1<?xml version="1.0" encoding="UTF-8"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> 4<head> 5<title>Android 4.3Compatibility Definition</title> 6<link rel="stylesheet" type="text/css" href="cdd.css"/> 7</head> 8<body> 9<div><img src="header.jpg" alt="Android logo"/></div> 10<h1>Android 4.3 Compatibility Definition</h1> 11<!-- 12<span style="color: red; font-weight: bold;"><h2>Revision 1</h2></span><br/> 13<span style="color: red;">Last updated: July 23, 2013</span> 14--> 15<p><b><font color="red">Revision 1</font></b><br/> 16Last updated: July 23, 2013 17</p> 18<p>Copyright © 2013, Google Inc. All rights reserved.<br/> 19<a href="mailto:compatibility@android.com">compatibility@android.com</a> 20</p> 21 22<h2> Table of Contents</h2> 23<div style="margin-left: 2em;"> 24 <a href="#section-1">1. Introduction</a><br/> 25 <a href="#section-2">2. Resources</a><br/> 26 <a href="#section-3">3. Software</a><br/> 27 <div style="margin-left: 2em;"> 28 <a href="#section-3.1">3.1. Managed API Compatibility</a><br/> 29 <a href="#section-3.2">3.2. Soft API Compatibility</a><br/> 30 <div style="margin-left: 2em;"> 31 <a href="#section-3.2.1">3.2.1. Permissions</a><br/> 32 <a href="#section-3.2.2">3.2.2. Build Parameters</a><br/> 33 <a href="#section-3.2.3">3.2.3. Intent Compatibility</a><br/> 34 <div style="margin-left: 2em;"> 35 <a href="#section-3.2.3.1">3.2.3.1. Core Application Intents</a><br/> 36 <a href="#section-3.2.3.2">3.2.3.2. Intent Overrides</a><br/> 37 <a href="#section-3.2.3.3">3.2.3.3. Intent Namespaces</a><br/> 38 <a href="#section-3.2.3.4">3.2.3.4. Broadcast Intents</a><br/> 39 </div> 40 </div> 41 <a href="#section-3.3">3.3. Native API Compatibility</a><br/> 42 <div style="margin-left: 2em;"> 43 <a href="#section-3.3.1">3.3.1 Application Binary Interfaces</a><br/> 44 </div> 45 <a href="#section-3.4">3.4. Web Compatibility</a><br/> 46 <div style="margin-left: 2em;"> 47 <a href="#section-3.4.1">3.4.1. WebView Compatibility</a><br/> 48 <a href="#section-3.4.2">3.4.2. Browser Compatibility</a><br/> 49 </div> 50 <a href="#section-3.5">3.5. API Behavioral Compatibility</a><br/> 51 <a href="#section-3.6">3.6. API Namespaces</a><br/> 52 <a href="#section-3.7">3.7. Virtual Machine Compatibility</a><br/> 53 <a href="#section-3.8">3.8. User Interface Compatibility</a><br/> 54 <div style="margin-left: 2em;"> 55 <a href="#section-3.8.1">3.8.1. Launcher (Home Screen)</a><br/> 56 <a href="#section-3.8.2">3.8.2. Widgets</a><br/> 57 <a href="#section-3.8.3">3.8.3. Notifications</a><br/> 58 <a href="#section-3.8.4">3.8.4. Search</a><br/> 59 <a href="#section-3.8.5">3.8.5. Toasts</a><br/> 60 <a href="#section-3.8.6">3.8.6. Themes</a><br/> 61 <a href="#section-3.8.7">3.8.7. Live Wallpapers</a><br/> 62 <a href="#section-3.8.8">3.8.8. Recent Application Display</a><br/> 63 <a href="#section-3.8.9">3.8.9. Input Management</a><br/> 64 <a href="#section-3.8.10">3.8.10. Lock Screen Media Remote Control</a><br/> 65 <a href="#section-3.8.11">3.8.11. Dreams</a><br/> 66 </div> 67 <a href="#section-3.9">3.9 Device Administration</a><br/> 68 <a href="#section-3.10">3.10 Accessibility</a><br/> 69 <a href="#section-3.11">3.11 Text-to-Speech</a><br/> 70 </div> 71 <a href="#section-4">4. Application Packaging Compatibility</a><br/> 72 <a href="#section-5">5. Multimedia Compatibility</a><br/> 73 <div style="margin-left: 2em;"> 74 <a href="#section-5.1">5.1. Media Codecs</a><br/> 75 <a href="#section-5.2">5.2. Video Encoding</a><br/> 76 <a href="#section-5.3">5.3. Video Decoding</a><br/> 77 <a href="#section-5.4">5.4. Audio Recording</a><br/> 78 <a href="#section-5.5">5.5. Audio Latency</a><br/> 79 <a href="#section-5.6">5.6. Network Protocols</a><br/> 80 </div> 81 <a href="#section-6">6. Developer Tools and Options Compatibility</a><br/> 82 <div style="margin-left: 2em;"> 83 <a href="#section-6.1">6.1. Developer Tools</a><br/> 84 <a href="#section-6.2">6.2. Developer Options</a><br/> 85 </div> 86 <a href="#section-7">7. Hardware Compatibility</a><br/> 87 <div style="margin-left: 2em;"> 88 <a href="#section-7.1">7.1. Display and Graphics</a><br/> 89 <div style="margin-left: 2em;"> 90 <a href="#section-7.1.1">7.1.1. Screen Configuration</a><br/> 91 <a href="#section-7.1.2">7.1.2. Display Metrics</a><br/> 92 <a href="#section-7.1.3">7.1.3. Screen Orientation</a><br/> 93 <a href="#section-7.1.4">7.1.4. 2D and 3D Graphics Acceleration</a><br/> 94 <a href="#section-7.1.5">7.1.5. Legacy Application Compatibility Mode</a><br/> 95 <a href="#section-7.1.6">7.1.6. Screen Types</a><br/> 96 <a href="#section-7.1.7">7.1.7. Screen Technology</a><br/> 97 <a href="#section-7.1.8">7.1.8. External Displays</a><br/> 98 </div> 99 <a href="#section-7.2">7.2. Input Devices</a><br/> 100 <div style="margin-left: 2em;"> 101 <a href="#section-7.2.1">7.2.1. Keyboard</a><br/> 102 <a href="#section-7.2.2">7.2.2. Non-touch Navigation</a><br/> 103 <a href="#section-7.2.3">7.2.3. Navigation keys</a><br/> 104 <a href="#section-7.2.4">7.2.4. Touchscreen input</a><br/> 105 <a href="#section-7.2.5">7.2.5. Fake touch input</a><br/> 106 <a href="#section-7.2.6">7.2.6. Microphone</a><br/> 107 </div> 108 <a href="#section-7.3">7.3. Sensors</a><br/> 109 <div style="margin-left: 2em;"> 110 <a href="#section-7.3.1">7.3.1. Accelerometer</a><br/> 111 <a href="#section-7.3.2">7.3.2. Magnetometer</a><br/> 112 <a href="#section-7.3.3">7.3.3. GPS</a><br/> 113 <a href="#section-7.3.4">7.3.4. Gyroscope</a><br/> 114 <a href="#section-7.3.5">7.3.5. Barometer</a><br/> 115 <a href="#section-7.3.6">7.3.6. Thermometer</a><br/> 116 <a href="#section-7.3.7">7.3.7. Photometer</a><br/> 117 <a href="#section-7.3.8">7.3.8. Proximity Sensor</a><br/> 118 </div> 119 <a href="#section-7.4">7.4. Data Connectivity</a><br/> 120 <div style="margin-left: 2em;"> 121 <a href="#section-7.4.1">7.4.1. Telephony</a><br/> 122 <a href="#section-7.4.2">7.4.2. IEEE 802.11 (WiFi)</a><br/> 123 <div style="margin-left: 2em;"> 124 <a href="#section-7.4.2.1">7.4.2.1. WiFi Direct</a><br/> 125 </div> 126 <a href="#section-7.4.3">7.4.3. Bluetooth</a><br/> 127 <a href="#section-7.4.4">7.4.4. Near-Field Communications</a><br/> 128 <a href="#section-7.4.5">7.4.5. Minimum Network Capability</a><br/> 129 </div> 130 <a href="#section-7.5">7.5. Cameras</a><br/> 131 <div style="margin-left: 2em;"> 132 <a href="#section-7.5.1">7.5.1. Rear-Facing Camera</a><br/> 133 <a href="#section-7.5.2">7.5.2. Front-Facing Camera</a><br/> 134 <a href="#section-7.5.3">7.5.3. Camera API Behavior</a><br/> 135 <a href="#section-7.5.4">7.5.4. Camera Orientation</a><br/> 136 </div> 137 <a href="#section-7.6">7.6. Memory and Storage</a><br/> 138 <div style="margin-left: 2em;"> 139 <a href="#section-7.6.1">7.6.1. Minimum Memory and Storage</a><br/> 140 <a href="#section-7.6.2">7.6.2. Application Shared Storage</a><br/> 141 </div> 142 <a href="#section-7.7">7.7. USB</a><br/> 143 </div> 144 <a href="#section-8">8. Performance Compatibility</a><br/> 145 <a href="#section-9">9. Security Model Compatibility</a><br/> 146 <div style="margin-left: 2em;"> 147 <a href="#section-9.1">9.1. Permissions</a><br/> 148 <a href="#section-9.2">9.2. UID and Process Isolation</a><br/> 149 <a href="#section-9.3">9.3. Filesystem Permissions</a><br/> 150 <a href="#section-9.4">9.4. Alternate Execution Environments</a><br/> 151 <a href="#section-9.5">9.5. Multi-User Support</a><br/> 152 <a href="#section-9.6">9.6. Premium SMS Warning</a><br/> 153 <a href="section-9.7">9.7. Kernel Security Features</a><br/> 154 </div> 155 <a href="#section-10">10. Software Compatibility Testing</a><br/> 156 <div style="margin-left: 2em;"> 157 <a href="#section-10.1">10.1. Compatibility Test Suite</a><br/> 158 <a href="#section-10.2">10.2. CTS Verifier</a><br/> 159 <a href="#section-10.3">10.3. Reference Applications</a><br/> 160 </div> 161 <a href="#section-11">11. Updatable Software</a><br/> 162 <a href="#section-12">12. Contact Us</a><br/> 163</div> 164 165<div style="page-break-before: always;"></div> 166 167<a name="section-1"></a><h2>1. Introduction</h2> 168<p>This document enumerates the requirements that must be met in order for 169devices to be compatible with Android 4.3.</p> 170<p>The use of "must", "must not", "required", "shall", "shall not", "should", 171"should not", "recommended", "may" and "optional" is per the IETF standard 172defined in RFC2119 [<a href="#resources01">Resources, 1</a>].</p> 173<p>As used in this document, a "device implementer" or "implementer" is a 174person or organization developing a hardware/software solution running Android 1754.3. A "device implementation" or "implementation" is the hardware/software 176solution so developed.</p> 177<p>To be considered compatible with Android 4.3, device implementations 178MUST meet the requirements presented in this Compatibility Definition, 179including any documents incorporated via reference.</p> 180<p>Where this definition or the software tests described in <a 181href="#section-10">Section 10</a> is silent, ambiguous, or incomplete, it is 182the responsibility of the device implementer to ensure compatibility with 183existing implementations.</p> 184<p>For this reason, the Android Open Source Project [<a 185href="#resources03">Resources, 3</a>] is both the reference and preferred 186implementation of Android. Device implementers are strongly encouraged to base 187their implementations to the greatest extent possible on the "upstream" source 188code available from the Android Open Source Project. While some components can 189hypothetically be replaced with alternate implementations this practice is 190strongly discouraged, as passing the software tests will become substantially 191more difficult. It is the implementer's responsibility to ensure full 192behavioral compatibility with the standard Android implementation, including 193and beyond the Compatibility Test Suite. Finally, note that certain component 194substitutions and modifications are explicitly forbidden by this document.</p> 195<a name="section-2"></a><h2>2. Resources</h2> 196<ol> 197<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> 198<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> 199<a name="resources03"></a><li>Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></li> 200<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> 201<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> 202<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> 203<a name="resources07"></a><li>Android 4.3 allowed version strings: <a href="http://source.android.com/compatibility/4.3/versions.html">http://source.android.com/compatibility/4.3/versions.html</a></li> 204<a name="resources08"></a><li>Renderscript: <a href="http://developer.android.com/guide/topics/graphics/renderscript.html">http://developer.android.com/guide/topics/graphics/renderscript.html</a></li> 205<a name="resources09"></a><li>Hardware Acceleration: <a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">http://developer.android.com/guide/topics/graphics/hardware-accel.html</a></li> 206<a name="resources10"></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> 207<a name="resources11"></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> 208<a name="resources12"></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> 209<a name="resources13"></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> 210<a name="resources14"></a><li>HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></li> 211<a name="resources15"></a><li>HTML5/W3C webdatabase API: <a href="http://www.w3.org/TR/webdatabase/">http://www.w3.org/TR/webdatabase/</a></li> 212<a name="resources16"></a><li>HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></li> 213<a name="resources17"></a><li>Dalvik Virtual Machine specification: available in the Android source code, at dalvik/docs</li> 214<a name="resources18"></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> 215<a name="resources19"></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> 216<a name="resources20"></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> 217<a name="resources21"></a><li>Status Bar icon style guide: <a href="http://developer.android.com/guide/practices/ui_guidelines/icon_design_status_bar.html">http://developer.android.com/guide/practices/ui_guidelines/icon_design_status_bar.html</a></li> 218<a name="resources22"></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> 219<a name="resources23"></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> 220<a name="resources24"></a><li>Themes: <a href="http://developer.android.com/guide/topics/ui/themes.html">http://developer.android.com/guide/topics/ui/themes.html</a></li> 221<a name="resources25"></a><li>R.style class: <a href="http://developer.android.com/reference/android/R.style.html">http://developer.android.com/reference/android/R.style.html</a></li> 222<a name="resources26"></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> 223<a name="resources27"></a><li>Android Device Administration: <a href="http://developer.android.com/guide/topics/admin/device-admin.html">http://developer.android.com/guide/topics/admin/device-admin.html</a></li> 224<a name="resources28"></a><li>DevicePolicyManager reference: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html</a></li> 225<a name="resources29"></a><li>Android Accessibility Service APIs: <a href="http://developer.android.com/reference/android/accessibilityservice/package-summary.html">http://developer.android.com/reference/android/accessibilityservice/package-summary.html</a></li> 226<a name="resources30"></a><li>Android Accessibility APIs: <a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">http://developer.android.com/reference/android/view/accessibility/package-summary.html</a></li> 227<a name="resources31"></a><li>Eyes Free project: <a href="http://http://code.google.com/p/eyes-free">http://code.google.com/p/eyes-free</a></li> 228<a name="resources32"></a><li>Text-To-Speech APIs: <a href="http://developer.android.com/reference/android/speech/tts/package-summary.html">http://developer.android.com/reference/android/speech/tts/package-summary.html</a></li> 229<a name="resources33"></a><li>Reference tool documentation (for adb, aapt, ddms, systrace): <a href="http://developer.android.com/guide/developing/tools/index.html">http://developer.android.com/guide/developing/tools/index.html</a></li> 230<a name="resources34"></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> 231<a name="resources35"></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> 232<a name="resources36"></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> 233<a name="resources37"></a><li>Android android.content.pm.PackageManager class and 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> 234<a name="resources38"></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> 235<a name="resources39"></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> 236<a name="resources40"></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> 237<a name="resources41"></a><li>android.hardware.SensorEvent: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">http://developer.android.com/reference/android/hardware/SensorEvent.html</a></li> 238<a name="resources42"></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> 239<a name="resources43"></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> 240<a name="resources44"></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> 241<a name="resources45"></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> 242<a name="resources46"></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> 243<a name="resources47"></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> 244<a name="resources48"></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> 245<a name="resources49"></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> 246<a name="resources50"></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> 247<a name="resources51"></a><li>Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.html">http://developer.android.com/reference/android/hardware/Camera.html</a></li> 248<a name="resources52"></a><li>Android Open Accessories: <a href="http://developer.android.com/guide/topics/usb/accessory.html">http://developer.android.com/guide/topics/usb/accessory.html</a></li> 249<a name="resources53"></a><li>USB Host API: <a href="http://developer.android.com/guide/topics/usb/host.html">http://developer.android.com/guide/topics/usb/host.html</a></li> 250<a name="resources54"></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> 251<a name="resources55"></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> 252<a name="resources56"></a><li>Android DownloadManager: <a href="http://developer.android.com/reference/android/app/DownloadManager.html">http://developer.android.com/reference/android/app/DownloadManager.html</a></li> 253<a name="resources57"></a><li>Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></li> 254<a name="resources58"></a><li>Android Media Formats: <a href="http://developer.android.com/guide/appendix/media-formats.html">http://developer.android.com/guide/appendix/media-formats.html</a></li> 255<a name="resources59"></a><li>HTTP Live Streaming Draft Protocol: <a href="http://tools.ietf.org/html/draft-pantos-http-live-streaming-03">http://tools.ietf.org/html/draft-pantos-http-live-streaming-03</a></li> 256<a name="resources60"></a><li>NFC Connection Handover: <a href="http://www.nfc-forum.org/specs/spec_list/#conn_handover/">http://www.nfc-forum.org/specs/spec_list/#conn_handover</a></li> 257<a name="resources61"></a><li>Bluetooth Secure Simple Pairing Using NFC: <a href="http://www.nfc-forum.org/resources/AppDocs/NFCForum_AD_BTSSP_1_0.pdf">http://www.nfc-forum.org/resources/AppDocs/NFCForum_AD_BTSSP_1_0.pdf</a></li> 258<a name="resources62"></a><li>Wifi Multicast API: <a href="http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html">http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html</a></li> 259<a name="resources63"></a><li>Action Assist: <a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST</a></li> 260<a name="resources64"></a><li>USB Charging Specification: <a href="http://www.usb.org/developers/devclass_docs/USB_Battery_Charging_1.2.pdf">http://www.usb.org/developers/devclass_docs/USB_Battery_Charging_1.2.pdf</a></li> 261<a name="resources65"></a><li>Android Beam: <a href="http://developer.android.com/guide/topics/nfc/nfc.html">http://developer.android.com/guide/topics/nfc/nfc.html</a></li> 262<a name="resources66"></a><li>Android USB Audio: <a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO</a></li> 263<a name="resources67"></a><li>Android NFC Sharing Settings: <a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS</a></li> 264<a name="resources68"></a><li>Wifi Direct (Wifi P2P): <a href="http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html">http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html</a></li> 265<a name="resources69"></a><li>Lock and Home Screen Widget: <a href="http://developer.android.com/reference/android/appwidget/AppWidgetProviderInfo.html">http://developer.android.com/reference/android/appwidget/AppWidgetProviderInfo.html</a></li> 266<a name="resources70"></a><li>UserManager reference: <a href="http://developer.android.com/reference/android/os/UserManager.html">http://developer.android.com/reference/android/os/UserManager.html</a></li> 267<a name="resources71"></a><li>External Storage reference: <a href="http://source.android.com/tech/storage">http://source.android.com/tech/storage</a></li> 268<a name="resources72"></a><li>External Storage APIs: <a href="http://developer.android.com/reference/android/os/Environment.html">http://developer.android.com/reference/android/os/Environment.html</a></li> 269<a name="resources73"></a><li>SMS Short Code: <a href="http://en.wikipedia.org/wiki/Short_code">http://en.wikipedia.org/wiki/Short_code</a></li> 270<a name="resources74"></a><li>Media Remote Control Client: <a href="http://developer.android.com/reference/android/media/RemoteControlClient.html">http://developer.android.com/reference/android/media/RemoteControlClient.html</a></li> 271<a name="resources75"></a><li>Display Manager: <a href="http://developer.android.com/reference/android/hardware/display/DisplayManager.html">http://developer.android.com/reference/android/hardware/display/DisplayManager.html</a></li> 272<a name="resources76"></a><li>Dreams: <a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">http://developer.android.com/reference/android/service/dreams/DreamService.html</a></li> 273<a name="resources77"></a><li>Android Application Development-Related Settings: <a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS">http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS</a></li> 274<a name="resources78"></a><li>Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">http://developer.android.com/reference/android/hardware/Camera.Parameters.html</a></li> 275<a name="resources79"></a><li>EGL Extension-EGL_ANDROID_RECORDABLE: <a href="http://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">http://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt</a></li> 276<a name="resources80"></a><li>Motion Event API: <a href="http://developer.android.com/reference/android/view/MotionEvent.html">http://developer.android.com/reference/android/view/MotionEvent.html</a></li> 277<a name="resources81"></a><li>Touch Input Configuration: <a href="http://source.android.com/devices/tech/input/touch-devices.html">http://source.android.com/devices/tech/input/touch-devices.html</a></li> 278</ol> 279<p>Many of these resources are derived directly or indirectly from the Android 2804.3 SDK, and will be functionally identical to the information in that SDK's 281documentation. In any cases where this Compatibility Definition or the 282Compatibility Test Suite disagrees with the SDK documentation, the SDK 283documentation is considered authoritative. Any technical details provided in 284the references included above are considered by inclusion to be part of this 285Compatibility Definition.