Merge "docs: Revised wording, section order for ShortcutManager API ref." into oc-mr1-dev

import java.util.List;

/**

 * The ShortcutManager manages an app's <em>shortcuts</em>. Shortcuts provide users with quick

 * access to activities other than an app's main activity in the currently-active launcher, provided

 * that the launcher supports app shortcuts.  For example, an email app may publish the "compose new

 * email" action, which will directly open the compose activity.  The {@link ShortcutInfo} class

 * contains information about each of the shortcuts themselves.

 * The ShortcutManager performs operations on an app's set of <em>shortcuts</em>. The

 * {@link ShortcutInfo} class contains information about each of the shortcuts themselves.

 *

 * <p>An app's shortcuts represent specific tasks and actions that users can take within your app.

 * When a user selects a shortcut in the currently-active launcher, your app opens an activity other

 * than the app's starting activity, provided that the currently-active launcher supports app

 * shortcuts.</p>

 *

 * <p>The types of shortcuts that you create for your app depend on the app's key use cases. For

 * example, an email app may publish the "compose new email" shortcut, which allows the app to

 * directly open the compose activity.</p>

 *

 * <p class="note"><b>Note:</b> Only main activities&mdash;activities that handle the

 * {@link Intent#ACTION_MAIN} action and the {@link Intent#CATEGORY_LAUNCHER} category—can

 * have shortcuts. If an app has multiple main activities, you need to define the set of shortcuts

 * for <em>each</em> activity.

 *

 * <p>This page discusses the implementation details of the <code>ShortcutManager</code> class. For

 * guidance on performing operations on app shortcuts within your app, see the

 * <a href="/guide/topics/ui/shortcuts.html">App Shortcuts</a> feature guide.

 * definitions of key terms and guidance on performing operations on shortcuts within your app, see

 * the <a href="/guide/topics/ui/shortcuts.html">App Shortcuts</a> feature guide.

 *

 * <h3>Shortcut characteristics</h3>

 *

 * <ul>

 *     <li>The user removes it.

 *     <li>The publisher app associated with the shortcut is uninstalled.

 *     <li>The user performs the clear data action on the publisher app from the device's

 *     <b>Settings</b> app.

 *     <li>The user selects <b>Clear data</b> from the publisher app's <i>Storage</i> screen, within

 *     the system's <b>Settings</b> app.

 * </ul>

 *

 * <p>Because the system performs

 * <p>When the launcher displays an app's shortcuts, they should appear in the following order:

 *

 * <ul>

 *   <li>Static shortcuts (if {@link ShortcutInfo#isDeclaredInManifest()} is {@code true}),

 *   and then show dynamic shortcuts (if {@link ShortcutInfo#isDynamic()} is {@code true}).

 *   <li>Within each shortcut type (static and dynamic), sort the shortcuts in order of increasing

 *   <li>Static shortcuts&mdash;shortcuts whose {@link ShortcutInfo#isDeclaredInManifest()} method

 *   returns {@code true}—followed by dynamic shortcuts—shortcuts whose

 *   {@link ShortcutInfo#isDynamic()} method returns {@code true}.

 *   <li>Within each shortcut type (static and dynamic), shortcuts are sorted in order of increasing

 *   rank according to {@link ShortcutInfo#getRank()}.

 * </ul>

 *

 * <h4>Shortcut ranks</h4>

 *

 * <p>Shortcut ranks are non-negative, sequential integers that determine the order in which

 * shortcuts appear, assuming that the shortcuts are all in the same category. You can update ranks

 * of existing shortcuts when you call {@link #updateShortcuts(List)},

 *

 * <h3>Options for static shortcuts</h3>

 *

 * The following list includes descriptions for the different attributes within a static shortcut:

 * The following list includes descriptions for the different attributes within a static shortcut.

 * You must provide a value for {@code android:shortcutId}, {@code android:shortcutShortLabel}; all

 * other values are optional.

 *

 * <dl>

 *   <dt>{@code android:shortcutId}</dt>

 *   <dd>Mandatory shortcut ID.

 *   <p>

 *   This must be a string literal.

