API Level: 11
For developers, the Android 3.0 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 3.0, 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 3.0, see the Platform Highlights.
Note: If you've already published an Android application, please test and optimize your application on Android 3.0 as soon as possible. You should do so to be sure your application provides the best experience possible on the latest Android-powered devices. For information about what you can do, read Optimizing Apps for Android 3.0.
To determine what revision of the Android 3.0 platform you have installed, refer to the "Installed Packages" listing in the Android SDK and AVD Manager.
Android 3.0, Revision 1 (February 2011)
Requires SDK Tools r10 or higher.
The sections below provide a technical overview of what's new for developers in Android 3.0, including new features and changes in the framework API since the previous version.
A fragment is a new framework component that allows you to separate distinct elements of an
activity into self-contained modules that define their own UI and lifecycle. To create a
fragment, you must extend the Fragment class and implement several lifecycle
callback methods, similar to an Activity. You can then combine multiple
fragments in a single activity to build a multi-pane UI in which each
pane manages its own lifecycle and user inputs.
You can also use a fragment without providing a UI and instead use the fragment as a worker for the activity, such as to manage the progress of a download that occurs only while the activity is running.
Additionally:
To manage the fragments in your activity, you must use the FragmentManager, which provides several APIs for interacting with fragments, such
as finding fragments in the activity and popping fragments off the back stack to restore their
previous state.
To perform a transaction, such as add or remove a fragment, you must create a FragmentTransaction. You can then call methods such as add() remove(), or replace(). Once you've applied all
the changes you want to perform for the transaction, you must call commit() and the system applies the fragment transaction to
the activity.
For more information about using fragments, read the Fragments documentation. Several samples are also available in the API Demos application.
The Action Bar is a replacement for the traditional title bar at the top of the activity window. It includes the application logo in the left corner and provides a new interface for items in the Options Menu. Additionally, the Action Bar allows you to:
In your XML declaration for the menu item, include the android:showAsAction attribute with a value of "ifRoom". When there's enough room, the menu
item appears directly in the Action Bar. Otherwise, the item is placed in the
overflow menu, revealed by the menu icon on the right side of the Action Bar.
In the XML declaration for the menu item, add the android:actionViewLayout attribute
with a layout resource or the android:actionViewClass attribute with the class name of a
widget. (You must also declare the android:showAsAction attribute so that the item appears
in the Action Bar.) If there's not enough room in the Action Bar and the item appears in the
overflow menu, it behaves like a regular menu item and does not show the widget.
The application logo is automatically assigned the android.R.id.home ID,
which the system delivers to your activity's onOptionsItemSelected() callback when touched. Simply respond to this ID in your callback
method to perform an action such as go to your application's "home" activity.
To replace the icon with a logo, specify your application logo in the manifest file with the
android:logo
attribute, then call setDisplayUseLogoEnabled(true) in your activity.
The Action Bar is standard for all applications that use the new holographic theme, which is
also standard when you set either the android:minSdkVersion or android:targetSdkVersion to "11".
For more information about the Action Bar, read the Action Bar documentation. Several samples are also available in the API Demos application.
Applications can now copy and paste data (beyond mere text) to and from the system-wide clipboard. Clipped data can be plain text, a URI, or an intent.
By providing the system access to the data you want the user to copy, through a content provider, the user can copy complex content (such as an image or data structure) from your application and paste it into another application that supports that type of content.
To start using the clipboard, get the global ClipboardManager object
by calling getSystemService(CLIPBOARD_SERVICE).
To copy an item to the clipboard, you need to create a new ClipData object, which holds one or more ClipData.Item
objects, each describing a single entity. To create a ClipData object
containing just one ClipData.Item, you can use one of the helper methods,
such as newPlainText(), newUri(), and newIntent(), which each return a ClipData object pre-loaded with the
ClipData.Item you provide.
To add the ClipData to the clipboard, pass it to setPrimaryClip() for your instance of ClipboardManager.
