android api2,Android 2.2 Platform

API Level: 8

Android 2.2 is a minor platform release including user

features, developer features, API changes, and bug

fixes. For information on developer features and API changes, see the

Framework API section.

For developers, the Android 2.2 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. To get started developing or testing against Android 2.2,

use the Android SDK Manager to download the platform into your SDK.

Platform Highlights

For a list of new user features and platform highlights, see the Android

2.2 Platform Highlights document.

API Level

The Android 2.2 platform delivers an updated version of

the framework API. The Android 2.2 API

is assigned an integer identifier —

8 — 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 2.2 in your

application, you need to set the proper value, "8", in the

android:minSdkVersion attributes of the

element in your application's manifest.

For more information about how to use API Level, see the API Levels document.

Framework API Changes

The sections below provide information about changes made to the application

framework API provided by the Android 2.2 platform.

App installation on external storage media

The Android platform now allows applications to request installation onto the

device's external storage media (such as the SD card), as an alternative to

installation onto the device's internal memory.

Application developers can express the preferred installation location for

their applications by means of a new attribute of

in the manifest file, android:installLocation. The attribute supports three values:

"internalOnly", "preferExternal", and

"auto". At install time, the system checks the value of

android:installLocation and installs the application

.apk according to the preferred location, if possible. If the

application has requested external installation, the system installs it into a

private, encrypted partition in the external media. Once an application .apk is

installed externally, the system lets the user change the storage location of

the .apk and move it onto the device's internal memory if needed (and vice

versa), through Manage Applications in the user settings.

By default, the system installs all applications onto the device's internal

memory, except for those that explicitly request external installation. This

means that the system will always install legacy applications onto internal

memory, since they do not have access to the

android:installLocation attribute. However, it is possible to

configure and compile a legacy application such that it is installed internally

on older versions of the platform and externally on Android 2.2 and later

platforms, if necessary.

Note that requesting installation onto the device's external media is not

suitable for all applications, particularly because the external media may be

removable and unmounting/remounting may disrupt the user experience and system

settings.

For more information about setting a preferred install location for your

application, including a discussion of what types of applications should and

should not request external installation, please read the App Install Location

document.

Data backup

The platform now provides a generalized backup service that

applications can use to backup and restore user data, to ensure that users can

maintain their data when switching devices or reinstalling the application. The

Backup Manager handles the work of transporting the application data to and from

the backup storage area in the cloud. The Backup Manager can store any type of

data, from arbitrary data to files, and manages backup and restore operations

in an atomic manner. For more information, see Data Backup.

Graphics

New OpenGL ES 2.0 APIs in

New

New

Media

New APIs in

New broadcast intent for routing audio to SCO —

New APIs in

New APIs in

New APIs in

New APIs for adding files to the media database, so that they are automatically scanned. See

Speech recognition and third-party recognition engines

The platform provides new speech-recognition APIs that allow applications to have a richer interaction with the available voice recognizer. For example, the APIs are sufficient to integrate voice recognition deeply into an IME.

The platform also provides a

New

New

Camera and camcorder

Changes to camera preview API to improve efficieny of preview pipeline.

New display orientation for camera (it can now work in portrait orientation).

New APIs in

New APIs

New

New

New support in

Device policy manager

New device policy management APIs allow developers to write "device

administrator" applications that can control security features of the device,

such as the minimum password strength, data wipe, and so on. Users can select

the administrators that are enabled on their devices. For more information, see

the DeviceAdminSample.java.

UI Framework

New UI modes "car mode" and "night mode" and

New

Improvements in the way that multitouch events are reported in

The layout attribute fill_parent is renamed to match_parent. This affects both XML and Java code (see fill_parent in legacy applications.

New layout attributes

Better support for managed dialogs in Activity.

Accounts and sync

New method

New manifest elements and attributes

For specifying the application's preferred install location (see App Installation on External Storage Media, above):

New android:installLocation attribute of the element. Specifies the default install location defined by an application.

For managing user data backup (see Backup manager, above, for more information):

New android:backupAgent attribute of the

element. Specifies the component name of the

BackupAgent subclass provided by the application to handle backup/restore

operations, if any.

New android:restoreAnyVersion attribute of the

element. Boolean value that indicates whether

the application is prepared to attempt a restore of any backed-up dataset, even

if the backup is apparently from a newer version of the application than is

currently installed on the device.

For managing the platform's JIT compiler:

New android:vmSafeMode attribute of the element. Boolean value that specifies whether to disable JIT compiler optimizations when running the application.

Permissions

android.permission.BIND_DEVICE_ADMIN — Any device administration broadcast receiver must require this permission, to ensure that only the system can interact with it.

android.permission.KILL_BACKGROUND_PROCESSES — Allows an application to call

android.permission.BIND_WALLPAPER — Any

android.permission.SET_TIME — Allows an application to set the system time.

API differences report

For a detailed view of all API changes in Android 2.2 (API

Level 8), see the API

Differences Report.