AccessibilityEvent.java revision 6254f4806dd3db53b7380e77fbb183065685573e
1/*
2 * Copyright (C) 2009 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.view.accessibility;
18
19import android.os.Parcel;
20import android.os.Parcelable;
21import android.text.TextUtils;
22import android.util.Pools.SynchronizedPool;
23
24import java.util.ArrayList;
25import java.util.List;
26
27/**
28 * <p>
29 * This class represents accessibility events that are sent by the system when
30 * something notable happens in the user interface. For example, when a
31 * {@link android.widget.Button} is clicked, a {@link android.view.View} is focused, etc.
32 * </p>
33 * <p>
34 * An accessibility event is fired by an individual view which populates the event with
35 * data for its state and requests from its parent to send the event to interested
36 * parties. The parent can optionally add an {@link AccessibilityRecord} for itself before
37 * dispatching a similar request to its parent. A parent can also choose not to respect the
38 * request for sending an event. The accessibility event is sent by the topmost view in the
39 * view tree. Therefore, an {@link android.accessibilityservice.AccessibilityService} can
40 * explore all records in an accessibility event to obtain more information about the
41 * context in which the event was fired.
42 * </p>
43 * <p>
44 * The main purpose of an accessibility event is to expose enough information for an
45 * {@link android.accessibilityservice.AccessibilityService} to provide meaningful feedback
46 * to the user. Sometimes however, an accessibility service may need more contextual
47 * information then the one in the event pay-load. In such cases the service can obtain
48 * the event source which is an {@link AccessibilityNodeInfo} (snapshot of a View state)
49 * which can be used for exploring the window content. Note that the privilege for accessing
50 * an event's source, thus the window content, has to be explicitly requested. For more
51 * details refer to {@link android.accessibilityservice.AccessibilityService}. If an
52 * accessibility service has not requested to retrieve the window content the event will
53 * not contain reference to its source. Also for events of type
54 * {@link #TYPE_NOTIFICATION_STATE_CHANGED} the source is never available.
55 * </p>
56 * <p>
57 * This class represents various semantically different accessibility event
58 * types. Each event type has an associated set of related properties. In other
59 * words, each event type is characterized via a subset of the properties exposed
60 * by this class. For each event type there is a corresponding constant defined
61 * in this class. Follows a specification of the event types and their associated properties:
62 * </p>
63 * <div class="special reference">
64 * <h3>Developer Guides</h3>
65 * <p>For more information about creating and processing AccessibilityEvents, read the
66 * <a href="{@docRoot}guide/topics/ui/accessibility/index.html">Accessibility</a>
67 * developer guide.</p>
68 * </div>
69 * <p>
70 * <b>VIEW TYPES</b></br>
71 * </p>
72 * <p>
73 * <b>View clicked</b> - represents the event of clicking on a {@link android.view.View}
74 * like {@link android.widget.Button}, {@link android.widget.CompoundButton}, etc.</br>
75 * <em>Type:</em>{@link #TYPE_VIEW_CLICKED}</br>
76 * <em>Properties:</em></br>
77 * <ul>
78 *   <li>{@link #getEventType()} - The type of the event.</li>
79 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
80 *   <li>{@link #getClassName()} - The class name of the source.</li>
81 *   <li>{@link #getPackageName()} - The package name of the source.</li>
82 *   <li>{@link #getEventTime()}  - The event time.</li>
83 *   <li>{@link #getText()} - The text of the source's sub-tree.</li>
84 *   <li>{@link #isEnabled()} - Whether the source is enabled.</li>
85 *   <li>{@link #isPassword()} - Whether the source is password.</li>
86 *   <li>{@link #isChecked()} - Whether the source is checked.</li>