 *   A resource string, such as <code>@string/foo</code>, cannot be used.

 *   <dd><p>A string literal, which represents the shortcut when a {@code ShortcutManager} object

 *   performs operations on it.</p>

 *   <p class="note"><b>Note: </b>You cannot set this attribute's value to a resource string, such

 *   as <code>@string/foo</code>.</p>

 *   </dd>

 *

 *   <dt>{@code android:enabled}</dt>

 *   <dd>Default is {@code true}.  Can be set to {@code false} in order

 *   to disable a static shortcut that was published in a previous version and set a custom

 *   disabled message.  If a custom disabled message is not needed, then a static shortcut can

 *   be simply removed from the XML file rather than keeping it with {@code enabled="false"}.</dd>

 *   <dd><p>Whether the user can interact with the shortcut from a supported launcher.</p>

 *   <p>The default value is {@code true}. If you set it to {@code false}, you should also set

 *   {@code android:shortcutDisabledMessage} to a message that explains why you've disabled the

 *   shortcut. If you don't think you need to provide such a message, it's easiest to just remove

 *   the shortcut from the XML file entirely, rather than changing the values of its

 *   {@code android:enabled} and {@code android:shortcutDisabledMessage} attributes.

 *   </dd>

 *

 *   <dt>{@code android:icon}</dt>

 *   <dd>Shortcut icon.</dd>

 *   <dd><p>The <a href="/topic/performance/graphics/index.html">bitmap</a> or

 *   <a href="/guide/practices/ui_guidelines/icon_design_adaptive.html">adaptive icon</a> that the

 *   launcher uses when displaying the shortcut to the user. This value can be either the path to an

 *   image or the resource file that contains the image. Use adaptive icons whenever possible to

 *   improve performance and consistency.</p>

 *   <p class="note"><b>Note: </b>Shortcut icons cannot include

 *   <a href="/training/material/drawables.html#DrawableTint">tints</a>.

 *   </dd>

 *

 *   <dt>{@code android:shortcutShortLabel}</dt>

 *   <dd>Mandatory shortcut short label.

 *   See {@link ShortcutInfo.Builder#setShortLabel(CharSequence)}.

 *   <p>

 *   This must be a resource string, such as <code>@string/shortcut_label</code>.

 *   <dd><p>A concise phrase that describes the shortcut's purpose. For more information, see

 *   {@link ShortcutInfo.Builder#setShortLabel(CharSequence)}.</p>

 *   <p class="note"><b>Note: </b>This attribute's value must be a resource string, such as

 *   <code>@string/shortcut_label</code>.</p>

 *   </dd>

 *

 *   <dt>{@code android:shortcutLongLabel}</dt>

 *   <dd>Shortcut long label.

 *   See {@link ShortcutInfo.Builder#setLongLabel(CharSequence)}.

 *   <p>

 *   This must be a resource string, such as <code>@string/shortcut_long_label</code>.

 *   <dd><p>An extended phrase that describes the shortcut's purpose. If there's enough space, the

 *   launcher displays this value instead of {@code android:shortcutShortLabel}. For more

 *   information, see {@link ShortcutInfo.Builder#setLongLabel(CharSequence)}.</p>

 *   <p class="note"><b>Note: </b>This attribute's value must be a resource string, such as

 *   <code>@string/shortcut_long_label</code>.</p>

 *   </dd>

 *

 *   <dt>{@code android:shortcutDisabledMessage}</dt>

 *   <dd>When {@code android:enabled} is set to

 *   {@code false}, this attribute is used to display a custom disabled message.

 *   <p>

 *   This must be a resource string, such as <code>@string/shortcut_disabled_message</code>.

 *   <dd><p>The message that appears in a supported launcher when the user attempts to launch a

 *   disabled shortcut. This attribute's value has no effect if {@code android:enabled} is

 *   {@code true}. The message should explain to the user why the shortcut is now disabled.</p>

 *   <p class="note"><b>Note: </b>This attribute's value must be a resource string, such as

 *   <code>@string/shortcut_disabled_message</code>.</p>

 *   </dd>

 * </dl>

 *

 * <h3>Inner elements that define static shortcuts</h3>

 *

 * <p>The XML file that lists an app's static shortcuts supports the following elements inside each

 * {@code <shortcut>} element. You must include an {@code intent} inner element for each

 * static shortcut that you define.</p>

 *

 * <dl>

 *   <dt>{@code intent}</dt>

 *   <dd>Intent to launch when the user selects the shortcut.