You can then read a file from the clipboard (in order to paste it) by calling getPrimaryClip() on the ClipboardManager. Handling the ClipData you receive can
be complicated and you need to be sure you can actually handle the data type in the clipboard
before attempting to paste it.
The clipboard holds only one piece of clipped data (a ClipData
object) at a time, but one ClipData can contain multiple ClipData.Items.
For more information, read the Copy and Paste documentation. You can also see a simple implementation of copy and paste in the API Demos and a more complete implementation in the Note Pad application.
New APIs simplify drag and drop operations in your application's user interface. A drag
operation is the transfer of some kind of data—carried in a ClipData
object—from one place to another. The start and end point for the drag operation is a View, so the APIs that directly handle the drag and drop operations are
in the View class.
A drag and drop operation has a lifecycle that's defined by several drag actions—each
defined by a DragEvent object—such as ACTION_DRAG_STARTED, ACTION_DRAG_ENTERED, and
ACTION_DROP. Each view that wants to participate in a drag
operation can listen for these actions.
To begin dragging content in your activity, call startDrag()
on a View, providing a ClipData object that represents
the data to drag, a View.DragShadowBuilder to facilitate the "shadow"
that users see under their fingers while dragging, and an Object that can share
information about the drag object with views that may receive the object.
To accept a drag object in a View (receive the "drop"), register the view
with an OnDragListener by calling setOnDragListener(). When a drag event occurs on the view, the
system calls onDrag() for the OnDragListener, which receives a DragEvent
describing the type of drag action has occurred (such as ACTION_DRAG_STARTED, ACTION_DRAG_ENTERED, and
ACTION_DROP). During a drag, the system repeatedly calls onDrag() for the view underneath the drag, to deliver a
stream of drag events. The receiving view can inquire the event type delivered to onDragEvent() by calling getAction() on the DragEvent.
Note: Although a drag event may carry a ClipData object, this is not related to the system clipboard. A drag and drop
operation should never put the dragged data in the system clipboard.
For more information, read the Dragging and Dropping documentation. You can also see an implementation of drag and drop in the API Demos application and the Honeycomb Gallery application.
Android 3.0 supports several new widget classes for more interactive app widgets on the users
Home screen, including: GridView, ListView, StackView, ViewFlipper, and AdapterViewFlipper.
More importantly, you can use the new RemoteViewsService to create app
widgets with collections, using widgets such as GridView, ListView, and StackView that are backed by remote data,
such as from a content provider.
The AppWidgetProviderInfo class (defined in XML with an <appwidget-provider> element) also supports two new fields: autoAdvanceViewId and previewImage. The autoAdvanceViewId field lets you specify the view ID of the
app widget subview that should be auto-advanced by the app widget’s host. The
previewImage field specifies a preview of what the
app widget looks like and is shown to the user from the widget picker. If this field is not
supplied, the app widget's icon is used for the preview.
To help create a preview image for your app widget (to specify in the autoAdvanceViewId field), the Android emulator includes an
application called "Widget Preview." To create a preview image, launch this application, select the
app widget for your application and set it up how you'd like your preview image to appear, then save
it and place it in your application's drawable resources.
You can see an implementation of the new app widget features in the StackView App Widget and Weather List Widget applications.
The Notification APIs have been extended to support more content-rich status
bar notifications, plus a new Notification.Builder class allows you to easily
create Notification objects.
New features include:
setLargeIcon(). This is usually for
social applications to show the contact photo of the person who is the source of the
notification or for media apps to show an album thumbnail.setTicker().PendingIntents, for more interactive notification widgets. For example, a
notification can control music playback without starting an activity.New framework APIs facilitate asynchronous loading of data using the Loader class. You can use it in combination with UI components such as views and
fragments to dynamically load data from worker threads. The CursorLoader subclass is specially designed to help you do so for data backed by
a ContentProvider.
All you need to do is implement the LoaderCallbacks interface to receive callbacks when a new loader is requested or the data has
changed, then call initLoader() to initialize the
loader for your activity or fragment.