87 *   <li>{@link #getContentDescription()} - The content description of the source.</li>
88 *   <li>{@link #getScrollX()} - The offset of the source left edge in pixels
89 *       (without descendants of AdapterView).</li>
90 *   <li>{@link #getScrollY()} - The offset of the source top edge in pixels
91 *       (without descendants of AdapterView).</li>
92 *   <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
93 *       inclusive (for descendants of AdapterView).</li>
94 *   <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
95 *       inclusive (for descendants of AdapterView).</li>
96 *   <li>{@link #getItemCount()} - The total items of the source
97 *       (for descendants of AdapterView).</li>
98 * </ul>
99 * </p>
100 * <p>
101 * <b>View long clicked</b> - represents the event of long clicking on a {@link android.view.View}
102 * like {@link android.widget.Button}, {@link android.widget.CompoundButton}, etc </br>
103 * <em>Type:</em>{@link #TYPE_VIEW_LONG_CLICKED}</br>
104 * <em>Properties:</em></br>
105 * <ul>
106 *   <li>{@link #getEventType()} - The type of the event.</li>
107 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
108 *   <li>{@link #getClassName()} - The class name of the source.</li>
109 *   <li>{@link #getPackageName()} - The package name of the source.</li>
110 *   <li>{@link #getEventTime()}  - The event time.</li>
111 *   <li>{@link #getText()} - The text of the source's sub-tree.</li>
112 *   <li>{@link #isEnabled()} - Whether the source is enabled.</li>
113 *   <li>{@link #isPassword()} - Whether the source is password.</li>
114 *   <li>{@link #isChecked()} - Whether the source is checked.</li>
115 *   <li>{@link #getContentDescription()} - The content description of the source.</li>
116 *   <li>{@link #getScrollX()} - The offset of the source left edge in pixels
117 *       (without descendants of AdapterView).</li>
118 *   <li>{@link #getScrollY()} - The offset of the source top edge in pixels
119 *       (without descendants of AdapterView).</li>
120 *   <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
121 *       inclusive (for descendants of AdapterView).</li>
122 *   <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
123 *       inclusive (for descendants of AdapterView).</li>
124 *   <li>{@link #getItemCount()} - The total items of the source
125 *       (for descendants of AdapterView).</li>
126 * </ul>
127 * </p>
128 * <p>
129 * <b>View selected</b> - represents the event of selecting an item usually in
130 * the context of an {@link android.widget.AdapterView}.</br>
131 * <em>Type:</em> {@link #TYPE_VIEW_SELECTED}</br>
132 * <em>Properties:</em></br>
133 * <ul>
134 *   <li>{@link #getEventType()} - The type of the event.</li>
135 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
136 *   <li>{@link #getClassName()} - The class name of the source.</li>
137 *   <li>{@link #getPackageName()} - The package name of the source.</li>
138 *   <li>{@link #getEventTime()}  - The event time.</li>
139 *   <li>{@link #getText()} - The text of the source's sub-tree.</li>
140 *   <li>{@link #isEnabled()} - Whether the source is enabled.</li>
141 *   <li>{@link #isPassword()} - Whether the source is password.</li>
142 *   <li>{@link #isChecked()} - Whether the source is checked.</li>
143 *   <li>{@link #getItemCount()} - The number of selectable items of the source.</li>
144 *   <li>{@link #getCurrentItemIndex()} - The currently selected item index.</li>
145 *   <li>{@link #getContentDescription()} - The content description of the source.</li>
146 *   <li>{@link #getScrollX()} - The offset of the source left edge in pixels
147 *       (without descendants of AdapterView).</li>
148 *   <li>{@link #getScrollY()} - The offset of the source top edge in pixels
149 *       (without descendants of AdapterView).</li>
150 *   <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
151 *       inclusive (for descendants of AdapterView).</li>
152 *   <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