</p> 286 287<a name="section-3"></a><h2>3. Software</h2> 288<a name="section-3.1"></a><h3>3.1. Managed API Compatibility</h3> 289<p>The managed (Dalvik-based) execution environment is the primary vehicle for 290Android applications. The Android application programming interface (API) is 291the set of Android platform interfaces exposed to applications running in the 292managed VM environment. Device implementations MUST provide complete 293implementations, including all documented behaviors, of any documented API 294exposed by the Android 4.3 SDK [<a href="#resources04">Resources, 4</a>].</p> 295<p>Device implementations MUST NOT omit any managed APIs, alter API interfaces 296or signatures, deviate from the documented behavior, or include no-ops, except 297where specifically allowed by this Compatibility Definition.</p> 298<p>This Compatibility Definition permits some types of hardware for which 299Android includes APIs to be omitted by device implementations. In such cases, 300the APIs MUST still be present and behave in a reasonable way. See 301<a href="#section-7">Section 7</a> for specific requirements for this scenario. 302</p> 303 304<a name="section-3.2"></a><h3>3.2. Soft API Compatibility</h3> 305<p>In addition to the managed APIs from Section 3.1, Android also includes a 306significant runtime-only "soft" API, in the form of such things such as 307Intents, permissions, and similar aspects of Android applications that cannot 308be enforced at application compile time.</p> 309<a name="section-3.2.1"></a><h4>3.2.1. Permissions</h4> 310<p>Device implementers MUST support and enforce all permission constants as 311documented by the Permission reference page [<a 312href="#resources05">Resources, 5</a>]. Note that Section 9 lists additional 313requirements related to the Android security model.</p> 314<a name="section-3.2.2"></a><h4>3.2.2. Build Parameters</h4> 315<p>The Android APIs include a number of constants on the <code>android.os.Build</code> 316class [<a href="#resources06">Resources, 6</a>] that are intended to describe 317the current device. To provide consistent, meaningful values across device 318implementations, the table below includes additional restrictions on the 319formats of these values to which device implementations MUST conform.</p> 320<table> 321<tbody> 322<tr> 323<td><b>Parameter</b></td> 324<td><b>Comments</b></td> 325</tr> 326<tr> 327<td>android.os.Build.VERSION.RELEASE</td> 328<td>The version of the currently-executing Android system, in human-readable 329format. This field MUST have one of the string values defined in [<a 330href="#resources07">Resources, 7</a>].</td> 331</tr> 332<tr> 333<td>android.os.Build.VERSION.SDK</td> 334<td>The version of the currently-executing Android system, in a format 335accessible to third-party application code. For Android 4.3, this 336field MUST have the integer value 18.</td> 337</tr> 338<tr> 339<td>android.os.Build.VERSION.SDK_INT</td> 340<td>The version of the currently-executing Android system, in a format 341accessible to third-party application code. For Android 4.3, this 342field MUST have the integer value 18.</td> 343</tr> 344<tr> 345<td>android.os.Build.VERSION.INCREMENTAL</td> 346<td>A value chosen by the device implementer designating the specific build of 347the currently-executing Android system, in human-readable format. This value 348MUST NOT be re-used for different builds made available to end users. A typical use 349of this field is to indicate which build number or source-control change 350identifier was used to generate the build. There are no requirements on the 351specific format of this field, except that it MUST NOT be null or the empty 352string ("").</td> 353</tr> 354<tr> 355<td>android.os.Build.BOARD</td> 356<td>A value chosen by the device implementer identifying the specific internal 357hardware used by the device, in human-readable format. A possible use of this 358field is to indicate the specific revision of the board powering the device. 359The value of this field MUST be encodable as 7-bit ASCII and match the regular expression 360<code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 361</tr> 362<tr> 363<td>android.os.Build.BRAND</td> 364<td>A value chosen by the device implementer identifying the name of the 365company, organization, individual, etc. who produced the device, in 366human-readable format. A possible use of this field is to indicate the OEM 367and/or carrier who sold the device. The value of this field MUST be 368encodable as 7-bit ASCII and match the regular expression 369<code>"^[a-zA-Z0-9.,_-]+$"</code>. 370</td> 371</tr> 372<tr> 373<td>android.os.Build.CPU_ABI</td> 374<td>The name of the instruction set (CPU type + ABI convention) of native code. 375See <a href="#section-3.3">Section 3.3: Native API Compatibility</a>. 376</td> 377</tr> 378<tr> 379<td>android.os.Build.CPU_ABI2</td> 380<td>The name of the second instruction set (CPU type + ABI convention) of native code. 381See <a href="#section-3.3">Section 3.3: Native API Compatibility</a>. 382</td> 383</tr> 384<tr> 385<td>android.os.Build.DEVICE</td> 386<td>A value chosen by the device implementer identifying the specific 387configuration or revision of the body (sometimes called "industrial design") 388of the device. The value of this field MUST be encodable as 7-bit ASCII and 389match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 390</tr> 391<tr> 392<td>android.os.Build.FINGERPRINT</td> 393<td>A string that uniquely identifies this build. It SHOULD be reasonably 394human-readable. It MUST follow this template: 395<br/><code>$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</code><br/> 396For example: 397<br/><code>acme/mydevice/generic:4.3/JRN53/3359:userdebug/test-keys</code><br/> 398The fingerprint MUST NOT include whitespace characters. If other fields included in the 399template above have whitespace characters, they MUST be replaced in the build 400fingerprint with another character, such as the underscore ("_") character. 401The value of this field MUST be encodable as 7-bit ASCII.</td> 402</tr> 403<tr> 404<td>android.os.Build.HARDWARE</td> 405<td>The name of the hardware (from the kernel command line or /proc). It SHOULD be 406reasonably human-readable. The value of this field MUST be encodable as 7-bit ASCII and 407match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 408</tr> 409<tr> 410<td>android.os.Build.HOST</td> 411<td>A string that uniquely identifies the host the build was built on, in 412human readable format. There are no requirements on the specific format of 413this field, except that it MUST NOT be null or the empty string ("").</td> 414</tr> 415<tr> 416<td>android.os.Build.ID</td> 417<td>An identifier chosen by the device implementer to refer to a specific 418release, in human readable format. This field can be the same as 419android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 420meaningful for end users to distinguish between software builds. The value of 421this field MUST be encodable as 7-bit ASCII and match the regular expression 422<code>"^[a-zA-Z0-9.,_-]+$"</code>. 423</td> 424</tr> 425<tr> 426<td>android.os.Build.MANUFACTURER</td> 427<td>The trade name of the Original Equipment Manufacturer (OEM) of the product. 428There are no requirements on the specific format of this field, except that it 429MUST NOT be null or the empty string ("").</td> 430</tr> 431<tr> 432<td>android.os.Build.MODEL</td> 433<td>A value chosen by the device implementer containing the name of the device 434as known to the end user. This SHOULD be the same name under which the device 435is marketed and sold to end users. There are no requirements on the specific 436format of this field, except that it MUST NOT be null or the empty string 437("").</td> 438</tr> 439<tr> 440<td>android.os.Build.PRODUCT</td> 441<td>A value chosen by the device implementer containing the development name 442or code name of the product (SKU). MUST be human-readable, but is not necessarily 443intended for view by end users. The value of this field MUST be encodable as 7-bit 444ASCII and match the regular expression 445<code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 446</tr> 447<tr> 448<td>android.os.Build.SERIAL</td> 449<td>A hardware serial number, if available. The value of this field MUST be encodable 450as 7-bit ASCII and match the regular expression 451<code>"^([a-zA-Z0-9]{0,20})$"</code>.</td> 452</tr> 453<tr> 454<td>android.os.Build.TAGS</td> 455<td>A comma-separated list of tags chosen by the device implementer that 456further distinguishes the build. For example, "unsigned,debug". The value of 457this field MUST be encodable as 7-bit ASCII and match the regular expression 458<code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 459</tr> 460<tr> 461<td>android.os.Build.TIME</td> 462<td>A value representing the timestamp of when the build occurred.</td> 463</tr> 464<tr> 465<td>android.os.Build.TYPE</td> 466<td>A value chosen by the device implementer specifying the runtime 467configuration of the build. This field SHOULD have one of the values 468corresponding to the three typical Android runtime configurations: "user", 469"userdebug", or "eng". The value of this field MUST be 470encodable as 7-bit ASCII and match the regular expression 471<code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 472</tr> 473<tr> 474<td>android.os.Build.USER</td> 475<td>A name or user ID of the user (or automated user) that generated the 476build. There are no requirements on the specific format of this field, except 477that it MUST NOT be null or the empty string ("").</td> 478</tr> 479</tbody> 480</table> 481<a name="section-3.2.3"></a><h4>3.2.3. Intent Compatibility</h4> 482<p> 483Device implementations MUST honor Android's loose-coupling Intent system, as 484described in the sections below. By "honored", it is meant that the device 485implementer MUST provide an Android Activity or Service that specifies a 486matching Intent filter and binds to and implements correct behavior for each 487specified Intent pattern.</p> 488<a name="section-3.2.3.1"></a><h4>3.2.3.1. Core Application Intents</h4> 489<p>The Android upstream project defines a number of core applications, such as 490contacts, calendar, photo gallery, music player, and so on. Device implementers 491MAY replace these applications with alternative versions.</p> 492<p>However, any such alternative versions MUST honor the same Intent patterns 493provided by the upstream project. For example, if a device contains an 494alternative music player, it must still honor the Intent pattern issued by 495third-party applications to pick a song.</p> 496<p>The following applications are considered core Android system 497applications:</p> 498<ul> 499<li>Desk Clock</li> 500<li>Browser</li> 501<li>Calendar</li> 502<li>Contacts</li> 503<!--<li>Email</li>--> 504<li>Gallery</li> 505<li>GlobalSearch</li> 506<li>Launcher</li> 507<!-- <li>LivePicker (that is, the Live Wallpaper picker application; MAY be omitted 508if the device does not support Live Wallpapers, per Section 3.8.5.)</li> --> 509<!-- <li>Messaging (AKA "Mms")</li> --> 510<li>Music</li> 511<!-- <li>Phone</li> --> 512<li>Settings</li> 513<!-- <li>SoundRecorder</li> --> 514</ul> 515<p>The core Android system applications include various Activity, or Service 516components that are considered "public". That is, the attribute 517"android:exported" may be absent, or may have the value "true".</p> 518<p>For every Activity or Service defined 519in one of the core Android system apps that is not marked as non-public via an 520android:exported attribute with the value "false", device implementations MUST 521include a component of the same type implementing the same Intent filter 522patterns as the core Android system app.</p> 523<p>In other words, a device implementation MAY replace core Android system 524apps; however, if it does, the device implementation MUST support all Intent 525patterns defined by each core Android system app being replaced.</p> 526<a name="section-3.2.3.2"></a><h4>3.2.3.2. Intent Overrides</h4> 527<p>As Android is an extensible platform, device implementations MUST allow each 528Intent pattern referenced in Section 3.2.3.2 to be overridden by third-party 529applications. The upstream Android open source implementation allows this by 530default; device implementers MUST NOT attach special privileges to system 531applications' use of these Intent patterns, or prevent third-party 532applications from binding to and assuming control of these patterns. This 533prohibition specifically includes but is not limited to disabling the 534"Chooser" user interface that allows the user to select between multiple 535applications which all handle the same Intent pattern.</p> 536<p>However, device implementations MAY provide default activities for specific 537URI patterns (eg. http://play.google.com) if the default activity provides a 538more specific filter for the data URI. For example, an intent filter specifying 539the data URI "http://www.android.com" is more specific than the browser filter 540for "http://". Device implementations MUST provide a user interface for users 541to modify the default activity for intents.</p> 542 543<a name="section-3.2.3.3"></a><h4>3.2.3.3. Intent Namespaces</h4> 544<p>Device implementations MUST NOT include any Android component that honors any 545new Intent or Broadcast Intent patterns using an ACTION, CATEGORY, or other 546key string in the android.* or com.android.* namespace. Device implementers 547MUST NOT include any Android components that honor any new Intent or Broadcast 548Intent patterns using an ACTION, CATEGORY, or other key string in a package 549space belonging to another organization. Device implementers MUST NOT alter or 550extend any of the Intent patterns used by the core apps listed in Section 5513.2.3.1. Device implementations MAY include Intent patterns using 552namespaces clearly and obviously associated with their own organization.</p> 553<p>This prohibition is analogous to that specified for Java language classes 554in Section 3.6.</p> 555<a name="section-3.2.3.4"></a><h4>3.2.3.4. Broadcast Intents</h4> 556<p>Third-party applications rely on the platform to broadcast certain Intents 557to notify them of changes in the hardware or software environment. 558Android-compatible devices MUST broadcast the public broadcast Intents in 559response to appropriate system events. Broadcast Intents are described in the 560SDK documentation.</p> 561 562<a name="section-3.3"></a><h3>3.3. Native API Compatibility</h3> 563<a name="section-3.3.1"></a><h4>3.3.1 Application Binary Interfaces</h4> 564<p>Managed code running in Dalvik can call into native code provided in the 565application .apk file as an ELF .so file compiled for the appropriate device 566hardware architecture. As native code is highly dependent on the underlying 567processor technology, Android defines a number of Application Binary 568Interfaces (ABIs) in the Android NDK, in the file 569<code>docs/CPU-ARCH-ABIS.html</code>. If a device implementation is compatible 570with one or more defined ABIs, it SHOULD implement compatibility with the 571Android NDK, as below.</p> 572<p>If a device implementation includes support for an Android ABI, it:</p> 573<ul> 574<li>MUST include support for code running in the managed environment to call 575into native code, using the standard Java Native Interface (JNI) 576semantics</li> 577<li>MUST be source-compatible (i.e. header compatible) and binary-compatible 578(for the ABI) with each required library in the list below</li> 579<li>MUST accurately report the native Application Binary Interface (ABI) 580supported by the device, via the <code>android.os.Build.CPU_ABI</code> 581API</li> 582<li>MUST report only those ABIs documented in the latest version of the 583Android NDK, in the file <code>docs/CPU-ARCH-ABIS.txt</code></li> 584<li>SHOULD be built using the source code and header files available in the 585upstream Android Open Source Project</li> 586</ul> 587<p>The following native code APIs MUST be available to apps that include 588native code:</p> 589<ul> 590<li>libc (C library)</li> 591<li>libm (math library)</li> 592<li>Minimal support for C++</li> 593<li>JNI interface</li> 594<li>liblog (Android logging)</li> 595<li>libz (Zlib compression)</li> 596<li>libdl (dynamic linker)</li> 597<li>libGLESv1_CM.so (OpenGL ES 1.0)</li> 598<li>libGLESv2.so (OpenGL ES 2.0)</li> 599<li>libGLESv3.so (OpenGL ES 3.0)</li> 600<li>libEGL.so (native OpenGL surface management)</li> 601<li>libjnigraphics.so</li> 602<li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li> 603<li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li> 604<li>libandroid.so (native Android activity support)</li> 605<li>Support for OpenGL, as described below</li> 606</ul> 607<p>Note that future releases of the Android NDK may introduce support for 608additional ABIs. If a device implementation is not compatible with an existing 609predefined ABI, it MUST NOT report support for any ABI at all.</p> 610<p>Note that device implementations MUST include libGLESv3.so and it MUST symlink (symbolic) 611link to libGLESv2.so. On device implementations that declare support for OpenGL ES 3.0, libGLESv2.so 612MUST export the OpenGL ES 3.0 function symbols in addition to the OpenGL ES 2.0 function symbols.</p> 613<p>Native code compatibility is challenging. For this reason, it should be 614repeated that device implementers are VERY strongly encouraged to use the 615upstream implementations of the libraries listed above to help ensure 616compatibility.