API Level: 9
For developers, the Android 2.3 platform is available as a downloadable component for the Android SDK. The downloadable platform includes an Android library and system image, as well as a set of emulator skins and more. The downloadable platform includes no external libraries.
To get started developing or testing against Android 2.3, use the Android SDK Manager to download the platform into your SDK. For more information, see Adding SDK Components. If you are new to Android, download the SDK Starter Package first.
For a high-level introduction to Android 2.3, see the Platform Highlights.
The sections below provide notes about successive releases of the Android 2.3 platform component for the Android SDK, as denoted by revision number. To determine what revision(s) of the Android 2.3 platforms are installed in your SDK environment, refer to the "Installed Packages" listing in the Android SDK and AVD Manager.
Android 2.3, Revision 1 (December 2010)
Requires SDK Tools r8 or higher.
The sections below provide a technical overview of what's new for developers in 2.3, including new features and changes in the framework API since the previous version.
The platform now includes a SIP protocol stack and framework API that lets developers build internet telephony applications. Using the API, applications can offer voice calling features without having to manage sessions, transport-level communication, or audio — these are handled transparently by the platform's SIP API and services.
The SIP API is available in the android.net.sip
package. The key class is SipManager, which applications
use to set up and manage SIP profiles, then initiate audio calls and receive
audio calls. Once an audio call is established, applications can mute calls,
turn on speaker mode, send DTMF tones, and more. Applications can also use the
SipManager to create generic SIP connections.
The platform’s underlying SIP stack and services are available on devices at
the discretion of the manufacturer and associated carrier. For this reason,
applications should use the isApiSupported() method to check whether SIP support is available, before
exposing calling functionality to users.
To use the SIP API, applications must request permission from the user by
declaring <uses-permission
android:name="android.permission.INTERNET"> and <uses-permission
android:name="android.permission.USE_SIP"> in their manifest files.
Additionally, developers can request filtering on Android Market, such that
their applications are not discoverable to users whose devices do not include
the platform’s SIP stack and services. To request filtering, add <uses-feature
android:name="android.software.sip"
android:required="true"> and <uses-feature
android:name="android.software.sip.voip"> to the application manifest.
To look at a sample application that uses the SIP API, see SIP Demo.
Android 2.3 includes an NFC stack and framework API that lets developers read NDEF tags that are discovered as a user touches an NFC-enabled device to tag elements embedded in stickers, smart posters, and even other devices.
The platform provides the underlying NFC services that work with the device hardware to discover tags when they come into range. On discovering a tag, the platform notifies applications by broadcasting an Intent, appending the tag's NDEF messages to the Intent as extras. Applications can create Intent filters to recognize and handle targeted tags and messages. For example, after receiving a tag by Intent, applications extract the NDEF messages, store them, alert the user, or handle them in other ways.
The NFC API is available in the android.nfc package. The key classes are:
NfcAdapter, which represents the NFC hardware on the device.NdefMessage, which represents an NDEF data message,
the standard format in which "records" carrying data are transmitted between
devices and tags. Applications can receive these messages from ACTION_TAG_DISCOVERED Intents.NdefRecord, delivered in an
NdefMessage, which describes the type of data being shared and
carries the data itself.NFC communication relies on wireless technology in the device hardware, so
support for the platform's NFC features on specific devices is determined by
their manufacturers. To determine the NFC support on the current device,
applications can call isEnabled() to
query the NfcAdapter. The NFC API is always present,
however, regardless of underlying hardware support.
To use the NFC API, applications must request permission from the user by
declaring <uses-permission
android:name="android.permission.NFC"> in their manifest files.
Additionally, developers can request filtering on Android Market, such that
their applications are not discoverable to users whose devices do not support
NFC. To request filtering, add
<uses-feature android:name="android.hardware.nfc"
android:required="true"> to the application's manifest.
To look at a sample application that uses the NFC API, see NFCDemo.
Android 2.3 adds platform and API support for several new sensor reading types — gyroscope, rotation vector, linear acceleration, gravity, and barometer. Developers can use the new sensor readings to create applications that respond quickly and smoothly to precise changes in device position and motion. The Sensor API reports gyroscope and other sensor changes to interested applications, whether they are running on the application framework or in native code.
Note that the specific set of hardware sensors available on any given device varies at the discretion of the device manufacturer.
Developers can request filtering in Android Market, such that their
applications are not discoverable to users whose devices do not offer a
gyroscope sensor. To do so, add <uses-feature
android:name="android.hardware.sensor.gyroscope"
android:required="true"> to the application manifest.
