path: root/docs/html/preview/api-changes.jd

page.title=Behavior Changes
page.keywords=preview,sdk,compatibility
page.tags=previewresources, androidm
@jd:body

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

<h2>In this document</h2>

<ol id="toc44" class="hide-nested">
    <li><a href="#behavior-runtime-permissions">Runtime Permissions</a></li>
    <li><a href="#behavior-notifications">Notifications</a></li>
    <li><a href="#behavior-openssl">OpenSSL</a></li>
    <li><a href="#behavior-project-volta">Project Volta</a>
        <ol>
            <li><a href="#behavior-doze">Doze Mode</a></li>
            <li><a href="#behavior-app-standby">App Standby Mode</a></li>
        </ol>
    </li>
    <li><a href="#behavior-adoptable-storage">Adoptable Storage Devices</a></li>
    <li><a href="#behavior-apache-http-client">Apache HTTP Client Removal</a></li>
    <li><a href="#behavior-audiomanager-Changes">AudioManager Changes</a></li>
    <li><a href="#behavior-test-selection">Text Selection</a></li>
    <li><a href="#behavior-keystore">Android Keystore Changes</a></li>
    <li><a href="#behavior-themeable-colorstatelists">Themeable ColorStateLists</a></li>
    <li><a href="#night-mode">Night Mode</a></li>
    <li><a href="#behavior-art-runtime">ART Runtime</a></li>
    <li><a href="#behavior-afw">Android for Work Changes</a></li>
</ol>

<h2>API Differences</h2>
<ol>
<li><a href="">API level 22 to M &raquo;</a> </li>
</ol>


<h2>See Also</h2>
<ol>
<li><a href="{@docRoot}preview/api-overview.html">M Developer Preview API Overview</a> </li>
</ol>

</div>
</div>

<p>API Level: M</p>
<p>Along with new features and capabilities, M includes a variety of
system changes and API behavior changes. This document highlights
some of the key changes that you should be understand and account for in your apps.</p>

<p>If you have previously published an app for Android, be aware that your app
  might be affected by these changes in M.</p>

<h2 id="behavior-runtime-permissions">Runtime Permissions</h1>
<p>This release introduces a new runtime permissions model, where users can now directly manage
their app permissions at runtime. This model gives users improved visibility and control over
permissions, while streamlining the installation and auto-update processes for app developers.
Users can set permissions on or off for all apps running on Android M. However, apps that don’t
target M cannot request permissions at runtime.</p>

<p>On your apps that target M, make sure to check and request for permissions at
runtime. To determine if your app has been granted a permission, call the
new {@code Context.checkSelfPermission()} method. To request for a permission, call the new
{@code Activity.requestPermission()} method.</p>

<p>For more information on supporting the new permissions model in your app, see the
<a href="{@docRoot}preview/features/runtime-permissions.html">
Android M Runtime Permissions guide</a>.</p>

<h2 id="behavior-openssl">OpenSSL</h2>
<p>Android is moving away from OpenSSL to the
<a href="https://boringssl.googlesource.com/boringssl/" class="external-link">BoringSSL</a>
library. If you’re using the Android NDK in your app, don't link against cryptographic libraries
that are not a part of the NDK API, such as {@code libcrypto.so} and {@code libssl.so}. These
libraries are not public APIs, and may change or break without notice across releases and devices.
In addition, you may expose yourself to security vulnerabilities. Instead, modify your
native code to call the Java cryptography APIs via JNI or to statically link against a
cryptography library of your choice.</p>

<h2 id="behavior-project-volta">Project Volta</h2>
<p>This release introduces new power-saving optimizations for idle devices and apps.</p>

<h3 id="behavior-doze">Doze mode</h3>
<p>If a device is unplugged and not used for up to an hour, it goes into <em>doze</em> mode where
it attempts to keep the system in a sleep state. In this mode, devices may briefly resume normal
operations for up to 5 minutes every few hours so that app syncing can occur and the system can
perform any pending operations.</p>

<p>The following restrictions apply to your apps while in device doze mode:</p>
<ul>
<li>Network access is disabled</li>
<li>Alarms scheduled with the {@link android.app.AlarmManager} class are disabled, except for
alarms that you've set with the
{@link android.app.AlarmManager#setAlarmClock(android.app.AlarmManager.AlarmClockInfo,android.app.PendingIntent) setAlarmClock()}
method</li>
<li>WiFi scans are not performed</li>
<li>Syncs and jobs for your sync adapters and {@link android.app.job.JobScheduler} are not
permitted to run</li>
</ul>
</p>
<p>When the system comes out of doze mode, it executes jobs and syncs that are pending.</p>