 *   {@code android:action} is mandatory.

 *   See <a href="{@docRoot}guide/topics/ui/settings.html#Intents">Using intents</a> for the

 *   other supported tags.

 *   <dd><p>The action that the system launches when the user selects the shortcut. This intent must

 *   provide a value for the {@code android:action} attribute.</p>

 *   <p>You can provide multiple intents for a single shortcut so that the last defined activity is

 *   launched with the other activities in the

 *   <a href="/guide/components/tasks-and-back-stack.html">back stack</a>. See

 *   {@link android.app.TaskStackBuilder} for details.

 *   <p><b>Note:</b> String resources may not be used within an {@code <intent>} element.

 *   <a href="/guide/topics/ui/shortcuts.html#static">Using Static Shortcuts</a> and the

 *   {@link android.app.TaskStackBuilder} class reference for details.</p>

 *   <p class="note"><b>Note:</b> This {@code intent} element cannot include string resources.</p>

 *   <p>For more information, see

 *   <a href="{@docRoot}guide/topics/ui/settings.html#Intents">Using intents</a>.</p>

 *   </dd>

 *

 *   <dt>{@code categories}</dt>

 *   <dd>Specify shortcut categories.  Currently only

 *   {@link ShortcutInfo#SHORTCUT_CATEGORY_CONVERSATION} is defined in the framework.

 *   <dd><p>Provides a grouping for the types of actions that your app's shortcuts perform, such as

 *   creating new chat messages.</p>

 *   <p>For a list of supported shortcut categories, see the {@link ShortcutInfo} class reference

 *   for a list of supported shortcut categories.

 *   </dd>

 * </dl>

 *

 * <h3>Updating shortcuts</h3>

 *

 * <p>Each app's launcher icon can contain at most {@link #getMaxShortcutCountPerActivity()} number

 * of static and dynamic shortcuts combined. There is no limit to the number of pinned shortcuts

 * that an app can create, though.

 *

 * <p>When a dynamic shortcut is pinned, even when the publisher removes it as a dynamic shortcut,

 * the pinned shortcut is still visible and launchable.  This allows an app to have more than

 * {@link #getMaxShortcutCountPerActivity()} number of shortcuts.

 *

 * <p>As an example, suppose {@link #getMaxShortcutCountPerActivity()} is 5:

 * <ol>

 *     <li>A chat app publishes 5 dynamic shortcuts for the 5 most recent

 *

 *     <li>The user pins all 5 of the shortcuts.

 *

 *     <li>Later, the user has started 3 additional conversations (c6, c7, and c8),

 *     so the publisher app

 *     re-publishes its dynamic shortcuts.  The new dynamic shortcut list is:

 *     c4, c5, ..., c8.

 *     The publisher app has to remove c1, c2, and c3 because it can't have more than

 *     5 dynamic shortcuts.

 *

 *     <li>However, even though c1, c2, and c3 are no longer dynamic shortcuts, the pinned

 *     shortcuts for these conversations are still available and launchable.

 *

 *     <li>At this point, the user can access a total of 8 shortcuts that link to activities in

 *     the publisher app, including the 3 pinned shortcuts, even though an app can have at most 5

 *     <li>Later, the user has started 3 additional conversations (c6, c7, and c8), so the publisher

 *     app re-publishes its dynamic shortcuts. The new dynamic shortcut list is: c4, c5, ..., c8.

 *     <p>The publisher app has to remove c1, c2, and c3 because it can't have more than 5 dynamic

 *     shortcuts. However, c1, c2, and c3 are still pinned shortcuts that the user can access and

 *     launch.

 *     <p>At this point, the user can access a total of 8 shortcuts that link to activities in the

 *     publisher app, including the 3 pinned shortcuts, even though an app can have at most 5

 *     dynamic shortcuts.

