* <p>
* An accessibility event is fired by an individual view which populates the event with
* data for its state and requests from its parent to send the event to interested
- * parties. The parent can optionally add an {@link AccessibilityRecord} for itself before
- * dispatching a similar request to its parent. A parent can also choose not to respect the
- * request for sending an event. The accessibility event is sent by the topmost view in the
- * view tree. Therefore, an {@link android.accessibilityservice.AccessibilityService} can
- * explore all records in an accessibility event to obtain more information about the
- * context in which the event was fired.
+ * parties. The parent can optionally modify or even block the event based on its broader
+ * understanding of the user interface's context.
* </p>
* <p>
- * The main purpose of an accessibility event is to expose enough information for an
- * {@link android.accessibilityservice.AccessibilityService} to provide meaningful feedback
- * to the user. Sometimes however, an accessibility service may need more contextual
- * information then the one in the event pay-load. In such cases the service can obtain
- * the event source which is an {@link AccessibilityNodeInfo} (snapshot of a View state)
+ * The main purpose of an accessibility event is to communicate changes in the UI to an
+ * {@link android.accessibilityservice.AccessibilityService}. The service may then inspect,
+ * if needed the user interface by examining the View hierarchy, as represented by a tree of
+ * {@link AccessibilityNodeInfo}s (snapshot of a View state)
* which can be used for exploring the window content. Note that the privilege for accessing
* an event's source, thus the window content, has to be explicitly requested. For more
* details refer to {@link android.accessibilityservice.AccessibilityService}. If an
* <li>{@link #getClassName()} - The class name of the source.</li>
* <li>{@link #getPackageName()} - The package name of the source.</li>
* <li>{@link #getEventTime()} - The event time.</li>
- * <li>{@link #getText()} - The text of the source's sub-tree.</li>
- * <li>{@link #isEnabled()} - Whether the source is enabled.</li>
- * <li>{@link #isPassword()} - Whether the source is password.</li>
- * <li>{@link #isChecked()} - Whether the source is checked.</li>
- * <li>{@link #getContentDescription()} - The content description of the source.</li>
- * <li>{@link #getScrollX()} - The offset of the source left edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getScrollY()} - The offset of the source top edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getItemCount()} - The total items of the source
- * (for descendants of AdapterView).</li>
* </ul>
* </p>
* <p>
* <li>{@link #getClassName()} - The class name of the source.</li>
* <li>{@link #getPackageName()} - The package name of the source.</li>
* <li>{@link #getEventTime()} - The event time.</li>
- * <li>{@link #getText()} - The text of the source's sub-tree.</li>
- * <li>{@link #isEnabled()} - Whether the source is enabled.</li>
- * <li>{@link #isPassword()} - Whether the source is password.</li>
- * <li>{@link #isChecked()} - Whether the source is checked.</li>
- * <li>{@link #getContentDescription()} - The content description of the source.</li>
- * <li>{@link #getScrollX()} - The offset of the source left edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getScrollY()} - The offset of the source top edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getItemCount()} - The total items of the source
- * (for descendants of AdapterView).</li>
* </ul>
* </p>
* <p>
* <li>{@link #getClassName()} - The class name of the source.</li>
* <li>{@link #getPackageName()} - The package name of the source.</li>
* <li>{@link #getEventTime()} - The event time.</li>
- * <li>{@link #getText()} - The text of the source's sub-tree.</li>
- * <li>{@link #isEnabled()} - Whether the source is enabled.</li>
- * <li>{@link #isPassword()} - Whether the source is password.</li>
- * <li>{@link #isChecked()} - Whether the source is checked.</li>