For more information, read the Loaders documentation. You can also see example code using loaders in the FragmentListCursorLoader and LoaderThrottle samples.
Android now includes APIs for applications to verify the state of connected Bluetooth A2DP and headset profile devices. For example, applications can identify when a Bluetooth headset is connected for listening to music and notify the user as appropriate. Applications can also receive broadcasts for vendor specific AT commands and notify the user about the state of the connected device, such as when the connected device's battery is low.
You can initialize the respective BluetoothProfile by calling getProfileProxy() with either the A2DP or HEADSET
profile constant and a BluetoothProfile.ServiceListener to receive
callbacks when the Bluetooth client is connected or disconnected.
An all new flexible animation framework allows you to animate arbitrary properties of any object (View, Drawable, Fragment, Object, or anything else). It allows you to define several aspects of an animation, such as:
You can define these animation aspects, and others, for an object's int, float, and hexadecimal
color values, by default. That is, when an object has a property field for one of these types, you
can change its value over time to affect an animation. To animate any other type of value, you tell
the system how to calculate the values for that given type, by implementing the TypeEvaluator interface.
There are two animators you can use to animate the values of a property: ValueAnimator and ObjectAnimator. The ValueAnimator computes the animation values, but is not aware of the specific
object or property that is animated as a result. It simply performs the calculations, and you must
listen for the updates and process the data with your own logic. The ObjectAnimator is a subclass of ValueAnimator and
allows you to set the object and property to animate, and it handles all animation work.
That is, you give the ObjectAnimator the object to animate, the
property of the object to change over time, and a set of values to apply to the property over
time, then start the animation.
Additionally, the LayoutTransition class enables automatic transition
animations for changes you make to your activity layout. To enable transitions for part of the
layout, create a LayoutTransition object and set it on
any ViewGroup by calling setLayoutTransition(). This causes default
animations to run whenever items are added to or removed from the group. To specify custom
animations, call setAnimator() on the LayoutTransition and provide a custom Animator,
such as a ValueAnimator or ObjectAnimator
discussed above.
For more information, see the Property Animation documentation. You can also see several samples using the animation APIs in the API Demos application.
New CHOICE_MODE_MULTIPLE_MODAL mode for setChoiceMode() allows users to select multiple items
from a ListView or GridView. When used in
conjunction with the Action Bar, users can select multiple items and then select the action to
perform from a list of options in the Action Bar (which has transformed into a Multi-choice
Action Mode).
To enable multiple-choice selection, call setChoiceMode(CHOICE_MODE_MULTIPLE_MODAL) and register a
MultiChoiceModeListener with setMultiChoiceModeListener().
When the user performs a long-press on an item, the Action Bar switches to the Multi-choice
Action Mode. The system notifies the MultiChoiceModeListener when items are selected by calling onItemCheckedStateChanged().
For an example of multiple-choice selection, see the List15. java class in the API Demos sample application.
New APIs allow you to easily apply 2D and 3D transformations to views in your activity layout. New transformations are made possible with a set of object properties that define the view's layout position, orientation, transparency and more.
New methods to set the view properties include: setAlpha(), setBottom(), setLeft(), setRight(), setBottom(), setPivotX(), setPivotY(), setRotationX(), setRotationY(), setScaleX(), setScaleY(), setAlpha(), and others.
Some methods also have a corresponding XML attribute that you can specify in your layout
file, to apply a default transformation. Available attributes include: translationX, translationY, rotation,
rotationX, rotationY, scaleX, scaleY, transformPivotX,
transformPivotY, and alpha.
Using some of these new view properties in combination with the new animation framework (discussed
above), you can easily apply some fancy animations to your views. For example, to rotate a
view on its y-axis, supply ObjectAnimator with the View, the "rotationY" property, and the start and end values:
ObjectAnimator animator = ObjectAnimator.ofFloat(myView, "rotationY", 0, 360); animator.setDuration(2000); animator.start();
The standard system widgets and overall look have been redesigned and incorporate a new "holographic" user interface theme. The system applies the new theme using the standard style and theme system.
