am b3803855: Merge "Doc change: document AppWidgetHost" into jb-mr1.1-docs
* commit 'b3803855b0554879836c18b4157194b9c2061219': Doc change: document AppWidgetHost
This commit is contained in:
@@ -76,9 +76,16 @@
|
||||
<span class="en">Permissions</span>
|
||||
</a>
|
||||
</li>
|
||||
<li><a href="<?cs var:toroot ?>guide/topics/appwidgets/index.html">
|
||||
<li class="nav-section">
|
||||
<div class="nav-section-header"><a href="<?cs var:toroot ?>guide/topics/appwidgets/index.html">
|
||||
<span class="en">App Widgets</span>
|
||||
</a></li>
|
||||
</a></div>
|
||||
<ul>
|
||||
<li><a href="<?cs var:toroot ?>guide/topics/appwidgets/host.html">
|
||||
<span class="en">App Widget Host</span>
|
||||
</a></li>
|
||||
</ul>
|
||||
</li>
|
||||
<li class="nav-section">
|
||||
<div class="nav-section-header"><a href="<?cs var:toroot ?>guide/topics/manifest/manifest-intro.html">
|
||||
<span class="en">Android Manifest</span>
|
||||
|
||||
392
docs/html/guide/topics/appwidgets/host.jd
Normal file
392
docs/html/guide/topics/appwidgets/host.jd
Normal file
@@ -0,0 +1,392 @@
|
||||
page.title=App Widget Host
|
||||
page.tags="AppWidgetHost","home screen","launcher"
|
||||
@jd:body
|
||||
|
||||
<div id="qv-wrapper">
|
||||
<div id="qv">
|
||||
|
||||
<h2>In this document</h2>
|
||||
<ol>
|
||||
<li><a href="#host-binding">Binding App Widgets</a>
|
||||
<ol>
|
||||
<li><a href="#binding-pre">Binding app widgets on Android 4.0 and lower</a></li>
|
||||
<li><a href="#binding-41">Binding app widgets on Android 4.1 and higher</a></li>
|
||||
</ol>
|
||||
</li>
|
||||
<li><a href="#host-state">Host Responsibilities</a>
|
||||
<ol>
|
||||
<li><a href="#30">Android 3.0</a></li>
|
||||
<li><a href="#31">Android 3.1</a></li>
|
||||
<li><a href="#40">Android 4.0</a></li>
|
||||
<li><a href="#41">Android 4.1</li>
|
||||
<li><a href="#42">Android 4.2</a></li>
|
||||
</ol>
|
||||
</li>
|
||||
</ol>
|
||||
</div>
|
||||
</div>
|
||||
|
||||
|
||||
<p>The Android Home screen available on most Android devices allows the user
|
||||
to embed <a href="{@docRoot}guide/topics/appwidgets/index.html">app widgets</a> for quick
|
||||
access to content. If you're building a Home replacement or a similar app,
|
||||
you can also allow the user to embed app widgets by implementing an
|
||||
{@link android.appwidget.AppWidgetHost}.
|
||||
This is not something that most apps will ever need to do, but if you are
|
||||
creating your own host, it's important to understand the contractual obligations
|
||||
a host implicitly agrees to.</p>
|
||||
|
||||
<p>This document focuses on the responsibilities involved in implementing a custom
|
||||
{@link android.appwidget.AppWidgetHost}. For an example of how to implement an
|
||||
{@link android.appwidget.AppWidgetHost}, see the source code for the
|
||||
Android Home screen
|
||||
<a href="https://android.googlesource.com/platform/packages/apps/Launcher2/+/master/src/com/android/launcher2/Launcher.java">
|
||||
Launcher</a>.
