliver events at 100 Hz or greater
  • MUST have 8-bits of accuracy or more

7.3.5. Barometer

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

  • MUST be able to deliver events at 5 Hz or greater
  • MUST have adequate precision to enable estimating altitude

7.3.7. Thermometer

Device implementations MAY but SHOULD NOT include a thermometer (ie temperature sensor.) If a device implementation does include a thermometer, it MUST measure the temperature of the device CPU. It MUST NOT measure any other temperature. (Note that this sensor type is deprecated in the Android 2.3 APIs.)

7.3.7. Photometer

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

7.3.8. Proximity Sensor

Device implementations MAY 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. If a device implementation has a proximity sensor, it MUST be have 1-bit of accuracy or more.

7.4. Data Connectivity

Network connectivity and access to the Internet are vital features of Android. Meanwhile, device-to-device interaction adds significant value to Android devices and applications. Device implementations MUST meet the data connectivity requirements in this section.

7.4.1。電話

"Telephony" as used by the Android 2.3 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 2.3 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 sub-features, regardless of whether they use a cellular network for data connectivity.

Android 2.3 MAY be used on devices that do not include telephony hardware. That is, Android 2.3 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.

7.4.2. IEEE 802.11 (WiFi)

Android 2.3 device implementations SHOULD include support for one or more forms of 802.11 (b/g/a/n, etc.) If a device implementation does include support for 802.11, it MUST implement the corresponding Android API.

7.4.3.藍牙

Device implementations SHOULD include a Bluetooth transceiver. Device implementations that do include a Bluetooth transceiver MUST enable the RFCOMM-based Bluetooth API as described in the SDK documentation [ Resources, 32 ]. Device implementations SHOULD implement relevant Bluetooth profiles, such as A2DP, AVRCP, OBEX, etc. as appropriate for the device.

The Compatibility Test Suite includes cases that cover basic operation of the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications protocol between devices, it cannot be fully tested by unit tests running on a single device. Consequently, device implementations MUST also pass the human-driven Bluetooth test procedure described in Appendix A.

7.4.4.近場通信

Device implementations SHOULD include a transceiver and related hardware for Near-Field Communications (NFC). If a device implementation does include NFC hardware, then it:

  • MUST report the android.hardware.nfc feature from the android.content.pm.PackageManager.hasSystemFeature() method. [ Resources, 27 ]
  • 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 6319-4)
      • NfcV (ISO 15693)
      • IsoDep (ISO 14443-4)
      • NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)
    • MUST be capable of transmitting and receiving data via the following peer-to-peer standards and protocols:
      • ISO 18092
      • LLCP 1.0 (defined by the NFC Forum)
      • SDP 1.0 (defined by the NFC Forum)
      • NDEF Push Protocol [ Resources, 33 ]
    • MUST scan for all supported technologies while in NFC discovery mode.
    • SHOULD be in NFC discovery mode while the device is awake with the screen active.

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

    Additionally, device implementations SHOULD support the following widely-deployed MIFARE technologies.

    Note that Android 2.3.3 includes APIs for these MIFARE types. If a device implementation supports MIFARE, 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. [ Resources, 27 ] Note that this is not a standard Android feature, and as such does not appear as a constant on the 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 [ Resources, 27 ], and MUST implement the Android 2.3 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, 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 (WiFi).

    Devices MAY implement more than one form of data connectivity.

    7.5。 Cameras

    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.

    7.5.1. Rear-Facing Camera

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

    • 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. Front-Facing Camera

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

    • MUST have a resolution of at least VGA (that is, 640x480 pixels)
    • MUST NOT use a front-facing camera as the default for the Camera API. That is, the camera API in Android 2.3 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() [ Resources, 40 ] 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 data returned to any "postview" camera callback handlers, in the same manner as the camera preview image stream. (If the device implementation does not support postview callbacks, 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. Camera API Behavior

    Device implementations MUST implement the following behaviors for the camera-related APIs, for both front- and rear-facing cameras:

    1. 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.
    2. 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.
    3. Device implementations SHOULD support the YV12 format (as denoted by the android.graphics.ImageFormat.YV12 constant) for camera previews for both front- and rear-facing cameras. Note that the Compatibility Definition for a future version is planned to change this requirement to "MUST". That is, YV12 support is optional in Android 2.3 but will be required by a future version. Existing and new devices that run Android 2.3 are very strongly encouraged to meet this requirement in Android 2.3 , or they will not be able to attain Android compatibility when upgraded to the future version.

