1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 2 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> 3 <head> 4 <title>Android 2.3 Compatibility Definition</title> 5 <link rel="stylesheet" type="text/css" href="cdd.css"/> 6 </head> 7 <body> 8 <h1>Android 2.3 Compatibility Definition</h1> 9 <!-- <span style="color: red; font-weight: bold;"><h2>DRAFT</h2></span> --> 10 <p>Copyright © 2010, Google Inc. All rights reserved.<br/> 11 <a href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> 12 </p> 13 14 <h2> Table of Contents</h2> 15 <div style="margin-left: 2em;"> 16 <a href="#section-1">1. Introduction</a><br/> 17 <a href="#section-2">2. Resources</a><br/> 18 <a href="#section-3">3. Software</a><br/> 19 <div style="margin-left: 2em;"> 20 <a href="#section-3.1">3.1. Managed API Compatibility</a><br/> 21 <a href="#section-3.2">3.2. Soft API Compatibility</a><br/> 22 <div style="margin-left: 2em;"> 23 <a href="#section-3.2.1">3.2.1. Permissions</a><br/> 24 <a href="#section-3.2.3">3.2.2. Build Parameters</a><br/> 25 <a href="#section-3.2.3">3.2.3. Intent Compatibility</a><br/> 26 <div style="margin-left: 2em;"> 27 <a href="#section-3.2.3.1">3.2.3.1. Core Application Intents</a><br/> 28 <a href="#section-3.2.3.2">3.2.3.2. Intent Overrides</a><br/> 29 <a href="#section-3.2.3.3">3.2.3.3. Intent Namespaces</a><br/> 30 <a href="#section-3.2.3.4">3.2.3.4. Broadcast Intents</a><br/> 31 </div> 32 </div> 33 <a href="#section-3.3">3.3. Native API Compatibility</a><br/> 34 <a href="#section-3.4">3.4. Web Compatibility</a><br/> 35 <div style="margin-left: 2em;"> 36 <a href="#section-3.4.1">3.4.1. WebView Compatibility</a><br/> 37 <a href="#section-3.4.2">3.4.2. Browser Compatibility</a><br/> 38 </div> 39 <a href="#section-3.5">3.5. API Behavioral Compatibility</a><br/> 40 <a href="#section-3.6">3.6. API Namespaces</a><br/> 41 <a href="#section-3.7">3.7. Virtual Machine Compatibility</a><br/> 42 <a href="#section-3.8">3.8. User Interface Compatibility</a><br/> 43 <div style="margin-left: 2em;"> 44 <a href="#section-3.8.1">3.8.1. Widgets</a><br/> 45 <a href="#section-3.8.2">3.8.2. Notifications</a><br/> 46 <a href="#section-3.8.3">3.8.3. Search</a><br/> 47 <a href="#section-3.8.4">3.8.4. Toasts</a><br/> 48 <a href="#section-3.8.5">3.8.5. Live Wallpapers</a><br/> 49 </div> 50 </div> 51 <a href="#section-4">4. Application Packaging Compatibility</a><br/> 52 <a href="#section-5">5. Multimedia Compatibility</a><br/> 53 <div style="margin-left: 2em;"> 54 <a href="#section-5.1">5.1. Media Codecs</a><br/> 55 <a href="#section-5.1.1">5.1.1. Media Decoders</a><br/> 56 <a href="#section-5.1.2">5.1.2. Media Encoders</a><br/> 57 <a href="#section-5.2">5.2. Audio Recording</a><br/> 58 <a href="#section-5.3">5.3. Audio Latency</a><br/> 59 </div> 60 <a href="#section-6">6. Developer Tool Compatibility</a><br/> 61 <a href="#section-7">7. Hardware Compatibility</a><br/> 62 <div style="margin-left: 2em;"> 63 <a href="#section-7.1">7.1. Display and Graphics</a><br/> 64 <div style="margin-left: 2em;"> 65 <a href="#section-7.1.1">7.1.1. Screen Configurations</a><br/> 66 <a href="#section-7.1.2">7.1.2. Display Metrics</a><br/> 67 <a href="#section-7.1.3">7.1.3. Declared Screen Support</a><br/> 68 <a href="#section-7.1.4">7.1.4. Screen Orientation</a><br/> 69 <a href="#section-7.1.5">7.1.5. 3D Graphics Accleration</a><br/> 70 </div> 71 <a href="#section-7.2">7.2. Input Devices</a><br/> 72 <div style="margin-left: 2em;"> 73 <a href="#section-7.2.1">7.2.1. Keyboard</a><br/> 74 <a href="#section-7.2.2">7.2.2. Non-touch Navigation</a><br/> 75 <a href="#section-7.2.3">7.2.3. Navigation keys</a><br/> 76 <a href="#section-7.2.4">7.2.4. Touchscreen input</a><br/> 77 </div> 78 <a href="#section-7.3">7.3. Sensors</a><br/> 79 <div style="margin-left: 2em;"> 80 <a href="#section-7.3.1">7.3.1. Accelerometer</a><br/> 81 <a href="#section-7.3.2">7.3.2. Magnetometer</a><br/> 82 <a href="#section-7.3.3">7.3.3. GPS</a><br/> 83 <a href="#section-7.3.4">7.3.4. Gyroscope</a><br/> 84 <a href="#section-7.3.5">7.3.5. Barometer</a><br/> 85 <a href="#section-7.3.6">7.3.6. Thermometer</a><br/> 86 <a href="#section-7.3.7">7.3.7. Photometer</a><br/> 87 <a href="#section-7.3.8">7.3.8. Proximity Sensor</a><br/> 88 </div> 89 <a href="#section-7.4">7.4. Data Connectivity</a><br/> 90 <div style="margin-left: 2em;"> 91 <a href="#section-7.4.1">7.4.1. Telephony</a><br/> 92 <a href="#section-7.4.2">7.4.2. IEEE 802.11 (WiFi)</a><br/> 93 <a href="#section-7.4.3">7.4.3. Bluetooth</a><br/> 94 <a href="#section-7.4.4">7.4.4. Near-Field Communications</a><br/> 95 <a href="#section-7.4.5">7.4.5. Minimum Network Capability</a><br/> 96 </div> 97 <a href="#section-7.5">7.5. Cameras</a><br/> 98 <div style="margin-left: 2em;"> 99 <a href="#section-7.5.1">7.5.1. Rear-Facing Camera</a><br/> 100 <a href="#section-7.5.2">7.5.2. Front-Facing Camera</a><br/> 101 <a href="#section-7.5.3">7.5.3. Camera API Behavior</a><br/> 102 <a href="#section-7.5.4">7.5.4. Camera Orientation</a><br/> 103 </div> 104 <a href="#section-7.6">7.6. Memory and Storage</a><br/> 105 <div style="margin-left: 2em;"> 106 <a href="#section-7.6.1">7.6.1. Minimum Memory and Storage</a><br/> 107 <a href="#section-7.6.2">7.6.2. Application Shared Storage</a><br/> 108 </div> 109 <a href="#section-7.7">7.7. USB</a><br/> 110 </div> 111 <a href="#section-8">8. Performance Compatibility</a><br/> 112 <a href="#section-9">9. Security Model Compatibility</a><br/> 113 <div style="margin-left: 2em;"> 114 <a href="#section-9.1">9.1. Permissions</a><br/> 115 <a href="#section-9.2">9.2. UID and Process Isolation</a><br/> 116 <a href="#section-9.3">9.3. Filesystem Permissions</a><br/> 117 <a href="#section-9.4">9.4. Alternate Execution Environments</a><br/> 118 </div> 119 <a href="#section-10">10. Software Compatibility Testing</a><br/> 120 <div style="margin-left: 2em;"> 121 <a href="#section-10.1">10.1. Compatibility Test Suite</a><br/> 122 <a href="#section-10.2">10.2. CTS Verifier</a><br/> 123 <a href="#section-10.3">10.3. Reference Applications</a><br/> 124 </div> 125 <a href="#section-11">11. Updatable Software</a><br/> 126 <a href="#section-12">12. Contact Us</a><br/> 127 <a href="#appendix-A">Appendix A - Bluetooth Test Procedure</a><br/> 128 </div> 129 130 <div style="page-break-before: always;"></div> 131 132 <a name="section-1"></a><h2>1. Introduction</h2> 133 <p>This document enumerates the requirements that must be met in order for 134 mobile phones to be compatible with Android 2.3.</p> 135 <p>The use of "must", "must not", "required", "shall", "shall not", "should", 136 "should not", "recommended", "may" and "optional" is per the IETF standard 137 defined in RFC2119 [<a href="#resources01">Resources, 1</a>].</p> 138 <p>As used in this document, a "device implementer" or "implementer" is a 139 person or organization developing a hardware/software solution running Android 140 2.3. A "device implementation" or "implementation" is the hardware/software 141 solution so developed.</p> 142 <p>To be considered compatible with Android 2.3, device implementations 143 MUST meet the requirements presented in this Compatibility Definition, 144 including any documents incorporated via reference.</p> 145 <p>Where this definition or the software tests described in <a 146 href="#section-10">Section 10</a> is silent, ambiguous, or incomplete, it is 147 the responsibility of the device implementer to ensure compatibility with 148 existing implementations. For this reason, the Android Open Source Project [<a 149 href="#resources03">Resources, 3</a>] is both the reference and preferred 150 implementation of Android. Device implementers are strongly encouraged to base 151 their implementations to the greatest extent possible on the "upstream" source 152 code available from the Android Open Source Project. While some components can 153 hypothetically be replaced with alternate implementations this practice is 154 strongly discouraged, as passing the software tests will become substantially 155 more difficult. It is the implementer's responsibility to ensure full 156 behavioral compatibility with the standard Android implementation, including 157 and beyond the Compatibility Test Suite. Finally, note that certain component 158 substitutions and modifications are explicitly forbidden by this document.</p> 159 <p>Please note that this Compatibility Definition is issued to correspond with 160 the 2.3.3 update to Android, which is API level 10. This Definition obsoletes 161 and replaces the Compatibility Definition for Android 2.3 versions prior to 162 2.3.3. (That is, versions 2.3.1 and 2.3.2 are obsolete.) Future 163 Android-compatible devices running Android 2.3 MUST ship with version 2.3.3 or 164 later.</p> 165 <a name="section-2"></a><h2>2. Resources</h2> 166 <ol> 167 <a name="resources01"></a><li>IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></li> 168 <a name="resources02"></a><li>Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></li> 169 <a name="resources03"></a><li>Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></li> 170 <a name="resources04"></a><li>API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></li> 171 <a name="resources05"></a><li>Android Permissions reference: <a href="http://developer.android.com/reference/android/Manifest.permission.html">http://developer.android.com/reference/android/Manifest.permission.html</a></li> 172 <a name="resources06"></a><li>android.os.Build reference: <a href="http://developer.android.com/reference/android/os/Build.html">http://developer.android.com/reference/android/os/Build.html</a></li> 173 <a name="resources07"></a><li>Android 2.3 allowed version strings: <a href="http://source.android.com/compatibility/2.3/versions.html">http://source.android.com/compatibility/2.3/versions.html</a></li> 174 <a name="resources08"></a><li>android.webkit.WebView class: <a href="http://developer.android.com/reference/android/webkit/WebView.html">http://developer.android.com/reference/android/webkit/WebView.html</a></li> 175 <a name="resources09"></a><li>HTML5: <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/">http://www.whatwg.org/specs/web-apps/current-work/multipage/</a></li> 176 <a name="resources10"></a><li>HTML5 offline capabilities: <a href="http://dev.w3.org/html5/spec/Overview.html#offline">http://dev.w3.org/html5/spec/Overview.html#offline</a></li> 177 <a name="resources11"></a><li>HTML5 video tag: <a href="http://dev.w3.org/html5/spec/Overview.html#video">http://dev.w3.org/html5/spec/Overview.html#video</a></li> 178 <a name="resources12"></a><li>HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></li> 179 <a name="resources13"></a><li>HTML5/W3C webdatabase API: <a href="http://www.w3.org/TR/webdatabase/">http://www.w3.org/TR/webdatabase/</a></li> 180 <a name="resources14"></a><li>HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></li> 181 <a name="resources15"></a><li>Dalvik Virtual Machine specification: available in the Android source code, at dalvik/docs</li> 182 <a name="resources16"></a><li>AppWidgets: <a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">http://developer.android.com/guide/practices/ui_guidelines/widget_design.html</a></li> 183 <a name="resources17"></a><li>Notifications: <a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">http://developer.android.com/guide/topics/ui/notifiers/notifications.html</a></li> 184 <a name="resources18"></a><li>Application Resources: <a href="http://code.google.com/android/reference/available-resources.html">http://code.google.com/android/reference/available-resources.html</a></li> 185 <a name="resources19"></a><li>Status Bar icon style guide: <a href="http://developer.android.com/guide/practices/ui_guidelines/icon_design.html#statusbarstructure">http://developer.android.com/guide/practices/ui_guideline /icon_design.html#statusbarstructure</a></li> 186 <a name="resources20"></a><li>Search Manager: <a href="http://developer.android.com/reference/android/app/SearchManager.html">http://developer.android.com/reference/android/app/SearchManager.html</a></li> 187 <a name="resources21"></a><li>Toasts: <a href="http://developer.android.com/reference/android/widget/Toast.html">http://developer.android.com/reference/android/widget/Toast.html</a></li> 188 <a name="resources22"></a><li>Live Wallpapers: <a href="http://developer.android.com/resources/articles/live-wallpapers.html">http://developer.android.com/resources/articles/live-wallpapers.html</a></li> 189 <a name="resources23"></a><li>Reference tool documentation (for adb, aapt, ddms): <a href="http://developer.android.com/guide/developing/tools/index.html">http://developer.android.com/guide/developing/tools/index.html</a></li> 190 <a name="resources24"></a><li>Android apk file description: <a href="http://developer.android.com/guide/topics/fundamentals.html">http://developer.android.com/guide/topics/fundamentals.html</a></li> 191 <a name="resources25"></a><li>Manifest files: <a href="http://developer.android.com/guide/topics/manifest/manifest-intro.html">http://developer.android.com/guide/topics/manifest/manifest-intro.html</a></li> 192 <a name="resources26"></a><li>Monkey testing tool: <a href="http://developer.android.com/guide/developing/tools/monkey.html">http://developer.android.com/guide/developing/tools/monkey.html</a></li> 193 <a name="resources27"></a><li>Android Hardware Features List: <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">http://developer.android.com/reference/android/content/pm/PackageManager.html</a></li> 194 <a name="resources28"></a><li>Supporting Multiple Screens: <a href="http://developer.android.com/guide/practices/screens_support.html">http://developer.android.com/guide/practices/screens_support.html</a></li> 195 <a name="resources29"></a><li>android.util.DisplayMetrics: <a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">http://developer.android.com/reference/android/util/DisplayMetrics.html</a></li> 196 <a name="resources30"></a><li>android.content.res.Configuration: <a href="http://developer.android.com/reference/android/content/res/Configuration.html">http://developer.android.com/reference/android/content/res/Configuration.html</a></li> 197 <a name="resources31"></a><li>Sensor coordinate space: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">http://developer.android.com/reference/android/hardware/SensorEvent.html</a></li> 198 <a name="resources32"></a><li>Bluetooth API: <a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">http://developer.android.com/reference/android/bluetooth/package-summary.html</a></li> 199 <a name="resources33"></a><li>NDEF Push Protocol: <a href="http://source.android.com/compatibility/ndef-push-protocol.pdf">http://source.android.com/compatibility/ndef-push-protocol.pdf</a></li> 200 <a name="resources34"></a><li>MIFARE MF1S503X: <a href="http://www.nxp.com/documents/data_sheet/MF1S503x.pdf">http://www.nxp.com/documents/data_sheet/MF1S503x.pdf</a></li> 201 <a name="resources35"></a><li>MIFARE MF1S703X: <a href="http://www.nxp.com/documents/data_sheet/MF1S703x.pdf">http://www.nxp.com/documents/data_sheet/MF1S703x.pdf</a></li> 202 <a name="resources36"></a><li>MIFARE MF0ICU1: <a href="http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf">http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf</a></li> 203 <a name="resources37"></a><li>MIFARE MF0ICU2: <a href="http://www.nxp.com/documents/short_data_sheet/MF0ICU2_SDS.pdf">http://www.nxp.com/documents/short_data_sheet/MF0ICU2_SDS.pdf</a></li> 204 <a name="resources38"></a><li>MIFARE AN130511: <a href="http://www.nxp.com/documents/application_note/AN130511.pdf">http://www.nxp.com/documents/application_note/AN130511.pdf</a></li> 205 <a name="resources39"></a><li>MIFARE AN130411: <a href="http://www.nxp.com/documents/application_note/AN130411.pdf">http://www.nxp.com/documents/application_note/AN130411.pdf</a></li> 206 <a name="resources40"></a><li>Camera orientation API: <a href="http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)">http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)</a></li> 207 <a name="resources41"></a><li>android.hardware.Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.html">http://developer.android.com/reference/android/hardware/Camera.html</a></li> 208 <a name="resources42"></a><li>Android Security and Permissions reference: <a href="http://developer.android.com/guide/topics/security/security.html">http://developer.android.com/guide/topics/security/security.html</a></li> 209 <a name="resources43"></a><li>Apps for Android: <a href="http://code.google.com/p/apps-for-android">http://code.google.com/p/apps-for-android</a></li> 210 </ol> 211 <p>Many of these resources are derived directly or indirectly from the Android 212 2.3 SDK, and will be functionally identical to the information in that SDK's 213 documentation. In any cases where this Compatibility Definition or the 214 Compatibility Test Suite disagrees with the SDK documentation, the SDK 215 documentation is considered authoritative. Any technical details provided in 216 the references included above are considered by inclusion to be part of this 217 Compatibility Definition.</p> 218 219 <a name="section-3"></a><h2>3. Software</h2> 220 <p>The Android platform includes a set of managed APIs, a set of native APIs, 221 and a body of so-called "soft" APIs such as the Intent system and 222 web-application APIs. This section details the hard and soft APIs that are 223 integral to compatibility, as well as certain other relevant technical and 224 user interface behaviors. Device implementations MUST comply with all the 225 requirements in this section.</p> 226 227 <a name="section-3.1"></a><h3>3.1. Managed API Compatibility</h3> 228 <p>The managed (Dalvik-based) execution environment is the primary vehicle for 229 Android applications. The Android application programming interface (API) is 230 the set of Android platform interfaces exposed to applications running in the 231 managed VM environment. Device implementations MUST provide complete 232 implementations, including all documented behaviors, of any documented API 233 exposed by the Android 2.3 SDK [<a href="#resources04">Resources, 4</a>].</p> 234 <p>Device implementations MUST NOT omit any managed APIs, alter API interfaces 235 or signatures, deviate from the documented behavior, or include no-ops, except 236 where specifically allowed by this Compatibility Definition.</p> 237 <p>This Compatibility Definition permits some types of hardware for which 238 Android includes APIs to be omitted by device implementations. In such cases, 239 the APIs MUST still be present and behave in a reasonable way. See Section 7 240 for specific requirements for this scenario.</p> 241 242 <a name="section-3.2"></a><h3>3.2. Soft API Compatibility</h3> 243 <p>In addition to the managed APIs from Section 3.1, Android also includes a 244 significant runtime-only "soft" API, in the form of such things such as 245 Intents, permissions, and similar aspects of Android applications that cannot 246 be enforced at application compile time. This section details the "soft" APIs 247 and system behaviors required for compatibility with Android 2.3. Device 248 implementations MUST meet all the requirements presented in this section.</p> 249 <a name="section-3.2.1"></a><h4>3.2.1. Permissions</h4> 250 <p>Device implementers MUST support and enforce all permission constants as 251 documented by the Permission reference page [<a 252 href="#resources05">Resources, 5</a>]. Note that Section 10 lists additional 253 requirements related to the Android security model.</p> 254 <a name="section-3.2.3"></a><h4>3.2.2. Build Parameters</h4> 255 <p>The Android APIs include a number of constants on the <code>android.os.Build</code> 256 class [<a href="#resources06">Resources, 6</a>] that are intended to describe 257 the current device. To provide consistent, meaningful values across device 258 implementations, the table below includes additional restrictions on the 259 formats of these values to which device implementations MUST conform.</p> 260 <table> 261 <tbody> 262 <tr> 263 <td><b>Parameter</b></td> 264 <td><b>Comments</b></td> 265 </tr> 266 <tr> 267 <td>android.os.Build.VERSION.RELEASE</td> 268 <td>The version of the currently-executing Android system, in human-readable 269 format. This field MUST have one of the string values defined in [<a 270 href="#resources07">Resources, 7</a>].</td> 271 </tr> 272 <tr> 273 <td>android.os.Build.VERSION.SDK</td> 274 <td>The version of the currently-executing Android system, in a format 275 accessible to third-party application code. For Android 2.3, this field MUST have 276 the integer value 9.</td> 277 </tr> 278 <tr> 279 <td>android.os.Build.VERSION.INCREMENTAL</td> 280 <td>A value chosen by the device implementer designating the specific build of 281 the currently-executing Android system, in human-readable format. This value 282 MUST NOT be re-used for different builds made available to end users. A typical use 283 of this field is to indicate which build number or source-control change 284 identifier was used to generate the build. There are no requirements on the 285 specific format of this field, except that it MUST NOT be null or the empty 286 string ("").</td> 287 </tr> 288 <tr> 289 <td>android.os.Build.BOARD</td> 290 <td>A value chosen by the device implementer identifying the specific internal 291 hardware used by the device, in human-readable format. A possible use of this 292 field is to indicate the specific revision of the board powering the device. 293 The value of this field MUST be encodable as 7-bit ASCII and match the regular expression 294 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 295 </tr> 296 <tr> 297 <td>android.os.Build.BRAND</td> 298 <td>A value chosen by the device implementer identifying the name of the 299 company, organization, individual, etc. who produced the device, in 300 human-readable format. A possible use of this field is to indicate the OEM 301 and/or carrier who sold the device. The value of this field MUST be 302 encodable as 7-bit ASCII and match the regular expression 303 <code>"^[a-zA-Z0-9.,_-]+$"</code>. 304 </td> 305 </tr> 306 <tr> 307 <td>android.os.Build.DEVICE</td> 308 <td>A value chosen by the device implementer identifying the specific 309 configuration or revision of the body (sometimes called "industrial design") 310 of the device. The value of this field MUST be encodable as 7-bit ASCII and 311 match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 312 </tr> 313 <tr> 314 <td>android.os.Build.FINGERPRINT</td> 315 <td>A string that uniquely identifies this build. It SHOULD be reasonably 316 human-readable. It MUST follow this template: 317 <br/><code>$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</code><br/> 318 For example: 319 <br/><code>acme/mydevice/generic/generic:2.3/ERC77/3359:userdebug/test-keys</code><br/> 320 The fingerprint MUST NOT include whitespace characters. If other fields included in the 321 template above have whitespace characters, they MUST be replaced in the build 322 fingerprint with another character, such as the underscore ("_") character. 323 The value of this field MUST be encodable as 7-bit ASCII.</td> 324 </tr> 325 <tr> 326 <td>android.os.Build.HOST</td> 327 <td>A string that uniquely identifies the host the build was built on, in 328 human readable format. There are no requirements on the specific format of 329 this field, except that it MUST NOT be null or the empty string ("").</td> 330 </tr> 331 <tr> 332 <td>android.os.Build.ID</td> 333 <td>An identifier chosen by the device implementer to refer to a specific 334 release, in human readable format. This field can be the same as 335 android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 336 meaningful for end users to distinguish between software builds. The value of 337 this field MUST be encodable as 7-bit ASCII and match the regular expression 338 <code>"^[a-zA-Z0-9.,_-]+$"</code>. 339 </td> 340 </tr> 341 <tr> 342 <td>android.os.Build.MODEL</td> 343 <td>A value chosen by the device implementer containing the name of the device 344 as known to the end user. This SHOULD be the same name under which the device 345 is marketed and sold to end users. There are no requirements on the specific 346 format of this field, except that it MUST NOT be null or the empty string 347 ("").</td> 348 </tr> 349 <tr> 350 <td>android.os.Build.PRODUCT</td> 351 <td>A value chosen by the device implementer containing the development name 352 or code name of the device. MUST be human-readable, but is not necessarily 353 intended for view by end users. The value of this field MUST be 354 encodable as 7-bit ASCII and match the regular expression 355 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 356 </tr> 357 <tr> 358 <td>android.os.Build.TAGS</td> 359 <td>A comma-separated list of tags chosen by the device implementer that 360 further distinguish the build. For example, "unsigned,debug". The value of 361 this field MUST be encodable as 7-bit ASCII and match the regular expression 362 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 363 </tr> 364 <tr> 365 <td>android.os.Build.TIME</td> 366 <td>A value representing the timestamp of when the build occurred.</td> 367 </tr> 368 <tr> 369 <td>android.os.Build.TYPE</td> 370 <td>A value chosen by the device implementer specifying the runtime 371 configuration of the build. This field SHOULD have one of the values 372 corresponding to the three typical Android runtime configurations: "user", 373 "userdebug", or "eng". The value of this field MUST be 374 encodable as 7-bit ASCII and match the regular expression 375 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 376 </tr> 377 <tr> 378 <td>android.os.Build.USER</td> 379 <td>A name or user ID of the user (or automated user) that generated the 380 build. There are no requirements on the specific format of this field, except 381 that it MUST NOT be null or the empty string ("").</td> 382 </tr> 383 </tbody> 384 </table> 385 <a name="section-3.2.3"></a><h4>3.2.3. Intent Compatibility</h4> 386 <p>Android uses Intents to achieve loosely-coupled integration between 387 applications. This section describes requirements related to the Intent 388 patterns that MUST be honored by device implementations. By "honored", it is 389 meant that the device implementer MUST provide an Android Activity or Service 390 that specifies a matching Intent filter and binds to and implements correct 391 behavior for each specified Intent pattern.</p> 392 <a name="section-3.2.3.1"></a><h4>3.2.3.1. Core Application Intents</h4> 393 <p>The Android upstream project defines a number of core applications, such as 394 a phone dialer, calendar, contacts book, music player, and so on. Device 395 implementers MAY replace these applications with alternative versions.</p> 396 <p>However, any such alternative versions MUST honor the same Intent patterns 397 provided by the upstream project. For example, if a device contains an 398 alternative music player, it must still honor the Intent pattern issued by 399 third-party applications to pick a song.</p> 400 <p>The following applications are considered core Android system 401 applications:</p> 402 <ul> 403 <li>Desk Clock</li> 404 <li>Browser</li> 405 <li>Calendar</li> 406 <li>Calculator</li> 407 <!-- <li>Camera</li> --> 408 <li>Contacts</li> 409 <li>Email</li> 410 <li>Gallery</li> 411 <li>GlobalSearch</li> 412 <li>Launcher</li> 413 <!-- <li>LivePicker (that is, the Live Wallpaper picker application; MAY be omitted 414 if the device does not support Live Wallpapers, per Section 3.8.5.)</li> --> 415 <!-- <li>Messaging (AKA "Mms")</li> --> 416 <li>Music</li> 417 <!-- <li>Phone</li> --> 418 <li>Settings</li> 419 <!-- <li>SoundRecorder</li> --> 420 </ul> 421 <p>The core Android system applications include various Activity, or Service 422 components that are considered "public". That is, the attribute 423 "android:exported" may be absent, or may have the value "true".</p> 424 <p>For every Activity or Service defined 425 in one of the core Android system apps that is not marked as non-public via an 426 android:exported attribute with the value "false", device implementations MUST 427 include a compontent of the same type implementing the same Intent filter 428 patterns as the core Android system app.</p> 429 <p>In other words, a device implementation MAY replace core Android system 430 apps; however, if it does, the device implementation MUST support all Intent 431 patterns defined by each core Android system app being replaced.