<h3 id="behavior-app-standby">App standby mode</h3>
<p>In M, the system may determine that apps are idle when they are not in active use by the user.
Your app goes into <em>app standby</em> mode after two days unless the system detects any of these
signals:</p>

<ul>
<li>The app has a process currently in the foreground (either as an activity or foreground service,
or in use by another activity or foreground service)</li>
<li>The app generates a notification that the user can see</li>
<li>The user explicitly asks for the app to remain running</li>
</ul>

<p>If the system is running on battery power, apps that are in standby mode will have their
network access disabled and their syncs and jobs suspended. When the system is plugged into a power
supply, it brings an app out of standby mode and executes any jobs and syncs that are pending.</p>

<p>Apps that use <a href="{@docRoot}google/gcm/index.html">Google Cloud Messaging</a> will
continue to receive messages even if they are idle. When the system is plugged into a power
supply, apps resume normal operations and can run any pending syncs and jobs.</p>

<p>You can test this feature by connecting a device running M to your development machine and
calling the following commands:
</p>
<pre>
$ adb shell am broadcast -a android.os.action.DISCHARGING
$ adb shell am set-idle &lt;packageName&gt; true
$ adb shell am set-idle &lt;packageName&gt; false
$ adb shell am get-idle &lt;packageName&gt;
</pre>

<h2 id="behavior-adoptable-storage">Adoptable Storage Devices</h2>
<p>
In M, users can adopt external storage devices such as SD cards. Adopting an external storage
device encrypts and formats the device to behave like internal storage. This feature allows users
to move both apps and private data of those apps between storage devices. When moving apps, the
system respects the <a href="{@docRoot}guide/topics/manifest/manifest-element.html#install">
{@code android:installLocation}</a> preference in the manifest.</p>

<p>If your app accesses the following APIs or fields, be aware that the file paths they return
will dynamically change when the app is moved between internal and external storage devices.
When building file paths, it is strongly recommended that you always call these APIs dynamically.
Don’t use hardcoded file paths or persist fully-qualified file paths that were built previously.</p>

<ul>
<li>{@link android.content.Context} methods:
    <ul>
        <li>{@link android.content.Context#getFilesDir() getFilesDir()}</li>
        <li>{@link android.content.Context#getCacheDir() getCacheDir()}</li>
        <li>{@link android.content.Context#getCodeCacheDir() getCodeCacheDir()}</li>
        <li>{@link android.content.Context#getDatabasePath(java.lang.String) getDatabasePath()}</li>
        <li>{@link android.content.Context#getDir(java.lang.String,int) getDir()}</li>
        <li>{@link android.content.Context#getNoBackupFilesDir() getNoBackupFilesDir()}</li>
        <li>{@link android.content.Context#getFileStreamPath(java.lang.String) getFileStreamPath()}</li>
        <li>{@link android.content.Context#getPackageCodePath() getPackageCodePath()}</li>
        <li>{@link android.content.Context#getPackageResourcePath() getPackageResourcePath()}</li>
    </ul>
</li>
<li>{@link android.content.pm.ApplicationInfo} fields:
    <ul>
        <li>{@link android.content.pm.ApplicationInfo#dataDir dataDir}</li>
        <li>{@link android.content.pm.ApplicationInfo#sourceDir sourceDir}</li>
        <li>{@link android.content.pm.ApplicationInfo#nativeLibraryDir nativeLibraryDir}</li>
        <li>{@link android.content.pm.ApplicationInfo#publicSourceDir publicSourceDir}</li>
        <li>{@link android.content.pm.ApplicationInfo#splitSourceDirs splitSourceDirs}</li>
        <li>{@link android.content.pm.ApplicationInfo#splitPublicSourceDirs splitPublicSourceDirs}</li>
    </ul>
</li>
</ul>

<p>To debug this feature in the developer preview, you can enable adoption of a USB drive that is
connected to an Android device through a USB On-The-Go (OTG) cable, by running these
commands:</p>

<pre>
$ adb root
$ sleep 2
$ adb shell setprop persist.fw.force_adoptable 1
$ adb reboot
</pre>

<h2 id="behavior-apache-http-client">Apache HTTP Client Removal</h2>
<p>This release removes support for the Apache HTTP client. If your app is using this client and
targets Android 2.3 (API level 9) or higher, use the {@link java.net.HttpURLConnection} class
instead. This API is more efficient because it reduces network use through transparent compression
and response caching, and minimizes power consumption. To continue using the Apache HTTP APIs, you
must first declare the following compile-time dependency in your {@code build.gradle} file:
</p>
<pre>
android {
    compileSdkVersion M
    useLibrary 'org.apache.http.legacy'
}
</pre>