    Device implementations MUST implement the full Camera API included in the Android 2.3 SDK documentation [ Resources, 41 ]), 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.

    7.5.4. Camera Orientation

    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 dimention. That is, when the device is held in the landscape orientation, a 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. Memory and Storage

    The fundamental function of Android 2.3 is to run applications. Device implementations MUST the requirements of this section, to ensure adequate storage and memory for applications to run properly.

    7.6.1. Minimum Memory and Storage

    Device implementations MUST have at least 128MB of memory available to the kernel and userspace. The 128MB MUST be in addition to any memory dedicated to hardware components such as radio, memory, and so on that is not under the kernel's control.

    Device implementations MUST have at least 150MB of non-volatile storage available for user data. That is, the /data partition MUST be at least 150MB.

    Beyond the requirements above, device implementations SHOULD have at least 1GB of non-volatile storage available for user data. Note that this higher requirement is planned to become a hard minimum in a future version of Android. Device implementations are strongly encouraged to meet these requirements now, or else they may not be eligible for compatibility for a future version of Android.

    The Android APIs include a Download Manager that applications may use to download data files. The Download Manager implementation MUST be capable of downloading individual files 55MB in size, or larger. The Download Manager implementation SHOULD be capable of downloading files 100MB in size, or larger.

    7.6.2. Application Shared Storage

    Device implementations MUST offer shared storage for applications. The shared storage provided MUST be at least 1GB in size.

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

    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 MAY have hardware for user-accessible removable storage, such as a Secure Digital card. Alternatively, device implementations MAY allocate internal (non-removable) storage as shared storage for apps.

    Regardless of the form of shared storage used, device implementations MUST provide some mechanism to access the contents of shared storage from a host computer, such as USB mass storage or Media Transfer Protocol.

    It is illustrative to consider two common examples. If a device implementation includes an SD card slot to satisfy the shared storage requirement, a FAT-formatted SD card 1GB in size or larger MUST be included with the device as sold to users, and MUST be mounted by default. Alternatively, if a device implementation uses internal fixed storage to satisfy this requirement, that storage MUST be 1GB in size or larger and mounted on /sdcard (or /sdcard MUST be a symbolic link to the physical location if it is mounted elsewhere.)

    Device implementations that include multiple shared storage paths (such as both an SD card slot and shared internal storage) SHOULD modify the core applications such as the media scanner and ContentProvider to transparently support files placed in both locations.

    7.7. USB

    Device implementations:

    • MUST implement a USB client, connectable to a USB host with a standard USB-A port
    • MUST implement the Android Debug Bridge over USB (as described in Section 7)
    • MUST implement the USB mass storage specification, to allow a host connected to the device to access the contents of the /sdcard volume
    • SHOULD use the micro USB form factor on the device side
    • MAY include a non-standard port on the device side, but if so MUST ship with a cable capable of connecting the custom pinout to standard USB-A port

    8. Performance Compatibility

    Compatible implementations must ensure not only that applications simply run correctly on the device, but that they do so with reasonable performance and overall good user experience. Device implementations MUST meet the key performance metrics of an Android 2.3 compatible device defined in the table below:

    Metric Performance Threshold註釋
    Application Launch Time The following applications should launch within the specified time.
    • Browser: less than 1300ms
    • MMS/SMS: less than 700ms
    • AlarmClock: less than 650ms
    The launch time is measured as the total time to complete loading the default activity for the application, including the time it takes to start the Linux process, load the Android package into the Dalvik VM, and call onCreate.
    Simultaneous Applications When multiple applications have been launched, re-launching an already-running application after it has been launched must take less than the original launch time.

    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 [ Resources, 42 ] 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 sub-sections.

    9.1.權限

    Device implementations MUST support the Android permissions model as defined in the Android developer documentation [ Resources, 42 ]. 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.

    9.2. UID and Process Isolation

    Device implementations MUST support the Android application sandbox model, in which each application runs as a unique Unix-style 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 [ Resources, 42 ].

    9.3. Filesystem Permissions

    Device implementations MUST support the Android file access permissions model as defined in as defined in the Security and Permissions reference [ Resources, 42 ].