</p> 617 618<a name="section-3.4"></a><h3>3.4. Web Compatibility</h3> 619<a name="section-3.4.1"></a><h4>3.4.1. WebView Compatibility</h4> 620<p>The Android Open Source implementation uses the WebKit rendering engine to 621implement the <code>android.webkit.WebView</code> [<a href="#resources10">Resources, 10</a>] . Because it is not feasible 622to develop a comprehensive test suite for a web rendering system, device 623implementers MUST use the specific upstream build of WebKit in the WebView 624implementation. Specifically:</p> 625<ul> 626<li>Device implementations' <code>android.webkit.WebView</code> 627implementations MUST be based on the 534.30 WebKit build from the upstream 628Android Open Source tree for Android 4.3. This build includes a specific set 629of functionality and security fixes for the WebView. Device implementers MAY 630include customizations to the WebKit implementation; however, any such 631customizations MUST NOT alter the behavior of the WebView, including rendering 632behavior.</li> 633<li>The user agent string reported by the WebView MUST be in this format:<br/> 634 <code>Mozilla/5.0 (Linux; U; Android $(VERSION); $(LOCALE); $(MODEL) Build/$(BUILD)) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30</code> 635 <ul> 636 <li>The value of the $(VERSION) string MUST be the same as the value for <code>android.os.Build.VERSION.RELEASE</code></li> 637 <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> 638 <li>The value of the $(MODEL) string MUST be the same as the value for <code>android.os.Build.MODEL</code></li> 639 <li>The value of the $(BUILD) string MUST be the same as the value for <code>android.os.Build.ID</code></li> 640 <li>Device implementations MAY omit <code>Mobile</code> in the user agent string</li> 641 </ul> 642</li> 643</ul> 644<p>The WebView component SHOULD include support for as much of HTML5 [<a 645href="#resources11">Resources, 11</a>] as possible. 646Minimally, device implementations MUST support each of these APIs associated 647with HTML5 in the WebView:</p> 648<ul> 649<li>application cache/offline operation [<a href="#resources12">Resources, 12</a>]</li> 650<li>the <video> tag [<a href="#resources13">Resources, 13</a>]</li> 651<li>geolocation [<a href="#resources14">Resources, 14</a>]</li> 652</ul> 653<p>Additionally, device implementations MUST support the HTML5/W3C webstorage 654API [<a href="#resources15">Resources, 15</a>], and SHOULD support the 655HTML5/W3C IndexedDB API [<a href="#resources16">Resources, 16</a>]. <i>Note 656that as the web development standards bodies are transitioning to favor 657IndexedDB over webstorage, IndexedDB is expected to become a required 658component in a future version of Android.</i></p> 659<p>HTML5 APIs, like all JavaScript APIs, MUST be disabled by default in a 660WebView, unless the developer explicitly enables them via the usual Android 661APIs.</p> 662 663<a name="section-3.4.2"></a><h4>3.4.2. Browser Compatibility</h4> 664<p>Device implementations MUST include a standalone Browser application for 665general user web browsing. The standalone Browser MAY be based on a 666browser technology other than WebKit. However, even if an alternate Browser 667application is used, the <code>android.webkit.WebView</code> component 668provided to third-party applications MUST be based on WebKit, as described in 669Section 3.4.1.</p> 670<p>Implementations MAY ship a custom user agent string in the standalone 671Browser application.</p> 672<p>The standalone Browser application (whether based on the upstream 673WebKit Browser application or a third-party replacement) SHOULD include support 674for as much of HTML5 [<a href="#resources11">Resources, 11</a>] as possible. 675Minimally, device implementations MUST support each of these APIs associated 676with HTML5:</p> 677<ul> 678<li>application cache/offline operation [<a href="#resources12">Resources, 12</a>]</li> 679<li>the <video> tag [<a href="#resources13">Resources, 13</a>]</li> 680<li>geolocation [<a href="#resources14">Resources, 14</a>]</li> 681</ul> 682<p>Additionally, device implementations MUST support the HTML5/W3C webstorage 683API [<a href="#resources15">Resources, 15</a>], and SHOULD support the 684HTML5/W3C IndexedDB API [<a href="#resources16">Resources, 16</a>]. <i>Note 685that as the web development standards bodies are transitioning to favor 686IndexedDB over webstorage, IndexedDB is expected to become a required 687component in a future version of Android.</i></p> 688 689<a name="section-3.5"></a><h3>3.5. API Behavioral Compatibility</h3> 690<p>The behaviors of each of the API types (managed, soft, native, and web) 691must be consistent with the preferred implementation of the upstream Android 692Open Source Project [<a href="#resources03">Resources, 3</a>]. Some specific areas 693of compatibility are:</p> 694<ul> 695<li>Devices MUST NOT change the behavior or semantics of a standard Intent</li> 696<li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a 697 particular type of system component (such as Service, Activity, 698 ContentProvider, etc.)</li> 699<li>Devices MUST NOT change the semantics of a standard permission</li> 700</ul> 701<p>The above list is not comprehensive. The Compatibility Test Suite (CTS) 702tests significant portions of the platform for behavioral compatibility, but 703not all. It is the responsibility of the implementer to ensure behavioral 704compatibility with the Android Open Source Project. For this reason, device 705implementers SHOULD use the source code available via the Android Open Source 706Project where possible, rather than re-implement significant parts of the 707system.</p> 708 709 710<a name="section-3.6"></a><h3>3.6. API Namespaces</h3> 711<p>Android follows the package and class namespace conventions defined by the 712Java programming language. To ensure compatibility with third-party 713applications, device implementers MUST NOT make any prohibited modifications 714(see below) to these package namespaces:</p> 715<ul> 716<li>java.*</li> 717<li>javax.*</li> 718<li>sun.*</li> 719<li>android.*</li> 720<li>com.android.*</li> 721</ul> 722<p>Prohibited modifications include:</p> 723<ul> 724<li>Device implementations MUST NOT modify the publicly exposed APIs on the 725Android platform by changing any method or class signatures, or by removing 726classes or class fields.</li> 727<li>Device implementers MAY modify the underlying implementation of the APIs, 728but such modifications MUST NOT impact the stated behavior and Java-language 729signature of any publicly exposed APIs.</li> 730<li>Device implementers MUST NOT add any publicly exposed elements (such as 731classes or interfaces, or fields or methods to existing classes or interfaces) 732to the APIs above.</li> 733</ul> 734<p>A "publicly exposed element" is any construct which is not decorated with 735the "@hide" marker as used in the upstream Android source code. In other 736words, device implementers MUST NOT expose new APIs or alter existing APIs in 737the namespaces noted above. Device implementers MAY make internal-only 738modifications, but those modifications MUST NOT be advertised or otherwise 739exposed to developers.</p> 740<p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 741namespace owned by or referring to another organization. For instance, device 742implementers MUST NOT add APIs to the com.google.* or similar namespace; only 743Google may do so. Similarly, Google MUST NOT add APIs to other companies' 744namespaces. Additionally, if a device implementation includes custom APIs 745outside the standard Android namespace, those APIs MUST be packaged in an 746Android shared library so that only apps that explicitly use them (via the 747<code><uses-library></code> mechanism) are affected by the increased 748memory usage of such APIs.</p> 749<p>If a device implementer proposes to improve one of the package namespaces 750above (such as by adding useful new functionality to an existing API, or 751adding a new API), the implementer SHOULD visit source.android.com and begin 752the process for contributing changes and code, according to the information on 753that site.</p> 754<p>Note that the restrictions above correspond to standard conventions for 755naming APIs in the Java programming language; this section simply aims to 756reinforce those conventions and make them binding through inclusion in this 757compatibility definition.</p> 758 759<a name="section-3.7"></a><h3>3.7. Virtual Machine Compatibility</h3> 760<p>Device implementations MUST support the full Dalvik Executable (DEX) 761bytecode specification and Dalvik Virtual Machine semantics [<a 762href="#resources17">Resources, 17</a>].</p> 763<p>Device implementations MUST configure Dalvik to allocate memory in 764accordance with the upstream Android platform, and as specified by the following 765table. (See <a href="#section-7.1.1">Section 7.1.1</a> for screen size and screen 766density definitions.)</p> 767 768<p>Note that memory values specified below are considered minimum values, 769and device implementations MAY allocate more memory per application.</p> 770<table> 771<tbody> 772<tr> 773<td><b>Screen Size</b></td> 774<td><b>Screen Density</b></td> 775<td><b>Application Memory</b></td> 776</tr> 777<tr> 778<td>small / normal / large</td> 779<td>ldpi / mdpi</td> 780<td>16MB</td> 781</tr> 782<tr> 783<td>small / normal / large</td> 784<td>tvdpi / hdpi</td> 785<td>32MB</td> 786</tr> 787<tr> 788<td>small / normal / large</td> 789<td>xhdpi</td> 790<td>64MB</td> 791</tr> 792<tr> 793<td>xlarge</td> 794<td>mdpi</td> 795<td>32MB</td> 796</tr> 797<tr> 798<td>xlarge</td> 799<td>tvdpi / hdpi</td> 800<td>64MB</td> 801</tr> 802<tr> 803<td>xlarge</td> 804<td>xhdpi</td> 805<td>128MB</td> 806</tr> 807</tbody> 808</table> 809 810<a name="section-3.8"></a><h3>3.8. User Interface Compatibility</h3> 811 812<a name="section-3.8.1"></a><h4>3.8.1. Launcher (Home Screen)</h4> 813<p>Android 4.3 includes a launcher application (home screen) and support for third party applications to replace the device 814launcher (home screen). Device implementations that allow third party applications to replace the device home screen 815MUST declare the platform feature <code>android.software.home_screen</code>.</p> 816 817<a name="section-3.8.2"></a><h4>3.8.2. Widgets</h4> 818<p>Android defines a component type and corresponding API and lifecycle that allows applications to expose an "AppWidget" 819to the end user [<a href="#resources18">Resources, 18</a>]. Device implementations that support embedding widgets on the 820home screen MUST meet the following requirements and declare support for platform feature <code>android.software.app_widgets</code>.</p> 821<ul> 822 <li>Device launchers MUST include built-in support for AppWidgets, and expose user 823 interface affordances to add, configure, view, and remove AppWidgets directly within the Launcher.</li> 824 <li>Device implementations MUST be capable of rendering widgets that are 4 x 4 in the standard grid size. 825 (See the App Widget Design Guidelines in the Android SDK documentation [<a href="#resources18">Resources, 18</a>] for details.</li> 826 <li>Device implementations that include support for lock screen MUST support application widgets on the lock screen.</li> 827</ul> 828 829<a name="section-3.8.3"></a><h4>3.8.3. Notifications</h4> 830<p>Android includes APIs that allow developers to notify users of notable 831events [<a href="#resources19">Resources, 19</a>], using hardware and software 832features of the device.</p> 833<p>Some APIs allow applications to perform notifications or attract attention 834using hardware, specifically sound, vibration, and light. Device implementations 835MUST support notifications that use hardware features, as described in the SDK 836documentation, and to the extent possible with the device implementation 837hardware. For instance, if a device implementation includes a vibrator, it 838MUST correctly implement the vibration APIs. If a device implementation lacks 839hardware, the corresponding APIs MUST be implemented as no-ops. Note that this 840behavior is further detailed in <a href="#section-7">Section 7.</a></p> 841<p>Additionally, the implementation MUST correctly render all resources 842(icons, sound files, etc.) provided for in the APIs [<a 843href="#resources20">Resources, 20</a>], or in the 844Status/System Bar icon style guide [<a href="#resources21">Resources, 21</a>]. 845Device implementers MAY provide an alternative user experience for 846notifications than that provided by the reference Android Open Source 847implementation; however, such alternative notification systems MUST support 848existing notification resources, as above.</p> 849<p>Android 4.3 includes support for rich notifications, such as interactive 850Views for ongoing notifications. Device implementations MUST properly display 851and execute rich notifications, as documented in the Android APIs.</p> 852<a name="section-3.8.4"></a><h4>3.8.4. Search</h4> 853<p>Android includes APIs [<a href="#resources22">Resources, 22</a>] that allow 854developers to incorporate search into their applications, and expose their 855application's data into the global system search. Generally speaking, this 856functionality consists of a single, system-wide user interface that allows users 857to enter queries, displays suggestions as users type, and displays results. The 858Android APIs allow developers to reuse this interface to provide search within 859their own apps, and allow developers to supply results to the common global 860search user interface.</p> 861<p>Device implementations MUST include a single, shared, system-wide search 862user interface capable of real-time suggestions in response to user input. 863Device implementations MUST implement the APIs that allow developers to reuse 864this user interface to provide search within their own applications. Device 865implementations MUST implement the APIs that allow third-party applications to 866add suggestions to the search box when it is run in global search mode. If no 867third-party applications are installed that make use of this functionality, 868the default behavior SHOULD be to display web search engine results and 869suggestions.</p> 870<a name="section-3.8.5"></a><h4>3.8.5. Toasts</h4> 871<p>Applications can use the "Toast" API (defined in [<a 872href="#resources23">Resources, 23</a>]) to 873display short non-modal strings to the end user, that disappear after a brief 874period of time. Device implementations MUST display Toasts from applications 875to end users in some high-visibility manner.</p> 876 877<a name="section-3.8.6"></a><h4>3.8.6. Themes</h4> 878<p>Android provides "themes" as a mechanism for applications to apply styles 879across an entire Activity or application. Android 4.3 includes a "Holo" 880or "holographic" theme as a set of defined styles for application developers to 881use if they want to match the Holo theme look and feel as defined by the Android 882SDK [<a href="#resources24">Resources, 24</a>]. Device implementations MUST NOT 883alter any of the Holo theme attributes exposed to applications 884[<a href="#resources25">Resources, 25</a>].</p> 885<p>Android 4.3 includes a new "Device Default" theme as a set of defined 886styles for application developers to use if they want to match the look and feel 887of the device theme as defined by the device implementer. Device implementations 888MAY modify the DeviceDefault theme attributes exposed to applications 889[<a href="#resources25">Resources, 25</a>].</p> 890 891<a name="section-3.8.7"></a><h4>3.8.7. Live Wallpapers</h4> 892<p>Android defines a component type and corresponding API and lifecycle that 893allows applications to expose one or more "Live Wallpapers" to the end user 894[<a href="#resources26">Resources, 26</a>]. Live Wallpapers are animations, 895patterns, or similar images with limited input capabilities that display as a 896wallpaper, behind other applications.</p> 897<p>Hardware is considered capable of reliably running live wallpapers if it 898can run all live wallpapers, with no limitations on functionality, at a 899reasonable framerate with no adverse affects on other applications. If 900limitations in the hardware cause wallpapers and/or applications to crash, 901malfunction, consume excessive CPU or battery power, or run at unacceptably 902low frame rates, the hardware is considered incapable of running live 903wallpaper. As an example, some live wallpapers may use an Open GL 1.0 or 2.0 904context to render their content. Live wallpaper will not run reliably on 905hardware that does not support multiple OpenGL contexts because the live 906wallpaper use of an OpenGL context may conflict with other applications that 907also use an OpenGL context.</p> 908<p>Device implementations capable of running live wallpapers reliably as 909described above SHOULD implement live wallpapers. Device implementations 910determined to not run live wallpapers reliably as described above MUST NOT 911implement live wallpapers.</p> 912<a name="section-3.8.8"></a><h4>3.8.8. Recent Application Display</h4> 913<p>The upstream Android 4.3 source code includes a user interface for 914displaying recent applications using a thumbnail image of the application's 915graphical state at the moment the user last left the application. Device 916implementations MAY alter or eliminate this user interface; however, a future 917version of Android is planned to make more extensive use of this 918functionality. Device implementations are strongly encouraged to use the 919upstream Android 4.3 user interface (or a similar thumbnail-based interface) 920for recent applications, or else they may not be compatible with a future 921version of Android.</p> 922<a name="section-3.8.9"></a><h4>3.8.9. Input Management </h4> 923<p>Android 4.3 includes support for Input Management and support for third party input method editors. 924Device implementations that allow users to use third party input methods on the device MUST declare the platform feature 925<code>android.software.input_methods</code> and support IME APIs as defined in the Android SDK documentation.</p> 926<p>Device implementations that declare the <code>android.software.input_methods</code> feature MUST provide a user-accessible mechanism 927to add and configure third party input methods. Device implementations MUST display the settings interface in response to the 928<code>android.settings.INPUT_METHOD_SETTINGS</code> intent.</p> 929 930<a name="section-3.8.10"></a><h4>3.8.10. Lock Screen Media Remote Control</h4> 931<p>Android 4.3 includes support for Remote Control API that lets media applications integrate with playback controls 932that are displayed in a remote view like the device lock screen [<a href="#resources74">Resources, 74</a>]. Device implementations 933that support lock screen in the device and allow users to add widgets on the home screen MUST 934include support for embedding remote controls in the device lock screen [<a href="#resources69">Resources, 69</a>].</p> 935 936<a name="section-3.8.11"></a><h4>3.8.11. Dreams</h4> 937<p>Android 4.3 includes support for interactive screensavers called Dreams [<a href="#resources76">Resources, 76</a>]. 938Dreams allows users to interact with applications when a charging device is idle, or docked in a desk dock. Device implementations 939MUST include support for Dreams and provide a settings option for users to configure Dreams.