Any application that targets the Android 3.0 platform—by setting either the android:minSdkVersion
or android:targetSdkVersion value to "11"—inherits the holographic theme by default.
However, if your application also applies its own theme, then your theme will override the
holographic theme, unless you update your styles to inherit the holographic theme.
To apply the holographic theme to individual activities or to inherit them in your own theme
definitions, use one of several new Theme.Holo
themes. If your application is compatible with version of Android lower than 3.0 and applies
custom themes, then you should select a theme based on platform
version.
AdapterViewAnimator
Base class for an AdapterView that performs animations when switching
between its views.
AdapterViewFlipper
Simple ViewAnimator that animates between two or more views that have
been added to it. Only one child is shown at a time. If requested, it can automatically flip
between
each child at a regular interval.
CalendarView
Allows users to select dates from a calendar by touching the date and can scroll or fling the calendar to a desired date. You can configure the range of dates available in the widget.
ListPopupWindow
Anchors itself to a host view and displays a list of choices, such as for a list of
suggestions when typing into an EditText view.
NumberPicker
Enables the user to select a number from a predefined range. The widget presents an input field and up and down buttons for selecting a number. Touching the input field allows the user to scroll through values or touch again to directly edit the current value. It also allows you to map positions to strings, so that the corresponding string is displayed instead of the index position.
PopupMenu
Displays a Menu in a modal popup window that's anchored to a view. The
popup appears below the anchor view if there is room, or above it if there is not. If the IME (soft
keyboard) is visible, the popup does not overlap the IME it until the user touches the
menu.
SearchView
Provides a search box that works in conjunction with the Search Manager (in the same manner as the traditional search dialog). It can also display recent query suggestions or custom suggestions as configured by the search provider. This widget is particularly useful for offering search in the Action Bar.
StackView
A view that displays its children in a 3D stack and allows users to swipe through views like a rolodex.
You can now enable the OpenGL renderer for your application by setting android:hardwareAccelerated="true" in your manifest element's <application>
element or for individual <activity>
elements.
This flag helps applications by making them draw faster. This results in smoother animations, smoother scrolling, and overall better performance and response to user interaction.
By default, a View has no layer specified. You can specify that the
view be backed by either a hardware or software layer, specified by values LAYER_TYPE_HARDWARE and LAYER_TYPE_SOFTWARE, using
setLayerType() or the layerType
attribute.
A hardware layer is backed by a hardware specific texture (generally Frame Buffer Objects or FBO on OpenGL hardware) and causes the view to be rendered using Android's hardware rendering pipeline, but only if hardware acceleration is turned on for the view hierarchy. When hardware acceleration is turned off, hardware layers behave exactly as software layers.
A software layer is backed by a bitmap and causes the view to be rendered using Android's software rendering pipeline, even if hardware acceleration is enabled. Software layers should be avoided when the affected view tree updates often. Every update will require to re-render the software layer, which can potentially be slow.
For more information, see the LAYER_TYPE_HARDWARE and LAYER_TYPE_SOFTWARE documentation.
Renderscript is a runtime 3D framework that provides both an API for building 3D scenes as well as a special, platform-independent shader language for maximum performance. Using Renderscript, you can accelerate graphics operations and data processing. Renderscript is an ideal way to create high-performance 3D effects for applications, wallpapers, carousels, and more.
For more information, see the 3D Rendering and Computation with Renderscript documentation.
Camcorder APIs now support the ability to record time lapse video. The setCaptureRate() sets the rate at which frames
should be captured.
New SurfaceTexture allows you to capture an image stream as an OpenGL ES
texture. By calling setPreviewTexture() for your
Camera instance, you can specify the SurfaceTexture upon which to draw video playback or preview frames from the
camera.
Applications can now pass an M3U playlist URL to the media framework to begin an HTTP Live streaming session. The media framework supports most of the HTTP Live streaming specification, including adaptive bit rate. See the Supported Media Formats document for more information.
The ExifInterface includes new fields for photo aperture, ISO, and exposure
time.