</p> 432 <a name="section-3.2.3.2"></a><h4>3.2.3.2. Intent Overrides</h4> 433 <p>As Android is an extensible platform, device implementers MUST allow each 434 Intent pattern referenced in Section 3.2.3.1 to be overridden by third-party 435 applications. The upstream Android open source project allows this by default; 436 device implementers MUST NOT attach special privileges to system applications' 437 use of these Intent patterns, or prevent third-party applications from binding 438 to and assuming control of these patterns. This prohibition specifically 439 includes but is not limited to disabling the "Chooser" user interface which 440 allows the user to select between multiple applications which all handle the 441 same Intent pattern.</p> 442 <a name="section-3.2.3.3"></a><h4>3.2.3.3. Intent Namespaces</h4> 443 <p>Device implementers MUST NOT include any Android component that honors any 444 new Intent or Broadcast Intent patterns using an ACTION, CATEGORY, or other 445 key string in the android.* namespace. Device implementers MUST NOT include 446 any Android components that honor any new Intent or Broadcast Intent patterns 447 using an ACTION, CATEGORY, or other key string in a package space belonging to 448 another organization. Device implementers MUST NOT alter or extend any of the 449 Intent patterns used by the core apps listed in Section 3.2.3.1.</p> 450 <p>This prohibition is analogous to that specified for Java language classes 451 in Section 3.6.</p> 452 <a name="section-3.2.3.4"></a><h4>3.2.3.4. Broadcast Intents</h4> 453 <p>Third-party applications rely on the platform to broadcast certain Intents 454 to notify them of changes in the hardware or software environment. 455 Android-compatible devices MUST broadcast the public broadcast Intents in 456 response to appropriate system events. Broadcast Intents are described in the 457 SDK documentation.</p> 458 459 <a name="section-3.3"></a><h3>3.3. Native API Compatibility</h3> 460 <p>Managed code running in Dalvik can call into native code provided in the 461 application .apk file as an ELF .so file compiled for the appropriate device 462 hardware architecture. As native code is highly dependent on the underlying 463 processor technology, Android defines a number of Application Binary 464 Interfaces (ABIs) in the Android NDK, in the file 465 <code>docs/CPU-ARCH-ABIS.txt</code>. If a device implementation is compatible 466 with one or more defined ABIs, it SHOULD implement compatibility with the 467 Android NDK, as below.</p> 468 <p>If a device implementation includes support for an Android ABI, it:</p> 469 <ul> 470 <li>MUST include support for code running in the managed environment to call 471 into native code, using the standard Java Native Interface (JNI) 472 semantics.</li> 473 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible 474 (for the ABI) with each required library in the list below</li> 475 <li>MUST accurately report the native Application Binary Interface (ABI) 476 supported by the device, via the <code>android.os.Build.CPU_ABI</code> 477 API</li> 478 <li>MUST report only those ABIs documented in the latest version of the 479 Android NDK, in the file <code>docs/CPU-ARCH-ABIS.txt</code></li> 480 <li>SHOULD be built using the source code and header files available in the 481 upstream Android open-source project</li> 482 </ul> 483 <p>The following native code APIs MUST be available to apps that include 484 native code:</p> 485 <ul> 486 <li>libc (C library)</li> 487 <li>libm (math library)</li> 488 <li>Minimal support for C++</li> 489 <li>JNI interface</li> 490 <li>liblog (Android logging)</li> 491 <li>libz (Zlib compression)</li> 492 <li>libdl (dynamic linker)</li> 493 <li>libGLESv1_CM.so (OpenGL ES 1.0)</li> 494 <li>libGLESv2.so (OpenGL ES 2.0)</li> 495 <li>libEGL.so (native OpenGL surface management)</li> 496 <li>libjnigraphics.so</li> 497 <li>libOpenSLES.so (Open Sound Library audio support)</li> 498 <li>libandroid.so (native Android activity support)</li> 499 <li>Support for OpenGL, as described below</li> 500 </ul> 501 <p>Note that future releases of the Android NDK may introduce support for 502 additional ABIs. If a device implementation is not compatible with an existing 503 predefined ABI, it MUST NOT report support for any ABI at all.</p> 504 <p>Native code compatibility is challenging. For this reason, it should be 505 repeated that device implementers are VERY strongly encouraged to use the 506 upstream implementations of the libraries listed above to help ensure 507 compatibility.</p> 508 509 <a name="section-3.4"></a><h3>3.4. Web Compatibility</h3> 510 <p>Many developers and applications rely on the behavior of the 511 <code>android.webkit.WebView</code> class [<a 512 href="#resources08">Resources, 8</a>] 513 for their user interfaces, so the WebView implementation must be 514 compatible across Android implementations. Similarly, a complete, modern web 515 broswer is central to the Android user experience. Device implementations MUST 516 include a version of <code>android.webkit.WebView</code> consistent with the 517 upstream Android software, and MUST include a modern HTML5-capable browser, as 518 described below.</p> 519 <a name="section-3.4.1"></a><h4>3.4.1. WebView Compatibility</h4> 520 <p>The Android Open Source implementation uses the WebKit rendering engine to 521 implement the <code>android.webkit.WebView</code>. Because it is not feasible 522 to develop a comprehensive test suite for a web rendering system, device 523 implementers MUST use the specific upstream build of WebKit in the WebView 524 implementation. Specifically:</p> 525 <ul> 526 <li>Device implementations' <code>android.webkit.WebView</code> 527 implementations MUST be based on the 533.1 WebKit build from the upstream 528 Android Open Source tree for Android 2.3. This build includes a specific set 529 of functionality and security fixes for the WebView. Device implementers MAY 530 include customizations to the WebKit implementation; however, any such 531 customizations MUST NOT alter the behavior of the WebView, including rendering 532 behavior.</li> 533 <li>The user agent string reported by the WebView MUST be in this format:<br/> 534 <code>Mozilla/5.0 (Linux; U; Android $(VERSION); $(LOCALE); $(MODEL) Build/$(BUILD)) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1</code> 535 <ul> 536 <li>The value of the $(VERSION) string MUST be the same as the value for <code>android.os.Build.VERSION.RELEASE</code></li> 537 <li>The value of the $(LOCALE) string SHOULD follow the ISO conventions for country code and language, and SHOULD refer to the current configured locale of the device</li> 538 <li>The value of the $(MODEL) string MUST be the same as the value for <code>android.os.Build.MODEL</code></li> 539 <li>The value of the $(BUILD) string MUST be the same as the value for <code>android.os.Build.ID</code></li> 540 </ul></li> 541 </ul> 542 <p>The WebView component SHOULD include support for as much of HTML5 [<a 543 href="#resources09">Resources, 9</a>] as possible. 544 Minimally, device implementations MUST support each of these APIs associated 545 with HTML5 in the WebView:</p> 546 <ul> 547 <li>application cache/offline operation [<a href="#resources10">Resources, 10</a>]</li> 548 <li>the <video> tag [<a href="#resources11">Resources, 11</a>]</li> 549 <li>geolocation [<a href="#resources12">Resources, 12</a>]</li> 550 </ul> 551 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage 552 API [<a href="#resources13">Resources, 13</a>], and SHOULD support the 553 HTML5/W3C IndexedDB API [<a href="#resources14">Resources, 14</a>]. <i>Note 554 that as the web development standards bodies are transitioning to favor 555 IndexedDB over webstorage, IndexedDB is expected to become a required 556 component in a future version of Android.</i></p> 557 <p>HTML5 APIs, like all JavaScript APIs, MUST be disabled by default in a 558 WebView, unless the developer explicitly enables them via the usual Android 559 APIs.</p> 560 561 <a name="section-3.4.2"></a><h4>3.4.2. Browser Compatibility</h4> 562 <p>Device implementations MUST include a standalone Browser application for 563 general user web browsing. The standalone Browser MAY be based on a 564 browser technology other than WebKit. However, even if an alternate Browser 565 application is used, the <code>android.webkit.WebView</code> component 566 provided to third-party applications MUST be based on WebKit, as described in 567 Section 3.4.1.</p> 568 <p>Implementations MAY ship a custom user agent string in the standalone 569 Browser application.</p> 570 <p>The standalone Browser application (whether based on the upstream 571 WebKit Browser application or a third-party replacement) SHOULD include support 572 for as much of HTML5 [<a href="#resources09">Resources, 9</a>] as possible. 573 Minimally, device implementations MUST support each of these APIs associated 574 with HTML5:</p> 575 <ul> 576 <li>application cache/offline operation [<a href="#resources10">Resources, 10</a>]</li> 577 <li>the <video> tag [<a href="#resources11">Resources, 11</a>]</li> 578 <li>geolocation [<a href="#resources12">Resources, 12</a>]</li> 579 </ul> 580 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage 581 API [<a href="#resources13">Resources, 13</a>], and SHOULD support the 582 HTML5/W3C IndexedDB API [<a href="#resources14">Resources, 14</a>]. <i>Note 583 that as the web development standards bodies are transitioning to favor 584 IndexedDB over webstorage, IndexedDB is expected to become a required 585 component in a future version of Android.</i></p> 586 587 <a name="section-3.5"></a><h3>3.5. API Behavioral Compatibility</h3> 588 <p>The behaviors of each of the API types (managed, soft, native, and web) 589 must be consistent with the preferred implementation of the upstream Android 590 open-source project [<a href="#resources03">Resources, 3</a>]. Some specific areas 591 of compatibility are:</p> 592 <ul> 593 <li>Devices MUST NOT change the behavior or semantics of a standard Intent</li> 594 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a 595 particular type of system component (such as Service, Activity, 596 ContentProvider, etc.)</li> 597 <li>Devices MUST NOT change the semantics of a standard permission</li> 598 </ul> 599 <p>The above list is not comprehensive. The Compatibility Test Suite (CTS) 600 tests significant portions of the platform for behavioral compatibility, but 601 not all. It is the responsibility of the implementer to ensure behavioral 602 compatibility with the Android Open Source Project. For this reason, device 603 implementers SHOULD use the source code available via the Android Open Source 604 Project where possible, rather than re-implement significant parts of the 605 system.</p> 606 607 608 <a name="section-3.6"></a><h3>3.6. API Namespaces</h3> 609 <p>Android follows the package and class namespace conventions defined by the 610 Java programming language. To ensure compatibility with third-party 611 applications, device implementers MUST NOT make any prohibited modifications 612 (see below) to these package namespaces:</p> 613 <ul> 614 <li>java.*</li> 615 <li>javax.*</li> 616 <li>sun.*</li> 617 <li>android.*</li> 618 <li>com.android.*</li> 619 </ul> 620 <p>Prohibited modifications include:</p> 621 <ul> 622 <li>Device implementations MUST NOT modify the publicly exposed APIs on the 623 Android platform by changing any method or class signatures, or by removing 624 classes or class fields.</li> 625 <li>Device implementers MAY modify the underlying implementation of the APIs, 626 but such modifications MUST NOT impact the stated behavior and Java-language 627 signature of any publicly exposed APIs.</li> 628 <li>Device implementers MUST NOT add any publicly exposed elements (such as 629 classes or interfaces, or fields or methods to existing classes or interfaces) 630 to the APIs above.</li> 631 </ul> 632 <p>A "publicly exposed element" is any construct which is not decorated with 633 the "@hide" marker as used in the upstream Android source code. In other 634 words, device implementers MUST NOT expose new APIs or alter existing APIs in 635 the namespaces noted above. Device implementers MAY make internal-only 636 modifications, but those modifications MUST NOT be advertised or otherwise 637 exposed to developers.</p> 638 <p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 639 namespace owned by or referring to another organization. For instance, device 640 implementers MUST NOT add APIs to the com.google.* or similar namespace; only 641 Google may do so. Similarly, Google MUST NOT add APIs to other companies' 642 namespaces. Additionally, if a device implementation includes custom APIs 643 outside the standard Android namespace, those APIs MUST be packaged in an 644 Android shared library so that only apps that explicitly use them (via the 645 <code><uses-library></code> mechanism) are affected by the increased 646 memory usage of such APIs.</p> 647 <p>If a device implementer proposes to improve one of the package namespaces 648 above (such as by adding useful new functionality to an existing API, or 649 adding a new API), the implementer SHOULD visit source.android.com and begin 650 the process for contributing changes and code, according to the information on 651 that site.</p> 652 <p>Note that the restrictions above correspond to standard conventions for 653 naming APIs in the Java programming language; this section simply aims to 654 reinforce those conventions and make them binding through inclusion in this 655 compatibility definition.</p> 656 657 <a name="section-3.7"></a><h3>3.7. Virtual Machine Compatibility</h3> 658 <p>Device implementations MUST support the full Dalvik Executable (DEX) 659 bytecode specification and Dalvik Virtual Machine semantics [<a 660 href="#resources15">Resources, 15</a>].</p> 661 <p>Device implementations with screens classified as medium- or low-density 662 MUST configure Dalvik to allocate at least 16MB of memory to each application. 