</p> 940 941<a name="section-3.9"></a><h3>3.9 Device Administration</h3> 942<p>Android 4.3 includes features that allow security-aware applications 943to perform device administration functions at the system level, such as enforcing 944password policies or performing remote wipe, through the Android Device 945Administration API [<a href="#resources27">Resources, 27</a>]. Device 946implementations MUST provide an implementation of the <code>DevicePolicyManager</code> 947class [<a href="#resources28">Resources, 28</a>]. Device implementations that include support for lock screen 948MUST support the full range of device administration policies defined in the Android SDK 949documentation [<a href="#resources27">Resources, 27</a>].</p> 950 951<a name="section-3.10"></a><h3>3.10 Accessibility</h3> 952<p>Android 4.3 provides an accessibility layer that helps users with disabilities 953to navigate their devices more easily. In addition, Android 4.3 provides 954platform APIs that enable accessibility service implementations to receive 955callbacks for user and system events and generate alternate feedback mechanisms, 956such as text-to-speech, haptic feedback, and trackball/d-pad navigation 957[<a href="#resources29">Resources, 29</a>]. Device implementations MUST provide an 958implementation of the Android accessibility framework consistent with the 959default Android implementation. Specifically, device implementations MUST meet 960the following requirements.</p> 961<ul> 962 <li>Device implementations MUST support third party accessibility service 963 implementations through the <code>android.accessibilityservice</code> 964 APIs [<a href="#resources30">Resources, 30</a>].</li> 965 <li>Device implementations MUST generate <code>AccessibilityEvents</code> 966 and deliver these events to all registered <code>AccessibilityService 967 </code> implementations in a manner consistent with the default Android 968 implementation.</li> 969 <li>Device implementations MUST provide a user-accessible mechanism to enable 970 and disable accessibility services, and MUST display this interface in 971 response to the 972 <code>android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS</code> 973 intent.</li> 974</ul> 975<p>Additionally, device implementations SHOULD provide an implementation 976of an accessibility service on the device, and SHOULD provide a mechanism 977for users to enable the accessibility service during device setup. An open 978source implementation of an accessibility service is available from the Eyes 979Free project [<a href="#resources31">Resources, 31</a>].</p> 980 981<a name="section-3.11"></a><h3>3.11 Text-to-Speech</h3> 982<p>Android 4.3 includes APIs that allow applications to make use of 983text-to-speech (TTS) services, and allows service providers to provide 984implementations of TTS services [<a href="#resources32">Resources, 32</a>]. 985Device implementations MUST meet these requirements related to the Android TTS 986framework:</p> 987<ul> 988 <li>Device implementations MUST support the Android TTS framework APIs and 989 SHOULD include a TTS engine supporting the languages available on the 990 device. Note that the upstream Android open source software includes a 991 full-featured TTS engine implementation.</li> 992 <li>Device implementations MUST support installation of third-party TTS 993 engines.</li> 994 <li>Device implementations MUST provide a user-accessible interface that allows 995 users to select a TTS engine for use at the system level.</li> 996</ul> 997 998<a name="section-4"></a><h2>4. Application Packaging Compatibility</h2> 999<p>Device implementations MUST install and run Android ".apk" files as 1000generated by the "aapt" tool included in the official Android SDK [<a 1001href="#resources33">Resources, 33</a>].</p> 1002<p>Devices implementations MUST NOT extend either the .apk [<a 1003href="#resources34">Resources, 34</a>], Android Manifest [<a 1004href="#resources35">Resources, 35</a>], 1005Dalvik bytecode [<a href="#resources17">Resources, 17</a>], or renderscript 1006bytecode formats in such a way that would prevent those files from installing 1007and running correctly on other compatible devices. Device implementers SHOULD 1008use the reference upstream implementation of Dalvik, and the reference 1009implementation's package management system.</p> 1010 1011<a name="section-5"></a><h2>5. Multimedia Compatibility</h2> 1012<p>Device implementations MUST include at least one form of audio output, such as 1013speakers, headphone jack, external speaker connection, etc.</p> 1014<a name="section-5.1"></a><h3>5.1. Media Codecs</h3> 1015<p>Device implementations MUST support the core media formats specified 1016in the Android SDK documentation [<a href="#resources58">Resources, 58</a>] except 1017where explicitly permitted in this document. Specifically, device implementations 1018MUST support the media formats, encoders, decoders, file types and container 1019formats defined in the tables below. All of these codecs are provided as 1020software implementations in the preferred Android implementation from the Android 1021Open Source Project.</p> 1022 1023<p><strong>Please note that neither Google nor the Open Handset Alliance make any 1024representation that these codecs are unencumbered by third-party patents. 1025Those intending to use this source code in hardware or software products are 1026advised that implementations of this code, including in open source software 1027or shareware, may require patent licenses from the relevant patent 1028holders.</strong></p> 1029 1030<p>Note that these tables do not list specific bitrate requirements for 1031most video codecs because current device hardware does not necessarily support 1032bitrates that map exactly to the required bitrates specified by the relevant 1033standards. Instead, device implementations SHOULD support the highest bitrate 1034practical on the hardware, up to the limits defined by the specifications.</p> 1035<div style="page-break-before: always;"></div> 1036<table> 1037<tbody> 1038 1039<tr> 1040<th>Type</th> 1041<th>Format / Codec</th> 1042<th>Encoder</th> 1043<th>Decoder</th> 1044<th>Details</th> 1045<th>File Type(s) / Container Formats</th> 1046</tr> 1047 1048<tr> 1049<td rowspan="11">Audio</td> 1050<td>MPEG-4 AAC Profile (AAC LC)</td> 1051<td>REQUIRED for device implementations that include microphone hardware 1052and define <code>android.hardware.microphone</code>.</td> 1053<td style="text-align: center;">REQUIRED</td> 1054<td rowspan="1"> Support for mono/stereo/5.0/5.1* content with standard sampling rates from 8 to 48 kHz.</td> 1055<td rowspan="4"> 1056 <ul> 1057 <li>3GPP (.3gp)</li> 1058 <li>MPEG-4 (.mp4, .m4a)</li> 1059 <li>ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not supported)</li> 1060 <li>MPEG-TS (.ts, not seekable, Android 3.0+)</li> 1061 </ul> 1062</td> 1063</tr> 1064 1065<tr> 1066<td>MPEG-4 HE AAC Profile (AAC+)</td> 1067<td>REQUIRED for device implementations that include microphone hardware and define android.hardware.microphone</td> 1068<td style="text-align: center;">REQUIRED</td> 1069<td>Support for mono/stereo/5.0/5.1* content with standard sampling rates from 16 to 48 kHz.</td> 1070</tr> 1071 1072<tr> 1073<td>MPEG-4 HE AAC v2 Profile (enhanced AAC+)</td> 1074<td> </td> 1075<td style="text-align: center;">REQUIRED</td> 1076<td>Support for mono/stereo/5.0/5.1* content with standard sampling rates from 16 to 48 kHz.</td> 1077</tr> 1078 1079<tr> 1080<td>MPEG-4 Audio Object Type ER AAC ELD (Enhanced Low Delay AAC)</td> 1081<td>REQUIRED for device implementations that include microphone hardware and define android.hardware.microphone</td> 1082<td style="text-align: center;">REQUIRED</td> 1083<td>Support for mono/stereo content with standard 1084sampling rates from 16 to 48 kHz.</td> 1085</tr> 1086 1087<tr> 1088<td>AMR-NB</td> 1089<td>REQUIRED for device implementations that include microphone hardware 1090and define <code>android.hardware.microphone</code>.</td> 1091<td style="text-align: center;">REQUIRED</td> 1092<td>4.75 to 12.2 kbps sampled @ 8kHz</td> 1093<td>3GPP (.3gp) 1094</td> 1095</tr> 1096 1097<tr> 1098<td>AMR-WB</td> 1099<td>REQUIRED for device implementations that include microphone hardware 1100and define <code>android.hardware.microphone</code>.</td> 1101<td style="text-align: center;">REQUIRED</td> 1102<td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 1103<td>3GPP (.3gp)</td> 1104</tr> 1105 1106<tr> 1107<td>FLAC</td> 1108<td> </td> 1109<td style="text-align: center;">REQUIRED<br/><small>(Android 3.1+)</small></td> 1110<td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 1111kHz is recommended on devices with 44.1 kHz output, as the 48 to 44.1 kHz 1112downsampler does not include a low-pass filter). 16-bit recommended; 1113no dither applied for 24-bit. 1114</td> 1115<td>FLAC (.flac) only</td> 1116</tr> 1117 1118<tr> 1119<td>MP3</td> 1120<td> </td> 1121<td style="text-align: center;">REQUIRED</td> 1122<td>Mono/Stereo 8-320Kbps constant (CBR) or variable bit-rate (VBR) 1123</td> 1124<td>MP3 (.mp3)</td> 1125</tr> 1126 1127<tr> 1128<td>MIDI</td> 1129<td> </td> 1130<td style="text-align: center;">REQUIRED</td> 1131<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> 1132<td> 1133 <ul> 1134 <li>Type 0 and 1 (.mid, .xmf, .mxmf)</li> 1135 <li>RTTTL/RTX (.rtttl, .rtx)</li> 1136 <li>OTA (.ota)</li> 1137 <li>iMelody (.imy)</li> 1138 </ul> 1139</td> 1140</tr> 1141 1142<tr> 1143<td>Vorbis</td> 1144<td> </td> 1145<td style="text-align: center;">REQUIRED</td> 1146<td> </td> 1147<td> 1148 <ul> 1149 <li>Ogg (.ogg)</li> 1150 <li>Matroska (.mkv)</li> 1151 </ul> 1152</td> 1153</tr> 1154 1155<tr> 1156<td>PCM/WAVE</td> 1157<td style="text-align: center;">REQUIRED</td> 1158<td style="text-align: center;">REQUIRED</td> 1159<td>8-bit and 16-bit linear PCM** (rates up to limit of hardware).Devices MUST support sampling rates 1160for raw PCM recording at 8000,16000 and 44100 Hz frequencies</td> 1161<td>WAVE (.wav)</td> 1162</tr> 1163 1164<tr> 1165<td rowspan="5">Image</td> 1166<td>JPEG</td> 1167<td style="text-align: center;">REQUIRED</td> 1168<td style="text-align: center;">REQUIRED</td> 1169<td>Base+progressive</td> 1170<td>JPEG (.jpg)</td> 1171</tr> 1172 1173<tr> 1174<td>GIF</td> 1175<td> </td> 1176<td style="text-align: center;">REQUIRED</td> 1177<td> </td> 1178<td>GIF (.gif)</td> 1179</tr> 1180 1181<tr> 1182<td>PNG</td> 1183<td style="text-align: center;">REQUIRED</td> 1184<td style="text-align: center;">REQUIRED</td> 1185<td> </td> 1186<td>PNG (.png)</td> 1187</tr> 1188 1189<tr> 1190<td>BMP</td> 1191<td> </td> 1192<td style="text-align: center;">REQUIRED</td> 1193<td> </td> 1194<td>BMP (.bmp)</td> 1195</tr> 1196 1197 1198<tr> 1199<td>WEBP</td> 1200<td style="text-align: center;">REQUIRED</td> 1201<td style="text-align: center;">REQUIRED</td> 1202<td> </td> 1203<td>WebP (.webp)</td> 1204</tr> 1205 1206<tr> 1207<td rowspan="4">Video</td> 1208<td>H.263</td> 1209<td>REQUIRED for device implementations that include camera hardware 1210and define <code>android.hardware.camera</code> or 1211<code>android.hardware.camera.front</code>.</td> 1212<td style="text-align: center;">REQUIRED</td> 1213<td> </td> 1214<td> 1215 <ul> 1216 <li>3GPP (.3gp)</li> 1217 <li>MPEG-4 (.mp4)</li> 1218 </ul> 1219</td> 1220</tr> 1221 1222<tr> 1223<td>H.264 AVC</td> 1224<td>REQUIRED for device implementations that include camera hardware 1225and define <code>android.hardware.camera</code> or 1226<code>android.hardware.camera.front</code>.</td> 1227<td style="text-align: center;">REQUIRED</td> 1228<td>Baseline Profile (BP)</td> 1229<td> 1230 <ul> 1231 <li>3GPP (.3gp)</li> 1232 <li>MPEG-4 (.mp4)</li> 1233 <li>MPEG-TS (.ts, AAC audio only, not seekable, Android 3.0+)</li> 1234 </ul> 1235</td> 1236</tr> 1237 1238<tr> 1239<td>MPEG-4 SP</td> 1240<td> </td> 1241<td style="text-align: center;">REQUIRED</td> 1242<td> </td> 1243<td>3GPP (.3gp)</td> 1244</tr> 1245 1246<tr> 1247<td>VP8</td> 1248<td style="text-align: center;">REQUIRED<br/><small>(Android 4.3+)</small></td> 1249<td style="text-align: center;">REQUIRED<br/><small>(Android 2.3.3+)</small></td> 1250<td> </td> 1251<td><a href="http://www.webmproject.org/">WebM</a> (.webm) and Matroska (.mkv, Android 4.0+)***</td> 1252</tr> 1253 1254</tbody></table> 1255<ul> 1256<li>*Note: Only downmix of 5.0/5.1 content is required; recording or rendering more than 2 channels is optional.</li> 1257<li>**Note: 16-bit linear PCM capture is mandatory. 8-bit linear PCM capture is not mandatory.</li> 1258<li>***Note: Device implementations SHOULD support writing Matroska WebM files.</li> 1259</ul> 1260 1261<a name="section-5.2"></a><h3>5.2 Video Encoding</h3> 1262<p>Android device implementations that include a rear-facing camera and declare 1263<code>android.hardware.camera</code> SHOULD support the following H.264 video encoding 1264profiles.</p> 1265<table> 1266 <thead> 1267 <tr> 1268 <th> </th> 1269 <th>SD (Low quality)</th> 1270 <th>SD (High quality)</th> 1271 <th>HD (When supported by hardware)</th> 1272 </tr> 1273 </thead> 1274 <tbody> 1275 <tr> 1276 <th>Video resolution</th> 1277 <td>176 x 144 px</td> 1278 <td>480 x 360 px</td> 1279 <td>1280 x 720 px</td> 1280 </tr> 1281 <tr> 1282 <th>Video frame rate</th> 1283 <td>12 fps</td> 1284 <td>30 fps</td> 1285 <td>30 fps</td> 1286 </tr> 1287 <tr> 1288 <th>Video bitrate</th> 1289 <td>56 Kbps</td> 1290 <td>500 Kbps or higher</td> 1291 <td>2 Mbps or higher</td> 1292 </tr> 1293 <tr> 1294 <th>Audio codec</th> 1295 <td>AAC-LC</td> 1296 <td>AAC-LC</td> 1297 <td>AAC-LC</td> 1298 </tr> 1299 <tr> 1300 <th>Audio channels</th> 1301 <td>1 (mono)</td> 1302 <td>2 (stereo)</td> 1303 <td>2 (stereo)</td> 1304 </tr> 1305 <tr> 1306 <th>Audio bitrate</th> 1307 <td>24 Kbps</td> 1308 <td>128 Kbps</td> 1309 <td>192 Kbps</td> 1310 </tr> 1311 </tbody> 1312</table> 1313 1314<p>Android device implementations that include a rear-facing camera and declare 1315<code>android.hardware.camera</code> SHOULD support the following VP8 video encoding profiles</p> 1316<table> 1317 <thead> 1318 <tr> 1319 <th> </th> 1320 <th>SD (Low quality)</th> 1321 <th>SD (High quality)</th> 1322 <th>HD 720p <br/> (When supported by hardware)</th> 1323 <th>HD 1080p <br/>(When supported by hardware)</th> 1324 </tr> 1325 </thead> 1326 <tbody> 1327 <tr> 1328 <th>Video resolution</th> 1329 <td>320 x 180 px</td> 1330 <td>640 x 360 px</td> 1331 <td>1280 x 720 px</td> 1332 <td>1920 x 1080 px</td> 1333 </tr> 1334 <tr> 1335 <th>Video frame rate</th> 1336 <td>30 fps</td> 1337 <td>30 fps</td> 1338 <td>30 fps</td> 1339 <td>30 fps</td> 1340 </tr> 1341 <tr> 1342 <th>Video bitrate</th> 1343 <td>800 Kbps</td> 1344 <td>2 Mbps</td> 1345 <td>4 Mbps</td> 1346 <td>10 Mbps</td> 1347 </tr> 1348 </tbody> 1349</table> 1350 1351<a name="section-5.3"></a><h3>5.3 Video Decoding</h3> 1352<p>Android device implementations SHOULD support the following VP8 and H.264 video decoding profiles.</p> 1353<table> 1354 <thead> 1355 <tr> 1356 <th> </th> 1357 <th>SD (Low quality)</th> 1358 <th>SD (High quality)</th> 1359 <th>HD 720p <br/> (When supported by hardware)</th> 1360 <th>HD 1080p <br/>(When supported by hardware)</th> 1361 </tr> 1362 </thead> 1363 <tbody> 1364 <tr> 1365 <th>Video resolution</th> 1366 <td>320 x 180 px</td> 1367 <td>640 x 360 px</td> 1368 <td>1280 x 720 px</td> 1369 <td>1920 x 1080 px</td> 1370 </tr> 1371 <tr> 1372 <th>Video frame rate</th> 1373 <td>30 fps</td> 1374 <td>30 fps</td> 1375 <td>30 fps</td> 1376 <td>30 fps</td> 1377 </tr> 1378 <tr> 1379 <th>Video bitrate</th> 1380 <td>800 Kbps</td> 1381 <td>2 Mbps</td> 1382 <td>8 Mbps</td> 1383 <td>20 Mbps</td> 1384 </tr> 1385 </tbody> 1386</table> 1387 1388<a name="section-5.4"></a><h3>5.4. Audio Recording</h3> 1389<p>When an application has used the <code>android.media.AudioRecord</code> API to 1390start recording an audio stream, device implementations that include microphone 1391hardware and declare <code>android.hardware.microphone</code> MUST sample and 1392record audio with each of these behaviors:</p> 1393<ul> 1394<li>The device SHOULD exhibit approximately flat amplitude versus frequency 1395 characteristics; specifically, ±3 dB, from 100 Hz to 4000 Hz</li> 1396<li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level 1397 (SPL) source at 1000 Hz yields RMS of 2500 for 16-bit samples.</li> 1398<li>PCM amplitude levels SHOULD linearly track input SPL changes over at least 1399 a 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.</li> 1400<li>Total harmonic distortion SHOULD be less than 1% for 1Khz at 90 dB SPL input level.</li> 1401</ul> 1402<p>In addition to the above recording specifications, when an application has 1403started recording an audio stream using the 1404<code>android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION</code> audio 1405source:</p> 1406<ul> 1407<li>Noise reduction processing, if present, MUST be disabled.</li> 1408<li>Automatic gain control, if present, MUST be disabled.</li> 1409</ul> 1410<p><b>Note:</b> while some of the requirements outlined above are stated as "SHOULD" 1411for Android 4.3, the Compatibility Definition for a future version is planned 1412to change these to "MUST". That is, these requirements are optional in Android 14134.3 but <b>will be required</b> by a future version. Existing and new devices 1414that run Android 4.3 are <b>very strongly encouraged to meet 1415these requirements in Android 4.3</b>, or they will not be able to attain 1416Android compatibility when upgraded to the future version.</p> 1417 1418<a name="section-5.5"></a><h3>5.5. Audio Latency</h3> 1419<p>Audio latency is the time delay as an audio signal passes through a system. 1420Many classes of 1421applications rely on short latencies, to achieve real-time sound effects.</p> 1422<p>For the purposes of this section:</p> 1423<ul> 1424<li>"output latency" is defined as the interval between when an application 1425writes a frame of PCM-coded data and when the corresponding sound can be heard 1426by an external listener or observed by a transducer</li> 1427<li>"cold output latency" is defined as the output latency for the first frame, when 1428 the audio output system has been idle and powered down prior to the request</li> 1429<li>"continuous output latency" is defined as the output latency for subsequent frames, 1430 after the device is already playing audio</li> 1431<li>"input latency" is the interval between when an external sound is presented 1432to the device and when an application reads the corresponding frame of PCM-coded data</li> 1433<li>"cold input latency" is defined as the sum of lost input time 1434 and the input latency for the first frame, when 1435 the audio input system has been idle and powered down prior to the request</li> 1436<li>"continuous input latency" is defined as the input latency for subsequent frames, 1437 while the device is already capturing audio</li> 1438<li>"OpenSL ES PCM buffer queue API" is the set of PCM-related OpenSL ES APIs within Android NDK; 1439see <i>NDK_root</i><code>/docs/opensles/index.html</code></li> 1440</ul> 1441<p>Per <a href="#section-5">Section 5</a>, 1442all compatible device implementations MUST include at least one form of audio output. 1443Device implementations SHOULD meet or exceed these output latency requirements:</p> 1444<ul> 1445<li>cold output latency of 100 milliseconds or less</li> 1446<li>continuous output latency of 45 milliseconds or less</li> 1447</ul> 1448<p>If a device implementation meets the requirements of this section 1449after any initial calibration 1450when using the OpenSL ES PCM buffer queue API, 1451for continuous output latency and cold output latency 1452over at least one supported audio output device, it MAY 1453report support for low-latency audio, by reporting the feature 1454"android.hardware.audio.low-latency" via the 1455<code>android.content.pm.PackageManager</code> class. [<a 1456href="#resources37">Resources, 37</a>] Conversely, if the device 1457implementation does not meet these requirements it MUST NOT report support for 1458low-latency audio.</p> 1459<p> 1460Per <a href="#section-7.2.5">Section 7.2.5</a>, 1461microphone hardware may be omitted by device implementations.