- * <li>{@link #getItemCount()} - The number of selectable items of the source.</li>
- * <li>{@link #getCurrentItemIndex()} - The currently selected item index.</li>
- * <li>{@link #getContentDescription()} - The content description of the source.</li>
- * <li>{@link #getScrollX()} - The offset of the source left edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getScrollY()} - The offset of the source top edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getItemCount()} - The total items of the source
- * (for descendants of AdapterView).</li>
* </ul>
* </p>
* <p>
* <li>{@link #getClassName()} - The class name of the source.</li>
* <li>{@link #getPackageName()} - The package name of the source.</li>
* <li>{@link #getEventTime()} - The event time.</li>
- * <li>{@link #getText()} - The text of the source's sub-tree.</li>
- * <li>{@link #isEnabled()} - Whether the source is enabled.</li>
- * <li>{@link #isPassword()} - Whether the source is password.</li>
- * <li>{@link #isChecked()} - Whether the source is checked.</li>
- * <li>{@link #getItemCount()} - The number of focusable items on the screen.</li>
- * <li>{@link #getCurrentItemIndex()} - The currently focused item index.</li>
- * <li>{@link #getContentDescription()} - The content description of the source.</li>
- * <li>{@link #getScrollX()} - The offset of the source left edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getScrollY()} - The offset of the source top edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getItemCount()} - The total items of the source
- * (for descendants of AdapterView).</li>
* </ul>
* </p>
* <p>
* <li>{@link #getClassName()} - The class name of the source.</li>
* <li>{@link #getPackageName()} - The package name of the source.</li>
* <li>{@link #getEventTime()} - The event time.</li>
- * <li>{@link #getText()} - The text of the source.</li>
- * <li>{@link #isEnabled()} - Whether the source is enabled.</li>
- * <li>{@link #isPassword()} - Whether the source is password.</li>
- * <li>{@link #isChecked()} - Whether the source is checked.</li>
+ * <li>{@link #getText()} - The new text of the source.</li>
+ * <li>{@link #getBeforeText()} - The text of the source before the change.</li>
* <li>{@link #getFromIndex()} - The text change start index.</li>
* <li>{@link #getAddedCount()} - The number of added characters.</li>
* <li>{@link #getRemovedCount()} - The number of removed characters.</li>
- * <li>{@link #getBeforeText()} - The text of the source before the change.</li>
- * <li>{@link #getContentDescription()} - The content description of the source.</li>
* </ul>
* </p>
* <p>
* <li>{@link #getClassName()} - The class name of the source.</li>
* <li>{@link #getPackageName()} - The package name of the source.</li>
* <li>{@link #getEventTime()} - The event time.</li>
- * <li>{@link #getText()} - The text of the source.</li>
- * <li>{@link #isPassword()} - Whether the source is password.</li>
- * <li>{@link #getFromIndex()} - The selection start index.</li>
- * <li>{@link #getToIndex()} - The selection end index.</li>
- * <li>{@link #getItemCount()} - The length of the source text.</li>
- * <li>{@link #isEnabled()} - Whether the source is enabled.</li>
- * <li>{@link #getContentDescription()} - The content description of the source.</li>
* </ul>
* </p>
* <b>View text traversed at movement granularity</b> - represents the event of traversing the
* <li>{@link #getToIndex()} - The end of the text that was skipped over in this movement.
* This is the ending point when moving forward through the text, but not when moving
* back.</li>
- * <li>{@link #isPassword()} - Whether the source is password.</li>
- * <li>{@link #isEnabled()} - Whether the source is enabled.</li>
- * <li>{@link #getContentDescription()} - The content description of the source.</li>
- * <li>{@link #getMovementGranularity()} - Sets the granularity at which a view's text
- * was traversed.</li>
* <li>{@link #getAction()} - Gets traversal action which specifies the direction.</li>
* </ul>
* </p>
* <p>
- * <b>View scrolled</b> - represents the event of scrolling a view. If
- * the source is a descendant of {@link android.widget.AdapterView} the