New hasProfile() method and several video
quality profiles (such as QUALITY_1080P, QUALITY_720P, QUALITY_CIF, and others) allow you to determine camcorder
quality options.
The platform includes built-in support for Media/Picture Transfer Protocol (MTP/PTP) over USB, which lets users easily transfer any type of media files between devices and to a host computer. Developers can build on this support, creating applications that let users create or manage rich media files that they may want to transfer or share across devices.
New extensible digital rights management (DRM) framework for checking and enforcing digital rights. It's implemented in two architectural layers:
For application developers, the framework offers an abstract, unified API that simplifies the management of protected content. The API hides the complexity of DRM operations and allows a consistent operation mode for both protected and unprotected content, and across a variety of DRM schemes.
For device manufacturers, content owners, and Internet digital media providers the DRM framework?s plugin API provides a means of adding support for a DRM scheme of choice into the Android system, for secure enforcement of content protection.
The preview release does not provide any native DRM plug-ins for checking and enforcing digital rights. However, device manufacturers may ship DRM plug-ins with their devices.
You can find all of the DRM APIs in the android.drm package.
META_CTRL_ON and related fields.getKeyboardType() and checking for KeyCharacterMap.FULLTextView now supports keyboard-based cut, copy, paste, and select-all,
using the key combinations Ctrl+X, Ctrl+C, Ctrl+V, and Ctrl+A. It also supports PageUp/PageDown,
Home/End, and keyboard-based text selection.KeyEvent adds several new methods to make it easier to check the key
modifier state correctly and consistently. See hasModifiers(int),
hasNoModifiers(),
metaStateHasModifiers(),
metaStateHasNoModifiers().Activity, Dialog, or View and implementing
onKeyShortcut(). The framework calls this method
whenever a key is combined with Ctrl key. When creating an Options Menu, you can register keyboard
shortcuts by setting either the android:alphabeticShortcut or android:numericShortcut attribute for each <item>
element (or with setShortcut()).KeyCharacterMap.VIRTUAL_KEYBOARD. The virtual
keyboard has a desktop-style US key map which is useful for synthesizing key events for testing
input.Previously, only a single view could accept touch events at one time. Android 3.0 adds support for splitting touch events across views and even windows, so different views can accept simultaneous touch events.
Split touch events is enabled by default when an application targets
Android 3.0. That is, when the application has set either the android:minSdkVersion
or android:targetSdkVersion attribute's value to "11".
However, the following properties allow you to disable split touch events across views inside specific view groups and across windows.
android:splitMotionEvents attribute for view groups
allows you to disable split touch events that occur between child views in a layout. For example:
<LinearLayout android:splitMotionEvents="false" ... >
...
</LinearLayout>
This way, child views in the linear layout cannot split touch events—only one view can receive touch events at a time.
android:windowEnableSplitTouch style property
allows you to disable split touch events across windows, by applying it to a theme for the activity
or entire application. For example:
<style name="NoSplitMotionEvents" parent="android:Theme.Holo">
<item name="android:windowEnableSplitTouch">false</item>
...
</style>
When this theme is applied to an <activity> or <application>,
only touch events within the current activity window are accepted. For example, by disabling split
touch events across windows, the system bar cannot receive touch events at the same time as the
activity. This does not affect whether views inside the activity can split touch
events—by default, the activity can still split touch events across views.
For more information about creating a theme, read Applying Styles and Themes.