|
||||
|
||||
|
||||
<p>Here is an overview of key classes and concepts involved in implementing a custom
|
||||
{@link android.appwidget.AppWidgetHost}:</p>
|
||||
<ul>
|
||||
<li><strong>App Widget Host</strong>—
|
||||
The {@link android.appwidget.AppWidgetHost} provides the interaction
|
||||
with the AppWidget service for apps, like the home screen, that want to embed
|
||||
app widgets in their UI. An {@link android.appwidget.AppWidgetHost} must have
|
||||
an ID that is unique within the host's own package. This ID remains persistent
|
||||
across all uses of the host. The ID is typically a hard-coded value that you assign
|
||||
in your application.</li>
|
||||
|
||||
<li><strong>App Widget ID</strong>—
|
||||
Each app widget instance is assigned a unique ID at the time of binding
|
||||
(see {@link android.appwidget.AppWidgetManager#bindAppWidgetIdIfAllowed bindAppWidgetIdIfAllowed()},
|
||||
discussed in more detail in <a href="#binding">Binding app widgets</a>).
|
||||
The unique ID is obtained by the host using {@link android.appwidget.AppWidgetHost#allocateAppWidgetId() allocateAppWidgetId()}. This ID is persistent across the lifetime of the widget,
|
||||
that is, until it is deleted from the host. Any host-specific state (such as the
|
||||
size and location of the widget) should be persisted by the hosting package and
|
||||
associated with the app widget ID.
|
||||
</li>
|
||||
|
||||
<li><strong>App Widget Host View</strong>—
|
||||
{@link android.appwidget.AppWidgetHostView} can be thought of as a frame
|
||||
that the widget is wrapped in whenever it needs to be displayed. An app widget
|
||||
is assigned to an {@link android.appwidget.AppWidgetHostView} every time the
|
||||
widget is inflated by the host. </li>
|
||||
<li><strong>Options Bundle</strong>—
|
||||
The {@link android.appwidget.AppWidgetHost} uses the options bundle to communicate
|
||||
information to the {@link android.appwidget.AppWidgetProvider} about how the
|
||||
widget is being displayed (for example, size range, and whether the widget is on
|
||||
a lockscreen or the home screen). This information allows the
|
||||
{@link android.appwidget.AppWidgetProvider} to tailor the widget's contents
|
||||
and appearance based on how and where it is displayed.
|
||||
You use
|
||||
{@link android.appwidget.AppWidgetHostView#updateAppWidgetOptions(android.os.Bundle) updateAppWidgetOptions()}
|
||||
and
|
||||
{@link android.appwidget.AppWidgetHostView#updateAppWidgetSize updateAppWidgetSize()}
|
||||
|
||||
to modify an app widget's
|
||||
bundle. Both of these methods trigger a callback to the
|
||||
{@link android.appwidget.AppWidgetProvider}.</p></li>
|
||||
</ul>
|
||||
|
||||
<h2 id="host-binding">Binding App Widgets</h2>
|
||||
|
||||
<p>When a user adds an app widget to a host, a process called
|
||||
<em>binding</em> occurs. <em>Binding</em> refers to associating
|
||||
a particular app widget ID to a specific host and to a specific
|
||||
{@link android.appwidget.AppWidgetProvider}. There are different
|
||||
ways of achieving this, depending on what version of Android your
|
||||
app is running on.</p>
|
||||
|
||||
<h3 id="binding-pre">Binding app widgets on Android 4.0 and lower</h3>
|
||||
|
||||
<p>On devices running Android version 4.0 and lower, users add app widgets
|
||||
via a system activity that allows users to select a widget. This implicitly
|
||||
does a permission check—that is, by adding the app widget, the user is
|
||||
implicitly granting permission to your app to add app widgets to the host.
|
||||
Here is an example that illustrates
|
||||
this approach, taken from the original
|
||||
<a href="https://android.googlesource.com/platform/packages/apps/Launcher/+/master/src/com/android/launcher/Launcher.java">Launcher</a>. In this snippet, an event handler invokes
|
||||
{@link android.app.Activity#startActivityForResult(android.content.Intent,int) startActivityForResult()}
|
||||
with the request code {@code REQUEST_PICK_APPWIDGET} in response to a
|
||||
user action:</p>
|
||||
|
||||
<pre>
|
||||
private static final int REQUEST_CREATE_APPWIDGET = 5;
|
||||
private static final int REQUEST_PICK_APPWIDGET = 9;
|
||||
...
|
||||
public void onClick(DialogInterface dialog, int which) {
|
||||
switch (which) {
|
||||
...