- * scroll is reported in terms of visible items - the first visible item,
- * the last visible item, and the total items - because the the source
- * is unaware of its pixel size since its adapter is responsible for
- * creating views. In all other cases the scroll is reported as the current
- * scroll on the X and Y axis respectively plus the height of the source in
- * pixels.</br>
+ * <b>View scrolled</b> - represents the event of scrolling a view. </br>
* <em>Type:</em> {@link #TYPE_VIEW_SCROLLED}</br>
* <em>Properties:</em></br>
* <ul>
* <li>{@link #getClassName()} - The class name of the source.</li>
* <li>{@link #getPackageName()} - The package name of the source.</li>
* <li>{@link #getEventTime()} - The event time.</li>
- * <li>{@link #getText()} - The text of the source's sub-tree.</li>
- * <li>{@link #isEnabled()} - Whether the source is enabled.</li>
- * <li>{@link #getContentDescription()} - The content description of the source.</li>
- * <li>{@link #getScrollX()} - The offset of the source left edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getScrollY()} - The offset of the source top edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getItemCount()} - The total items of the source
- * (for descendants of AdapterView).</li>
+ * <li>{@link #getScrollDeltaX()} - The difference in the horizontal position.</li>
+ * <li>{@link #getScrollDeltaY()} - The difference in the vertical position.</li>
* </ul>
- * <em>Note:</em> This event type is not dispatched to descendants though
- * {@link android.view.View#dispatchPopulateAccessibilityEvent(AccessibilityEvent)
- * View.dispatchPopulateAccessibilityEvent(AccessibilityEvent)}, hence the event
- * source {@link android.view.View} and the sub-tree rooted at it will not receive
- * calls to {@link android.view.View#onPopulateAccessibilityEvent(AccessibilityEvent)
- * View.onPopulateAccessibilityEvent(AccessibilityEvent)}. The preferred way to add
- * text content to such events is by setting the
- * {@link android.R.styleable#View_contentDescription contentDescription} of the source
- * view.</br>
* </p>
* <p>
* <b>TRANSITION TYPES</b></br>
* <li>{@link #getPackageName()} - The package name of the source.</li>
* <li>{@link #getEventTime()} - The event time.</li>
* <li>{@link #getText()} - The text of the source's sub-tree.</li>
- * <li>{@link #isEnabled()} - Whether the source is enabled.</li>
* </ul>
* </p>
* <p>
* a view size, etc.</br>
* </p>
* <p>
- * <strong>Note:</strong> This event is fired only for the window source of the
- * last accessibility event different from {@link #TYPE_NOTIFICATION_STATE_CHANGED}
- * and its purpose is to notify clients that the content of the user interaction
- * window has changed.</br>
* <em>Type:</em> {@link #TYPE_WINDOW_CONTENT_CHANGED}</br>
* <em>Properties:</em></br>
* <ul>
* <li>{@link #getPackageName()} - The package name of the source.</li>
* <li>{@link #getEventTime()} - The event time.</li>
* </ul>
- * <em>Note:</em> This event type is not dispatched to descendants though
- * {@link android.view.View#dispatchPopulateAccessibilityEvent(AccessibilityEvent)
- * View.dispatchPopulateAccessibilityEvent(AccessibilityEvent)}, hence the event
- * source {@link android.view.View} and the sub-tree rooted at it will not receive
- * calls to {@link android.view.View#onPopulateAccessibilityEvent(AccessibilityEvent)
- * View.onPopulateAccessibilityEvent(AccessibilityEvent)}. The preferred way to add
- * text content to such events is by setting the
- * {@link android.R.styleable#View_contentDescription contentDescription} of the source
- * view.</br>
* </p>
* <p>
* <b>Windows changed</b> - represents a change in the windows shown on
* the screen such as a window appeared, a window disappeared, a window size changed,
* a window layer changed, etc. These events should only come from the system, which is responsible
- * for managing windows. For regions of the user interface that are presented as windows but are
+ * for managing windows. The list of windows is available from
+ * {@link android.accessibilityservice.AccessibilityService#getWindows()}.