663 Device implementations with screens classified as high-density or 664 extra-high-density MUST configure Dalvik to allocate at least 24MB of memory 665 to each application. Note that device implementations MAY allocate more memory 666 than these figures.</p> 667 668 <a name="section-3.8"></a><h3>3.8. User Interface Compatibility</h3> 669 <p>The Android platform includes some developer APIs that allow developers to 670 hook into the system user interface. Device implementations MUST incorporate 671 these standard UI APIs into custom user interfaces they develop, as explained 672 below.</p> 673 <a name="section-3.8.1"></a><h4>3.8.1. Widgets</h4> 674 <p>Android defines a component type and corresponding API and lifecycle that 675 allows applications to expose an "AppWidget" to the end user [<a 676 href="#resources16">Resources, 16</a>]. 677 The Android Open Source reference release includes a Launcher application that 678 includes user interface elements allowing the user to add, view, and remove 679 AppWidgets from the home screen.</p> 680 <p>Device implementers MAY substitute an alternative to the reference Launcher 681 (i.e. home screen). Alternative Launchers SHOULD include built-in support for 682 AppWidgets, and expose user interface elements to add, configure, view, and remove 683 AppWidgets directly within the Launcher. Alternative Launchers MAY omit these 684 user interface elements; however, if they are omitted, the device implementer 685 MUST provide a separate application accessible from the Launcher that allows 686 users to add, configure, view, and remove AppWidgets.</p> 687 <a name="section-3.8.2"></a><h4>3.8.2. Notifications</h4> 688 <p>Android includes APIs that allow developers to notify users of notable 689 events [<a href="#resources17">Resources, 17</a>]. Device implementers MUST provide support for each 690 class of notification so defined; specifically: sounds, vibration, light and 691 status bar.</p> 692 <p>Additionally, the implementation MUST correctly render all resources 693 (icons, sound files, etc.) provided for in the APIs [<a 694 href="#resources18">Resources, 18</a>], or in the 695 Status Bar icon style guide [<a href="#resources19">Resources, 19</a>]. Device implementers MAY provide 696 an alternative user experience for notifications than that provided by the 697 reference Android Open Source implementation; however, such alternative 698 notification systems MUST support existing notification resources, as 699 above.</p> 700 <a name="section-3.8.3"></a><h4>3.8.3. Search</h4> 701 <p>Android includes APIs [<a href="#resources20">Resources, 20</a>] that allow developers to incorporate 702 search into their applications, and expose their application's data into the 703 global system search. Generally speaking, this functionality consists of a 704 single, system-wide user interface that allows users to enter queries, 705 displays suggestions as users type, and displays results. The Android APIs 706 allow developers to reuse this interface to provide search within their own 707 apps, and allow developers to supply results to the common global search user 708 interface.</p> 709 <p>Device implementations MUST include a single, shared, system-wide search 710 user interface capable of real-time suggestions in response to user input. 711 Device implementations MUST implement the APIs that allow developers to reuse 712 this user interface to provide search within their own applications. Device 713 implementations MUST implement the APIs that allow third-party applications to 714 add suggestions to the search box when it is run in global search mode. If no 715 third-party applications are installed that make use of this functionality, 716 the default behavior SHOULD be to display web search engine results and 717 suggestions.</p> 718 <p>Device implementations MAY ship alternate search user interfaces, but 719 SHOULD include a hard or soft dedicated search button, that can be used at any 720 time within any app to invoke the search framework, with the behavior provided 721 for in the API documentation.</p> 722 <a name="section-3.8.4"></a><h4>3.8.4. Toasts</h4> 723 <p>Applications can use the "Toast" API (defined in [<a 724 href="#resources21">Resources, 21</a>]) to 725 display short non-modal strings to the end user, that disappear after a brief 726 period of time. Device implementations MUST display Toasts from applications 727 to end users in some high-visibility manner.</p> 728 <a name="section-3.8.5"></a><h4>3.8.5. Live Wallpapers</h4> 729 <p>Android defines a component type and corresponding API and lifecycle that 730 allows applications to expose one or more "Live Wallpapers" to the end user 731 [<a href="#resources22">Resources, 22</a>]. Live Wallpapers are animations, 732 patterns, or similar images with limited input capabilities that display as a 733 wallpaper, behind other applications.</p> 734 <p>Hardware is considered capable of reliably running live wallpapers if it 735 can run all live wallpapers, with no limitations on functionality, at a 736 reasonable framerate with no adverse affects on other applications. If 737 limitations in the hardware cause wallpapers and/or applications to crash, 738 malfunction, consume excessive CPU or battery power, or run at unacceptably 739 low frame rates, the hardware is considered incapable of running live 740 wallpaper. As an example, some live wallpapers may use an Open GL 1.0 or 2.0 741 context to render their content. Live wallpaper will not run reliably on 742 hardware that does not support multiple OpenGL contexts because the live 743 wallpaper use of an OpenGL context may conflict with other applications that 744 also use an OpenGL context.</p> 745 <p>Device implementations capable of running live wallpapers reliably as 746 described above SHOULD implement live wallpapers. Device implementations 747 determined to not run live wallpapers reliably as described above MUST NOT 748 implement live wallpapers.</p> 749 750 <a name="section-4"></a><h2>4. Application Packaging Compatibility</h2> 751 <p>Device implementations MUST install and run Android ".apk" files as 752 generated by the "aapt" tool included in the official Android SDK [<a 753 href="#resources23">Resources, 23</a>].</p> 754 <p>Devices implementations MUST NOT extend either the .apk [<a 755 href="#resources24">Resources, 24</a>], Android Manifest [<a 756 href="#resources25">Resources, 25</a>], 757 or Dalvik bytecode [<a href="#resources15">Resources, 15</a>] formats in such 758 a way that would prevent those files from 759 installing and running correctly on other compatible devices. Device 760 implementers SHOULD use the reference upstream implementation of Dalvik, and 761 the reference implementation's package management system.</p> 762 763 <a name="section-5"></a><h2>5. Multimedia Compatibility</h2> 764 <p>Device implementations MUST fully implement all multimedia APIs. Device 765 implementations MUST include support for all multimedia codecs described 766 below, and SHOULD meet the sound processing guidelines described below. Device 767 implementations MUST include at least one form of audio output, such as 768 speakers, headphone jack, external speaker connection, etc.</p> 769 <a name="section-5.1"></a><h3>5.1. Media Codecs</h3> 770 <p>Device implementations MUST support the multimedia codecs as detailed in 771 the following sections. All of these codecs are provided as software 772 implementations in the preferred Android implementation from the Android 773 Open-Source Project.</p> 774 <p>Please note that neither Google nor the Open Handset Alliance make any 775 representation that these codecs are unencumbered by third-party patents. 776 Those intending to use this source code in hardware or software products are 777 advised that implementations of this code, including in open source software 778 or shareware, may require patent licenses from the relevant patent 779 holders.</p> 780 <p>The tables below do not list specific bitrate requirements for 781 most video codecs. The reason for this is that in practice, current device 782 hardware does not necessarily support bitrates that map exactly to the 783 required bitrates specified by the relevant standards. Instead, device 784 implementations SHOULD support the highest bitrate practical on the hardware, 785 up to the limits defined by the specifications.</p> 786 <a name="section-5.1.1"></a><h3>5.1.1. Media Decoders</h3> 787 <p>Device implementations MUST include an implementation of an decoder for 788 each codec and format described in the table below. Note that decoders for 789 each of these media types are provided by the upstream Android Open-Source 790 Project.</p> 791 <table><tbody> 792 <tr> 793 <td rowspan="11"><b>Audio</b></td> 794 </tr> 795 <tr> 796 <td><b>Name</b></td> 797 <td><b>Details</b></td> 798 <td><b>File/Container Format</b></td> 799 </tr> 800 <tr> 801 <td>AAC LC/LTP</td> 802 <td rowspan="3">Mono/Stereo content in any combination of standard bit rates up to 160 kbps and sampling rates between 8 to 48kHz</td> 803 <td rowspan="3">3GPP (.3gp) and MPEG-4 (.mp4, .m4a). No support for raw AAC (.aac)</td> 804 </tr> 805 <tr> 806 <td>HE-AACv1 (AAC+)</td> 807 </tr> 808 <tr> 809 <td>HE-AACv2 (enhanced AAC+)</td> 810 </tr> 811 <tr> 812 <td>AMR-NB</td> 813 <td>4.75 to 12.2 kbps sampled @ 8kHz</td> 814 <td>3GPP (.3gp)</td> 815 </tr> 816 <tr> 817 <td>AMR-WB</td> 818 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 819 <td>3GPP (.3gp)</td> 820 </tr> 821 <tr> 822 <td>MP3</td> 823 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bit-rate (VBR)</td> 824 <td>MP3 (.mp3)</td> 825 </tr> 826 <tr> 827 <td>MIDI</td> 828 <td>MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for ringtone formats RTTTL/RTX, OTA, and iMelody</td> 829 <td>Type 0 and 1 (.mid, .xmf, .mxmf). Also RTTTL/RTX (.rtttl, .rtx), OTA (.ota), and iMelody (.imy)</td> 830 </tr> 831 <tr> 832 <td>Ogg Vorbis</td> 833 <td> </td> 834 <td>Ogg (.ogg)</td> 835 </tr> 836 <tr> 837 <td>PCM</td> 838 <td>8- and 16-bit linear PCM (rates up to limit of hardware)</td> 839 <td>WAVE (.wav)</td> 840 </tr> 841 <tr> 842 <td rowspan="5"><b>Image</b></td> 843 </tr> 844 <tr> 845 <td>JPEG</td> 846 <td>base+progressive</td> 847 <td> </td> 848 </tr> 849 <tr> 850 <td>GIF</td> 851 <td> </td> 852 <td> </td> 853 </tr> 854 <tr> 855 <td>PNG</td> 856 <td> </td> 857 <td> </td> 858 </tr> 859 <tr> 860 <td>BMP</td> 861 <td> </td> 862 <td> </td> 863 </tr> 864 <tr> 865 <td rowspan="4"><b>Video</b></td> 866 </tr> 867 <tr> 868 <td>H.263</td> 869 <td> </td> 870 <td>3GPP (.3gp) files</td> 871 </tr> 872 <tr> 873 <td>H.264</td> 874 <td> </td> 875 <td>3GPP (.3gp) and MPEG-4 (.mp4) files</td> 876 </tr> 877 <tr> 878 <td>MPEG4 Simple Profile</td> 879 <td> </td> 880 <td>3GPP (.3gp) file</td> 881 </tr> 882 </tbody> 883 </table> 884 885 <a name="section-5.1.2"></a><h3>5.1.2. Media Encoders</h3> 886 <p>Device implementations SHOULD include encoders for as many of the media 887 formats listed in Section 5.1.1. as possible. However, some encoders do not 888 make sense for devices that lack certain optional hardware; for instance, 889 an encoder for the H.263 video does not make sense, if the device lacks any 890 cameras. Device implementations MUST therefore implement media encoders 891 according to the conditions described in the table below.</p> 892 <p>See Section 7 for details on the conditions under which hardware may be 893 omitted by device implementations.</p> 894 <table><tbody> 895 <tr> 896 <td rowspan="5"><b>Audio</b></td> 897 </tr> 898 <tr> 899 <td><b>Name</b></td> 900 <td><b>Details</b></td> 901 <td><b>File/Container Format</b></td> 902 <td><b>Conditions</b></td> 903 </tr> 904 <tr> 905 <td>AMR-NB</td> 906 <td>4.75 to 12.2 kbps sampled @ 8kHz</td> 907 <td>3GPP (.3gp)</td> 908 <td rowspan="3">Device implementations that include microphone hardware and define 909 <code>android.hardware.microphone</code> MUST include encoders for these audio 910 formats.</td> 911 </tr> 912 <tr> 913 <td>AMR-WB</td> 914 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 915 <td>3GPP (.3gp)</td> 916 </tr> 917 <tr> 918 <td>AAC LC/LTP</td> 919 <td rowspan="1">Mono/Stereo content in any combination of standard bit rates up to 160 kbps and sampling rates between 8 to 48kHz</td> 920 <td rowspan="1">3GPP (.3gp) and MPEG-4 (.mp4, .m4a).</td> 921 </tr> 922 <tr> 923 <td rowspan="2"><b>Image</b></td> 924 <td>JPEG</td> 925 <td>base+progressive</td> 926 <td> </td> 927 <td rowspan="2">All device implementations MUST include encoders for these 928 image formats, as Android 2.3 includes APIs that applications can use to 929 programmatically generate files of these types.</td> 930 </tr> 931 <tr> 932 <td>PNG</td> 933 <td> </td> 934 <td> </td> 935 </tr> 936 <tr> 937 <td><b>Video</b></td> 938 <td>H.263</td> 939 <td> </td> 940 <td>3GPP (.3gp) files</td> 941 <td>Device implementations that include camera hardware and define 942 either <code>android.hardware.camera</code> or 943 <code>android.hardware.camera.front</code> MUST include encoders for these 944 video formats.</td> 945 </tr> 946 </tbody> 947 </table> 948 <p>In addition to the encoders listed above, device implementations SHOULD include an H.264 949 encoder. Note that the Compatibility Definition for a future version is planned 950 to change this requirement to "MUST". That is, H.264 encoding is optional in Android 951 2.3 but <b>will be required</b> by a future version. Existing and new devices 952 that run Android 2.3 are <b>very strongly encouraged to meet 953 this requirement in Android 2.3</b>, or they will not be able to attain 954 Android compatibility when upgraded to the future version.</p> 955 956 <a name="section-5.2"></a><h3>5.2. Audio Recording</h3> 957 <p>When an application has used the <code>android.media.AudioRecord</code> API to 958 start recording an audio stream, device implementations SHOULD sample and 959 record audio with each of these behaviors:</p> 960 <ul> 961 <li>Noise reduction processing, if present, SHOULD be disabled.</li> 962 <li>Automatic gain control, if present, SHOULD be disabled.</li> 963 <li>The device SHOULD exhibit approximately flat amplitude versus frequency 964 characteristics; specifically, ±3 dB, from 100 Hz to 4000 Hz</li> 965 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level 966 (SPL) source at 1000 Hz yields RMS of 5000 for 16-bit samples.