For API details, see Sensor
Applications can now make use of any cameras that are available on a device,
for either photo or video capture. The Camera lets
applications query for the number of cameras available and the unique
characteristics of each.
Camera.CameraInfo class stores a camera's
positional characteristics (orientation, front-facing or back-facing).getNumberOfCameras(), getCameraInfo(), and
getNumberOfCameras() methods in the Camera class let applications query for the cameras available
and open the camera that they need.get(int,int) method lets
applications retrieve a CamcorderProfile for a specific camera. To look at sample code for accessing a front-facing camera, see CameraPreview.java in the ApiDemos sample application.
The Camera API also adds:
getFocusDistances(), getPreviewFpsRange(), and getSupportedPreviewFpsRange() for getting camera parameters, as well as setPreviewFpsRange() for setting preview framerate. The platform's media framework adds support for new per-track or global audio effects, including bass boost, headphone virtualization, equalization, and reverb.
android.media.audiofx package provides the
API to access audio effects.AudioEffect is the base class
for controlling audio effects provided by the Android audio framework.
AudioTrack or MediaPlayer.AudioTrack class constructor that lets you create an AudioTrack with a specific session ID. New attachAuxEffect(), getAudioSessionId(), and setAuxEffectSendLevel()
methods.attachAuxEffect(), getAudioSessionId(), setAudioSessionId(int), and setAuxEffectSendLevel()
methods and supporting types.To look at sample code for audio effects, see AudioFxDemo.java in the ApiDemos sample application.
The media framework also adds:
getAltitude() method to
retrieve the value of the EXIF altitude tag.setOrientationHint() method lets an application tell MediaRecorder of the orientation during video capture.The platform includes a new DownloadManager system service
that handles long-running HTTP downloads. Applications can request that a URI be
downloaded to a particular destination file. The DownloadManager
will conduct the download in the background, taking care of HTTP interactions
and retrying downloads after failures or across connectivity changes and system
reboots.
DownloadManager
class by calling getSystemService(String) and passing
DOWNLOAD_SERVICE. Applications that request
downloads through this API should register a broadcast receiver for ACTION_NOTIFICATION_CLICKED, to appropriately
handle when the user clicks on a running download in a notification or from the
Downloads UI.DownloadManager.Request class lets an
application provide all the information necessary to request a new download,
such as request URI and download destination. A request URI is the only required
parameter. Note that the default download destination is a shared volume where
the system can delete your file if it needs to reclaim space for system use. For
persistent storage of a download, specify a download destination on external
storage (see setDestinationUri(Uri)).DownloadManager.Query class provides methods that let
an application query for and filter active downloads.To help developers monitor and improve the performance of their applications,
the platform offers a new system facility called StrictMode.
When implemented in an application, StrictMode catches and notifies the
developer of accidental disk or network activity that could degrade application
performance, such as activity taking place on the application's main thread
(where UI operations are received and animations are also taking place).
Developers can evaluate the network and disk usages issues raised in StrictMode
and correct them if needed, keeping the main thread more responsive and
preventing ANR dialogs from being shown to users.
StrictMode is the core class and is the main integration
point with the system and VM. The class provides convenience methods for
managing the thread and VM policies that apply to the instance.StrictMode.ThreadPolicy and StrictMode.VmPolicy hold the policies that you define and apply to
thread and VM instances.For more information about how to use StrictMode to optimize your
application, see the class documentation and sample code at android.os.StrictMode.
android.view.View and android.widget.OverScroller. ViewConfiguration also provides methods getScaledOverflingDistance() and getScaledOverscrollDistance().overScrollMode, overScrollFooter, and
overScrollHeader attributes for <ListView> elements,
for controlling overscroll behavior.filterTouchesWhenObscured attribute for view elements,
which declares whether to filter touches when the view's window is obscured by
another visible window. When set to "true", the view will not
receive touches whenever a toast, dialog or other window appears above the
view's window. Refer to View security
documentation for details.To look at sample code for touch filtering, see SecureView.java in the ApiDemos sample application.