|
||||
case AddAdapter.ITEM_APPWIDGET: {
|
||||
...
|
||||
int appWidgetId =
|
||||
Launcher.this.mAppWidgetHost.allocateAppWidgetId();
|
||||
Intent pickIntent =
|
||||
new Intent(AppWidgetManager.ACTION_APPWIDGET_PICK);
|
||||
pickIntent.putExtra
|
||||
(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
|
||||
...
|
||||
startActivityForResult(pickIntent, REQUEST_PICK_APPWIDGET);
|
||||
break;
|
||||
}
|
||||
...
|
||||
}</pre>
|
||||
|
||||
<p>When the system activity finishes, it returns a result with the user's chosen
|
||||
app widget to your activity. In the following example, the activity responds
|
||||
by calling {@code addAppWidget()} to add the app widget:</p>
|
||||
|
||||
<pre>public final class Launcher extends Activity
|
||||
implements View.OnClickListener, OnLongClickListener {
|
||||
...
|
||||
@Override
|
||||
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
|
||||
mWaitingForResult = false;
|
||||
|
||||
if (resultCode == RESULT_OK && mAddItemCellInfo != null) {
|
||||
switch (requestCode) {
|
||||
...
|
||||
case REQUEST_PICK_APPWIDGET:
|
||||
addAppWidget(data);
|
||||
break;
|
||||
case REQUEST_CREATE_APPWIDGET:
|
||||
completeAddAppWidget(data, mAddItemCellInfo, !mDesktopLocked);
|
||||
break;
|
||||
}
|
||||
}
|
||||
...
|
||||
}
|
||||
}</pre>
|
||||
|
||||
<p>The method {@code addAppWidget()} checks to see if the app widget
|
||||
needs to be configured before it's added:</p>
|
||||
|
||||
<pre>void addAppWidget(Intent data) {
|
||||
int appWidgetId = data.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, -1);
|
||||
|
||||
String customWidget = data.getStringExtra(EXTRA_CUSTOM_WIDGET);
|
||||
AppWidgetProviderInfo appWidget =
|
||||
mAppWidgetManager.getAppWidgetInfo(appWidgetId);
|
||||
|
||||
if (appWidget.configure != null) {
|
||||
// Launch over to configure widget, if needed.
|
||||
Intent intent = new Intent(AppWidgetManager.ACTION_APPWIDGET_CONFIGURE);
|
||||
intent.setComponent(appWidget.configure);
|
||||
intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
|
||||
startActivityForResult(intent, REQUEST_CREATE_APPWIDGET);
|
||||
} else {
|
||||
// Otherwise, finish adding the widget.
|
||||
}
|
||||
}</pre>
|
||||
|
||||
<p>For more discussion of configuration,
|
||||
see <a href="{@docRoot}guide/topics/appwidgets/index.html#Configuring">Creating an
|
||||
App Widget Configuration Activity</a>.</p>
|
||||
|
||||
<p>Once the app widget is ready, the next step is to do the
|
||||
actual work of adding it to the workspace. The
|
||||
<a href="https://android.googlesource.com/platform/packages/apps/Launcher/+/master/src/com/android/launcher/Launcher.java">original Launcher</a> uses a method called {@code completeAddAppWidget()}
|
||||
to do this.</p>
|
||||
|
||||
<h3 id="binding-41">Binding app widgets on Android 4.1 and higher</h3>
|
||||
|
||||
<p>Android 4.1 adds APIs for a more streamlined binding process.
|
||||
These APIs also make it possible for a host to provide a custom UI for
|
||||
binding. To use this improved process, your app must declare the
|
||||
{@link android.Manifest.permission#BIND_APPWIDGET} permission in its manifest:</p>
|
||||
|
||||
<pre><uses-permission android:name="android.permission.BIND_APPWIDGET" />
|
||||
</pre>
|
||||
|
||||
|
||||
<p>But this is just the first step. At runtime the user must
|
||||
explicitly grant permission to your app to allow it to add app widgets
|
||||
to the host. To test whether your app has permission to add the widget,
|
||||
you use the
|
||||
{@link android.appwidget.AppWidgetManager#bindAppWidgetIdIfAllowed bindAppWidgetIdIfAllowed()}
|
||||
method.