</p> 1462<p> 1463Device implementations that include microphone 1464hardware and declare <code>android.hardware.microphone</code> SHOULD 1465meet these input audio latency requirements:</p> 1466<ul> 1467<li>cold input latency of 100 milliseconds or less</li> 1468<li>continuous input latency of 50 milliseconds or less</li> 1469</ul> 1470 1471<a name="section-5.6"></a><h3>5.6. Network Protocols</h3> 1472<p>Devices MUST support the media network protocols for audio and video playback 1473as specified in the Android SDK documentation 1474[<a href="#resources58">Resources, 58</a>]. Specifically, devices MUST support 1475the following media network protocols:</p> 1476<ul> 1477<li>RTSP (RTP, SDP)</li> 1478<li>HTTP(S) progressive streaming</li> 1479<li>HTTP(S) Live Streaming draft protocol, Version 3 [<a href="#resources59">Resources, 59</a>]</li> 1480</ul> 1481<a name="section-6"></a><h2>6. Developer Tools and Options Compatibility</h2> 1482 1483<a name="section-6.1"></a><h3>6.1 Developer Tools</h3> 1484<p>Device implementations MUST support the Android Developer Tools provided in the Android SDK. 1485Specifically, Android-compatible devices MUST be compatible with:</p> 1486<ul> 1487<li><b>Android Debug Bridge (known as adb)</b> [<a href="#resources33">Resources, 33</a>]<br/> 1488Device implementations MUST support all <code>adb</code> functions as 1489documented in the Android SDK. The device-side <code>adb</code> daemon MUST 1490be inactive by default, and there MUST be a user-accessible mechanism to turn 1491on the Android Debug Bridge.</li> 1492<li>Android 4.3 includes support for secure adb. Secure adb enables adb on known authenticated hosts. 1493Device implementations MUST support secure adb.</li> 1494<li><b>Dalvik Debug Monitor Service (known as ddms)</b> [<a href="#resources33">Resources, 33</a>]<br/> 1495Device implementations MUST support all <code>ddms</code> features as documented in the 1496Android SDK. As <code>ddms</code> uses <code>adb</code>, support for 1497<code>ddms</code> SHOULD be inactive by default, 1498but MUST be supported whenever the user has activated the Android Debug 1499Bridge, as above.</li> 1500<li><b>Monkey</b> [<a href="#resources36">Resources, 36</a>]<br/> 1501Device implementations MUST include the Monkey framework, and make it 1502available for applications to use.</li> 1503<li><b>SysTrace</b> [<a href="#resources33">Resources, 33</a>]<br/> 1504Device implementations MUST support systrace tool as documented in the Android SDK. 1505Systrace must be inactive by default, and there MUST be a user-accessible mechanism to turn 1506on Systrace.</li> 1507</ul> 1508<p>Most Linux-based systems and Apple Macintosh systems recognize Android 1509devices using the standard Android SDK tools, without additional support; 1510however Microsoft Windows systems typically require a driver for new Android 1511devices. (For instance, new vendor IDs and sometimes new device IDs require 1512custom USB drivers for Windows systems.) If a device implementation is 1513unrecognized by the <code>adb</code> tool as provided in the standard Android 1514SDK, device implementers MUST provide Windows drivers allowing developers to 1515connect to the device using the <code>adb</code> protocol. These drivers MUST 1516be provided for Windows XP, Windows Vista, Windows 7, and Windows 8, in both 32-bit and 151764-bit versions.</p> 1518 1519<a name="section-6.2"></a><h3>6.2 Developer Options</h3> 1520<p>Android 4.3 includes support for developers to configure application development-related settings. 1521Device implementations MUST honor the android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show 1522application development-related settings [<a href="#resources77">Resources, 77</a>]. The upstream Android 1523implementation hides the Developer Options menu by default, and enables users to launch Developer Options 1524after pressing seven (7) times on the Settings > About Device > Build Number menu item. Device implementations 1525MUST provide a consistent experience for Developer Options. Specifically, device implementations MUST hide 1526Developer Options by default and MUST provide a mechanism to enable Developer Options that is consistent with 1527the upstream Android implementation.</p> 1528 1529<a name="section-7"></a><h2>7. Hardware Compatibility</h2> 1530<p>If a device includes a particular hardware component that has a 1531corresponding API for third-party developers, the device implementation MUST 1532implement that API as described in the Android SDK documentation. If an API in 1533the SDK interacts with a hardware component that is stated to be optional and 1534the device implementation does not possess that component:</p> 1535<ul> 1536<li>complete class definitions (as documented by the SDK) for the component's 1537APIs MUST still be present</li> 1538<li>the API's behaviors MUST be implemented as no-ops in some reasonable 1539fashion</li> 1540<li>API methods MUST return null values where permitted by the SDK 1541documentation</li> 1542<li>API methods MUST return no-op implementations of classes where null 1543values are not permitted by the SDK documentation</li> 1544<li>API methods MUST NOT throw exceptions not documented by the SDK 1545documentation</li> 1546</ul> 1547<p>A typical example of a scenario where these requirements apply is the 1548telephony API: even on non-phone devices, these APIs must be implemented as 1549reasonable no-ops.</p> 1550<p>Device implementations MUST accurately report accurate hardware configuration 1551information via the <code>getSystemAvailableFeatures()</code> and 1552<code>hasSystemFeature(String)</code> methods on the 1553<code>android.content.pm.PackageManager</code> class. [<a 1554href="#resources37">Resources, 37</a>]</p> 1555 1556<a name="section-7.1"></a><h3>7.1. Display and Graphics</h3> 1557<p>Android 4.3 includes facilities that automatically adjust application 1558assets and UI layouts appropriately for the device, to ensure that third-party 1559applications run well on a variety of hardware configurations [<a 1560href="#resources38">Resources, 38</a>]. Devices MUST properly implement these 1561APIs and behaviors, as detailed in this section.</p> 1562 1563<p>The units referenced by the requirements in this section are defined as follows:</p> 1564<ul> 1565<li>"Physical diagonal size" is the distance in inches between two opposing 1566corners of the illuminated portion of the display.</li> 1567<li>"dpi" (meaning "dots per inch") is the number of pixels encompassed by a 1568linear horizontal or vertical span of 1". Where dpi values are listed, both 1569horizontal and vertical dpi must fall within the range.</li> 1570<li>"Aspect ratio" is the ratio of the longer dimension of the screen to the 1571shorter dimension. For example, a display of 480x854 pixels would be 854 / 480 1572= 1.779, or roughly "16:9".</li> 1573<li>A "density-independent pixel" or ("dp") is the virtual pixel unit normalized to a 1574160 dpi screen, calculated as: 1575<code>pixels = dps * (density / 160)</code>.</li> 1576</ul> 1577 1578 1579<a name="section-7.1.1"></a><h4>7.1.1. Screen Configuration</h4> 1580 1581<p style="font-weight:bold;">Screen Size</p> 1582<p>The Android UI framework supports a variety of different screen sizes, and 1583allows applications to query the device screen size (aka "screen layout") via 1584<code>android.content.res.Configuration.screenLayout</code> with the 1585<code>SCREENLAYOUT_SIZE_MASK</code>. Device implementations MUST report the 1586correct screen size as defined in the Android SDK documentation 1587[<a href="#resources38">Resources, 38</a>] and determined by the upstream 1588Android platform. Specifically, device implementations must report the correct 1589screen size according to the following logical density-independent pixel (dp) 1590screen dimensions.</p> 1591<ul> 1592<li>Devices MUST have screen sizes of at least 426 dp x 320 dp ('small')</li> 1593<li>Devices that report screen size 'normal' MUST have screen sizes of at least 1594480 dp x 320 dp</li> 1595<li>Devices that report screen size 'large' MUST have screen sizes of at least 1596640 dp x 480 dp</li> 1597<li>Devices that report screen size 'xlarge' MUST have screen sizes of at least 1598960 dp x 720 dp</li> 1599</ul> 1600<p>In addition, devices MUST have screen sizes of at least 2.5 inches in 1601physical diagonal size.</p> 1602 1603<p>Devices MUST NOT change their reported screen size at any time.</p> 1604<p>Applications optionally indicate which screen sizes they support via the 1605<code><supports-screens></code> attribute in the AndroidManifest.xml 1606file. Device implementations MUST correctly honor applications' stated support 1607for small, normal, large, and xlarge screens, as described in the Android 1608SDK documentation.</p> 1609 1610<p style="font-weight:bold;">Screen Aspect Ratio</p> 1611<p>The aspect ratio MUST be between 1.3333 (4:3) and 1.85 (16:9).</p> 1612 1613<p style="font-weight:bold;">Screen Density</p> 1614<p>The Android UI framework defines a set of standard logical densities to 1615help application developers target application resources. Device 1616implementations MUST report one of the following logical Android framework 1617densities through the <code>android.util.DisplayMetrics</code> APIs, and MUST 1618execute applications at this standard density. 1619<ul> 1620<li>120 dpi, known as 'ldpi'</li> 1621<li>160 dpi, known as 'mdpi'</li> 1622<li>213 dpi, known as 'tvdpi'</li> 1623<li>240 dpi, known as 'hdpi'</li> 1624<li>320 dpi, known as 'xhdpi'</li> 1625<li>480 dpi, known as 'xxhdpi'</li> 1626<li>640 dpi, known as 'xxxhdpi'</li> 1627</ul> 1628Device implementations SHOULD define the standard Android framework density 1629that is numerically closest to the physical density of the screen, unless that 1630logical density pushes the reported screen size below the minimum supported. 1631If the standard Android framework density that is numerically closest to the 1632physical density results in a screen size that is smaller than the smallest 1633supported compatible screen size (320 dp width), device implementations SHOULD 1634report the next lowest standard Android framework density.</p> 1635 1636<a name="section-7.1.2"></a><h4>7.1.2. Display Metrics</h4> 1637<p>Device implementations MUST report correct values for all display metrics 1638defined in <code>android.util.DisplayMetrics</code> [<a 1639href="#resources39">Resources, 39</a>].</p> 1640 1641<a name="section-7.1.3"></a><h4>7.1.3. Screen Orientation</h4> 1642<p>Devices MUST support dynamic orientation by applications to 1643either portrait or landscape screen orientation. That is, the device must 1644respect the application's request for a specific screen orientation. Device 1645implementations MAY select either portrait or landscape orientation as the 1646default.</p> 1647<p>Devices MUST report the correct value for the device's current orientation, 1648whenever queried via the android.content.res.Configuration.orientation, 1649android.view.Display.getOrientation(), or other APIs.</p> 1650<p>Devices MUST NOT change the reported screen size or density when changing 1651orientation.</p> 1652<p>Devices MUST report which screen orientations they support ( 1653<code>android.hardware.screen.portrait</code> and/or 1654<code>android.hardware.screen.landscape</code>) and MUST report at least one 1655supported orientation. For example, a device with a fixed-orientation 1656landscape screen, such as a television or laptop, MUST only report 1657<code>android.hardware.screen.landscape</code>.</p> 1658 1659<a name="section-7.1.4"></a><h4>7.1.4. 2D and 3D Graphics Acceleration</h4> 1660<p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied 1661and detailed in the Android SDK documentations. Device implementations SHOULD support 1662OpenGL ES 3.0 on devices capable of supporting OpenGL ES 3.0. 1663Device implementations MUST also support Android Renderscript, as detailed in the Android SDK 1664documentation [<a href="#resources08">Resources, 8</a>].</p> 1665<p>Device implementations MUST also correctly identify themselves as 1666supporting OpenGL ES 1.0, OpenGL ES 2.0, or OpenGL ES 3.0. That is:</p> 1667<ul> 1668<li>The managed APIs (such as via the <code>GLES10.getString()</code> method) 1669MUST report support for OpenGL ES 1.0 and OpenGL ES 2.0 </li> 1670<li>The native C/C++ OpenGL APIs (that is, those available to apps via 1671libGLES_v1CM.so, libGLES_v2.so, or libEGL.so) MUST report support for 1672OpenGL ES 1.0 and OpenGL ES 2.0.</li> 1673<li>Device implementations that declare support for OpenGL ES 3.0 MUST support 1674OpenGL ES 3.0 managed APIs and include support for native C/C++ APIs. On device 1675implementations that declare support for OpenGL ES 3.0, libGLESv2.so MUST export the OpenGL ES 3.0 1676function symbols in addition to the OpenGL ES 2.0 function symbols. 1677</li> 1678</ul> 1679 1680<p>Device implementations MAY implement any desired OpenGL ES extensions. 1681However, device implementations MUST report via the OpenGL ES managed and 1682native APIs all extension strings that they do support, and conversely MUST 1683NOT report extension strings that they do not support.</p> 1684<p>Note that Android 4.3 includes support for applications to optionally 1685specify that they require specific OpenGL texture compression formats. These 1686formats are typically vendor-specific. Device implementations are not required 1687by Android 4.3 to implement any specific texture compression format. However, 1688they SHOULD accurately report any texture compression formats that they do 1689support, via the <code>getString()</code> method in the OpenGL API.</p> 1690 1691<p>Android 4.3 includes a mechanism for applications to declare that they 1692wanted to enable hardware acceleration for 2D graphics at the Application, 1693Activity, Window or View level through the use of a manifest tag 1694<code>android:hardwareAccelerated</code> or direct API calls 1695[<a href="#resources09">Resources, 9</a>].</p> 1696<p>In Android 4.3, device implementations MUST enable hardware acceleration by 1697default, and MUST disable hardware acceleration if the developer so requests 1698by setting <code>android:hardwareAccelerated="false"</code> or disabling 1699hardware acceleration directly through the Android View APIs.</p> 1700<p>In addition, device implementations MUST exhibit behavior consistent with the 1701Android SDK documentation on hardware acceleration 1702[<a href="#resources09">Resources, 9</a>].</p> 1703<p>Android 4.3 includes a <code>TextureView</code> object that lets developers 1704directly integrate hardware-accelerated OpenGL ES textures as rendering targets 1705in a UI hierarchy. Device implementations MUST support the <code>TextureView 1706</code> API, and MUST exhibit consistent behavior with the upstream Android 1707implementation.</p> 1708<p>Android 4.3 includes support for <code>EGL_ANDROID_RECORDABLE</code>, a EGLConfig attribute 1709that indicates whether the EGLConfig supports rendering to an ANativeWindow that records images to a video. 1710Device implementations MUST support <code>EGL_ANDROID_RECORDABLE</code> extension [<a href="#resources79">Resources, 79</a>].</p> 1711 1712<a name="section-7.1.5"></a><h4>7.1.5. Legacy Application Compatibility Mode</h4> 1713<p>Android 4.3 specifies a "compatibility mode" in which the framework 1714operates in an 'normal' screen size equivalent (320dp width) mode for the benefit 1715of legacy applications not developed for old versions of Android that pre-date 1716screen-size independence. Device implementations MUST include support for legacy 1717application compatibility mode as implemented by the upstream Android open source 1718code. That is, device implementations MUST NOT alter the triggers or thresholds at 1719which compatibility mode is activated, and MUST NOT alter the behavior of the 1720compatibility mode itself.</p> 1721 1722<a name="section-7.1.6"></a><h4>7.1.6. Screen Types</h4> 1723<p>Device implementation screens are classified as one of two types:</p> 1724<ul> 1725<li>Fixed-pixel display implementations: the screen is a single panel that supports only a 1726single pixel width and height. Typically the screen is physically integrated with 1727the device. Examples include mobile phones, tablets, and so on.</li> 1728<li>Variable-pixel display implementations: the device implementation either has no 1729embedded screen and includes a video output port such as VGA, HDMI or a wireless port 1730for display, or has an embedded screen that can change pixel dimensions. Examples 1731include televisions, set-top boxes, and so on.</li> 1732</ul> 1733<p style="font-weight: bold;">Fixed-Pixel Device Implementations</p> 1734<p>Fixed-pixel device implementations MAY use screens of any pixel dimensions, provided 1735that they meet the requirements defined this Compatibility Definition.</p> 1736<p>Fixed-pixel implementations MAY include a video output port for use with an 1737external display. However, if that display is ever used for running apps, the 1738device MUST meet the following requirements:</p> 1739<ul> 1740<li>The device MUST report the same screen configuration and display metrics, as detailed 1741in Sections 7.1.1 and 7.1.2, as the fixed-pixel display.</li> 1742<li>The device MUST report the same logical density as the fixed-pixel display.</li> 1743<li>The device MUST report screen dimensions that are the same as, or very close to, 1744the fixed-pixel display.</li> 1745</ul> 1746<p>For example, a tablet that is 7" diagonal size with a 1024x600 pixel resolution is 1747considered a fixed-pixel large mdpi display implementation. If it contains a video 1748output port that displays at 720p or 1080p, the device implementation MUST scale the output so that 1749applications are only executed in a large mdpi window, regardless of whether the fixed-pixel display 1750or video output port is in use.</p> 1751 1752<p style="font-weight: bold;">Variable-Pixel Device Implementations</p> 1753<p>Variable-pixel device implementations MUST support one or both of 1280x720, 1754or 1920x1080 (that is, 720p or 1080p). Device implementations with 1755variable-pixel displays MUST NOT support any other screen configuration or 1756mode. Device implementations with variable-pixel screens MAY change screen 1757configuration or mode at runtime or boot-time. For example, a user of a 1758set-top box may replace a 720p display with a 1080p display, and the device 1759implementation may adjust accordingly.</p> 1760 1761<p>Additionally, variable-pixel device implementations MUST report the following 1762configuration buckets for these pixel dimensions:</p> 1763<ul> 1764<li>1280x720 (also known as 720p): 'large' screen size, 'tvdpi' (213 dpi) 1765density</li> 1766<li>1920x1080 (also known as 1080p): 'large' screen size, 'xhdpi' (320 dpi) 1767density</li> 1768</ul> 1769<p>For clarity, device implementations with variable pixel dimensions are 1770restricted to 720p or 1080p in Android 4.3, and MUST be configured to report 1771screen size and density buckets as noted above.</p> 1772 1773<a name="section-7.1.7"></a><h4>7.1.7. Screen Technology</h4> 1774<p>The Android platform includes APIs that allow applications to render rich 1775graphics to the display. Devices MUST support all of these APIs as defined by 1776the Android SDK unless specifically allowed in this document. Specifically:</p> 1777<ul> 1778<li>Devices MUST support displays capable of rendering 16-bit color graphics and 1779SHOULD support displays capable of 24-bit color graphics.</li> 1780<li>Devices MUST support displays capable of rendering animations.</li> 1781<li>The display technology used MUST have a pixel aspect ratio (PAR) between 1782 0.9 and 1.1. That is, the pixel aspect ratio MUST be near square (1.0) with 1783 a 10% tolerance.