path: root/docs/html/about/versions/android-2.3.3.jd

page.title=Android 2.3.3 APIs
sdk.platform.version=2.3.3
sdk.platform.apiLevel=10


@jd:body

<div id="qv-wrapper">
<div id="qv">

<h2>In this document</h2>
<ol>
  <li><a href="#api">API Overview</a></li>
  <li><a href="#api-level">API Level</a></li>
</ol>

<h2>Reference</h2>
<ol>
<li><a
href="{@docRoot}sdk/api_diff/{@sdkPlatformApiLevel}/changes.html">API
Differences Report &raquo;</a> </li>
</ol>

</div>
</div>

<p>
<em>API Level:</em>&nbsp;<strong>{@sdkPlatformApiLevel}</strong></p>

<p>Android 2.3.3 ({@link android.os.Build.VERSION_CODES#GINGERBREAD_MR1})
is a small feature release that adds several improvements
and APIs to the Android 2.3 platform.</p>

<p>For developers, the Android {@sdkPlatformVersion} 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 {@sdkPlatformVersion},
use the Android SDK Manager to download the platform into your SDK.</p>



<h2 id="api">API Overview</h2>

<p>The sections below provide a technical overview of what's new for developers
in {@sdkPlatformVersion}, including new features and changes in the framework
API since the previous version.</p>

<h3 id="nfc">Near Field Communications (NFC)</h3>

<p>Android 2.3.3 provides improved and extended support for NFC, to allow
applications to interact with more types of tags in new ways.</p>

<p>A new, comprehensive set of APIs give applications read and write access
to a wider range of standard tag technologies, including:</p>

<ul>
<li>NFC-A (ISO 14443-3A)</li>
<li>NFC-B (ISO 14443-3B)</li>
<li>NFC-F (JIS 6319-4)</li>
<li>NFC-V (ISO 15693)</li>
<li>ISO-DEP (ISO 14443-4)</li>
<li>MIFARE Classic</li>
<li>MIFARE Ultralight</li>
<li>NFC Forum NDEF tags</li>
</ul>

<p>The platform also provides a limited peer-to-peer communication protocol
and API. Foreground Activities can use the API to register an NDEF
message that will get pushed to other NFC devices when they connect.</p>

<p>Advanced tag dispatching now gives applications more control over how and
when they are launched, when an NFC tag is discovered. Previously, the platform
used a single-step intent dispatch to notify interested applications that a tag
was discovered. The platform now uses a four-step process that enables the
foreground application to take control of a tag event before it is passed to any
other applications (<code>android.nfc.NfcAdapter.enableForegroundDispatch()</code>).

The new dispatch process also lets apps listen for specific tag content and
tag technologies, based on two new intent actions &mdash;
<code>android.nfc.action.NDEF_DISCOVERED</code> and
<code>android.nfc.action.TECH_DISCOVERED</code>.</p>

<p>The NFC API is available in the {@link android.nfc} and 
{@link android.nfc.tech} packages. The key classes are: </p>

<ul>
<li>{@link android.nfc.NfcAdapter}, which represents the NFC hardware on the device.</li>
<li>{@link android.nfc.NdefMessage}, which represents an NDEF data message,
the standard format in which "records" carrying data are transmitted between
devices and tags. An NDEF message certain many NDEF records of different types.
Applications can receive these messages from 
{@link android.nfc.NfcAdapter#ACTION_NDEF_DISCOVERED NDEF_DISCOVERED},
{@link android.nfc.NfcAdapter#ACTION_TECH_DISCOVERED TECH_DISCOVERED}, or
{@link android.nfc.NfcAdapter#ACTION_TAG_DISCOVERED TAG_DISCOVERED} Intents.</li>
<li>{@link android.nfc.NdefRecord}, delivered in an
{@link android.nfc.NdefMessage}, which describes the type of data being shared
and carries the data itself.</li>
<li>{@link android.nfc.Tag}, which represents a tag scanned by the device.
Multiple types of tags are supported, based on the underlying tag
technology.</li>
<li>{@link android.nfc.tech.TagTechnology}, an interface that gives applications
access to tag properties and I/O operations based on the technologies present
in the tag. For a full list of tag technologies supported in Android 2.3.3, see
{@link android.nfc.tech}.</li>
</ul>