InputEvent. The class
provides methods that let applications determine the meaning of the event, such
as by querying for the InputDevice from which the event orginated. The KeyEvent and MotionEvent are subclasses of
InputEvent.InputDevice. The
class stores information about the capabilities of a particular input device and
provides methods that let applications determine how to interpret events from an
input device.MotionEvent API is extended to include "pointer ID"
information, which lets applications to keep track of individual fingers as they
move up and down. The class adds a variety of methods that let an application
work efficiently with motion events.setComposingRegion method lets an application mark a
region of text as composing text, maintaining the current styling. A
getSelectedText method returns the selected text to the
application. The methods are available in BaseInputConnection, InputConnection, and InputConnectionWrapper.textSelectHandle, textSelectHandleLeft,
textSelectHandleRight, and textSelectHandleWindowStyle
attributes for <TextView>, for referencing drawables that will be
used to display text-selection anchors and the style for the containing
window.ActivityInfo adds new constants for managing
Activity orientation:
SCREEN_ORIENTATION_FULL_SENSOR,
SCREEN_ORIENTATION_REVERSE_LANDSCAPE,
SCREEN_ORIENTATION_REVERSE_PORTRAIT,
SCREEN_ORIENTATION_SENSOR_LANDSCAPE,
and
SCREEN_ORIENTATION_SENSOR_PORTRAIT.
IMPORTANCE_PERCEPTIBLE for
the importance field
in ActivityManager.RunningAppProcessInfo. The value
indicates that a specific process is running something that is considered to be
actively perceptible to the user. An example would be an application performing
background music playback.setPersistent(boolean) method to mark an
Activity as persistent is now deprecated and the implementation is a no-op.TextAppearance.StatusBar.EventContent,
TextAppearance.StatusBar.EventContent.Title,
TextAppearance.StatusBar.Icon, and
TextAppearance.StatusBar.Title for managing
notification style.setUseWebViewBackgroundForOverscrollBackground() method lets a WebView specify whether to use its own background for the
overscroll background. The platform now supports extra large screen sizes, such as those that might
be found on tablet devices. Developers can indicate that their applications are
designed to support extra large screen sizes by adding a <supports
screens ... android:xlargeScreens="true"> element to their manifest
files. Applications can use a new resource qualifier, xlarge, to
tag resources that are specific to extra large screens. For
details on how to support extra large and other screen sizes, see Supporting Multiple
Screens.
glDrawElements() and
glVertexAttribPointer() in the android.opengl.GLES20 class.YV12 pixel format, a
planar 4:2:0 YCrCb format.AlarmClock provider class for setting an alarm
or handling an alarm. The provider contains a ACTION_SET_ALARM Intent
action and extras that can be used to start an Activity to set a new alarm in an
alarm clock application. Applications that wish to receive the
SET_ALARM Intent should create an activity that requires the
the SET_ALARM permission. Applications that wish to create a new
alarm should use Context.startActivity(), so that the user has the option of choosing
which alarm clock application to use.MediaStore supports a new Intent action, PLAY_FROM_SEARCH, that lets an application search for music media and
automatically play content from the result when possible. For example, an
application could fire this Intent as the result of a voice recognition command
to listen to music.MediaStore also adds a new MEDIA_IGNORE_FILENAME flag that tells the media
scanner to ignore media in the containing directory and its subdirectories.
Developers can use this to avoid having graphics appear in the Gallery and
likewise prevent application sounds and music from showing up in the Music
app.Settings provider adds the new Activity actions
APPLICATION_DETAILS_SETTINGS and MANAGE_ALL_APPLICATIONS_SETTINGS, which let an application show the details
screen for a specific application or show the Manage Applications screen. ContactsContract provider adds the ContactsContract.CommonDataKinds.SipAddress data kind, for
storing a contact's SIP (Internet telephony) address. LocationManager now tracks application
requests that result in wake locks or wifi locks according to
WorkSource, a system-managed class that identifies the
application.
The LocationManager keeps track
of all clients requesting periodic updates, and tells its providers
about them as a WorkSource parameter, when setting their minimum
update times.
The network location provider uses WorkSource to track the
wake and wifi locks initiated by an application and adds it to the application's
battery usage reported in Manage Applications.
LocationManager adds several new methods that
let an Activity register to receive periodic or one-time location updates based
on specified criteria (see below).Criteria class lets an application specify a
set of criteria for selecting a location provider. For example, providers may be
ordered according to accuracy, power usage, ability to report altitude, speed,
and bearing, and monetary cost. StorageManager that
supports OBB (Opaque Binary Blob) files. Although platform support for OBB is
available in Android 2.3, development tools for creating and managing OBB files
will not be availble until early 2011.isExternalStorageRemovable(), lets applications
determine whether a physical SD card is present.PackageInfo adds new firstInstallTime and lastUpdateTime fields that store the time of the
package installation and last update. getProviderInfo() method for retrieving all of the information known about
a particular content provider class.TelephonyManager adds the constant NETWORK_TYPE_EVDO_B for specifying the CDMA
EVDO Rev B network type.getPsc() method returns
the primary scrambling code of the serving cell on a UMTS network.Android 2.3 exposes a broad set of APIs to applications that use native code. Framework classes of interest to such applications include:
NativeActivity is a new type of Activity class, whose
lifecycle callbacks are implemented directly in native code. A
NativeActivity and its underlying native code run in the system
just as do other Activities — specifically they run in the Android
application's system process and execute on the application's main UI thread,
and they receive the same lifecycle callbacks as do other Activities. InputQueue class and callback interface lets native
code manage event queueing. SurfaceHolder.Callback2 interface lets native code
manage a SurfaceHolder. takeInputQueue and takeSurface() methods in Window let native code manage
events and surfaces.For full information on working with native code or to download the NDK, see the Android NDK page.