153 *       inclusive (for descendants of AdapterView).</li>
154 *   <li>{@link #getItemCount()} - The total items of the source
155 *       (for descendants of AdapterView).</li>
156 * </ul>
157 * </p>
158 * <p>
159 * <b>View focused</b> - represents the event of focusing a
160 * {@link android.view.View}.</br>
161 * <em>Type:</em> {@link #TYPE_VIEW_FOCUSED}</br>
162 * <em>Properties:</em></br>
163 * <ul>
164 *   <li>{@link #getEventType()} - The type of the event.</li>
165 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
166 *   <li>{@link #getClassName()} - The class name of the source.</li>
167 *   <li>{@link #getPackageName()} - The package name of the source.</li>
168 *   <li>{@link #getEventTime()}  - The event time.</li>
169 *   <li>{@link #getText()} - The text of the source's sub-tree.</li>
170 *   <li>{@link #isEnabled()} - Whether the source is enabled.</li>
171 *   <li>{@link #isPassword()} - Whether the source is password.</li>
172 *   <li>{@link #isChecked()} - Whether the source is checked.</li>
173 *   <li>{@link #getItemCount()} - The number of focusable items on the screen.</li>
174 *   <li>{@link #getCurrentItemIndex()} - The currently focused item index.</li>
175 *   <li>{@link #getContentDescription()} - The content description of the source.</li>
176 *   <li>{@link #getScrollX()} - The offset of the source left edge in pixels
177 *       (without descendants of AdapterView).</li>
178 *   <li>{@link #getScrollY()} - The offset of the source top edge in pixels
179 *       (without descendants of AdapterView).</li>
180 *   <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
181 *       inclusive (for descendants of AdapterView).</li>
182 *   <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
183 *       inclusive (for descendants of AdapterView).</li>
184 *   <li>{@link #getItemCount()} - The total items of the source
185 *       (for descendants of AdapterView).</li>
186 * </ul>
187 * </p>
188 * <p>
189 * <b>View text changed</b> - represents the event of changing the text of an
190 * {@link android.widget.EditText}.</br>
191 * <em>Type:</em> {@link #TYPE_VIEW_TEXT_CHANGED}</br>
192 * <em>Properties:</em></br>
193 * <ul>
194 *   <li>{@link #getEventType()} - The type of the event.</li>
195 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
196 *   <li>{@link #getClassName()} - The class name of the source.</li>
197 *   <li>{@link #getPackageName()} - The package name of the source.</li>
198 *   <li>{@link #getEventTime()}  - The event time.</li>
199 *   <li>{@link #getText()} - The text of the source.</li>
200 *   <li>{@link #isEnabled()} - Whether the source is enabled.</li>
201 *   <li>{@link #isPassword()} - Whether the source is password.</li>
202 *   <li>{@link #isChecked()} - Whether the source is checked.</li>
203 *   <li>{@link #getFromIndex()} - The text change start index.</li>
204 *   <li>{@link #getAddedCount()} - The number of added characters.</li>
205 *   <li>{@link #getRemovedCount()} - The number of removed characters.</li>
206 *   <li>{@link #getBeforeText()} - The text of the source before the change.</li>
207 *   <li>{@link #getContentDescription()} - The content description of the source.</li>
208 * </ul>
209 * </p>
210 * <p>
211 * <b>View text selection changed</b> - represents the event of changing the text
212 * selection of an {@link android.widget.EditText}.</br>
213 * <em>Type:</em> {@link #TYPE_VIEW_TEXT_SELECTION_CHANGED} </br>
214 * <em>Properties:</em></br>
215 * <ul>
216 *   <li>{@link #getEventType()} - The type of the event.</li>
217 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
218 *   <li>{@link #getClassName()} - The class name of the source.</li>
219 *   <li>{@link #getPackageName()} - The package name of the source.</li>
220 *   <li>{@link #getEventTime()}  - The event time.</li>
221 *   <li>{@link #getText()} - The text of the source.</li>
222 *   <li>{@link #isPassword()} - Whether the source is password.</li>
223 *   <li>{@link #getFromIndex()} - The selection start index.</li>