</li> 1784</ul> 1785<a name="section-7.1.8"></a><h4>7.1.8. External Displays</h4> 1786<p>Android 4.3 includes support for secondary display to enable media sharing capabilities and 1787developer APIs for accessing external displays. If a device supports an external display either via 1788a wired, wireless or an embedded additional display connection then the device implementation MUST 1789implement the display manager API as described in the Android SDK documentation [<a href="#resources75">Resources, 75</a>]. 1790Device implementations that support secure video output and are capable of supporting secure surfaces MUST declare support 1791for <code>Display.FLAG_SECURE</code>. Specifically, device implementations that declare support for <code>Display.FLAG_SECURE</code>, 1792MUST support <b>HDCP 2.x or higher</b> for Miracast wireless displays or <b>HDCP 1.2 or higher</b> for wired displays. The upstream 1793Android open source implementation includes support for wireless (Miracast) and wired (HDMI) displays that satisfies this requirement.</p> 1794 1795<a name="section-7.2"></a><h3>7.2. Input Devices</h3> 1796<a name="section-7.2.1"></a><h4>7.2.1. Keyboard</h4> 1797<p>Device implementations:</p> 1798<ul> 1799<li>MUST include support for the Input Management Framework (which allows third 1800party developers to create Input Management Engines - i.e. soft keyboard) as 1801detailed at <a href="http://developer.android.com">http://developer.android.com</a> 1802</li> 1803<li>MUST provide at least one soft keyboard implementation (regardless of whether 1804a hard keyboard is present)</li> 1805<li>MAY include additional soft keyboard implementations</li> 1806<li>MAY include a hardware keyboard</li> 1807<li>MUST NOT include a hardware keyboard that does not match one of the 1808formats specified in <code>android.content.res.Configuration.keyboard</code> 1809[<a href="#resources40">Resources, 40</a>] (that is, QWERTY, or 12-key)</li> 1810</ul> 1811<a name="section-7.2.2"></a><h4>7.2.2. Non-touch Navigation</h4> 1812<p>Device implementations:</p> 1813<ul> 1814<li>MAY omit a non-touch navigation option (that is, may omit a trackball, d-pad, 1815or wheel)</li> 1816<li>MUST report the correct value for 1817<code>android.content.res.Configuration.navigation</code> 1818[<a href="#resources40">Resources, 40</a>]</li> 1819<li>MUST provide a reasonable alternative user interface mechanism for the 1820selection and editing of text, compatible with Input Management Engines. The 1821upstream Android open source implementation includes a selection mechanism suitable 1822for use with devices that lack non-touch navigation inputs.</li> 1823</ul> 1824<a name="section-7.2.3"></a><h4>7.2.3. Navigation keys</h4> 1825<p>The Home, Menu and Back functions are essential to the Android navigation 1826paradigm. Device implementations MUST make these functions available to the 1827user at all times when running applications. These functions MAY be implemented 1828via dedicated physical buttons (such as mechanical or capacitive touch buttons), 1829or MAY be implemented using dedicated software keys, gestures, touch panel, etc. 1830Android 4.3 supports both implementations.</p> 1831 1832<p>Android 4.3 includes support for assist action [<a href="#resources63">Resources, 63</a>]. 1833Device implementations MUST make the assist action available to the user at all times when running applications. 1834This function MAY be implemented via hardware or software keys.</p> 1835 1836<p>Device implementations MAY use a distinct portion of the screen to display 1837the navigation keys, but if so, MUST meet these requirements:</p> 1838 1839<ul> 1840 <li>Device implementation navigation keys MUST use a distinct portion of the 1841 screen, not available to applications, and MUST NOT obscure or otherwise 1842 interfere with the portion of the screen available to applications.</li> 1843 <li>Device implementations MUST make available a portion of the display to 1844 applications that meets the requirements defined in 1845 <a href="section-7.1.1">Section 7.1.1</a>.</li> 1846 <li>Device implementations MUST display the navigation keys when applications 1847 do not specify a system UI mode, or specify 1848 <code>SYSTEM_UI_FLAG_VISIBLE</code>.</li> 1849 <li>Device implementations MUST present the navigation keys in an unobtrusive 1850 "low profile" (eg. dimmed) mode when applications specify 1851 <code>SYSTEM_UI_FLAG_LOW_PROFILE</code>.</li> 1852 <li>Device implementations MUST hide the navigation keys when applications 1853 specify <code>SYSTEM_UI_FLAG_HIDE_NAVIGATION</code>.</li> 1854 <li>Device implementation MUST present a Menu key to applications when 1855 targetSdkVersion <= 10 and SHOULD NOT present a Menu key when the 1856 targetSdkVersion > 10.</li> 1857</ul> 1858<a name="section-7.2.4"></a><h4>7.2.4. Touchscreen input</h4> 1859<p>Device implementations SHOULD have a pointer input system of some kind (either mouse-like, or touch). However, if a device 1860implementation does not support a pointer input system, it MUST NOT report the <code>android.hardware.touchscreen</code> or 1861<code>android.hardware.faketouch</code> feature constant. Device implementations that do include a pointer input system:</p> 1862<ul> 1863<li>SHOULD support fully independently tracked pointers, if the device input system supports multiple pointers</li> 1864<li>MUST report the value of <code>android.content.res.Configuration.touchscreen</code> [<a href="#resources40">Resources, 40</a>] 1865corresponding to the type of the specific touchscreen on the device</li> 1866</ul> 1867 1868<p>Android 4.3 includes support for a variety of touch screens, touch pads, and fake touch input devices. 1869Touch screen based device implementations are associated with a display [<a href="#resources81">Resources, 81</a>] 1870such that the user has the impression of directly manipulating items on screen. Since the user is directly touching the screen, 1871the system does not require any additional affordances to indicate the objects being manipulated. 1872In contrast, a fake touch interface provides a user input system that approximates a subset of touchscreen capabilities. 1873For example, a mouse or remote control that drives an on-screen cursor approximates touch, but requires the user to first 1874point or focus then click. Numerous input devices like the mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, 1875and multi-touch trackpad can support fake touch interactions. Android 4.0 includes the feature constant <code>android.hardware.faketouch</code>, 1876which corresponds to a high-fidelity non-touch (that is, pointer-based) input device such as a mouse or trackpad that can adequately emulate touch-based 1877input (including basic gesture support), and indicates that the device supports an emulated subset of touchscreen 1878functionality. Device implementations that declare the fake touch feature MUST meet the fake touch requirements in <a href="section 7.2.5">Section 7.2.5</a>.</p> 1879 1880<p>Device implementations MUST report the correct feature corresponding to the type of input used. Device implementations that 1881include a touchscreen (single-touch or better) MUST report the platform feature constant <code>android.hardware.touchscreen</code>. 1882Device implementations that report the platform feature constant <code>android.hardware.touchscreen</code> MUST also report the platform feature constant 1883<code>android.hardware.faketouch</code>. Device implementations that do not include a touchscreen (and rely on a pointer device only) MUST NOT report any 1884touchscreen feature, and MUST report only <code>android.hardware.faketouch</code> if they meet the fake touch requirements in <a href="section 7.2.5">Section 7.2.5</a>.</p> 1885 1886<a name="section-7.2.5"></a><h4>7.2.5. Fake touch input</h4> 1887<p>Device implementations that declare support for <code>android.hardware.faketouch</code></p> 1888<ul> 1889<li> MUST report the absolute X and Y screen positions of the pointer location and display a visual pointer on the screen [<a href="#resources80">Resources, 80</a>] </li> 1890<li> MUST report touch event with the action code [<a href="#resources80">Resources, 80</a>] that specifies the state change 1891that occurs on the pointer going <code>down</code> or <code>up</code> on the screen [<a href="#resources80">Resources, 80</a>] </li> 1892<li> MUST support pointer <code>down</code> and <code>up</code> on an object on the screen, which allows users to emulate tap on an object on the screen</li> 1893<li> MUST support pointer <code>down</code>, pointer <code>up</code>, pointer <code>down</code> then pointer <code>up</code> in the same place on an object on the screen 1894within a time threshold, which allows users to emulate double tap on an object on the screen [<a href="#resources80">Resources, 80</a>]</li> 1895<li>MUST support pointer <code>down</code> on an arbitrary point on the screen, pointer move to any other arbitrary point on the screen, 1896followed by a pointer <code>up</code>, which allows users to emulate a touch drag</li> 1897<li> MUST support pointer <code>down</code> then allow users to quickly move the object to a different position on the screen 1898and then pointer <code>up</code> on the screen, which allows users to fling an object on the screen</li> 1899</ul> 1900 1901<p>Devices that declare support for <code>android.hardware.faketouch.multitouch.distinct</code> MUST meet the requirements for 1902faketouch above, and MUST also support distinct tracking of two or more independent pointer inputs.</p> 1903 1904<a name="section-7.2.6"></a><h4>7.2.6. Microphone</h4> 1905<p>Device implementations MAY omit a microphone. However, if a device 1906implementation omits a microphone, it MUST NOT report the 1907<code>android.hardware.microphone</code> feature constant, and must implement 1908the audio recording API as no-ops, per <a href="section-7">Section 7</a>. 1909Conversely, device implementations that do possess a microphone:</p> 1910<ul> 1911<li>MUST report the <code>android.hardware.microphone</code> feature constant</li> 1912<li>SHOULD meet the audio quality requirements in <a href="section-5.4">Section 5.4</a></li> 1913<li>SHOULD meet the audio latency requirements in <a href="section-5.5">Section 5.5</a></li> 1914</ul> 1915 1916<a name="section-7.3"></a><h3>7.3. Sensors</h3> 1917<p>Android 4.3 includes APIs for accessing a variety of sensor types. Devices 1918implementations generally MAY omit these sensors, as provided for in the 1919following subsections. If a device includes a particular sensor type that has a 1920corresponding API for third-party developers, the device implementation MUST 1921implement that API as described in the Android SDK documentation. For example, 1922device implementations:</p> 1923<ul> 1924<li>MUST accurately report the presence or absence of sensors per the 1925<code>android.content.pm.PackageManager</code> class. [<a 1926href="#resources37">Resources, 37</a>]</li> 1927<li>MUST return an accurate list of supported sensors via the 1928<code>SensorManager.getSensorList()</code> and similar methods</li> 1929<li>MUST behave reasonably for all other sensor APIs (for example, by 1930returning true or false as appropriate when applications attempt to register 1931listeners, not calling sensor listeners when the corresponding sensors are not 1932present; etc.)</li> 1933<li>MUST report all sensor measurements using the relevant International System 1934of Units (i.e. metric) values for each sensor type as defined in the Android SDK 1935documentation [<a href="#resources41">Resources, 41</a>]</li> 1936</ul> 1937<p>The list above is not comprehensive; the documented behavior of the Android 1938SDK is to be considered authoritative.</p> 1939<p>Some sensor types are synthetic, meaning they can be derived from data 1940provided by one or more other sensors. (Examples include the orientation 1941sensor, and the linear acceleration sensor.) Device implementations SHOULD 1942implement these sensor types, when they include the prerequisite physical 1943sensors.</p> 1944<p>The Android 4.3 includes a notion of a "streaming" sensor, which is 1945one that returns data continuously, rather than only when the data changes. 1946Device implementations MUST continuously provide periodic data samples for any 1947API indicated by the Android 4.3 SDK documentation to be a streaming 1948sensor. Note that the device implementations MUST ensure that the sensor stream must not 1949prevent the device CPU from entering a suspend state or waking up from a suspend state.</p> 1950 1951<a name="section-7.3.1"></a><h4>7.3.1. Accelerometer</h4> 1952<p>Device implementations SHOULD include a 3-axis accelerometer. If a device 1953implementation does include a 3-axis accelerometer, it:</p> 1954<ul> 1955<li>SHOULD be able to deliver events at 120 Hz or greater. Note that while the 1956accelerometer frequency above is stated as "SHOULD" for Android 4.3, the Compatibility Definition 1957for a future version is planned to change these to "MUST". That is, these standards are 1958optional in Android 4.3 but <b>will be required</b> in future versions. Existing and 1959new devices that run Android 4.3 are <b>very strongly encouraged to meet these requirements 1960in Android 4.3</b> so they will be able to upgrade to the future platform releases 1961</li> 1962<li>MUST comply with the Android sensor coordinate system as detailed 1963in the Android APIs (see [<a href="#resources41">Resources, 41</a>])</li> 1964<li>MUST be capable of measuring from freefall up to twice gravity (2g) or 1965more on any three-dimensional vector</li> 1966<li>MUST have 8-bits of accuracy or more</li> 1967<li>MUST have a standard deviation no greater than 0.05 m/s^2</li> 1968</ul> 1969<a name="section-7.3.2"></a><h4>7.3.2. Magnetometer</h4> 1970<p>Device implementations SHOULD include a 3-axis magnetometer (i.e. compass.) 1971If a device does include a 3-axis magnetometer, it:</p> 1972<ul> 1973<li>MUST be able to deliver events at 10 Hz or greater</li> 1974<li>MUST comply with the Android sensor coordinate system as detailed 1975in the Android APIs (see [<a href="#resources41">Resources, 41</a>]).</li> 1976<li>MUST be capable of sampling a range of field strengths adequate to cover the 1977geomagnetic field</li> 1978<li>MUST have 8-bits of accuracy or more</li> 1979<li>MUST have a standard deviation no greater than 0.5 µT</li> 1980</ul> 1981<a name="section-7.3.3"></a><h4>7.3.3. GPS</h4> 1982<p>Device implementations SHOULD include a GPS receiver. If a device 1983implementation does include a GPS receiver, it SHOULD include 1984some form of "assisted GPS" technique to minimize GPS lock-on time.</p> 1985<a name="section-7.3.4"></a><h4>7.3.4. Gyroscope</h4> 1986<p>Device implementations SHOULD include a gyroscope (i.e. angular change 1987sensor.) Devices SHOULD NOT include a gyroscope sensor unless a 3-axis 1988accelerometer is also included. If a device implementation includes a 1989gyroscope, it:</p> 1990<ul> 1991<li>MUST be temperature compensated</li> 1992<li>MUST be capable of measuring orientation changes up to 5.5*Pi 1993radians/second (that is, approximately 1,000 degrees per second)</li> 1994<li>SHOULD be able to deliver events at 200 Hz or greater. Note that while the 1995gyroscope frequency above is stated as "SHOULD" for Android 4.3, the Compatibility Definition 1996for a future version is planned to change these to "MUST". That is, these standards are 1997optional in Android 4.3 but <b>will be required</b> in future versions. Existing and 1998new devices that run Android 4.3 are <b>very strongly encouraged to meet these requirements 1999in Android 4.3</b> so they will be able to upgrade to the future platform releases 2000</li> 2001<li>MUST have 12-bits of accuracy or more</li> 2002<li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, or rad^2 / s). 2003The variance is allowed to vary with the sampling rate, but must be constrained by this value. 2004In other words, if you measure the variance of the gyro at 1 Hz sampling rate it should be no 2005greater than 1e-7 rad^2/s^2. </li> 2006<li>MUST have timestamps as close to when the hardware event happened as possible. The constant latency must be removed.</li> 2007</ul> 2008<a name="section-7.3.5"></a><h4>7.3.5. Barometer</h4> 2009<p>Device implementations MAY include a barometer (i.e. ambient air pressure 2010sensor.) If a device implementation includes a barometer, it:</p> 2011<ul> 2012<li>MUST be able to deliver events at 5 Hz or greater</li> 2013<li>MUST have adequate precision to enable estimating altitude</li> 2014<li>MUST be temperature compensated</li> 2015</ul> 2016<a name="section-7.3.6"></a><h4>7.3.6. Thermometer</h4> 2017<p>Device implementations MAY but SHOULD NOT include a thermometer (i.e. 2018temperature sensor.) If a device implementation does include a thermometer, it 2019MUST measure the temperature of the device CPU. It MUST NOT measure any other 2020temperature. (Note that this sensor type is deprecated in the Android 4.3 2021APIs.)</p> 2022<a name="section-7.3.7"></a><h4>7.3.7. Photometer</h4> 2023<p>Device implementations MAY include a photometer (i.e. ambient light 2024sensor.)</p> 2025<a name="section-7.3.8"></a><h4>7.3.8. Proximity Sensor</h4> 2026<p>Device implementations MAY include a proximity sensor. If a device 2027implementation does include a proximity sensor, it MUST measure the proximity 2028of an object in the same direction as the screen. That is, the proximity 2029sensor MUST be oriented to detect objects close to the screen, as the 2030primary intent of this sensor type is to detect a phone in use by the 2031user. If a device implementation includes a proximity sensor with any other 2032orientation, it MUST NOT be accessible through this API. If a device 2033implementation has a proximity sensor, it MUST be have 1-bit of accuracy or 2034more.</p> 2035 2036<a name="section-7.4"></a><h3>7.4. Data Connectivity</h3> 2037<a name="section-7.4.1"></a><h4>7.4.1. Telephony</h4> 2038<p>"Telephony" as used by the Android 4.3 APIs and this document refers 2039specifically to hardware related to placing voice calls and sending SMS 2040messages via a GSM or CDMA network. While these voice calls may or may not be 2041packet-switched, they are for the purposes of Android 4.3 considered 2042independent of any data connectivity that may be implemented using the same 2043network. In other words, the Android "telephony" functionality and APIs refer 2044specifically to voice calls and SMS; for instance, device implementations that 2045cannot place calls or send/receive SMS messages MUST NOT report the 2046"android.hardware.telephony" feature or any sub-features, regardless of 2047whether they use a cellular network for data connectivity.</p> 2048<p>Android 4.3 MAY be used on devices that do not include telephony hardware. 2049That is, Android 4.3 is compatible with devices that are not phones. 2050However, if a device implementation does include GSM or CDMA telephony, it 2051MUST implement full support for the API for that technology. Device 2052implementations that do not include telephony hardware MUST implement the full 2053APIs as no-ops.</p> 2054<a name="section-7.4.2"></a><h4>7.4.2. IEEE 802.11 (WiFi)</h4> 2055<p>Android 4.3 device implementations SHOULD include support for one or more 2056forms of 802.11 (b/g/a/n, etc.) If a device implementation does include 2057support for 802.11, it MUST implement the corresponding Android API.</p> 2058<p>Device implementations MUST implement the multicast API as described in 2059the SDK documentation [<a href="#resources62">Resources, 62</a>]. Device 2060implementations that do include Wifi support MUST support multicast DNS (mDNS). 