</li> 967 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least 968 a 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.</li> 969 <li>Total harmonic distortion SHOULD be less than 1% from 100 Hz to 4000 Hz at 970 90 dB SPL input level.</li> 971 </ul> 972 <p><b>Note:</b> while the requirements outlined above are stated as "SHOULD" 973 for Android 2.3, the Compatibility Definition for a future version is planned 974 to change these to "MUST". That is, these requirements are optional in Android 975 2.3 but <b>will be required</b> by a future version. Existing and new devices 976 that run Android 2.3 are <b>very strongly encouraged to meet 977 these requirements in Android 2.3</b>, or they will not be able to attain 978 Android compatibility when upgraded to the future version.</p> 979 980 <a name="section-5.3"></a><h3>5.3. Audio Latency</h3> 981 <p>Audio latency is broadly defined as the interval between when an 982 application requests an audio playback or record operation, and when the 983 device implementation actually begins the operation. Many classes of 984 applications rely on short latencies, to achieve real-time effects such sound 985 effects or VOIP communication. Device implementations that include microphone 986 hardware and declare <code>android.hardware.microphone</code> SHOULD meet all 987 audio latency requirements outlined in this section. See Section 7 for 988 details on the conditions under which microphone hardware may be omitted by 989 device implementations.</p> 990 <p>For the purposes of this section:</p> 991 <ul> 992 <li>"cold output latency" is defined to be the interval between when an 993 application requests audio playback and when sound begins playing, when 994 the audio system has been idle and powered down prior to the request</li> 995 <li>"warm output latency" is defined to be the interval between when an 996 application requests audio playback and when sound begins playing, when 997 the audio system has been recently used but is currently idle (that is, 998 silent)</li> 999 <li>"continuous output latency" is defined to be the interval between when an 1000 application issues a sample to be played and when the speaker physically 1001 plays the corresponding sound, while the device is currently playing back 1002 audio</li> 1003 <li>"cold input latency" is defined to be the interval between when an 1004 application requests audio recording and when the first sample is 1005 delivered to the application via its callback, when the audio system and 1006 microphone has been idle and powered down prior to the request</li> 1007 <li>"continuous input latency" is defined to be when an ambient sound occurs 1008 and when the sample corresponding to that sound is delivered to a 1009 recording application via its callback, while the device is in recording 1010 mode</li> 1011 </ul> 1012 <p>Using the above definitions, device implementations SHOULD exhibit each of 1013 these properties:</p> 1014 <ul> 1015 <li>cold output latency of 100 milliseconds or less</li> 1016 <li>warm output latency of 10 milliseconds or less</li> 1017 <li>continuous output latency of 45 milliseconds or less</li> 1018 <li>cold input latency of 100 milliseconds or less</li> 1019 <li>continuous input latency of 50 milliseconds or less</li> 1020 </ul> 1021 <p><b>Note:</b> while the requirements outlined above are stated as "SHOULD" 1022 for Android 2.3, the Compatibility Definition for a future version is planned 1023 to change these to "MUST". That is, these requirements are optional in Android 1024 2.3 but <b>will be required</b> by a future version. Existing and new devices 1025 that run Android 2.3 are <b>very strongly encouraged to meet 1026 these requirements in Android 2.3</b>, or they will not be able to attain 1027 Android compatibility when upgraded to the future version.</p> 1028 <p>If a device implementation meets the requirements of this section, it MAY 1029 report support for low-latency audio, by reporting the feature 1030 "android.hardware.audio.low-latency" via the 1031 <code>android.content.pm.PackageManager</code> class. [<a 1032 href="#resources27">Resources, 27</a>] Conversely, if the device 1033 implementation does not meet these requirements it MUST NOT report support for 1034 low-latency audio.</p> 1035 1036 <a name="section-6"></a><h2>6. Developer Tool Compatibility</h2> 1037 <p>Device implementations MUST support the Android Developer Tools provided in 1038 the Android SDK. Specifically, Android-compatible devices MUST be compatible 1039 with:</p> 1040 <ul> 1041 <li><b>Android Debug Bridge (known as adb)</b> [<a href="#resources23">Resources, 23</a>]<br/> 1042 Device implementations MUST support all <code>adb</code> functions as 1043 documented in the Android SDK. The device-side <code>adb</code> daemon SHOULD 1044 be inactive by default, but there MUST be a user-accessible mechanism to turn 1045 on the Android Debug Bridge.</li> 1046 <li><b>Dalvik Debug Monitor Service (known as ddms)</b> [<a href="#resources23">Resources, 23</a>]<br/> 1047 Device implementations MUST support all <code>ddms</code> features as documented in the 1048 Android SDK. As <code>ddms</code> uses <code>adb</code>, support for 1049 <code>ddms</code> SHOULD be inactive by default, 1050 but MUST be supported whenever the user has activated the Android Debug 1051 Bridge, as above.</li> 1052 <li><b>Monkey</b> [<a href="#resources26">Resources, 26</a>]<br/> 1053 Device implementations MUST include the Monkey framework, and make it 1054 available for applications to use.</li> 1055 </ul> 1056 <p>Most Linux-based systems and Apple Macintosh systems recognize Android 1057 devices using the standard Android SDK tools, without additional support; 1058 however Microsoft Windows systems typically require a driver for new Android 1059 devices. (For instance, new vendor IDs and sometimes new device IDs require 1060 custom USB drivers for Windows systems.) If a device implementation is 1061 unrecognized by the <code>adb</code> tool as provided in the standard Android 1062 SDK, device implementers MUST provide Windows drivers allowing developers to 1063 connect to the device using the <code>adb</code> protocol. These drivers MUST 1064 be provided for Windows XP, Windows Vista, and Windows 7, in both 32-bit and 1065 64-bit versions.</p> 1066 1067 <a name="section-7"></a><h2>7. Hardware Compatibility</h2> 1068 <p>Android is intended to enable device implementers to create innovative form 1069 factors and configurations. At the same time Android developers write 1070 innovative applications that rely on the various hardware and features 1071 available through the Android APIs. The requirements in this section strike a 1072 balance between innovations available to device implementers, and the needs of 1073 developers to ensure their apps are only available to devices where they will 1074 run properly.</p> 1075 <p>If a device includes a particular hardware component that has a 1076 corresponding API for third-party developers, the device implementation MUST 1077 implement that API as described in the Android SDK documentation. If an API in 1078 the SDK interacts with a hardware component that is stated to be optional and the device 1079 implementation does not possess that component:</p> 1080 <ul> 1081 <li>complete class definitions (as documented by the SDK) for the component's APIs MUST still be present</li> 1082 <li>the API's behaviors MUST be implemented as no-ops in some reasonable fashion</li> 1083 <li>API methods MUST return null values where permitted by the SDK documentation</li> 1084 <li>API methods MUST return no-op implementations of classes where null values are not permitted by the SDK documentation</li> 1085 <li>API methods MUST NOT throw exceptions not documented by the SDK documentation</li> 1086 </ul> 1087 <p>A typical example of a scenario where these requirements apply is the 1088 telephony API: even on non-phone devices, these APIs must be implemented as 1089 reasonable no-ops.</p> 1090 <p>Device implementations MUST accurately report accurate hardware configuration 1091 information via the <code>getSystemAvailableFeatures()</code> and 1092 <code>hasSystemFeature(String)</code> methods on the 1093 <code>android.content.pm.PackageManager</code> class. [<a 1094 href="#resources27">Resources, 27</a>]</p> 1095 1096 <a name="section-7.1"></a><h3>7.1. Display and Graphics</h3> 1097 <p>Android 2.3 includes facilities that automatically adjust application 1098 assets and UI layouts appropriately for the device, to ensure that third-party 1099 applications run well on a variety of hardware configurations [<a 1100 href="#resources28">Resources, 28</a>]. Devices MUST properly implement these 1101 APIs and behaviors, as detailed in this section.</p> 1102 <a name="section-7.1.1"></a><h4>7.1.1. Screen Configurations</h4> 1103 <p>Device implementations MAY use screens of any pixel dimensions, provided 1104 that they meet the following requirements:</p> 1105 <ul> 1106 <li>screens MUST be at least 2.5 inches in physical diagonal size</li> 1107 <li>density MUST be at least 100 dpi</li> 1108 <li>the aspect ratio MUST be between 1.333 (4:3) and 1.779 (16:9)</li> 1109 <li>the display technology used consists of square pixels</li> 1110 </ul> 1111 <p>Device implementations with a screen meeting the requirements above are 1112 considered compatible, and no additional action is necessary. The Android 1113 framework implementation automatically computes display characteristics such 1114 as screen size bucket and density bucket. In the majority of cases, the 1115 framework decisions are the correct ones. If the default framework 1116 computations are used, no additional action is necessary. Device implementers 1117 wishing to change the defaults, or use a screen that does not meet the 1118 requirements above MUST contact the Android Compatibility Team for guidance, 1119 as provided for in Section 12.</p> 1120 <p>The units used by the requirements above are defined as follows:</p> 1121 <ul> 1122 <li>"Physical diagonal size" is the distance in inches between two opposing 1123 corners of the illuminated portion of the display.</li> 1124 <li>"dpi" (meaning "dots per inch") is the number of pixels encompassed by a 1125 linear horizontal or vertical span of 1". Where dpi values are listed, both 1126 horizontal and vertical dpi must fall within the range.</li> 1127 <li>"Aspect ratio" is the ratio of the longer dimension of the screen to the 1128 shorter dimension. For example, a display of 480x854 pixels would be 854 / 480 1129 = 1.779, or roughly "16:9".</li> 1130 </ul> 1131 <p>Device implementations MUST use only displays with a single static 1132 configuration. That is, device implementations MUST NOT enable multiple 1133 screen configurations. For instance, since a typical television supports 1134 multiple resolutions such as 1080p, 720p, and so on, this configuration is not 1135 compatible with Android 2.3. (However, support for such configurations is 1136 under investigation and planned for a future version of Android.)</p> 1137 <a name="section-7.1.2"></a><h4>7.1.2. Display Metrics</h4> 1138 <p>Device implementations MUST report correct values for all display metrics 1139 defined in <code>android.util.DisplayMetrics</code> [<a 1140 href="#resources29">Resources, 29</a>].</p> 1141 <a name="section-7.1.3"></a><h4>7.1.3. Declared Screen Support</h4> 1142 <p>Applications optionally indicate which screen sizes they support via the 1143 <code><supports-screens></code> attribute in the AndroidManifest.xml 1144 file. Device implementations MUST correctly honor applications' stated support 1145 for small, medium, and large screens, as described in the Android 1146 SDK documentation.</p> 1147 <a name="section-7.1.4"></a><h4>7.1.4. Screen Orientation</h4> 1148 <p>Compatible devices MUST support dynamic orientation by applications to 1149 either portrait or landscape screen orientation. That is, the device must 1150 respect the application's request for a specific screen orientation. Device 1151 implementations MAY select either portrait or landscape orientation as the 1152 default. Devices that cannot be physically rotated MAY meet this requirement 1153 by "letterboxing" applications that request portrait mode, using only a 1154 portion of the available display.</p> 1155 <p>Devices MUST report the correct value for the device's current orientation, 1156 whenever queried via the android.content.res.Configuration.orientation, 1157 android.view.Display.getOrientation(), or other APIs.</p> 1158 <a name="section-7.1.5"></a><h4>7.1.5. 3D Graphics Acceleration</h4> 1159 <p>Device implementations MUST support OpenGL ES 1.0, as required by the 1160 Android 2.3 APIs. For devices that lack 3D acceleration hardware, a software 1161 implementation of OpenGL ES 1.0 is provided by the upstream Android 1162 Open-Source Project. Device implementations SHOULD support OpenGL ES 2.0.</p> 1163 <p>Implementations MAY omit Open GL ES 2.0 support; however if support is 1164 omitted, device implementations MUST NOT report as supporting OpenGL ES 2.0. 1165 Specifically, if a device implementations lacks OpenGL ES 2.0 support:</p> 1166 <ul> 1167 <li>the managed APIs (such as via the <code>GLES10.getString()</code> method) 1168 MUST NOT report support for OpenGL ES 2.0</li> 1169 <li>the native C/C++ OpenGL APIs (that is, those available to apps via 1170 libGLES_v1CM.so, libGLES_v2.so, or libEGL.so) MUST NOT report support for 1171 OpenGL ES 2.0.</li> 1172 </ul> 1173 <p>Conversely, if a device implementation <i>does</i> support OpenGL ES 2.0, 1174 it MUST accurately report that support via the routes just listed.</p> 1175 <p>Note that Android 2.3 includes support for applications to optionally 1176 specify that they require specific OpenGL texture compression formats. These 1177 formats are typically vendor-specific. Device implementations are not required 1178 by Android 2.3 to implement any specific texture compression format. However, 1179 they SHOULD accurately report any texture compression formats that they do 1180 support, via the <code>getString()</code> method in the OpenGL API.