WebViewFragment class to create a fragment composed of a
WebView.WebSettings methods:
setDisplayZoomControls() allows you to hide
the on-screen zoom controls while still allowing the user to zoom with finger gestures (setBuiltInZoomControls() must be set
true).WebSettings method, setEnableSmoothTransition(), allows you
to enable smooth transitions when panning and zooming. When enabled, WebView will choose a solution
to maximize the performance (for example, the WebView's content may not update during the
transition).WebView methods:
onPause() callback, to pause any processing
associated with the WebView when it becomes hidden. This is useful to reduce unnecessary CPU or
network traffic when the WebView is not in the foreground.onResume() callback, to resume processing
associated with the WebView, which was paused during onPause().saveWebArchive() allows you to save the
current view as a web archive on the device.showFindDialog() initiates a text search in
the current view.The Browser application adds the following features to support web applications:
As defined by the HTML Media Capture specification, the Browser allows web applications to access audio, image and video capture capabilities of the device. For example, the following HTML provides an input for the user to capture a photo to upload:
<input type="file" accept="image/*;capture=camera" />
Or by excluding the capture=camera parameter, the user can choose to either capture a
new image with the camera or select one from the device (such as from the Gallery application).
As defined by the Device Orientation Event specification, the Browser allows web applications to listen to DOM events that provide information about the physical orientation and motion of the device.
The device orientation is expressed with the x, y, and z axes, in degrees and motion is
expressed with acceleration and rotation rate data. A web page can register for orientation
events by calling window.addEventListener with event type "deviceorientation"
and register for motion events by registering the "devicemotion" event type.
As defined by the CSS 3D Transform Module specification, the Browser allows elements rendered by CSS to be transformed in three dimensions.
New classes, JsonReader and JsonWriter, help you
read and write JSON streams. The new APIs compliment the org.json classes which manipulate a
document in memory.
You can create an instance of JsonReader by calling
its constructor method and passing the InputStreamReader that feeds the JSON string.
Then begin reading an object by calling beginObject(), read a
key name with nextName(), read the value using methods
respective to the type, such as nextString() and nextInt(), and continue doing so while hasNext() is true.
You can create an instance of JsonWriter by calling its constructor and
passing the appropriate OutputStreamWriter. Then write the JSON data in a manner
similar to the reader, using name() to add a property name
and an appropriate value() method to add the respective
value.
These classes are strict by default. The setLenient()
method in each class configures them to be more liberal in what they accept. This lenient
parse mode is also compatible with the org.json's default parser.
The <uses-feature>
manfest element should be used to inform external entities (such as Android Market) of the set of
hardware and software features on which your application depends. In this release, Android adds the
following new constants that applications can declare with this element:
"android.hardware.faketouch"
When declared, this indicates that the application is compatible with a device that offers an emulated touchscreen (or better). A device that offers an emulated touchscreen provides a user input system that can emulate a subset of touchscreen capabilities. An example of such an input system is a mouse or remote control that drives an on-screen cursor. Such input systems support basic touch events like click down, click up, and drag. However, more complicated input types (such as gestures, flings, etc.) may be more difficult or impossible on faketouch devices (and multitouch gestures are definitely not possible).
If your application does not require complicated gestures and you do
not want your application filtered from devices with an emulated touchscreen, you
should declare "android.hardware.faketouch" with a <uses-feature>
element. This way, your application will be available to the greatest number of device types,
including those that provide only an emulated touchscreen input.
All devices that include a touchscreen also support "android.hardware.faketouch", because
touchscreen capabilities are a superset of faketouch capabilities. Thus, unless you actually require
a touchscreen, you should add a <uses-feature>
element for faketouch.
"android.permission.BIND_REMOTEVIEWS"
This must be declared as a required permission in the <service> manifest
element for an implementation of RemoteViewsService. For example, when
creating an App Widget that uses RemoteViewsService to populate a
collection view, the manifest entry may look like this:
<service android:name=".widget.WidgetService"
android:exported="false"
android:permission="android.permission.BIND_REMOTEVIEWS" />
For a detailed view of all API changes in Android 3.0 (API Level 11), see the API Differences Report.
The Android 3.0 platform delivers an updated version of the framework API. The Android 3.0 API is assigned an integer identifier — 11 — 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 3.0 in your application,
you need compile the application against the Android library that is provided in
the Android 3.0 SDK platform. Depending on your needs, you might
also need to add an android:minSdkVersion="11"
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 3.0 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 the following emulator skin:
For more information about how to develop an application that displays and functions properly on all Android-powered devices, see Supporting Multiple Screens.