2061Device implementations MUST NOT filter mDNS packets (224.0.0.251) at any time 2062of operation including when the screen is not in an active state.</p> 2063 2064<a name="section-7.4.2.1"></a><h4>7.4.2.1. WiFi Direct</h4> 2065<p>Device implementations SHOULD include support for Wifi direct (Wifi peer-to-peer). 2066If a device implementation does include support for Wifi direct, it MUST implement the corresponding 2067Android API as described in the SDK documentation [<a href="#resources68">Resources, 68</a>]. 2068If a device implementation includes support for Wifi direct, then it:</p> 2069<ul> 2070 <li>MUST support regular Wifi operation</li> 2071 <li>SHOULD support concurrent wifi and wifi Direct operation</li> 2072</ul> 2073 2074<a name="section-7.4.3"></a><h4>7.4.3. Bluetooth</h4> 2075<p>Device implementations SHOULD include a Bluetooth transceiver. Device 2076implementations that do include a Bluetooth transceiver MUST enable the 2077RFCOMM-based Bluetooth API as described in the SDK documentation and declare 2078hardware feature android.hardware.bluetooth [<a href="#resources42">Resources, 42</a>]. 2079Device implementations SHOULD implement relevant Bluetooth profiles, such as A2DP, AVRCP, OBEX, etc. as 2080appropriate for the device.</p> 2081 2082<p>Device implementations that do include support for Bluetooth GATT (generic attribute profile) 2083to enable communication with Bluetooth Smart or Smart Ready devices MUST enable the 2084GATT-based Bluetooth API as described in the SDK documentation and declare hardware feature 2085android.hardware.bluetooth_le [<a href="#resources42">Resources, 42</a>].</p> 2086 2087<a name="section-7.4.4"></a><h4>7.4.4. Near-Field Communications</h4> 2088<p>Device implementations SHOULD include a transceiver and related hardware 2089for Near-Field Communications (NFC). If a device implementation does include 2090NFC hardware, then it:</p> 2091<ul> 2092 <li>MUST report the android.hardware.nfc feature from the 2093 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. 2094 [<a href="#resources37">Resources, 37</a>]</li> 2095 <li>MUST be capable of reading and writing NDEF messages via the following NFC 2096 standards: 2097 <ul> 2098 <li>MUST be capable of acting as an NFC Forum reader/writer 2099 (as defined by the NFC Forum technical specification 2100 NFCForum-TS-DigitalProtocol-1.0) via the following NFC standards: 2101 <ul> 2102 <li>NfcA (ISO14443-3A)</li> 2103 <li>NfcB (ISO14443-3B) </li> 2104 <li>NfcF (JIS 6319-4)</li> 2105 <li>IsoDep (ISO 14443-4)</li> 2106 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li> 2107 </ul> 2108 </li> 2109 </ul> 2110 </li> 2111 <li>SHOULD be capable of reading and writing NDEF messages via the following 2112 NFC standards. Note that while the NFC standards below are stated as 2113 "SHOULD" for Android 4.3, the Compatibility Definition for a future 2114 version is planned to change these to "MUST". That is, these standards are 2115 optional in Android 4.3 but <b>will be required</b> in future versions. 2116 Existing and new devices that run Android 4.3 are <b>very strongly 2117 encouraged to meet these requirements in Android 4.3</b> so they will be 2118 able to upgrade to the future platform releases. 2119 <ul> 2120 <li>NfcV (ISO 15693)</li> 2121 </ul> 2122 </li> 2123 <li>MUST be capable of transmitting and receiving data via the following 2124 peer-to-peer standards and protocols: 2125 <ul> 2126 <li>ISO 18092</li> 2127 <li>LLCP 1.0 (defined by the NFC Forum)</li> 2128 <li>SDP 1.0 (defined by the NFC Forum)</li> 2129 <li>NDEF Push Protocol [<a href="#resources43">Resources, 43</a>]</li> 2130 <li>SNEP 1.0 (defined by the NFC Forum)</li> 2131 </ul> 2132 </li> 2133 <li>MUST include support for Android Beam [<a href="#resources65">Resources, 65</a>]: 2134 <ul> 2135 <li>MUST implement the SNEP default server. Valid NDEF messages received 2136 by the default SNEP server MUST be dispatched to applications using 2137 the android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam 2138 in settings MUST NOT disable dispatch of incoming NDEF message.</li> 2139 <li>Device implementations MUST honor the android.settings.NFCSHARING_SETTINGS intent 2140 to show NFC sharing settings [<a href="#resources67">Resources, 67</a>].</li> 2141 <li>MUST implement the NPP server. Messages received by the NPP server MUST 2142 be processed the same way as the SNEP default server.</li> 2143 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to 2144 the default SNEP server when Android Beam is enabled. If no default 2145 SNEP server is found then the client MUST attempt to send to an NPP 2146 server.</li> 2147 <li>MUST allow foreground activities to set the outbound P2P NDEF message 2148 using android.nfc.NfcAdapter.setNdefPushMessage, and 2149 android.nfc.NfcAdapter.setNdefPushMessageCallback, and 2150 android.nfc.NfcAdapter.enableForegroundNdefPush.</li> 2151 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', 2152 before sending outbound P2P NDEF messages.</li> 2153 <li>SHOULD enable Android Beam by default</li> 2154 <li>MUST support NFC Connection handover to Bluetooth when the device supports Bluetooth Object Push Profile. 2155 Device implementations must support connection handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, 2156 by implementing the "Connection Handover version 1.2" [<a href="#resources60">Resources, 60</a>] 2157 and "Bluetooth Secure Simple Pairing Using NFC version 1.0" [<a href="#resources61">Resources, 61</a>] 2158 specs from the NFC Forum. Such an implementation SHOULD use SNEP GET 2159 requests for exchanging the handover request / select records over NFC, and it MUST 2160 use the Bluetooth Object Push Profile for the actual Bluetooth data transfer.</li> 2161 </ul> 2162 </li> 2163 <li>MUST poll for all supported technologies while in NFC discovery mode.</li> 2164 <li>SHOULD be in NFC discovery mode while the device is awake with the screen active 2165 and the lock-screen unlocked.</li> 2166</ul> 2167 2168<p>(Note that publicly available links are not available for the JIS, ISO, and 2169NFC Forum specifications cited above.)</p> 2170<p>Additionally, device implementations MAY include reader/writer support for 2171the following MIFARE technologies.</p> 2172<ul> 2173 <li>MIFARE Classic (NXP MF1S503x [<a href="#resources44">Resources, 44</a>], 2174 MF1S703x [<a href="#resources45">Resources, 45</a>])</li> 2175 <li>MIFARE Ultralight (NXP MF0ICU1 [<a href="#resources46">Resources, 46</a>], 2176 MF0ICU2 [<a href="#resources47">Resources, 47</a>])</li> 2177 <li>NDEF on MIFARE Classic (NXP AN130511 [<a href="#resources48">Resources, 48</a>], 2178 AN130411 [<a href="#resources49">Resources, 49</a>])</li> 2179</ul> 2180<p>Note that Android 4.3 includes APIs for these MIFARE types. If a 2181device implementation supports MIFARE in the reader/writer role, it:</p> 2182<ul> 2183 <li>MUST implement the corresponding Android APIs as documented by the 2184 Android SDK</li> 2185 <li>MUST report the feature com.nxp.mifare from the 2186 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. 2187 [<a href="#resources37">Resources, 37</a>] Note that this is not a standard 2188 Android feature, and as such does not appear as a constant on the 2189 <code>PackageManager</code> class.</li> 2190 <li>MUST NOT implement the corresponding Android APIs nor report the 2191 com.nxp.mifare feature unless it also implements general NFC support as 2192 described in this section</li> 2193</ul> 2194<p>If a device implementation does not include NFC hardware, it MUST NOT 2195declare the android.hardware.nfc feature from the 2196<code>android.content.pm.PackageManager.hasSystemFeature()</code> method [<a 2197href="#resources37">Resources, 37</a>], and MUST implement the Android 4.3 NFC 2198API as a no-op.</p> 2199<p>As the classes <code>android.nfc.NdefMessage</code> and 2200<code>android.nfc.NdefRecord</code> represent a protocol-independent data 2201representation format, device implementations MUST implement these APIs even 2202if they do not include support for NFC or declare the android.hardware.nfc 2203feature.</p> 2204<a name="section-7.4.5"></a><h4>7.4.5. Minimum Network Capability</h4> 2205<p>Device implementations MUST include support for one or more forms of data 2206networking. Specifically, device implementations MUST include support for at 2207least one data standard capable of 200Kbit/sec or greater. Examples of 2208technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 2209Ethernet, etc.</p> 2210<p>Device implementations where a physical networking standard (such as 2211Ethernet) is the primary data connection SHOULD also include support for at 2212least one common wireless data standard, such as 802.11 (WiFi).</p> 2213<p>Devices MAY implement more than one form of data connectivity.</p> 2214 2215 2216<a name="section-7.5"></a><h3>7.5. Cameras</h3> 2217<p>Device implementations SHOULD include a rear-facing camera, and MAY include 2218a front-facing camera. A rear-facing camera is a camera located on the side of 2219the device opposite the display; that is, it images scenes on the far side of 2220the device, like a traditional camera. A front-facing camera is a camera 2221located on the same side of the device as the display; that is, a camera 2222typically used to image the user, such as for video conferencing and similar 2223applications.</p> 2224<a name="section-7.5.1"></a><h4>7.5.1. Rear-Facing Camera</h4> 2225<p>Device implementations SHOULD include a rear-facing camera. If a device 2226implementation includes a rear-facing camera, it:</p> 2227<ul> 2228<li>MUST have a resolution of at least 2 megapixels</li> 2229<li>SHOULD have either hardware auto-focus, or software auto-focus implemented 2230in the camera driver (transparent to application software)</li> 2231<li>MAY have fixed-focus or EDOF (extended depth of field) hardware</li> 2232<li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST 2233NOT be lit while an android.hardware.Camera.PreviewCallback instance has been 2234registered on a Camera preview surface, unless the application has explicitly 2235enabled the flash by enabling the <code>FLASH_MODE_AUTO</code> or 2236<code>FLASH_MODE_ON</code> attributes of a <code>Camera.Parameters</code> 2237object. Note that this constraint does not apply to the device's built-in 2238system camera application, but only to third-party applications using 2239<code>Camera.PreviewCallback</code>.</li> 2240</ul> 2241<a name="section-7.5.2"></a><h4>7.5.2. Front-Facing Camera</h4> 2242<p>Device implementations MAY include a front-facing camera. If a device 2243implementation includes a front-facing camera, it:</p> 2244<ul> 2245<li>MUST have a resolution of at least VGA (that is, 640x480 pixels)</li> 2246<li>MUST NOT use a front-facing camera as the default for the Camera API. 2247That is, the camera API in Android 4.3 has specific support for front-facing 2248cameras, and device implementations MUST NOT configure the API to to treat a 2249front-facing camera as the default rear-facing camera, even if it is the only 2250camera on the device.</li> 2251<li>MAY include features (such as auto-focus, flash, etc.) 2252available to rear-facing cameras as described in Section 7.5.1.</li> 2253<li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 2254CameraPreview, as follows:</li> 2255<ul> 2256<li>If the device implementation is capable of being rotated by user (such as 2257automatically via an accelerometer or manually via user input), the camera 2258preview MUST be mirrored horizontally relative to the device's current 2259orientation.</li> 2260<li>If the current application has explicitly requested that the Camera 2261display be rotated via a call to the 2262<code>android.hardware.Camera.setDisplayOrientation()</code> [<a 2263href="#resources50">Resources, 50</a>] method, the camera preview MUST be 2264mirrored horizontally relative to the orientation specified by the 2265application.</li> 2266<li>Otherwise, the preview MUST be mirrored along the device's default horizontal axis.</li> 2267</ul> 2268<li>MUST mirror the image displayed by the postview in the same manner as 2269the camera preview image stream. (If the device implementation does not 2270support postview, this requirement obviously does not apply.)</li> 2271<li>MUST NOT mirror the final captured still image or video streams returned 2272to application callbacks or committed to media storage</li> 2273</ul> 2274<a name="section-7.5.3"></a><h4>7.5.3. Camera API Behavior</h4> 2275<p>Device implementations MUST implement the following behaviors for the 2276camera-related APIs, for both front- and rear-facing cameras:</p> 2277<ol> 2278<li>If an application has never called 2279<code>android.hardware.Camera.Parameters.setPreviewFormat(int)</code>, then the 2280device MUST use <code>android.hardware.PixelFormat.YCbCr_420_SP</code> for 2281preview data provided to application callbacks.</li> 2282<li>If an application registers an <code>android.hardware.Camera.PreviewCallback 2283</code> instance and the system calls the <code>onPreviewFrame()</code> method 2284when the preview format is YCbCr_420_SP, the data in the <code>byte[]</code> 2285passed into <code>onPreviewFrame()</code> must further be in the NV21 encoding 2286format. That is, NV21 MUST be the default.</li> 2287<li>Device implementations MUST support the YV12 format (as denoted by the 2288<code>android.graphics.ImageFormat.YV12</code> constant) for camera previews 2289for both front- and rear-facing cameras. (The hardware video encoder and camera 2290may use any native pixel format, but the device implementation MUST support conversion 2291to YV12.)</li> 2292</ol> 2293<p>Device implementations MUST implement the full Camera API included in the 2294Android 4.3 SDK documentation [<a href="#resources51">Resources, 51</a>]), 2295regardless of whether the device includes hardware autofocus or other 2296capabilities. For instance, cameras that lack autofocus MUST still call any 2297registered <code>android.hardware.Camera.AutoFocusCallback</code> instances (even though 2298this has no relevance to a non-autofocus camera.) Note that this does apply 2299to front-facing cameras; for instance, even though most front-facing cameras 2300do not support autofocus, the API callbacks must still be "faked" as 2301described.</p> 2302<p>Device implementations MUST recognize and honor each parameter name defined 2303as a constant on the <code>android.hardware.Camera.Parameters</code> class, if the 2304underlying hardware supports the feature. If the device hardware does not 2305support a feature, the API must behave as documented. Conversely, Device 2306implementations MUST NOT honor or recognize string constants passed 2307to the <code>android.hardware.Camera.setParameters()</code> method other than 2308those documented as constants on the 2309<code>android.hardware.Camera.Parameters</code>. That is, 2310device implementations MUST support all standard Camera parameters if the 2311hardware allows, and MUST NOT support custom Camera parameter types. 2312For instance, device implementations that support image capture using high dynamic range (HDR) 2313imaging techniques MUST support camera parameter <code>Camera.SCENE_MODE_HDR</code> 2314[<a href="#resources78">Resources, 78</a>]).</p> 2315<p>Device implementations MUST broadcast the <code>Camera.ACTION_NEW_PICTURE</code> 2316intent whenever a new picture is taken by the camera and the entry of the picture 2317has been added to the media store.</p> 2318<p>Device implementations MUST broadcast the <code>Camera.ACTION_NEW_VIDEO</code> 2319intent whenever a new video is recorded by the camera and the entry of the picture 2320has been added to the media store.</p> 2321<a name="section-7.5.4"></a><h4>7.5.4. Camera Orientation</h4> 2322<p>Both front- and rear-facing cameras, if present, MUST be oriented so that 2323the long dimension of the camera aligns with the screen's long dimension. That 2324is, when the device is held in the landscape orientation, cameras MUST 2325capture images in the landscape orientation. This applies regardless of the 2326device's natural orientation; that is, it applies to landscape-primary devices 2327as well as portrait-primary devices.</p> 2328 2329<a name="section-7.6"></a><h3>7.6. Memory and Storage</h3> 2330<a name="section-7.6.1"></a><h4>7.6.1. Minimum Memory and Storage</h4> 2331<p>Device implementations MUST have at least 340MB of memory available to the 2332kernel and userspace. The 340MB MUST be in addition to any memory dedicated to 2333hardware components such as radio, video, and so on that is not under the 2334kernel's control.</p> 2335<p>Device implementations MUST have at least 512MB of non-volatile storage available 2336for application private data. That is, the <code>/data</code> partition MUST be at 2337least 512MB. Device implementations that run Android 4.3 are <b>very strongly encouraged to 2338have at least 1GB of non-volatile storage for application private data</b> so they will be 2339able to upgrade to the future platform releases.</p> 2340 2341<p>The Android APIs include a Download Manager that applications may use to 2342download data files [<a href="#resources56">Resources, 56</a>]. The device 2343implementation of the Download Manager MUST be capable of downloading individual 2344files of at least 100MB in size to the default "cache" location.</p> 2345<a name="section-7.6.2"></a><h4>7.6.2. Application Shared Storage</h4> 2346<p>Device implementations MUST offer shared storage for applications. The 2347shared storage provided MUST be at least 1GB in size.</p> 2348<p>Device implementations MUST be configured with shared storage mounted by 2349default, "out of the box". If the shared storage is not mounted on the Linux 2350path <code>/sdcard</code>, then the device MUST include a Linux symbolic link 2351from <code>/sdcard</code> to the actual mount point.</p> 2352<p>Device implementations MUST enforce as documented the 2353<code>android.permission.WRITE_EXTERNAL_STORAGE</code> permission on this 2354shared storage. Shared storage MUST otherwise be writable by any application 2355that obtains that permission.</p> 2356<p>Device implementations MAY have hardware for user-accessible removable 2357storage, such as a Secure Digital card. Alternatively, device implementations 2358MAY allocate internal (non-removable) storage as shared storage for apps.</p> 2359<p>Regardless of the form of shared storage used, device implementations MUST 2360provide some mechanism to access the contents of shared storage from a host 2361computer, such as USB mass storage (UMS) or Media Transfer Protocol (MTP). Device 2362implementations MAY use USB mass storage, but SHOULD use Media Transfer 2363Protocol. If the device implementation supports Media Transfer Protocol:</p> 2364<ul> 2365<li>The device implementation SHOULD be compatible with the reference Android 2366MTP host, Android File Transfer [<a href="#resources57">Resources, 57</a>].</li> 2367<li>The device implementation SHOULD report a USB device class of <code>0x00</code>.</li> 2368<li>The device implementation SHOULD report a USB interface name of 'MTP'.</li> 2369</ul> 2370<p>If the device implementation lacks USB ports, it MUST provide a host 2371computer with access to the contents of shared storage by some other means, 2372such as a network file system.</p> 2373<p>It is illustrative to consider two common examples. If a device 2374implementation includes an SD card slot to satisfy the shared storage 2375requirement, a FAT-formatted SD card 1GB in size or larger MUST be included 2376with the device as sold to users, and MUST be mounted by default. 