</p> 1181 1182 <a name="section-7.2"></a><h3>7.2. Input Devices</h3> 1183 <p>Android 2.3 supports a number of modalities for user input. Device 1184 implementations MUST support user input devices as provided for in this 1185 section.</p> 1186 <a name="section-7.2.1"></a><h4>7.2.1. Keyboard</h4> 1187 <p>Device implementations:</p> 1188 <ul> 1189 <li>MUST include support for the Input Management Framework (which allows third party developers to create Input Management Engines -- i.e. soft keyboard) as detailed at developer.android.com</li> 1190 <li>MUST provide at least one soft keyboard implementation (regardless of whether a hard keyboard is present)</li> 1191 <li>MAY include additional soft keyboard implementations</li> 1192 <li>MAY include a hardware keyboard</li> 1193 <li>MUST NOT include a hardware keyboard that does not match one of the 1194 formats specified in <code>android.content.res.Configuration.keyboard</code> 1195 [<a href="#resources30">Resources, 30</a>] (that is, QWERTY, or 12-key)</li> 1196 </ul> 1197 <a name="section-7.2.2"></a><h4>7.2.2. Non-touch Navigation</h4> 1198 <p>Device implementations:</p> 1199 <ul> 1200 <li>MAY omit a non-touch navigation option (that is, may omit a trackball, d-pad, or wheel)</li> 1201 <li>MUST report the correct value for 1202 <code>android.content.res.Configuration.navigation</code> [<a href="#resources30">Resources, 30</a>]</li> 1203 <li>MUST provide a reasonable alternative user interface mechanism for the 1204 selection and editing of text, compatible with Input Management Engines. The 1205 upstream Android Open-Source code includes a selection mechanism suitable for 1206 use with devices that lack non-touch navigation inputs.</li> 1207 </ul> 1208 <a name="section-7.2.3"></a><h4>7.2.3. Navigation keys</h4> 1209 <p>The Home, Menu and Back functions are essential to the Android navigation 1210 paradigm. Device implementations MUST make these functions available to the 1211 user at all times, regardless of application state. These functions SHOULD be 1212 implemented via dedicated buttons. They MAY be implemented using software, 1213 gestures, touch panel, etc., but if so they MUST be always accessible and not 1214 obscure or interfere with the available application display area.</p> 1215 <p>Device implementers SHOULD also provide a dedicated search key. Device 1216 implementers MAY also provide send and end keys for phone calls.</p> 1217 <a name="section-7.2.4"></a><h4>7.2.4. Touchscreen input</h4> 1218 <p>Device implementations:</p> 1219 <ul> 1220 <li>MUST have a touchscreen</li> 1221 <li>MAY have either capacitive or resistive touchscreen</li> 1222 <li>MUST report the value of <code>android.content.res.Configuration</code> 1223 [<a href="#resources30">Resources, 30</a>] 1224 reflecting corresponding to the type of the specific touchscreen on the 1225 device</li> 1226 <li>SHOULD support fully independently tracked pointers, if the touchscreen supports multiple pointers</li> 1227 </ul> 1228 1229 <a name="section-7.3"></a><h3>7.3. Sensors</h3> 1230 <p>Android 2.3 includes APIs for accessing a variety of sensor types. Devices 1231 implementations generally MAY omit these sensors, as provided for in the 1232 following subsections. If a device includes a particular sensor type that has a 1233 corresponding API for third-party developers, the device implementation MUST 1234 implement that API as described in the Android SDK documentation. For example, 1235 device implementations:</p> 1236 <ul> 1237 <li>MUST accurately report the presence or absence of sensors per the 1238 <code>android.content.pm.PackageManager</code> class. [<a 1239 href="#resources27">Resources, 27</a>]</li> 1240 <li>MUST return an accurate list of supported sensors via the 1241 <code>SensorManager.getSensorList()</code> and similar methods</li> 1242 <li>MUST behave reasonably for all other sensor APIs (for example, by 1243 returning true or false as appropriate when applications attempt to register 1244 listeners, not calling sensor listeners when the corresponding sensors are not 1245 present; etc.)</li> 1246 </ul> 1247 <p>The list above is not comprehensive; the documented behavior of the Android 1248 SDK is to be considered authoritative.</p> 1249 <p>Some sensor types are synthetic, meaning they can be derived from data 1250 provided by one or more other sensors. (Examples include the orientation 1251 sensor, and the linear acceleration sensor.) Device implementations SHOULD 1252 implement these sensor types, when they include the prerequisite physical 1253 sensors.</p> 1254 <p>The Android 2.3 APIs introduce a notion of a "streaming" sensor, which is 1255 one that returns data continuously, rather than only when the data changes. 1256 Device implementations MUST continuously provide periodic data samples for any 1257 API indicated by the Android 2.3 SDK documentation to be a streaming 1258 sensor.</p> 1259 <a name="section-7.3.1"></a><h4>7.3.1. Accelerometer</h4> 1260 <p>Device implementations SHOULD include a 3-axis accelerometer. If a device 1261 implementation does include a 3-axis accelerometer, it:</p> 1262 <ul> 1263 <li>MUST be able to deliver events at 50 Hz or greater</li> 1264 <li>MUST comply with the Android sensor coordinate system as detailed 1265 in the Android APIs (see [<a href="#resources31">Resources, 31</a>])</li> 1266 <li>MUST be capable of measuring from freefall up to twice gravity (2g) or 1267 more on any three-dimensional vector</li> 1268 <li>MUST have 8-bits of accuracy or more</li> 1269 <li>MUST have a standard deviation no greater than 0.05 m/s^2</li> 1270 </ul> 1271 <a name="section-7.3.2"></a><h4>7.3.2. Magnetometer</h4> 1272 <p>Device implementations SHOULD include a 3-axis magnetometer (i.e. compass.) 1273 If a device does include a 3-axis magnetometer, it:</p> 1274 <ul> 1275 <li>MUST be able to deliver events at 10 Hz or greater</li> 1276 <li>MUST comply with the Android sensor coordinate system as detailed 1277 in the Android APIs (see [<a href="#resources31">Resources, 31</a>]).</li> 1278 <li>MUST be capable of sampling a range of field strengths adequate to cover the geomagnetic field</li> 1279 <li>MUST have 8-bits of accuracy or more</li> 1280 <li>MUST have a standard deviation no greater than 0.5 µT</li> 1281 </ul> 1282 <a name="section-7.3.3"></a><h4>7.3.3. GPS</h4> 1283 <p>Device implementations SHOULD include a GPS receiver. If a device 1284 implementation does include a GPS receiver, it SHOULD include 1285 some form of "assisted GPS" technique to minimize GPS lock-on time.</p> 1286 <a name="section-7.3.4"></a><h4>7.3.4. Gyroscope</h4> 1287 <p>Device implementations SHOULD include a gyroscope (i.e. angular change 1288 sensor.) Devices SHOULD NOT include a gyroscope sensor unless a 3-axis 1289 accelerometer is also included. If a device implementation includes a 1290 gyroscope, it:</p> 1291 <ul> 1292 <li>MUST be capable of measuring orientation changes up to 5.5*Pi 1293 radians/second (that is, approximately 1,000 degrees per second)</li> 1294 <li>MUST be able to deliver events at 100 Hz or greater</li> 1295 <li>MUST have 8-bits of accuracy or more</li> 1296 </ul> 1297 <a name="section-7.3.5"></a><h4>7.3.5. Barometer</h4> 1298 <p>Device implementations MAY include a barometer (i.e. ambient air pressure 1299 sensor.) If a device implementation includes a barometer, it:</p> 1300 <ul> 1301 <li>MUST be able to deliver events at 5 Hz or greater</li> 1302 <li>MUST have adequate precision to enable estimating altitude</li> 1303 </ul> 1304 <a name="section-7.3.6"></a><h4>7.3.7. Thermometer</h4> 1305 <p>Device implementations MAY but SHOULD NOT include a thermometer (i.e. 1306 temperature sensor.) If a device implementation does include a thermometer, it 1307 MUST measure the temperature of the device CPU. It MUST NOT measure any other 1308 temperature. (Note that this sensor type is deprecated in the Android 2.3 1309 APIs.)</p> 1310 <a name="section-7.3.7"></a><h4>7.3.7. Photometer</h4> 1311 <p>Device implementations MAY include a photometer (i.e. ambient light 1312 sensor.)</p> 1313 <a name="section-7.3.8"></a><h4>7.3.8. Proximity Sensor</h4> 1314 <p>Device implementations MAY include a proximity sensor. If a device 1315 implementation does include a proximity sensor, it MUST measure the proximity 1316 of an object in the same direction as the screen. That is, the proximity 1317 sensor MUST be oriented to detect objects close to the screen, as the 1318 primary intent of this sensor type is to detect a phone in use by the 1319 user. If a device implementation includes a proximity sensor with any other 1320 orientation, it MUST NOT be accessible through this API. If a device 1321 implementation has a proximity sensor, it MUST be have 1-bit of accuracy or 1322 more.</p> 1323 1324 <a name="section-7.4"></a><h3>7.4. Data Connectivity</h3> 1325 <p>Network connectivity and access to the Internet are vital features of 1326 Android. Meanwhile, device-to-device interaction adds significant value to 1327 Android devices and applications. Device implementations MUST meet the 1328 data connectivity requirements in this section.</p> 1329 <a name="section-7.4.1"></a><h4>7.4.1. Telephony</h4> 1330 <p>"Telephony" as used by the Android 2.3 APIs and this document refers 1331 specifically to hardware related to placing voice calls and sending SMS 1332 messages via a GSM or CDMA network. While these voice calls may or may not be 1333 packet-switched, they are for the purposes of Android 2.3 considered 1334 independent of any data connectivity that may be implemented using the same 1335 network. In other words, the Android "telephony" functionality and APIs refer 1336 specifically to voice calls and SMS; for instance, device implementations that 1337 cannot place calls or send/receive SMS messages MUST NOT report the 1338 "android.hardware.telephony" feature or any sub-features, regardless of 1339 whether they use a cellular network for data connectivity.</p> 1340 <p>Android 2.3 MAY be used on devices that do not include telephony hardware. 1341 That is, Android 2.3 is compatible with devices that are not phones. 1342 However, if a device implementation does include GSM or CDMA telephony, it 1343 MUST implement full support for the API for that technology. Device 1344 implementations that do not include telephony hardware MUST implement the full 1345 APIs as no-ops.</p> 1346 <a name="section-7.4.2"></a><h4>7.4.2. IEEE 802.11 (WiFi)</h4> 1347 <p>Android 2.3 device implementations SHOULD include support for one or more 1348 forms of 802.11 (b/g/a/n, etc.) If a device implementation does include 1349 support for 802.11, it MUST implement the corresponding Android API.</p> 1350 <a name="section-7.4.3"></a><h4>7.4.3. Bluetooth</h4> 1351 <p>Device implementations SHOULD include a Bluetooth transceiver. Device 1352 implementations that do include a Bluetooth transceiver MUST enable the 1353 RFCOMM-based Bluetooth API as described in the SDK documentation [<a 1354 href="#resources32">Resources, 32</a>]. Device implementations SHOULD 1355 implement relevant Bluetooth profiles, such as A2DP, AVRCP, OBEX, etc. as 1356 appropriate for the device.</p> 1357 <p>The Compatibility Test Suite includes cases that cover basic operation of 1358 the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications 1359 protocol between devices, it cannot be fully tested by unit tests running on a 1360 single device. Consequently, device implementations MUST also pass the 1361 human-driven Bluetooth test procedure described in Appendix A.</p> 1362 <a name="section-7.4.4"></a><h4>7.4.4. Near-Field Communications</h4> 1363 <p>Device implementations SHOULD include a transceiver and related hardware 1364 for Near-Field Communications (NFC). If a device implementation does include 1365 NFC hardware, then it:</p> 1366 <ul> 1367 <li>MUST report the android.hardware.nfc feature from the 1368 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. [<a href="#resources27">Resources, 27</a>]</li> 1369 <li>MUST be capable of reading and writing NDEF messages via the following NFC 1370 standards:<ul> 1371 <li>MUST be capable of acting as an NFC Forum reader/writer 1372 (as defined by the NFC Forum technical specification 1373 NFCForum-TS-DigitalProtocol-1.0) via the following NFC standards:<ul> 1374 <li>NfcA (ISO14443-3A)</li> 1375 <li>NfcB (ISO14443-3B) </li> 1376 <li>NfcF (JIS 6319-4)</li> 1377 <li>NfcV (ISO 15693)</li> 1378 <li>IsoDep (ISO 14443-4)</li> 1379 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li> 1380 </ul></li> 1381 <li>MUST be capable of transmitting and receiving data via the following 1382 peer-to-peer standards and protocols:<ul> 1383 <li>ISO 18092</li> 1384 <li>LLCP 1.0 (defined by the NFC Forum)</li> 1385 <li>SDP 1.0 (defined by the NFC Forum)</li> 1386 <li>NDEF Push Protocol [<a href="#resources33">Resources, 33</a>]</li> 1387 </ul></li> 1388 <li>MUST scan for all supported technologies while in NFC discovery mode.</li> 1389 <li>SHOULD be in NFC discovery mode while the device is awake with the screen active.</li> 1390 </ul> 1391 <p>(Note that publicly available links are not available for the JIS, ISO, and 1392 NFC Forum specifications cited above.)</p> 1393 <p>Additionally, device implementations SHOULD support the following 1394 widely-deployed MIFARE technologies.</p> 1395 <ul> 1396 <li>MIFARE Classic (NXP MF1S503x [<a href="#resources34">Resources, 34</a>], MF1S703x [<a href="#resources35">Resources, 35</a>])</li> 1397 <li>MIFARE Ultralight (NXP MF0ICU1 [<a href="#resources36">Resources, 36</a>], MF0ICU2 [<a href="#resources37">Resources, 37</a>])</li> 1398 <li>NDEF on MIFARE Classic (NXP AN130511 [<a href="#resources38">Resources, 38</a>], AN130411 [<a href="#resources39">Resources, 39</a>])</li> 1399 </ul> 1400 <p>Note that Android 2.3.3 includes APIs for these MIFARE types. If a 1401 device implementation supports MIFARE, it:</p> 1402 <ul> 1403 <li>MUST implement the corresponding Android APIs as documented by the 1404 Android SDK</li> 1405 <li>MUST report the feature com.nxp.mifare from the 1406 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. 1407 [<a href="#resources27">Resources, 27</a>] Note that this is not a standard 1408 Android feature, and as such does not appear as a constant on the 1409 <code>PackageManager</code> class.