|
||||
If {@link android.appwidget.AppWidgetManager#bindAppWidgetIdIfAllowed bindAppWidgetIdIfAllowed()}
|
||||
returns {@code false}, your app must display a dialog prompting the
|
||||
user to grant permission
|
||||
("allow" or "always allow," to cover all future app widget additions).
|
||||
This snippet gives an example of how to display the dialog:</p>
|
||||
|
||||
<pre>Intent intent = new Intent(AppWidgetManager.ACTION_APPWIDGET_BIND);
|
||||
intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
|
||||
intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_PROVIDER, info.componentName);
|
||||
// This is the options bundle discussed above
|
||||
intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_OPTIONS, options);
|
||||
startActivityForResult(intent, REQUEST_BIND_APPWIDGET);
|
||||
</pre>
|
||||
|
||||
<p>The host also has to check whether the user added
|
||||
an app widget that needs configuration. For more discussion of this topic,
|
||||
see
|
||||
<a href="{@docRoot}guide/topics/appwidgets/index.html#Configuring">Creating
|
||||
an App Widget Configuration Activity</a>.</p>
|
||||
|
||||
<h2 id="host-state">Host Responsibilities</h2>
|
||||
|
||||
<div class="sidebox-wrapper">
|
||||
<div class="sidebox">
|
||||
<h2>What Version are You Targeting?</h2>
|
||||
<p>The approach you use in implementing your host should depend on what Android version
|
||||
you're targeting. Many of the features described in this section were introduced
|
||||
in 3.0 or later. For example:</p>
|
||||
<ul>
|
||||
<li>Android 3.0 (API Level 11) introduces auto-advance behavior for widgets.</li>
|
||||
<li>Android 3.1 (API Level 12) introduces the ability to resize widgets.</li>
|
||||
<li>Android 4.0 (API Level 15) introduces a change in padding policy that
|
||||
puts the responsibility on the
|
||||
host to manage padding.</li>
|
||||
<li>Android 4.1 (API Level 16) adds an API that allows the widget provider
|
||||
to get more detailed information about the environment in which its
|
||||
widget instances are being hosted.</li>
|
||||
<li>Android 4.2 (API Level 17) introduces the options bundle and the
|
||||
{@link android.appwidget.AppWidgetManager#bindAppWidgetIdIfAllowed(int,android.content.ComponentName,android.os.Bundle) bindAppWidgetIdIfAllowed()}
|
||||
method. It also introduces lockscreen widgets.</li>
|
||||
</ul>
|
||||
<p>If you are targeting earlier devices, refer to the original
|
||||
<a href="https://android.googlesource.com/platform/packages/apps/Launcher/+/master/src/com/android/launcher/Launcher.java">Launcher</a> as an example.
|
||||
</div>
|
||||
</div>
|
||||
|
||||
<p>Widget developers can specify a number of configuration settings
|
||||
for widgets using the <a href="{@docRoot}guide/topics/appwidgets/index.html#MetaData">
|
||||
AppWidgetProviderInfo metadata</a>.
|
||||
These configuration options, discussed in more detail below, can be
|
||||
retrieved by the host from the {@link android.appwidget.AppWidgetProviderInfo}
|
||||
object associated with a widget provider.</p>
|
||||
|
||||
<p>Regardless of the version of Android you are targeting, all hosts
|
||||
have the following responsibilities:</p>
|
||||
|
||||
<ul>
|
||||
<li>When adding a widget, you must allocate the widget ID as described above.
|
||||
You must also make sure that when a widget is removed from the host, you call {@link android.appwidget.AppWidgetHost#deleteAppWidgetId deleteAppWidgetId()}
|
||||
to deallocate the widget ID.</li>
|
||||
|
||||
<li>When adding a widget, be sure to launch its configuration activity
|
||||
if it exists, as described in
|
||||
<a href="{@docRoot}guide/topics/appwidgets/index.html#UpdatingFromTheConfiguration">
|
||||
Updating the App Widget
|
||||
from the Configuration Activity</a>. This is a necessary step for many app widgets before
|
||||
they can be properly displayed.</li>
|
||||
|
||||
<li>Every app widget specifies a minimum width and height in dps, as defined in the {@link android.appwidget.AppWidgetProviderInfo} metadata
|
||||
(using {@link android.appwidget.AppWidgetProviderInfo#minWidth android:minWidth} and
|
||||
{@link android.appwidget.AppWidgetProviderInfo#minHeight android:minHeight}).