dalvik.system
removes several classes that were previously deprecated.ArrayDeque, NavigableMap,
ConcurrentSkipListMap,
LinkedBlockingDequeArrays utilities: binarySearch(),
copyOf(), copyOfRange(), and others.CookieManager for HttpURLConnection.InterfaceAddress,
NetworkInterface and IDNFile read and write controlsString.isEmpty()Normalizer and Normalizer.Formjavax.net.ssl server sockets.xlargeScreens attribute for <supports-screens>
element, to indicate whether the application supports
extra large screen form-factors. For details, see Supporting Multiple
Screens.android:screenOrientation attribute of
<activity> element:
"reverseLandscape" — The Activity would like to have the
screen in landscape orientation, turned in the opposite direction from normal
landscape."reversePortait" — The Activity would like to have the
screen in portrait orientation, turned in the opposite direction from normal
portrait."sensorLandscape" — The Activity would like to have the
screen in landscape orientation, but can use the sensor to change which
direction the screen is facing."sensorPortrait" — The Activity would like to have the
screen in portrait orientation, but can use the sensor to change which direction
the screen is facing."fullSensor" — Orientation is determined by a physical
orientation sensor: the display will rotate based on how the user moves the
device. This allows any of the 4 possible rotations, regardless of what the
device will normally do (for example some devices won't normally use 180 degree
rotation).com.android.permission.SET_ALARM — Allows an application
to broadcast an Intent to set an alarm for the user. An Activity that handles
the SET_ALARM Intent action
should require this permission.android.permission.USE_SIP — Allows an application to use
the SIP API to make or receive internet calls.
android.permission.NFC — Allows an application to use the
NFC API to make or receive internet calls.The platform adds several new hardware features that developers can declare in their application manifests as being required by their applications. This lets developers control how their application is filtered, when published on Android Market.
android.hardware.audio.low_latency — The application uses a low-latency
audio pipeline on the device and is sensitive to delays or lag in sound input or
output.android.hardware.camera.front — The application uses a front-facing
camera on the device.android.hardware.nfc
— The application uses NFC radio features in the device.android.hardware.sensor.barometer — The application uses the device's
barometer.android.hardware.sensor.gyroscope — The application uses the device's
gyroscope sensor.android.software.sip
— The application uses the SIP API on the device.android.software.sip.voip — The application uses a SIP-based VOIP
service on the device.android.hardware.touchscreen.multitouch.jazzhand — The application uses
advanced multipoint multitouch capabilities on the device screen, for tracking
up to five points fully independently.For full information about how to declare features and use them for
filtering, see the documentation for <uses-feature>.
For a detailed view of all API changes in Android 2.3 (API Level 9), see the API Differences Report.
The Android 2.3 platform delivers an updated version of the framework API. The Android 2.3 API is assigned an integer identifier — 9 — that is stored in the system itself. This identifier, called the "API Level", allows the system to correctly determine whether an application is compatible with the system, prior to installing the application.
To use APIs introduced in Android 2.3 in your application,
you need compile the application against the Android library that is provided in
the Android 2.3 SDK platform. Depending on your needs, you might
also need to add an android:minSdkVersion="9"
attribute to the <uses-sdk> element in the application's
manifest. If your application is designed to run only on Android 2.3 and higher,
declaring the attribute prevents the application from being installed on earlier
versions of the platform.
For more information about how to use API Level, see the API Levels document.
The system image included in the downloadable platform provides these built-in applications:
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The system image included in the downloadable SDK platform provides a variety of built-in locales. In some cases, region-specific strings are available for the locales. In other cases, a default version of the language is used. The languages that are available in the Android 2.3 system image are listed below (with language_country/region locale descriptor).
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Note: The Android platform may support more locales than are included in the SDK system image. All of the supported locales are available in the Android Open Source Project.
The downloadable platform includes a set of emulator skins that you can use for modeling your application in different screen sizes and resolutions. The emulator skins are:
For more information about how to develop an application that displays and functions properly on all Android-powered devices, see Supporting Multiple Screens.