</li> 1410 <li>MUST NOT implement the corresponding Android APIs nor report the 1411 com.nxp.mifare feature unless it also implements general NFC support as 1412 described in this section</li> 1413 </ul> 1414 <p>If a device implementation does not include NFC hardware, it MUST NOT 1415 declare the android.hardware.nfc feature from the 1416 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method [<a 1417 href="#resources27">Resources, 27</a>], and MUST implement the Android 2.3 NFC 1418 API as a no-op.</p> 1419 <p>As the classes <code>android.nfc.NdefMessage</code> and 1420 <code>android.nfc.NdefRecord</code> represent a protocol-independent data 1421 representation format, device implementations MUST implement these APIs even 1422 if they do not include support for NFC or declare the android.hardware.nfc 1423 feature.</p> 1424 <a name="section-7.4.5"></a><h4>7.4.5. Minimum Network Capability</h4> 1425 <p>Device implementations MUST include support for one or more forms of data 1426 networking. Specifically, device implementations MUST include support for at 1427 least one data standard capable of 200Kbit/sec or greater. Examples of 1428 technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 1429 Ethernet, etc.</p> 1430 <p>Device implementations where a physical networking standard (such as 1431 Ethernet) is the primary data connection SHOULD also include support for at 1432 least one common wireless data standard, such as 802.11 (WiFi).</p> 1433 <p>Devices MAY implement more than one form of data connectivity.</p> 1434 1435 1436 <a name="section-7.5"></a><h3>7.5. Cameras</h3> 1437 <p>Device implementations SHOULD include a rear-facing camera, and MAY include 1438 a front-facing camera. A rear-facing camera is a camera located on the side of 1439 the device opposite the display; that is, it images scenes on the far side of 1440 the device, like a traditional camera. A front-facing camera is a camera 1441 located on the same side of the device as the display; that is, a camera 1442 typically used to image the user, such as for video conferencing and similar 1443 applications.</p> 1444 <a name="section-7.5.1"></a><h4>7.5.1. Rear-Facing Camera</h4> 1445 <p>Device implementations SHOULD include a rear-facing camera. If a device 1446 implementation includes a rear-facing camera, it:</p> 1447 <ul> 1448 <li>MUST have a resolution of at least 2 megapixels</li> 1449 <li>SHOULD have either hardware auto-focus, or software auto-focus implemented 1450 in the camera driver (transparent to application software)</li> 1451 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware</li> 1452 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST 1453 NOT be lit while an android.hardware.Camera.PreviewCallback instance has been 1454 registered on a Camera preview surface, unless the application has explicitly 1455 enabled the flash by enabling the <code>FLASH_MODE_AUTO</code> or 1456 <code>FLASH_MODE_ON</code> attributes of a <code>Camera.Parameters</code> 1457 object. Note that this constraint does not apply to the device's built-in 1458 system camera application, but only to third-party applications using 1459 <code>Camera.PreviewCallback</code>.</li> 1460 </ul> 1461 <a name="section-7.5.2"></a><h4>7.5.2. Front-Facing Camera</h4> 1462 <p>Device implementations MAY include a front-facing camera. If a device 1463 implementation includes a front-facing camera, it:</p> 1464 <ul> 1465 <li>MUST have a resolution of at least VGA (that is, 640x480 pixels)</li> 1466 <li>MUST NOT use a front-facing camera as the default for the Camera API. 1467 That is, the camera API in Android 2.3 has specific support for front-facing 1468 cameras, and device implementations MUST NOT configure the API to to treat a 1469 front-facing camera as the default rear-facing camera, even if it is the only 1470 camera on the device.</li> 1471 <li>MAY include features (such as auto-focus, flash, etc.) 1472 available to rear-facing cameras as described in Section 7.5.1.</li> 1473 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 1474 CameraPreview, as follows:</li> 1475 <ul> 1476 <li>If the device implementation is capable of being rotated by user (such as 1477 automatically via an accelerometer or manually via user input), the camera 1478 preview MUST be mirrored horizontally relative to the device's current 1479 orientation.</li> 1480 <li>If the current application has explicitly requested that the Camera 1481 display be rotated via a call to the 1482 <code>android.hardware.Camera.setDisplayOrientation()</code> [<a 1483 href="#resources40">Resources, 40</a>] method, the camera preview MUST be 1484 mirrored horizontally relative to the orientation specified by the 1485 application.</li> 1486 <li>Otherwise, the preview MUST be mirrored along the device's default horizontal axis.</li> 1487 </ul> 1488 <li>MUST mirror the image data returned to any "postview" camera callback 1489 handlers, in the same manner as the camera preview image stream. (If the device 1490 implementation does not support postview callbacks, this requirement obviously 1491 does not apply.)</li> 1492 <li>MUST NOT mirror the final captured still image or video streams returned 1493 to application callbacks or committed to media storage</li> 1494 </ul> 1495 <a name="section-7.5.3"></a><h4>7.5.3. Camera API Behavior</h4> 1496 <p>Device implementations MUST implement the following behaviors for the 1497 camera-related APIs, for both front- and rear-facing cameras:</p> 1498 <ol> 1499 <li>If an application has never called 1500 android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST 1501 use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to 1502 application callbacks.</li> 1503 <li>If an application registers an android.hardware.Camera.PreviewCallback 1504 instance and the system calls the onPreviewFrame() method when the preview 1505 format is YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() 1506 must further be in the NV21 encoding format. That is, NV21 MUST be the default.</li> 1507 <li>Device implementations SHOULD support the YV12 format (as denoted by the 1508 <code>android.graphics.ImageFormat.YV12</code> constant) for camera previews 1509 for both front- and rear-facing cameras. Note that the Compatibility 1510 Definition for a future version is planned to change this requirement to 1511 "MUST". That is, YV12 support is optional in Android 2.3 but <b>will be 1512 required</b> by a future version. Existing and new devices that run Android 1513 2.3 are <b>very strongly encouraged to meet this requirement in Android 1514 2.3</b>, or they will not be able to attain Android compatibility when 1515 upgraded to the future version.</li> 1516 </ol> 1517 <p>Device implementations MUST implement the full Camera API included in the 1518 Android 2.3 SDK documentation [<a href="#resources41">Resources, 41</a>]), 1519 regardless of whether the device includes hardware autofocus or other 1520 capabilities. For instance, cameras that lack autofocus MUST still call any 1521 registered <code>android.hardware.Camera.AutoFocusCallback</code> instances (even though 1522 this has no relevance to a non-autofocus camera.) Note that this does apply 1523 to front-facing cameras; for instance, even though most front-facing cameras 1524 do not support autofocus, the API callbacks must still be "faked" as 1525 described.</p> 1526 <p>Device implementations MUST recognize and honor each parameter name defined 1527 as a constant on the <code>android.hardware.Camera.Parameters</code> class, if the 1528 underlying hardware supports the feature. If the device hardware does not 1529 support a feature, the API must behave as documented. Conversely, Device 1530 implementations MUST NOT honor or recognize string constants passed 1531 to the <code>android.hardware.Camera.setParameters()</code> method other than 1532 those documented as constants on the 1533 <code>android.hardware.Camera.Parameters</code>. That is, 1534 device implementations MUST support all standard Camera parameters if the 1535 hardware allows, and MUST NOT support custom Camera parameter types.</p> 1536 <a name="section-7.5.4"></a><h4>7.5.4. Camera Orientation</h4> 1537 <p>Both front- and rear-facing cameras, if present, MUST be oriented so that 1538 the long dimension of the camera aligns with the screen's long dimention. That 1539 is, when the device is held in the landscape orientation, a cameras MUST 1540 capture images in the landscape orientation. This applies regardless of the 1541 device's natural orientation; that is, it applies to landscape-primary devices 1542 as well as portrait-primary devices.</p> 1543 1544 1545 <a name="section-7.6"></a><h3>7.6. Memory and Storage</h3> 1546 <p>The fundamental function of Android 2.3 is to run applications. Device 1547 implementations MUST the requirements of this section, to ensure adequate 1548 storage and memory for applications to run properly.</p> 1549 <a name="section-7.6.1"></a><h4>7.6.1. Minimum Memory and Storage</h4> 1550 <p>Device implementations MUST have at least 128MB of memory available to the 1551 kernel and userspace. The 128MB MUST be in addition to any memory dedicated to 1552 hardware components such as radio, memory, and so on that is not under the 1553 kernel's control.</p> 1554 <p>Device implementations MUST have at least 150MB of non-volatile storage 1555 available for user data. That is, the <code>/data</code> partition MUST be at 1556 least 150MB.</p> 1557 <p>Beyond the requirements above, device implementations SHOULD have at least 1558 1GB of non-volatile storage available for user data. Note that this higher 1559 requirement is planned to become a hard minimum in a future version of 1560 Android. Device implementations are strongly encouraged to meet these 1561 requirements now, or else they may not be eligible for compatibility for a 1562 future version of Android.</p> 1563 <p>The Android APIs include a Download Manager that applications may use to 1564 download data files. The Download Manager implementation MUST be capable of 1565 downloading individual files 55MB in size, or larger. The Download Manager 1566 implementation SHOULD be capable of downloading files 100MB in size, or 1567 larger.</p> 1568 <a name="section-7.6.2"></a><h4>7.6.2. Application Shared Storage</h4> 1569 <p>Device implementations MUST offer shared storage for applications. The 1570 shared storage provided MUST be at least 1GB in size.</p> 1571 <p>Device implementations MUST be configured with shared storage mounted by 1572 default, "out of the box". If the shared storage is not mounted on the Linux 1573 path <code>/sdcard</code>, then the device MUST include a Linux symbolic link 1574 from <code>/sdcard</code> to the actual mount point.</p> 1575 <p>Device implementations MUST enforce as documented the 1576 <code>android.permission.WRITE_EXTERNAL_STORAGE</code> permission on this 1577 shared storage. Shared storage MUST otherwise be writable by any application 1578 that obtains that permission.</p> 1579 <p>Device implementations MAY have hardware for user-accessible removable 1580 storage, such as a Secure Digital card. Alternatively, device implementations 1581 MAY allocate internal (non-removable) storage as shared storage for apps.</p> 1582 <p>Regardless of the form of shared storage used, device implementations MUST 1583 provide some mechanism to access the contents of shared storage from a host 1584 computer, such as USB mass storage or Media Transfer Protocol.</p> 1585 <p>It is illustrative to consider two common examples. If a device 1586 implementation includes an SD card slot to satisfy the shared storage 1587 requirement, a FAT-formatted SD card 1GB in size or larger MUST be included 1588 with the device as sold to users, and MUST be mounted by default. 1589 Alternatively, if a device implementation uses internal fixed storage to 1590 satisfy this requirement, that storage MUST be 1GB in size or larger 1591 and mounted on <code>/sdcard</code> (or <code>/sdcard</code> 1592 MUST be a symbolic link to the physical location if it is mounted elsewhere.)</p> 1593 <p>Device implementations that include multiple shared storage paths (such as 1594 both an SD card slot and shared internal storage) SHOULD modify the core 1595 applications such as the media scanner and ContentProvider to transparently 1596 support files placed in both locations.</p> 1597 1598 <a name="section-7.7"></a><h3>7.7. USB</h3> 1599 <p>Device implementations:</p> 1600 <ul> 1601 <li>MUST implement a USB client, connectable to a USB host with a standard 1602 USB-A port</li> 1603 <li>MUST implement the Android Debug Bridge over USB (as described in Section 1604 7)</li> 1605 <li>MUST implement the USB mass storage specification, to allow a host 1606 connected to the device to access the contents of the /sdcard volume </li> 1607 <li>SHOULD use the micro USB form factor on the device side</li> 1608 <li>MAY include a non-standard port on the device side, but if so MUST ship 1609 with a cable capable of connecting the custom pinout to standard USB-A 1610 port</li> 1611 </ul> 1612 1613 1614 <a name="section-8"></a><h2>8. Performance Compatibility</h2> 1615 <p>Compatible implementations must ensure not only that applications simply 1616 run correctly on the device, but that they do so with reasonable performance 1617 and overall good user experience. Device implementations MUST meet the key 1618 performance metrics of an Android 2.3 compatible device defined in the table 1619 below:</p> 1620 <table><tbody><tr> 1621 <td><b>Metric</b></td> 1622 <td><b>Performance Threshold</b></td> 1623 <td><b>Comments</b></td> 1624 </tr> 1625 <tr> 1626 <td>Application Launch Time</td> 1627 <td>The following applications should launch within the specified time.<ul> 1628 <li>Browser: less than 1300ms</li> 1629 <li>MMS/SMS: less than 700ms</li> 1630 <li>AlarmClock: less than 650ms</li> 1631 </ul></td> 1632 <td>The launch time is measured as the total time to 1633 complete loading the default activity for the application, including the time 1634 it takes to start the Linux process, load the Android package into the Dalvik 1635 VM, and call onCreate.