|
||||
Make sure that the widget is laid out with at least this many dps.
|
||||
For example, many hosts align icons and widgets in a grid. In this scenario,
|
||||
by default the host should add the app widget using the minimum number of
|
||||
cells that satisfy the {@code minWidth} and {@code minHeight} constraints.</li>
|
||||
|
||||
</ul>
|
||||
|
||||
<p>In addition to the requirements listed above, specific platform
|
||||
versions introduce features that place new responsibilities on the
|
||||
host. These are described in the following sections.</p>
|
||||
|
||||
<h3 id="30">Android 3.0</h3>
|
||||
|
||||
<p>Android 3.0 (API Level 11) introduces the ability for a widget to specify {@link android.appwidget.AppWidgetProviderInfo#autoAdvanceViewId autoAdvanceViewId()}.
|
||||
This view ID should point to an instance of an
|
||||
{@link android.widget.Advanceable}, such as {@link android.widget.StackView}
|
||||
or {@link android.widget.AdapterViewFlipper}. This indicates that the host
|
||||
should call {@link android.widget.Advanceable#advance advance()} on this
|
||||
view at an interval deemed appropriate by the host (taking into account whether
|
||||
it makes sense to advance the widget—for example, the host probably
|
||||
wouldn't want to advance a widget if it were on another page, or
|
||||
if the screen were turned off).</p>
|
||||
|
||||
<h3 id="31">Android 3.1</h3>
|
||||
|
||||
<p>Android 3.1 (API Level 12) introduces the ability to resize widgets.
|
||||
A widget can specify that it is resizable using the
|
||||
{@link android.appwidget.AppWidgetProviderInfo#resizeMode android:resizeMode}
|
||||
attribute in the {@link android.appwidget.AppWidgetProviderInfo}
|
||||
metadata, and indicate whether it supports horizontal and/or
|
||||
vertical resizing. Introduced in Android 4.0 (API Level 14), the widget can also specify a
|
||||
{@link android.appwidget.AppWidgetProviderInfo#minResizeWidth android:minResizeWidth}
|
||||
and/or {@link android.appwidget.AppWidgetProviderInfo#minResizeHeight android:minResizeHeight}.</p>
|
||||
|
||||
<p>It is the host’s responsibility to make it possible for the
|
||||
widget to be resized horizontally and/or vertically, as specified
|
||||
by the widget. A widget that specifies that it is resizable can be
|
||||
resized arbitrarily large, but should not be resized smaller than
|
||||
the values specified by {@link
|
||||
android.appwidget.AppWidgetProviderInfo#minResizeWidth android:minResizeWidth}
|
||||
and {@link
|
||||
android.appwidget.AppWidgetProviderInfo#minResizeHeight android:minResizeHeight}.
|
||||
For a sample implementation, see <a href="https://android.googlesource.com/platform/packages/apps/Launcher2/+/master/src/com/android/launcher2/AppWidgetResizeFrame.java">
|
||||
{@code AppWidgetResizeFrame}</a> in {@code Launcher2}.</p>
|
||||
|
||||
|
||||
<h3 id="40">Android 4.0</h3>
|
||||
|
||||
<p>Android 4.0 (API Level 15) introduces a change in padding policy that
|
||||
puts the responsibility on the host to manage padding. As of 4.0, app
|
||||
widgets no longer include their own padding. Instead, the system adds
|
||||
padding for each widget, based the characteristics of the current screen.
|
||||
This leads to a more uniform, consistent presentation of widgets in a grid.
|
||||
To assist applications that host app widgets, the platform provides
|
||||
the method
|
||||
{@link android.appwidget.AppWidgetHostView#getDefaultPaddingForWidget getDefaultPaddingForWidget()}.