2377Alternatively, if a device implementation uses internal fixed storage to 2378satisfy this requirement, that storage MUST be 1GB in size or larger 2379and mounted on <code>/sdcard</code> (or <code>/sdcard</code> 2380MUST be a symbolic link to the physical location if it is mounted elsewhere.)</p> 2381<p>Device implementations that include multiple shared storage paths (such as 2382both an SD card slot and shared internal storage) SHOULD modify the core 2383applications such as the media scanner and ContentProvider to transparently 2384support files placed in both locations.</p> 2385 2386<a name="section-7.7"></a><h3>7.7. USB</h3> 2387<p>Device implementations SHOULD include a USB client port, and SHOULD include 2388a USB host port.</p> 2389<p>If a device implementation includes a USB client port:</p> 2390<ul> 2391<li>the port MUST be connectable to a USB host with a standard USB-A port</li> 2392<li>the port SHOULD use the micro USB form factor on the device side. Existing and 2393new devices that run Android 4.3 are <b>very strongly encouraged to meet these requirements 2394in Android 4.3</b> so they will be able to upgrade to the future platform releases</li> 2395<li>the port SHOULD be centered in the middle of an edge. Device implementations SHOULD either 2396locate the port on the bottom of the device (according to natural orientation) or enable software 2397screen rotation for all apps (including home screen), so that the display draws correctly when the device 2398is oriented with the port at bottom. Existing and new devices that run Android 4.3 are <b>very strongly 2399encouraged to meet these requirements in Android 4.3</b> so they will be able to upgrade to future platform releases.</li> 2400<li>if the device has other ports (such as a non-USB charging port) it SHOULD be on the same edge as the 2401micro-USB port</li> 2402<li>it MUST allow a host connected to the device to access the contents of the 2403shared storage volume using either USB mass storage or Media Transfer 2404Protocol</li> 2405<li>it MUST implement the Android Open Accessory API and specification as documented 2406in the Android SDK documentation, and MUST declare support for the hardware 2407feature <code>android.hardware.usb.accessory</code> [<a href="#resources52">Resources, 240852</a>]</li> 2409<li>it MUST implement the USB audio class as documented in the Android SDK documentation [<a href="#resources66">Resources, 66</a>]</li> 2410<li>it SHOULD implement support for USB battery charging specification [<a href="#resources64">Resources, 64</a>] 2411Existing and new devices that run Android 4.3 are <b>very strongly encouraged to meet these requirements in Android 4.3</b> 2412so they will be able to upgrade to the future platform releases</li> 2413 2414</ul> 2415<p>If a device implementation includes a USB host port:</p> 2416<ul> 2417<li>it MAY use a non-standard port form factor, but if so MUST ship with a 2418cable or cables adapting the port to standard USB-A</li> 2419<li>it MUST implement the Android USB host API as documented in the Android 2420SDK, and MUST declare support for the hardware feature 2421<code>android.hardware.usb.host</code> [<a href="#resources53">Resources, 53</a>]</li> 2422</ul> 2423<p>Device implementations MUST implement the Android Debug Bridge. If a device 2424implementation omits a USB client port, it MUST implement the Android Debug 2425Bridge via local-area network (such as Ethernet or 802.11)</p> 2426 2427<a name="section-8"></a><h2>8. Performance Compatibility</h2> 2428<p>Device implementations MUST meet the key performance metrics of an Android 24294.3 compatible device defined in the table below:</p> 2430<table><tbody><tr> 2431<td><b>Metric</b></td> 2432<td><b>Performance Threshold</b></td> 2433<td><b>Comments</b></td> 2434</tr> 2435<tr> 2436<td>Application Launch Time</td> 2437<td>The following applications should launch within the specified time.<ul> 2438<li>Browser: less than 1300ms</li> 2439<li>Contacts: less than 700ms</li> 2440<li>Settings: less than 700ms</li> 2441</ul></td> 2442<td>The launch time is measured as the total time to 2443complete loading the default activity for the application, including the time 2444it takes to start the Linux process, load the Android package into the Dalvik 2445VM, and call onCreate.</td> 2446</tr> 2447<tr> 2448<td>Simultaneous Applications</td> 2449<td>When multiple applications have been launched, re-launching an 2450already-running application after it has been launched must take less than the 2451original launch time.</td> 2452<td> </td> 2453</tr> 2454</tbody> 2455</table> 2456 2457<a name="section-9"></a><h2>9. Security Model Compatibility</h2> 2458<p>Device implementations MUST implement a security model consistent with the 2459Android platform security model as defined in Security and Permissions 2460reference document in the APIs [<a href="#resources54">Resources, 54</a>] in the 2461Android developer documentation. Device implementations MUST support 2462installation of self-signed applications without requiring any additional 2463permissions/certificates from any third parties/authorities. Specifically, 2464compatible devices MUST support the security mechanisms described in the 2465follow sub-sections.</p> 2466<a name="section-9.1"></a><h3>9.1. Permissions</h3> 2467<p>Device implementations MUST support the Android permissions model as 2468defined in the Android developer documentation [<a 2469href="#resources54">Resources, 54</a>]. Specifically, 2470implementations MUST enforce each permission defined as described in the SDK 2471documentation; no permissions may be omitted, altered, or ignored. 2472Implementations MAY add additional permissions, provided the new permission ID 2473strings are not in the android.* namespace.</p> 2474<a name="section-9.2"></a><h3>9.2. UID and Process Isolation</h3> 2475<p>Device implementations MUST support the Android application sandbox model, 2476in which each application runs as a unique Unix-style UID and in a separate 2477process. Device implementations MUST support running multiple applications as 2478the same Linux user ID, provided that the applications are properly signed and 2479constructed, as defined in the Security and Permissions reference [<a 2480href="#resources54">Resources, 54</a>].</p> 2481<a name="section-9.3"></a><h3>9.3. Filesystem Permissions</h3> 2482<p>Device implementations MUST support the Android file access permissions 2483model as defined in the Security and Permissions reference [<a 2484href="#resources54">Resources, 54</a>].</p> 2485<a name="section-9.4"></a><h3>9.4. Alternate Execution Environments</h3> 2486<p>Device implementations MAY include runtime environments that execute 2487applications using some other software or technology than the Dalvik virtual 2488machine or native code. However, such alternate execution environments MUST 2489NOT compromise the Android security model or the security of installed Android 2490applications, as described in this section.</p> 2491<p>Alternate runtimes MUST themselves be Android applications, and abide by 2492 the standard Android security model, as described elsewhere in Section 9.</p> 2493<p>Alternate runtimes MUST NOT be granted access to resources protected by 2494 permissions not requested in the runtime's AndroidManifest.xml file via the 2495 <code><uses-permission></code> mechanism.</p> 2496<p>Alternate runtimes MUST NOT permit applications to make use of features 2497 protected by Android permissions restricted to system applications.</p> 2498<p>Alternate runtimes MUST abide by the Android sandbox model. Specifically:</p> 2499<ul> 2500<li>Alternate runtimes SHOULD install apps via the PackageManager into 2501 separate Android sandboxes (that is, Linux user IDs, etc.)</li> 2502<li>Alternate runtimes MAY provide a single Android sandbox shared by all 2503 applications using the alternate runtime</li> 2504<li>Alternate runtimes and installed applications using an alternate runtime 2505 MUST NOT reuse the sandbox of any other app installed on the device, except 2506 through the standard Android mechanisms of shared user ID and signing 2507 certificate</li> 2508<li>Alternate runtimes MUST NOT launch with, grant, or be granted access to 2509 the sandboxes corresponding to other Android applications</li> 2510</ul> 2511<p>Alternate runtimes MUST NOT be launched with, be granted, or grant to other 2512 applications any privileges of the superuser (root), or of any other user ID.</p> 2513<p>The .apk files of alternate runtimes MAY be included in the system image of 2514 a device implementation, but MUST be signed with a key distinct 2515 from the key used to sign other applications included with the device 2516 implementation.</p> 2517<p>When installing applications, alternate runtimes MUST obtain user consent 2518 for the Android permissions used by the application. That is, if an 2519 application needs to make use of a device resource for which there is a 2520 corresponding Android permission (such as Camera, GPS, etc.), the alternate 2521 runtime MUST inform the user that the application will be able to access 2522 that resource. If the runtime environment does not record application 2523 capabilities in this manner, the runtime environment MUST list all 2524 permissions held by the runtime itself when installing any application 2525 using that runtime.</p> 2526 2527<a name="section-9.5"></a><h3>9.5. Multi-User Support </h3> 2528<p>Android 4.3 includes support for multiple users and provides support for full user isolation 2529[<a href="#resources70">Resources, 70</a>].</p> 2530<p>Device implementations MUST meet these requirements related to multi-user support [<a href="#resources71">Resources, 71</a>]:</p> 2531<ul> 2532<li>As the behavior of the telephony APIs on devices with multiple users is currently undefined, device implementations that 2533declare android.hardware.telephony MUST NOT enable multi-user support. </li> 2534<li>Device implementations MUST, for each user, implement a security model consistent with the Android platform security model 2535as defined in Security and Permissions reference document in the APIs [Resources, 54]</li> 2536<li>Android 4.3 includes support for restricted profiles, a feature that allows device owners to manage additional users and their capabilities 2537on the device. With restricted profiles, device owners can quickly set up separate environments for additional users to work in, with the ability to 2538manage finer-grained restrictions in the apps that are available in those environments. Device implementations that include support for multiple users 2539MUST include support for restricted profiles. The upstream Android Open Source Project includes an implementation that satisfies this requirement.</li> 2540</ul> 2541 2542<p>Each user instance on an Android device MUST have separate and isolated external storage directories. Device implementations MAY store multiple users' data on the same volume or filesystem. 2543However, the device implementation MUST ensure that applications owned by and running on behalf a given user cannot list, read, or write to data owned by any other user. 2544Note that removable media, such as SD card slots, can allow one user to access another's data by means of a host PC. For this reason, device implementations that use removable media for the 2545external storage APIs MUST encrypt the contents of the SD card if multi-user is enabled using a key stored only on non-removable media accessible only to the system. As this will make the 2546media unreadable by a host PC, device implementations will be required to switch to MTP or a similar system to provide host PCs with access to the current user's data. Accordingly, device 2547implementations MAY but SHOULD NOT enable multi-user if they use removable media [<a href="#resources72">Resources, 72</a>] for primary external storage. The upstream Android Open Source 2548Project includes an implementation that uses internal device storage for application external storage APIs; device implementations SHOULD use this configuration and software implementation. 2549Device implementations that include multiple external storage paths MUST NOT allow Android applications to write to the secondary external storage.</p> 2550 2551<a name="section-9.6"></a><h3>9.6. Premium SMS Warning</h3> 2552<p>Android 4.3 includes support for warning users for any outgoing premium SMS message [<a href="#resources73">Resources, 73</a>] . Premium SMS messages are text messages sent to a service registered with a carrier that may incur a charge to the user. 2553Device implementations that declare support for <code>android.hardware.telephony</code> MUST warn users before sending a SMS message to numbers identified by regular expressions defined in <code>/data/misc/sms/codes.xml</code> file in the device. 2554The upstream Android Open Source Project provides an implementation that satisfies this requirement. 2555</p> 2556 2557<a name="section-9.7"></a><h3>9.7. Kernel Security Features</h3> 2558<p>The Android Sandbox in Android 4.3 includes features that can use the SELinux 2559mandatory access control system (MAC) and other security features in the Linux kernel. 2560Device implementations MUST support SELinux MAC. Note that the upstream Android Open Source 2561Project provides an implementation that satisfies this requirement.</p> 2562 2563<p>SELinux or any security features implemented below the Android framework MUST maintain 2564compatibility with existing applications. These features SHOULD be invisible to users and developers. 2565These features SHOULD NOT be user or developer configurable. If any API for configuration of policy is 2566exposed to an application that can affect another application (such as a Device Administration API), 2567the API MUST NOT allow configurations that break compatibility. To ensure continued compatibility the 2568reference implementation allows the use of SELinux in a permissive mode and supports dynamic policy updates 2569without requiring a system image update. Device implementations using SELinux MUST support this permissive 2570mode, support dynamic policy updates and log any policy violations without breaking applications or affecting 2571system behavior. Implementations using SELinux SHOULD load policy from <code>/sepolicy</code> file on the device. 2572The upstream Android Open Source Project provides an implementation that satisfies this requirement. 2573Device implementations SHOULD use the reference implementation in the Android Open Source Project, and 2574device implementations MUST be compatible with the upstream Android Open Source Project.</p> 2575 2576<a name="section-10"></a><h2>10. Software Compatibility Testing</h2> 2577<p>Device implementations MUST pass all tests described in this section.</p> 2578<p>However, note that no software test package is fully comprehensive. For 2579this reason, device implementers are very strongly encouraged to make the 2580minimum number of changes as possible to the reference and preferred 2581implementation of Android 4.3 available from the Android Open Source Project. 2582This will minimize the risk of introducing bugs that create incompatibilities 2583requiring rework and potential device updates.</p> 2584<a name="section-10.1"></a><h3>10.1. Compatibility Test Suite</h3> 2585<p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) 2586[<a href="#resources02">Resources, 2</a>] available from the Android Open Source 2587Project, using the final shipping software on the device. Additionally, device 2588implementers SHOULD use the reference implementation in the Android Open 2589Source tree as much as possible, and MUST ensure compatibility in cases of 2590ambiguity in CTS and for any reimplementations of parts of the reference 2591source code.</p> 2592<p>The CTS is designed to be run on an actual device. Like any software, the 2593CTS may itself contain bugs. The CTS will be versioned independently of this 2594Compatibility Definition, and multiple revisions of the CTS may be released 2595for Android 4.3. Device implementations MUST pass the latest CTS version 2596available at the time the device software is completed.</p> 2597<a name="section-10.2"></a><h3>10.2. CTS Verifier</h3> 2598<p>Device implementations MUST correctly execute all applicable cases in the 2599CTS Verifier. The CTS Verifier is included with the Compatibility Test Suite, 2600and is intended to be run by a human operator to test functionality that 2601cannot be tested by an automated system, such as correct functioning of a 2602camera and sensors.</p> 2603<p>The CTS Verifier has tests for many kinds of hardware, including some 2604hardware that is optional. Device implementations MUST pass all tests for 2605hardware which they possess; for instance, if a device possesses an 2606accelerometer, it MUST correctly execute the Accelerometer test case in the 2607CTS Verifier. Test cases for features noted as optional by this Compatibility 2608Definition Document MAY be skipped or omitted.</p> 2609<p>Every device and every build MUST correctly run the CTS Verifier, as noted 2610above. However, since many builds are very similar, device implementers are 2611not expected to explicitly run the CTS Verifier on builds that differ only in 2612trivial ways. Specifically, device implementations that differ from an 2613implementation that has passed the CTS Verifier only by the set of included 2614locales, branding, etc. MAY omit the CTS Verifier test.</p> 2615<a name="section-10.3"></a><h3>10.3. Reference Applications</h3> 2616<p>Device implementers MUST test implementation compatibility using the 2617following open source applications:</p> 2618<ul> 2619<li>The "Apps for Android" applications [<a href="#resources55">Resources, 55</a>]</li> 2620<li>Replica Island (available in Google Play Store)</li> 2621</ul> 2622<p>Each app above MUST launch and behave correctly on the implementation, for 2623the implementation to be considered compatible.</p> 2624 2625 2626<a name="section-11"></a><h2>11. Updatable Software</h2> 2627<p>Device implementations MUST include a mechanism to replace the entirety of 2628the system software. The mechanism need not perform "live" upgrades - that 2629is, a device restart MAY be required.</p> 2630<p>Any method can be used, provided that it can replace the entirety of the 2631software preinstalled on the device. For instance, any of the following 2632approaches will satisfy this requirement:</p> 2633<ul> 2634<li>Over-the-air (OTA) downloads with offline update via reboot</li> 2635<li>"Tethered" updates over USB from a host PC</li> 2636<li>"Offline" updates via a reboot and update from a file on removable 2637storage</li> 2638</ul> 2639<p>The update mechanism used MUST support updates without wiping user data. 2640That is, the update mechanism MUST preserve application private data 2641and application shared data. Note that the upstream Android software includes 2642an update mechanism that satisfies this requirement.</p> 2643<p>If an error is found in a device implementation after it has been released 2644but within its reasonable product lifetime that is determined in consultation 2645with the Android Compatibility Team to affect the compatibility of third-party 2646applications, the device implementer MUST correct the error via a software 2647update available that can be applied per the mechanism just described.</p> 2648 2649<a name="section-12"></a><h2>12. Contact Us</h2> 2650<p>You can contact the document authors at <a 2651href="mailto:compatibility@android.com">compatibility@android.com</a> for 2652clarifications and to bring up any issues that you think the document does not 2653cover.</p> 2654 2655<div style="page-break-before: always;"></div> 2656 2657<div id="footerContent" xmlns:pdf="http://whatever"> 2658<pdf:pagenumber/> 2659</div> 2660</body> 2661</html> 2662