    9.4。備用執行環境

    Device implementations MAY include runtime environments that execute applications using some other software or technology than the Dalvik virtual machine 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.具體來說:

    • Alternate runtimes SHOULD install apps via the PackageManager into separate Android sandboxes (that is, Linux user IDs, etc.)
    • Alternate runtimes MAY provide a single Android sandbox shared by all applications using the alternate runtime.
    • Alternate runtimes and 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
    • Alternate runtimes MUST NOT launch with, grant, or be granted access to the sandboxes corresponding to other Android applications.

    Alternate runtimes 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. That is, 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.

    10. 軟件兼容性測試

    The Android Open-Source Project includes various testing tools to verify that device implementations are compatible. 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 very strongly encouraged to make the minimum number of changes as possible to the reference and preferred implementation of Android 2.3 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。兼容性測試套件

    Device implementations MUST pass the Android Compatibility Test Suite (CTS) [ Resources, 2 ] 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 2.3. Device implementations MUST pass the latest CTS version available at the time the device software is completed.

    必須通過設備實施軟件完成時可用的最新版本的 Android 兼容性測試套件 (CTS)。 (CTS 作為 Android 開源項目 [資源,2 ] 的一部分提供。)CTS 測試了本文檔中列出的許多(但不是全部)組件。

    10.2. CTS 驗證者

    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 which 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 Verfier only by the set of included locales, branding, etc. MAY omit the CTS Verifier test.

    10.3.參考應用

    Device implementers MUST test implementation compatibility using the following open-source applications:

    • The "Apps for Android" applications [ Resources, 43 ].
    • Replica Island (available in Android Market; only required for device implementations that support with OpenGL ES 2.0)

    Each app above MUST launch and behave correctly on the implementation, for the implementation to be considered compatible.

    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

    The update mechanism used MUST support updates without wiping user data. Note that the upstream Android software includes an update mechanism that satisfies this requirement.

    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.

    12. Contact Us

    You can contact the document authors at compatibility@android.com for clarifications and to bring up any issues that you think the document does not cover.

    Appendix A - Bluetooth Test Procedure

    The Compatibility Test Suite includes cases that cover basic operation of the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications protocol between devices, it cannot be fully tested by unit tests running on a single device. Consequently, device implementations MUST also pass the human-operated Bluetooth test procedure described below.

    The test procedure is based on the BluetoothChat sample app included in the Android open-source project tree. The procedure requires two devices:

    • a candidate device implementation running the software build to be tested
    • a separate device implementation already known to be compatible, and of a model from the device implementation being tested -- that is, a "known good" device implementation

    The test procedure below refers to these devices as the "candidate" and "known good" devices, respectively.

    Setup and Installation

    1. Build BluetoothChat.apk via 'make samples' from an Android source code tree.
    2. Install BluetoothChat.apk on the known-good device.
    3. Install BluetoothChat.apk on the candidate device.

    Test Bluetooth Control by Apps

    1. Launch BluetoothChat on the candidate device, while Bluetooth is disabled.
    2. Verify that the candidate device either turns on Bluetooth, or prompts the user with a dialog to turn on Bluetooth.

    Test Pairing and Communication

    1. Launch the Bluetooth Chat app on both devices.
    2. Make the known-good device discoverable from within BluetoothChat (using the Menu).
    3. On the candidate device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the known-good device.
    4. Send 10 or more messages from each device, and verify that the other device receives them correctly.
    5. Close the BluetoothChat app on both devices by pressing Home .
    6. Unpair each device from the other, using the device Settings app.

    Test Pairing and Communication in the Reverse Direction

    1. Launch the Bluetooth Chat app on both devices.
    2. Make the candidate device discoverable from within BluetoothChat (using the Menu).
    3. On the known-good device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the candidate device.
    4. Send 10 or messages from each device, and verify that the other device receives them correctly.
    5. Close the Bluetooth Chat app on both devices by pressing Back repeatedly to get to the Launcher.

    Test Re-Launches

    1. Re-launch the Bluetooth Chat app on both devices.
    2. Send 10 or messages from each device, and verify that the other device receives them correctly.

    Note: the above tests have some cases which end a test section by using Home, and some using Back. These tests are not redundant and are not optional: the objective is to verify that the Bluetooth API and stack works correctly both when Activities are explicitly terminated (via the user pressing Back, which calls finish()), and implicitly sent to background (via the user pressing Home.) Each test sequence MUST be performed as described.