</td> 1636 </tr> 1637 <tr> 1638 <td>Simultaneous Applications</td> 1639 <td>When multiple applications have been launched, re-launching an 1640 already-running application after it has been launched must take less than the 1641 original launch time.</td> 1642 <td> </td> 1643 </tr> 1644 </tbody> 1645 </table> 1646 1647 <a name="section-9"></a><h2>9. Security Model Compatibility</h2> 1648 <p>Device implementations MUST implement a security model consistent with the 1649 Android platform security model as defined in Security and Permissions 1650 reference document in the APIs [<a href="#resources42">Resources, 42</a>] in the 1651 Android developer documentation. Device implementations MUST support 1652 installation of self-signed applications without requiring any additional 1653 permissions/certificates from any third parties/authorities. Specifically, 1654 compatible devices MUST support the security mechanisms described in the 1655 follow sub-sections.</p> 1656 <a name="section-9.1"></a><h3>9.1. Permissions</h3> 1657 <p>Device implementations MUST support the Android permissions model as 1658 defined in the Android developer documentation [<a 1659 href="#resources42">Resources, 42</a>]. Specifically, 1660 implementations MUST enforce each permission defined as described in the SDK 1661 documentation; no permissions may be omitted, altered, or ignored. 1662 Implementations MAY add additional permissions, provided the new permission ID 1663 strings are not in the android.* namespace.</p> 1664 <a name="section-9.2"></a><h3>9.2. UID and Process Isolation</h3> 1665 <p>Device implementations MUST support the Android application sandbox model, 1666 in which each application runs as a unique Unix-style UID and in a separate 1667 process. Device implementations MUST support running multiple applications as 1668 the same Linux user ID, provided that the applications are properly signed and 1669 constructed, as defined in the Security and Permissions reference [<a 1670 href="#resources42">Resources, 42</a>].</p> 1671 <a name="section-9.3"></a><h3>9.3. Filesystem Permissions</h3> 1672 <p>Device implementations MUST support the Android file access permissions 1673 model as defined in as defined in the Security and Permissions reference [<a 1674 href="#resources42">Resources, 42</a>].</p> 1675 <a name="section-9.4"></a><h3>9.4. Alternate Execution Environments</h3> 1676 <p>Device implementations MAY include runtime environments that execute 1677 applications using some other software or technology than the Dalvik virtual 1678 machine or native code. However, such alternate execution environments MUST 1679 NOT compromise the Android security model or the security of installed Android 1680 applications, as described in this section.</p> 1681 <p>Alternate runtimes MUST themselves be Android applications, and abide by 1682 the standard Android security model, as described elsewhere in Section 9.</p> 1683 <p>Alternate runtimes MUST NOT be granted access to resources protected by 1684 permissions not requested in the runtime's AndroidManifest.xml file via the 1685 <code><uses-permission></code> mechanism.</p> 1686 <p>Alternate runtimes MUST NOT permit applications to make use of features 1687 protected by Android permissions restricted to system applications.</p> 1688 <p>Alternate runtimes MUST abide by the Android sandbox model. Specifically:</p> 1689 <ul> 1690 <li>Alternate runtimes SHOULD install apps via the PackageManager into 1691 separate Android sandboxes (that is, Linux user IDs, etc.)</li> 1692 <li>Alternate runtimes MAY provide a single Android sandbox shared by all 1693 applications using the alternate runtime.</li> 1694 <li>Alternate runtimes and installed applications using an alternate runtime 1695 MUST NOT reuse the sandbox of any other app installed on the device, except 1696 through the standard Android mechanisms of shared user ID and signing 1697 certificate</li> 1698 <li>Alternate runtimes MUST NOT launch with, grant, or be granted access to 1699 the sandboxes corresponding to other Android applications.</li> 1700 </ul> 1701 <p>Alternate runtimes MUST NOT be launched with, be granted, or grant to other 1702 applications any privileges of the superuser (root), or of any other user ID.</p> 1703 <p>The .apk files of alternate runtimes MAY be included in the system image of 1704 a device implementation, but MUST be signed with a key distinct 1705 from the key used to sign other applications included with the device 1706 implementation.</p> 1707 <p>When installing applications, alternate runtimes MUST obtain user consent 1708 for the Android permissions used by the application. That is, if an 1709 application needs to make use of a device resource for which there is a 1710 corresponding Android permission (such as Camera, GPS, etc.), the alternate 1711 runtime MUST inform the user that the application will be able to access 1712 that resource. If the runtime environment does not record application 1713 capabilities in this manner, the runtime environment MUST list all 1714 permissions held by the runtime itself when installing any application 1715 using that runtime.</p> 1716 1717 <a name="section-10"></a><h2>10. Software Compatibility Testing</h2> 1718 <p>The Android Open-Source Project includes various testing tools to verify 1719 that device implementations are compatible. Device implementations MUST pass 1720 all tests described in this section.</p> 1721 <p>However, note that no software test package is fully comprehensive. For 1722 this reason, device implementers are very strongly encouraged to make the 1723 minimum number of changes as possible to the reference and preferred 1724 implementation of Android 2.3 available from the Android Open-Source Project. 1725 This will minimize the risk of introducing bugs that create incompatibilities 1726 requiring rework and potential device updates.</p> 1727 <a name="section-10.1"></a><h3>10.1. Compatibility Test Suite</h3> 1728 <p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) 1729 [<a href="#resources02">Resources, 2</a>] available from the Android Open Source 1730 Project, using the final shipping software on the device. Additionally, device 1731 implementers SHOULD use the reference implementation in the Android Open 1732 Source tree as much as possible, and MUST ensure compatibility in cases of 1733 ambiguity in CTS and for any reimplementations of parts of the reference 1734 source code.</p> 1735 <p>The CTS is designed to be run on an actual device. Like any software, the 1736 CTS may itself contain bugs. The CTS will be versioned independently of this 1737 Compatibility Definition, and multiple revisions of the CTS may be released 1738 for Android 2.3. Device implementations MUST pass the latest CTS version 1739 available at the time the device software is completed.</p> 1740 <p>MUST pass the most recent version of the Android Compatibility Test Suite 1741 (CTS) available at the time of the device implementation's software is 1742 completed. (The CTS is available as part of the Android Open Source Project [<a 1743 href="#resources02">Resources, 2</a>].) The CTS tests many, but not all, of the 1744 components outlined in this document.</p> 1745 <a name="section-10.2"></a><h3>10.2. CTS Verifier</h3> 1746 <p>Device implementations MUST correctly execute all applicable cases in the 1747 CTS Verifier. The CTS Verifier is included with the Compatibility Test Suite, 1748 and is intended to be run by a human operator to test functionality that 1749 cannot be tested by an automated system, such as correct functioning of a 1750 camera and sensors.</p> 1751 <p>The CTS Verifier has tests for many kinds of hardware, including some 1752 hardware that is optional. Device implementations MUST pass all tests for 1753 hardware which they possess; for instance, if a device possesses an 1754 accelerometer, it MUST correctly execute the Accelerometer test case in the 1755 CTS Verifier. Test cases for features noted as optional by this Compatibility 1756 Definition Document MAY be skipped or omitted.</p> 1757 <p>Every device and every build MUST correctly run the CTS Verifier, as noted 1758 above. However, since many builds are very similar, device implementers are 1759 not expected to explicitly run the CTS Verifier on builds that differ only in 1760 trivial ways. Specifically, device implementations that differ from an 1761 implementation that has passed the CTS Verfier only by the set of included 1762 locales, branding, etc. MAY omit the CTS Verifier test.</p> 1763 <a name="section-10.3"></a><h3>10.3. Reference Applications</h3> 1764 <p>Device implementers MUST test implementation compatibility using the 1765 following open-source applications:</p> 1766 <ul> 1767 <li>The "Apps for Android" applications [<a href="#resources43">Resources, 43</a>].</li> 1768 <li>Replica Island (available in Android Market; only required for device 1769 implementations that support with OpenGL ES 2.0)</li> 1770 </ul> 1771 <p>Each app above MUST launch and behave correctly on the implementation, for 1772 the implementation to be considered compatible.</p> 1773 1774 1775 <a name="section-11"></a><h2>11. Updatable Software</h2> 1776 <p>Device implementations MUST include a mechanism to replace the entirety of 1777 the system software. The mechanism need not perform "live" upgrades -- that 1778 is, a device restart MAY be required.</p> 1779 <p>Any method can be used, provided that it can replace the entirety of the 1780 software preinstalled on the device. For instance, any of the following 1781 approaches will satisfy this requirement:</p> 1782 <ul> 1783 <li>Over-the-air (OTA) downloads with offline update via reboot</li> 1784 <li>"Tethered" updates over USB from a host PC</li> 1785 <li>"Offline" updates via a reboot and update from a file on removable 1786 storage</li> 1787 </ul> 1788 <p>The update mechanism used MUST support updates without wiping user data. 1789 Note that the upstream Android software includes an update mechanism that 1790 satisfies this requirement.</p> 1791 <p>If an error is found in a device implementation after it has been released 1792 but within its reasonable product lifetime that is determined in consultation 1793 with the Android Compatibility Team to affect the compatibility of third-party 1794 applications, the device implementer MUST correct the error via a software 1795 update available that can be applied per the mechanism just described.</p> 1796 1797 <a name="section-12"></a><h2>12. Contact Us</h2> 1798 <p>You can contact the document authors at <a 1799 href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> for 1800 clarifications and to bring up any issues that you think the document does not 1801 cover.</p> 1802 1803 <div style="page-break-before: always;"></div> 1804 1805 <a name="appendix-A"></a><h2>Appendix A - Bluetooth Test Procedure</h2> 1806 <p>The Compatibility Test Suite includes cases that cover basic operation of 1807 the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications 1808 protocol between devices, it cannot be fully tested by unit tests running on a 1809 single device. Consequently, device implementations MUST also pass the 1810 human-operated Bluetooth test procedure described below.</p> 1811 <p>The test procedure is based on the BluetoothChat sample app included in the 1812 Android open-source project tree. The procedure requires two devices:</p> 1813 <ul> 1814 <li>a candidate device implementation running the software build to be tested</li> 1815 <li>a separate device implementation already known to be compatible, and of a 1816 model from the device implementation being tested -- that is, a "known 1817 good" device implementation</li> 1818 </ul> 1819 <p>The test procedure below refers to these devices as the "candidate" and "known 1820 good" devices, respectively.</p> 1821 <h3>Setup and Installation</h3> 1822 <ol> 1823 <li>Build BluetoothChat.apk via 'make samples' from an Android source code tree.</li> 1824 <li>Install BluetoothChat.apk on the known-good device.</li> 1825 <li>Install BluetoothChat.apk on the candidate device.</li> 1826 </ol> 1827 <h3>Test Bluetooth Control by Apps</h3> 1828 <ol> 1829 <li>Launch BluetoothChat on the candidate device, while Bluetooth is disabled.</li> 1830 <li>Verify that the candidate device either turns on Bluetooth, or prompts the user with a dialog to turn on Bluetooth.</li> 1831 </ol> 1832 <h3>Test Pairing and Communication</h3> 1833 <ol> 1834 <li>Launch the Bluetooth Chat app on both devices.</li> 1835 <li>Make the known-good device discoverable from within BluetoothChat (using the Menu).</li> 1836 <li>On the candidate device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the known-good device.</li> 1837 <li>Send 10 or more messages from each device, and verify that the other device receives them correctly.</li> 1838 <li>Close the BluetoothChat app on both devices by pressing <b>Home</b>.</li> 1839 <li>Unpair each device from the other, using the device Settings app.</li> 1840 </ol> 1841 <h3>Test Pairing and Communication in the Reverse Direction</h3> 1842 <ol> 1843 <li>Launch the Bluetooth Chat app on both devices.</li> 1844 <li>Make the candidate device discoverable from within BluetoothChat (using the Menu).</li> 1845 <li>On the known-good device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the candidate device.</li> 1846 <li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li> 1847 <li>Close the Bluetooth Chat app on both devices by pressing Back repeatedly to get to the Launcher.</li> 1848 </ol> 1849 <h3>Test Re-Launches</h3> 1850 <ol> 1851 <li>Re-launch the Bluetooth Chat app on both devices.</li> 1852 <li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li> 1853 </ol> 1854 <p>Note: the above tests have some cases which end a test section by using 1855 Home, and some using Back. These tests are not redundant and are not optional: 1856 the objective is to verify that the Bluetooth API and stack works correctly 1857 both when Activities are explicitly terminated (via the user pressing Back, 1858 which calls finish()), and implicitly sent to background (via the user 1859 pressing Home.) Each test sequence MUST be performed as described.</p> 1860 <div id="footerContent"> 1861 </div> 1862 </body> 1863 </html> 1864