|
||||
Applications can call this method to get the system-defined padding
|
||||
and account for it when computing the number of cells to allocate to the widget.</p>
|
||||
|
||||
<h3 id="41">Android 4.1</h3>
|
||||
|
||||
<p>Android 4.1 (API Level 16) adds an API that allows the widget provider
|
||||
to get more detailed information about the environment in which its
|
||||
widget instances are being hosted. Specifically, the host hints to the
|
||||
widget provider about the size at which the widget is being displayed.
|
||||
It is the host’s responsibility to provide this size information.</p>
|
||||
|
||||
<p>The host provides this information via
|
||||
{@link android.appwidget.AppWidgetHostView#updateAppWidgetSize updateAppWidgetSize()}.
|
||||
The size is specified as a minimum and maximum width/height in dps.
|
||||
The reason that a range is specified (as opposed to a fixed size)
|
||||
is because the width and height of a widget may change with orientation.
|
||||
You don’t want the host to have to update all of its widgets on rotation,
|
||||
as this could cause serious system slowdown. These values should be
|
||||
updated once upon the widget being placed, any time the widget is resized,
|
||||
and any time the launcher inflates the widget for the first time in a
|
||||
given boot (as the values aren’t persisted across boot).</p>
|
||||
|
||||
|
||||
<h3 id="42">Android 4.2</h3>
|
||||
|
||||
<p>Android 4.2 (API Level 17) adds the ability for the options bundle
|
||||
to be specified at bind time. This is the ideal way to specify app
|
||||
widget options, including size, as it gives the {@link
|
||||
android.appwidget.AppWidgetProvider} immediate access to the options
|
||||
data on the first update. This can be achieved by using the method {@link android.appwidget.AppWidgetManager#bindAppWidgetIdIfAllowed(int,android.content.ComponentName,android.os.Bundle) bindAppWidgetIdIfAllowed()}. For more discussion of this topic,
|
||||
see <a href="#host-binding">Binding app widgets</a>.</p>
|
||||
|
||||
<p>Android 4.2 also introduces lockscreen widgets. When hosting widgets
|
||||
on the lockscreen, the host must specify this information within the app
|
||||
widget options bundle (the {@link
|
||||
android.appwidget.AppWidgetProvider} can use this information to style
|
||||
the widget appropriately). To designate a widget as a lockscreen widget, use {@link android.appwidget.AppWidgetHostView#updateAppWidgetOptions updateAppWidgetOptions()}
|
||||
and include the field
|
||||
{@link android.appwidget.AppWidgetManager#OPTION_APPWIDGET_HOST_CATEGORY}
|
||||
with the value {@link android.appwidget.AppWidgetProviderInfo#WIDGET_CATEGORY_KEYGUARD}.
|
||||
This option defaults to
|
||||
{@link android.appwidget.AppWidgetProviderInfo#WIDGET_CATEGORY_HOME_SCREEN},
|
||||
so it is not explicitly required to set this for a home screen host.</p>
|
||||
|
||||
<p>Make sure that your host adds only app widgets that are appropriate
|
||||
for your app—for example, if your host is a home screen, ensure
|
||||
that the
|
||||
{@link android.appwidget.AppWidgetProviderInfo#widgetCategory android:widgetCategory}
|
||||
attribute in the
|
||||
{@link android.appwidget.AppWidgetProviderInfo} metadata includes
|
||||
the flag {@link android.appwidget.AppWidgetProviderInfo#WIDGET_CATEGORY_HOME_SCREEN}.