<h2 id="behavior-audiomanager-Changes">AudioManager Changes</h2>
<p>Setting the volume directly or muting specific streams via the {@link android.media.AudioManager}
class is no longer supported. The {@link android.media.AudioManager#setStreamSolo(int,boolean)
setStreamSolo()} method is deprecated, and you should call the
{@code AudioManager.requestAudioFocus()} method instead. Similarly, the
{@link android.media.AudioManager#setStreamMute(int,boolean) setStreamMute()} method is
deprecated; instead, call the {@code AudioManager.adjustStreamVolume()} method
and pass in the direction value {@code ADJUST_MUTE} or {@code ADJUST_UNMUTE}.</p>

<h2 id="behavior-test-selection">Text Selection</h2>

<img src="{@docRoot}preview/images/text-selection.gif"
style="float:right; margin:0 0 20px 30px" width="270" height="480" />

<p>When users selects text in your app, you can now display text selection actions such as
<em>Cut</em>, <em>Copy</em>, and <em>Paste</em> in a
<a href="http://www.google.com/design/spec/patterns/selection.html#selection-text-selection"
class="external-link">floating toolbar</a>. The user interaction implementation is similar to that
for the contextual action bar, as described in
<a href="{@docRoot}guide/topics/ui/menus.html#CABforViews">
Enabling the contextual action mode for individual views</a>.</p>

<p>To implement a floating toolbar for text selection, make the following changes in your existing
apps:</p>
<ol>
<li>In your {@link android.view.View} or {@link android.app.Activity} object, change your
{@link android.view.ActionMode} calls from
{@code startActionMode(Callback)} to {@code startActionMode(Callback, ActionMode.TYPE_FLOATING)}.</li>
<li>Take your existing implementation of ActionMode.Callback and make it extend
{@code ActionMode.Callback2} instead.</li>
<li>Override the {@code Callback2.onGetContentRect()} method to provide the coordinates of the
content {@link android.graphics.Rect} object (such as a text selection rectangle) in the view.</li>
<li>If the rectangle positioning is no longer valid, and this is the only element to be invalidated,
call the {@code ActionMode.invalidateContentRect()} method.</li>
</ol>

<p>If you are using <a href="{@docRoot}tools/support-library/index.html">
Android Support Library</a> revision 22.2, be aware that floating toolbars are not
backward-compatible and appcompat takes control over {@link android.view.ActionMode} objects by
default. This prevents floating toolbars from being displayed in M. To enable
{@link android.view.ActionMode} support in an
{@link android.support.v7.app.AppCompatActivity}, call
{@code android.support.v7.app.AppCompatActivity.getDelegate()}, then call
{@code android.support.v7.app.AppCompatDelegate.setHandleNativeActionModesEnabled()} on the returned
{@link android.support.v7.app.AppCompatDelegate} object and set the input
parameter to {@code false}. This call returns control of {@link android.view.ActionMode} objects to
the framework. In devices running M, that allows the framework to support
{@link android.support.v7.app.ActionBar} or floating toolbar modes, while on pre-M devices, only the
{@link android.support.v7.app.ActionBar} modes are supported.</p>

<h2 id="behavior-keystore">Android Keystore Changes</h2>
<p>Starting this release, the
<a href="{@docRoot}training/articles/keystore.html">Android Keystore provider</a> no longer supports
DSA. ECDSA is still supported.</p>

<p>Keys which do not require encryption at rest will no longer be deleted when secure lock screen
is disabled or reset (for example, by the user or a Device Administrator). Keys which require
encryption at rest will be deleted during these events.</p>

<h2 id="behavior-themeable-colorstatelists">Themeable ColorStateLists</h2>
<p>Theme attributes are now supported in
{@link android.content.res.ColorStateList} for devices running M. The
{@link android.content.res.Resources#getColorStateList(int) getColorStateList()} and
{@link android.content.res.Resources#getColor(int) getColor()} methods have been deprecated. If
you are calling these APIs, call the new {@code Context.getColorStateList()} or
{@code Context.getColor()} methods instead. These methods are also available in the
v4 appcompat library via {@link android.support.v4.content.ContextCompat}.</p>