 *

 *     <li>The app can use {@link #updateShortcuts(List)} to update <em>any</em> of the existing

 * Dynamic shortcuts can be published with any set of {@link Intent#addFlags Intent} flags.

 * Typically, {@link Intent#FLAG_ACTIVITY_CLEAR_TASK} is specified, possibly along with other

 * flags; otherwise, if the app is already running, the app is simply brought to

 * the foreground, and the target activity may not appear.

 * the foreground, and the target activity might not appear.

 *

 * <p>Static shortcuts <b>cannot</b> have custom intent flags.

 * The first intent of a static shortcut will always have {@link Intent#FLAG_ACTIVITY_NEW_TASK}

 * and {@link Intent#FLAG_ACTIVITY_CLEAR_TASK} set. This means, when the app is already running, all

 * the existing activities in your app will be destroyed when a static shortcut is launched.

 * the existing activities in your app are destroyed when a static shortcut is launched.

 * If this behavior is not desirable, you can use a <em>trampoline activity</em>, or an invisible

 * activity that starts another activity in {@link Activity#onCreate}, then calls

 * {@link Activity#finish()}:

 * <ol>

 *     <li>In the <code>AndroidManifest.xml</code> file, the trampoline activity should include the

 *     attribute assignment {@code android:taskAffinity=""}.

 *     <li>In the shortcuts resource file, the intent within the static shortcut should point at

 *     <li>In the shortcuts resource file, the intent within the static shortcut should reference

 *     the trampoline activity.

 * </ol>

 *

 * <h3>Handling system locale changes</h3>

 *

 * <p>Apps should update dynamic and pinned shortcuts when the system locale changes using the

 * {@link Intent#ACTION_LOCALE_CHANGED} broadcast. When the system locale changes,

 * <a href="/guide/topics/ui/shortcuts.html#rate-limit">rate limiting</a> is reset, so even

 * background apps can add and update dynamic shortcuts until the rate limit is reached again.

 *

 * <h3>Shortcut limits</h3>

 *

 * <p>Only main activities&mdash;activities that handle the {@code MAIN} action and the

 * {@code LAUNCHER} category—can have shortcuts. If an app has multiple main activities, you

 * need to define the set of shortcuts for <em>each</em> activity.

 *

 * <p>Each launcher icon can have at most {@link #getMaxShortcutCountPerActivity()} number of

 * static and dynamic shortcuts combined. There is no limit to the number of pinned shortcuts that

 * an app can create.

 *

 * <p>When a dynamic shortcut is pinned, even when the publisher removes it as a dynamic shortcut,

 * the pinned shortcut is still visible and launchable.  This allows an app to have more than

 * {@link #getMaxShortcutCountPerActivity()} number of shortcuts.

 *

 * <h4>Rate limiting</h4>

 * <h3>Rate limiting</h3>

 *

 * <p>When <a href="/guide/topics/ui/shortcuts.html#rate-limit">rate limiting</a> is active,

 * {@link #isRateLimitingActive()} returns {@code true}.

 * <ul>

 *   <li>An app comes to the foreground.

 *   <li>The system locale changes.

 *   <li>The user performs the <strong>inline reply</strong> action on a notification.

 *   <li>The user performs the <a href="/guide/topics/ui/notifiers/notifications.html#direct">inline

 *   reply</a> action on a notification.

 * </ul>

 *

 * <h3>Handling system locale changes</h3>

 *

 * <p>Apps should update dynamic and pinned shortcuts when they receive the

 * {@link Intent#ACTION_LOCALE_CHANGED} broadcast, indicating that the system locale has changed.

 * <p>When the system locale changes, <a href="/guide/topics/ui/shortcuts.html#rate-limit">rate

 * limiting</a> is reset, so even background apps can add and update dynamic shortcuts until the

 * rate limit is reached again.

 *

 * <h3>Retrieving class instances</h3>

 * <!-- Provides a heading for the content filled in by the @SystemService annotation below -->

 */

@SystemService(Context.SHORTCUT_SERVICE)

public class ShortcutManager {