+ * For regions of the user interface that are presented as windows but are
* controlled by an app's process, use {@link #TYPE_WINDOW_STATE_CHANGED}.</br>
* <em>Type:</em> {@link #TYPE_WINDOWS_CHANGED}</br>
* <em>Properties:</em></br>
* <li>{@link #getClassName()} - The class name of the source.</li>
* <li>{@link #getPackageName()} - The package name of the source.</li>
* <li>{@link #getEventTime()} - The event time.</li>
- * <li>{@link #getText()} - The text of the source's sub-tree.</li>
- * <li>{@link #isEnabled()} - Whether the source is enabled.</li>
- * <li>{@link #getContentDescription()} - The content description of the source.</li>
- * <li>{@link #getScrollX()} - The offset of the source left edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getScrollY()} - The offset of the source top edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getItemCount()} - The total items of the source
- * (for descendants of AdapterView).</li>
* </ul>
* </p>
* <b>View hover exit</b> - represents the event of stopping to hover
* <li>{@link #getClassName()} - The class name of the source.</li>
* <li>{@link #getPackageName()} - The package name of the source.</li>
* <li>{@link #getEventTime()} - The event time.</li>
- * <li>{@link #getText()} - The text of the source's sub-tree.</li>
- * <li>{@link #isEnabled()} - Whether the source is enabled.</li>
- * <li>{@link #getContentDescription()} - The content description of the source.</li>
- * <li>{@link #getScrollX()} - The offset of the source left edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getScrollY()} - The offset of the source top edge in pixels
- * (without descendants of AdapterView).</li>
- * <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
- * inclusive (for descendants of AdapterView).</li>
- * <li>{@link #getItemCount()} - The total items of the source
- * (for descendants of AdapterView).</li>
* </ul>
* </p>
* <p>
* <b>MISCELLANEOUS TYPES</b></br>
* </p>
* <p>
- * <b>Announcement</b> - represents the event of an application making an
- * announcement. Usually this announcement is related to some sort of a context
- * change for which none of the events representing UI transitions is a good fit.
- * For example, announcing a new page in a book.</br>
+ * <b>Announcement</b> - represents the event of an application requesting a screen reader to make
+ * an announcement. Because the event carries no semantic meaning, this event is appropriate only
+ * in exceptional situations where additional screen reader output is needed but other types of
+ * accessibility services do not need to be aware of the change.</br>
* <em>Type:</em> {@link #TYPE_ANNOUNCEMENT}</br>
* <em>Properties:</em></br>
* <ul>
* <li>{@link #getPackageName()} - The package name of the source.</li>
* <li>{@link #getEventTime()} - The event time.</li>
* <li>{@link #getText()} - The text of the announcement.</li>
- * <li>{@link #isEnabled()} - Whether the source is enabled.</li>
* </ul>
* </p>
*
public static final int TYPE_TOUCH_INTERACTION_END = 0x00200000;
/**
- * Represents the event change in the windows shown on the screen.
+ * Represents the event change in the system windows shown on the screen. This event type should
+ * only be dispatched by the system.
*/
public static final int TYPE_WINDOWS_CHANGED = 0x00400000;
/**
* Change type for {@link #TYPE_WINDOW_CONTENT_CHANGED} event:
- * A node in the subtree rooted at the source node was added or removed.
+ * One or more content changes occurred in the the subtree rooted at the source node,
+ * or the subtree's structure changed when a node was added or removed.
*/
public static final int CONTENT_CHANGE_TYPE_SUBTREE = 0x00000001;
public @interface WindowsChangeTypes {}
/** @hide */
+ @Retention(RetentionPolicy.SOURCE)
+ @IntDef(flag = true, prefix = { "CONTENT_CHANGE_TYPE_" },
+ value = {
+ CONTENT_CHANGE_TYPE_UNDEFINED,
+ CONTENT_CHANGE_TYPE_SUBTREE,
+ CONTENT_CHANGE_TYPE_TEXT,
+ CONTENT_CHANGE_TYPE_CONTENT_DESCRIPTION
+ })
+ public @interface ContentChangeTypes {}
+
+ /** @hide */
@IntDef(flag = true, prefix = { "TYPE_" }, value = {
TYPE_VIEW_CLICKED,
TYPE_VIEW_LONG_CLICKED,
* <li>{@link AccessibilityEvent#CONTENT_CHANGE_TYPE_UNDEFINED}
* </ul>
*/
+ @ContentChangeTypes
public int getContentChangeTypes() {
return mContentChangeTypes;
}
* @throws IllegalStateException If called from an AccessibilityService.
* @see #getContentChangeTypes()
*/
- public void setContentChangeTypes(int changeTypes) {
+ public void setContentChangeTypes(@ContentChangeTypes int changeTypes) {
enforceNotSealed();
mContentChangeTypes = changeTypes;
}
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