<p>NFC communication relies on wireless technology in the device hardware, and
is not present in all Android devices. Android devices that do not support
NFC will return a null object when
{@link android.nfc.NfcAdapter#getDefaultAdapter(android.content.Context)
getDefaultAdapter(Context)} is called, and
<code>context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_NFC)</code>
will return <code>false</code>. The NFC API is always present, however, regardless of
underlying hardware support.</p>

<p>To use the NFC API, applications must request permission from the user by
declaring <code>&lt;uses-permission
android:name="android.permission.NFC"&gt;</code> in their manifest files.</p>

<p>Additionally, developers can request filtering on Google Play, such that
their applications are not discoverable to users whose devices do not support
NFC. To request filtering, add
<code>&lt;uses-feature android:name="android.hardware.nfc"
android:required="true"&gt;</code> to the application's manifest.</p>

<p class="note">For more information, read the 
  <a href="{@docRoot}guide/topics/connectivity/nfc/index.html">NFC</a> developer guide.</p>

<h3 id="bluetooth">Bluetooth</h3>

<p>Android 2.3.3 adds platform and API support for Bluetooth nonsecure socket
connections. This lets applications communicate with simple devices that may not
offer a UI for authentication. See 
{@link android.bluetooth.BluetoothDevice#createInsecureRfcommSocketToServiceRecord(java.util.UUID)} and 
{@link android.bluetooth.BluetoothAdapter#listenUsingInsecureRfcommWithServiceRecord(java.lang.String, java.util.UUID)}
for more information. </p>

<h3 id="graphics">Graphics</h3>

<ul>
<li>A new {@link android.graphics.BitmapRegionDecoder} class lets applications
decode a rectangle region from an image. The API is particularly useful when an
original image is large and and the application only need parts of the image.
</li>
<li>A new {@link
android.graphics.BitmapFactory.Options#inPreferQualityOverSpeed} field in {@link
android.graphics.BitmapFactory.Options} allows applications to use a more accurate
but slightly slower IDCT method in JPEG decode. This in turn improves the
quality of the reconstructed image.</li>
</ul>


<h3 id="media">Media framework</h3>

<ul>
<li>A new {@link android.media.MediaMetadataRetriever} class provides a unified
interface for retrieving frame and metadata from an input media file.</li>
<li>{@link android.media.MediaRecorder.AudioEncoder} and {@link
android.media.MediaRecorder.OutputFormat} include new fields for specifying AMR
Wideband and AAC formats. </li>
</ul>


<h3 id="speech">Speech recognition</h3>

<p>The speech-recognition API includes new constants to let you manage voice
search results in new ways. Although the new constants are not needed for normal
use of speech recognition, you could use them to offer a different view of voice
search results in your application. For information, see {@link
android.speech.RecognizerResultsIntent}.</p>


<h2 id="api-level">API Level</h2>

<p>The Android {@sdkPlatformVersion} platform delivers an updated version of
the framework API. The Android {@sdkPlatformVersion} API
is assigned an integer identifier &mdash;
<strong>{@sdkPlatformApiLevel}</strong> &mdash; 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. </p>

<p>To use APIs introduced in Android {@sdkPlatformVersion} in your application,
you need compile the application against the Android library that is provided in
the Android {@sdkPlatformVersion} SDK platform. Depending on your needs, you might 
also need to add an <code>android:minSdkVersion="{@sdkPlatformApiLevel}"</code>
attribute to the <code>&lt;uses-sdk&gt;</code> 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.</p>

<p>For more information, read <a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#ApiLevels">What is API
Level?</a></p>