<h2 id="night-mode">Night Mode (User-configurable Dark Theme)</h2>
<p>
Support for the {@code -night} resource qualifier has been updated in M. Previously, night mode was
only available when a device was docked and in car mode. Starting in M, night mode is available on
all devices and is user-configurable via <em>Settings > Display > Theme</em>. You can adjust this
setting globally using {@link android.app.UiModeManager#setNightMode(int) setNightMode()}. The
Dark theme corresponds to {@link android.app.UiModeManager#MODE_NIGHT_YES}. When the device is in
night mode, the resource framework will prefer resources that have the -night qualifier. To
take advantage of user-configurable Dark mode in your app, extend from the
{@code Theme.Material.DayNight} set of themes rather than {@code Theme.Material} or
{@code Theme.Material.Light}.
</p>

<h2 id="behavior-art-runtime">ART Runtime</h2>
<p>The ART runtime now properly implements access rules for the
{@link java.lang.reflect.Constructor#newInstance(java.lang.Object...) newInstance()} method. This
change fixes a problem where Dalvik was checking access rules incorrectly in previous versions.
If your app uses the
{@link java.lang.reflect.Constructor#newInstance(java.lang.Object...) newInstance()} method and you
want to override access checks, call the
{@link java.lang.reflect.Constructor#setAccessible(boolean) setAccessible()} method with the input
parameter set to {@code true}. If your app uses the
<a href="{@docRoot}tools/support-library/features.html#v7">v7 appcompat library</a> or the
<a href="{@docRoot}tools/support-library/features.html#v7-recyclerview">v7 recyclerview library</a>,
you must update your app to use to the latest versions of these libraries. Otherwise, make sure that
any custom classes referenced from XML are updated so that their class constructors are accessible.</p>

<p>The M release updates the behavior of the dynamic linker. The dynamic linker now understands the
difference between a library’s {@code soname} and its path
(<a href="https://code.google.com/p/android/issues/detail?id=6670" class="external-link">
public bug 6670</a>), and search by {@code soname} is now
implemented. Apps which previously worked that have bad {@code DT_NEEDED} entries
(usually absolute paths on the build machine’s file system) may fail when loaded on M.</p>

<p>The {@code dlopen(3) RTLD_LOCAL} flag is now correctly implemented in M. Note that
{@code RTLD_LOCAL} is the default, so calls to {@code dlopen(3)} that didn’t explicitly use
{@code RTLD_LOCAL} will be affected (unless your app explicitly used {@code RTLD_GLOBAL}). With
{@code RTLD_LOCAL}, symbols will not be made available to libraries loaded by later calls to
{@code dlopen(3)} (as opposed to being referenced by {@code DT_NEEDED} entries).</p>
</p>

<h2 id="behavior-afw">Android for Work Changes</h2>
<p>This release includes the following behavior changes for Android for Work:</p>
<ul>
<li><strong>Work contacts in personal contexts.</strong> Google Messenger and the Google Dialer
Call Log now display work contacts when the user views past messages or calls. Furthermore, both
work and personal contacts are now available to devices over Bluetooth, but you can hide work
profile contacts through a device policy by calling the new
{@code DevicePolicyManager.setBluetoothContactSharingDisabled()} method. Initiating a call or
creating a new message will only show personal contacts, as consistent with the experience in
Android 5.0.
</li>
<li><strong>WiFi configuration removal:</strong> WiFi configurations added by a Profile Owner
(for example, through calls to the
{@link android.net.wifi.WifiManager#addNetwork(android.net.wifi.WifiConfiguration)
addNetwork()} method) are now removed if that work profile is deleted.</li>
<li><strong>WiFi configuration lockdown:</strong> Any WiFi configuration created by an active Device
Owner can no longer be modified or deleted by the user. The user can still create and
modify their own WiFi configurations, so long as the {@link android.os.UserManager} constant
{@link android.os.UserManager#DISALLOW_CONFIG_WIFI} has not been set for that user.</li>
<li><strong>VPN in Settings:</strong> VPN apps are now visible in <em>Settings > More > VPN</em>.
Additionally, the notifications that accompany VPN usage are now specific to whether that VPN is
configured for a managed profile or the entire device.</li>
<li><strong>Work status notification:</strong> A status bar briefcase icon now appears whenever
an app from the managed profile has an activity in the foreground. Furthermore, if the device is
unlocked directly to the activity of an app in the managed profile, a toast is displayed notifying
the user that they are within the work profile.
</li>
<li><strong>Download Work Policy Controller via Google account addition:</strong> When a Google
account that requires management via a Work Policy Controller (WPC) app is added to a device
outside of a managed context, the add account flow now prompts the user to install the
appropriate WPC. This behavior also applies to accounts added via
<em>Settings > Accounts</em> in the initial device setup wizard.</li>
</ul>