|
||||
Similarly, for the lockscreen, ensure that field includes the flag {@link android.appwidget.AppWidgetProviderInfo#WIDGET_CATEGORY_KEYGUARD}. For more
|
||||
discussion of this topic, see
|
||||
<a href="{@docRoot}guide/topics/appwidgets/index.html#lockscreen">
|
||||
Enabling App Widgets on the Lockscreen</a>.</p>
|
||||
|
||||
|
||||
|
||||
|
||||
@@ -22,15 +22,16 @@ Activity</a>
|
||||
<ol>
|
||||
<li><a href="#UpdatingFromTheConfiguration">Updating the App Widget
|
||||
from
|
||||
the configuration Activity</a></li>
|
||||
the Configuration Activity</a></li>
|
||||
</ol>
|
||||
</li>
|
||||
<li><a href="#preview">Setting a Preview Image</a></li>
|
||||
<li><a href="#lockscreen">Enabling App Widgets on the Lockscreen
|
||||
<li><a href="#lockscreen">Enabling App Widgets on the Lockscreen</a>
|
||||
<ol>
|
||||
<li><a href="#lockscreen-sizing">Sizing guidelines</li>
|
||||
<li><a href="#lockscreen-sizing">Sizing guidelines</a></li>
|
||||
</ol>
|
||||
</li>
|
||||
|
||||
<li><a href="#collections">Using App Widgets with Collections</a>
|
||||
<ol>
|
||||
<li><a href="#collection_sample">Sample application</a></li>
|
||||
@@ -66,7 +67,9 @@ the Music App Widget.</p>
|
||||
<img src="{@docRoot}images/appwidgets/appwidget.png" alt="" />
|
||||
|
||||
<p>This document describes how to publish an App Widget using an App Widget
|
||||
provider.</p>
|
||||
provider. For a discussion of creating your own {@link android.appwidget.AppWidgetHost}
|
||||
to host app widgets, see <a href="{@docRoot}guide/topics/appwidgets/host.html">
|
||||
Implementing a Custom App Widget Host</a>.</p>
|
||||
|
||||
<div class="note design">
|
||||
<p><strong>Widget Design</strong></p>
|
||||
@@ -100,7 +103,7 @@ an optional
|
||||
and allows him or her
|
||||
to modify App Widget settings at create-time.</p>
|
||||
|
||||
<p>The following sections describe how to setup each of these components.</p>
|
||||
<p>The following sections describe how to set up each of these components.</p>
|
||||
|
||||
|
||||
<h2 id="Manifest">Declaring an App Widget in the Manifest</h2>
|
||||
@@ -165,8 +168,8 @@ folder.</p>
|
||||
|
||||
<pre>
|
||||
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
|
||||
android:minWidth="294dp"
|
||||
android:minHeight="72dp"
|
||||
android:minWidth="40dp"
|
||||
android:minHeight="40dp"
|
||||
android:updatePeriodMillis="86400000"
|
||||
android:previewImage="@drawable/preview"
|
||||
android:initialLayout="@layout/example_appwidget"
|
||||
@@ -270,6 +273,14 @@ handles to change the size on the layout grid. Values for the
|
||||
To declare a widget as resizeable horizontally and vertically, supply the value
|
||||
"horizontal|vertical". Introduced in Android 3.1.</li>
|
||||
|
||||
<li>The <code>minResizeHeight</code> attribute specifies the minimum height (in dps) to which
|
||||
the widget can be resized. This field has no effect if it is greater than {@code minHeight} or if
|
||||
vertical resizing isn't enabled (see <code>resizeMode</code>). Introduced in Android 4.0.</li>
|
||||
|
||||
<li>The <code> minResizeWidth </code> attribute specifies the minimum width (in dps) to which
|
||||
the widget can be resized. This field has no effect if it is greater than {@code minWidth} or if
|
||||
horizontal resizing isn't enabled (see <code>resizeMode</code>). Introduced in Android 4.0.</li>
|
||||
|
||||
<li>The <code>widgetCategory</code> attribute declares whether your App Widget can be displayed on the home screen,
|
||||
the lock screen (keyguard), or both. Values for this attribute include "home_screen" and "keyguard". A widget that
|
||||
is displayed on both needs to ensure that it follows the design guidelines for both widget classes. For more
|
||||
@@ -788,12 +799,12 @@ int baseLayout = isKeyguard ? R.layout.keyguard_widget_layout : R.layout.widget_
|
||||
|
||||
<h2 id="collections">Using App Widgets with Collections</h2>
|
||||
|
||||
<p>Android 3.0 introduces App Widgets with collections. These kinds of App
|
||||
<p>Android 3.0 introduces app widgets with collections. These kinds of App
|
||||
Widgets use the {@link android.widget.RemoteViewsService} to display collections
|
||||
that are backed by remote data, such as from a <a
|
||||
href="{@docRoot}guide/topics/providers/content-providers.html">content
|
||||
provider</a>. The data provided by the {@link android.widget.RemoteViewsService}
|
||||
is presented in the App Widget using one of the following view types, which
|
||||
is presented in the app widget using one of the following view types, which
|
||||
we’ll refer to as “collection views:”</p>
|
||||
|
||||
<dl>
|
||||
@@ -900,15 +911,15 @@ how this is implemented, see
|
||||
</ul>
|
||||
<h3 id="implementing_collections">Implementing app widgets with collections</h3>
|
||||
|
||||
<p>To implement an App Widget with collections, you follow the same basic steps
|
||||
<p>To implement an app widget with collections, you follow the same basic steps
|
||||
you would use to implement any app widget. The following sections describe the
|
||||
additional steps you need to perform to implement an App Widget with
|
||||
additional steps you need to perform to implement an app widget with
|
||||
collections.</p>
|
||||
|
||||
<h4>Manifest for app widgets with collections</h4>
|
||||
|
||||
<p> In addition to the requirements listed in <a href="#Manifest">Declaring an
|
||||
App Widget in the Manifest</a>, to make it possible for App Widgets with
|
||||
app widget in the Manifest</a>, to make it possible for app widgets with
|
||||
collections to bind to your {@link android.widget.RemoteViewsService}, you must
|
||||
declare the service in your manifest file with the permission {@link
|
||||
android.Manifest.permission#BIND_REMOTEVIEWS}. This prevents other applications
|
||||
@@ -987,7 +998,7 @@ android.widget.RemoteViewsService} can then return your implementation of {@link
|
||||
android.widget.RemoteViewsService.RemoteViewsFactory RemoteViewsFactory}, and
|
||||
the widget can serve up the appropriate data. When you call this method, you
|
||||
must pass an intent that points to your implementation of {@link
|
||||
android.widget.RemoteViewsService} and the App Widget ID that specifies the app
|
||||
android.widget.RemoteViewsService} and the app widget ID that specifies the app
|
||||
widget to update.</p>
|
||||
|
||||
|
||||
@@ -1009,7 +1020,7 @@ int[] appWidgetIds) {
|
||||
// Add the app widget ID to the intent extras.
|
||||
intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetIds[i]);
|
||||
intent.setData(Uri.parse(intent.toUri(Intent.URI_INTENT_SCHEME)));
|
||||
// Instantiate the RemoteViews object for the App Widget layout.
|
||||
// Instantiate the RemoteViews object for the app widget layout.
|
||||
RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.widget_layout);
|
||||
// Set up the RemoteViews object to use a RemoteViews adapter.
|
||||
// This adapter connects
|
||||
@@ -1367,15 +1378,15 @@ class StackRemoteViewsFactory implements RemoteViewsService.RemoteViewsFactory {
|
||||
|
||||
<h3 id="fresh">Keeping Collection Data Fresh</h3>
|
||||
|
||||
<p>The following figure illustrates the flow that occurs in an App Widget that
|
||||
<p>The following figure illustrates the flow that occurs in an app widget that
|
||||
uses
|
||||
collections when updates occur. It shows how the App Widget code interacts with
|
||||
collections when updates occur. It shows how the app widget code interacts with
|
||||
the {@link android.widget.RemoteViewsService.RemoteViewsFactory
|
||||
RemoteViewsFactory}, and how you can trigger updates:</p>
|
||||
|
||||
<img src="{@docRoot}images/appwidgets/appwidget_collections.png" alt="" />
|
||||
|
||||
<p>One feature of App Widgets that use collections is the ability to provide
|
||||
<p>One feature of app widgets that use collections is the ability to provide
|
||||
users with up-to-date content. For example, consider the Android 3.0 Gmail
|
||||
app widget, which provides users with a snapshot of their inbox. To make this
|
||||
possible, you need to be able to trigger your {@link
|
||||
|
||||
Reference in New Issue
Block a user