224 *   <li>{@link #getToIndex()} - The selection end index.</li>
225 *   <li>{@link #getItemCount()} - The length of the source text.</li>
226 *   <li>{@link #isEnabled()} - Whether the source is enabled.</li>
227 *   <li>{@link #getContentDescription()} - The content description of the source.</li>
228 * </ul>
229 * </p>
230 * <b>View text traversed at movement granularity</b> - represents the event of traversing the
231 * text of a view at a given granularity. For example, moving to the next word.</br>
232 * <em>Type:</em> {@link #TYPE_VIEW_TEXT_TRAVERSED_AT_MOVEMENT_GRANULARITY} </br>
233 * <em>Properties:</em></br>
234 * <ul>
235 *   <li>{@link #getEventType()} - The type of the event.</li>
236 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
237 *   <li>{@link #getClassName()} - The class name of the source.</li>
238 *   <li>{@link #getPackageName()} - The package name of the source.</li>
239 *   <li>{@link #getEventTime()}  - The event time.</li>
240 *   <li>{@link #getMovementGranularity()} - Sets the granularity at which a view's text
241 *       was traversed.</li>
242 *   <li>{@link #getText()} -  The text of the source's sub-tree.</li>
243 *   <li>{@link #getFromIndex()} - The start of the next/previous text at the specified granularity
244 *           - inclusive.</li>
245 *   <li>{@link #getToIndex()} - The end of the next/previous text at the specified granularity
246 *           - exclusive.</li>
247 *   <li>{@link #isPassword()} - Whether the source is password.</li>
248 *   <li>{@link #isEnabled()} - Whether the source is enabled.</li>
249 *   <li>{@link #getContentDescription()} - The content description of the source.</li>
250 *   <li>{@link #getMovementGranularity()} - Sets the granularity at which a view's text
251 *       was traversed.</li>
252 *   <li>{@link #getAction()} - Gets traversal action which specifies the direction.</li>
253 * </ul>
254 * </p>
255 * <p>
256 * <b>View scrolled</b> - represents the event of scrolling a view. If
257 * the source is a descendant of {@link android.widget.AdapterView} the
258 * scroll is reported in terms of visible items - the first visible item,
259 * the last visible item, and the total items - because the the source
260 * is unaware of its pixel size since its adapter is responsible for
261 * creating views. In all other cases the scroll is reported as the current
262 * scroll on the X and Y axis respectively plus the height of the source in
263 * pixels.</br>
264 * <em>Type:</em> {@link #TYPE_VIEW_SCROLLED}</br>
265 * <em>Properties:</em></br>
266 * <ul>
267 *   <li>{@link #getEventType()} - The type of the event.</li>
268 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
269 *   <li>{@link #getClassName()} - The class name of the source.</li>
270 *   <li>{@link #getPackageName()} - The package name of the source.</li>
271 *   <li>{@link #getEventTime()}  - The event time.</li>
272 *   <li>{@link #getText()} - The text of the source's sub-tree.</li>
273 *   <li>{@link #isEnabled()} - Whether the source is enabled.</li>
274 *   <li>{@link #getContentDescription()} - The content description of the source.</li>
275 *   <li>{@link #getScrollX()} - The offset of the source left edge in pixels
276 *       (without descendants of AdapterView).</li>
277 *   <li>{@link #getScrollY()} - The offset of the source top edge in pixels
278 *       (without descendants of AdapterView).</li>
279 *   <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
280 *       inclusive (for descendants of AdapterView).</li>
281 *   <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
282 *       inclusive (for descendants of AdapterView).</li>
283 *   <li>{@link #getItemCount()} - The total items of the source
284 *       (for descendants of AdapterView).</li>
285 * </ul>
286 * <em>Note:</em> This event type is not dispatched to descendants though
287 * {@link android.view.View#dispatchPopulateAccessibilityEvent(AccessibilityEvent)
288 * View.dispatchPopulateAccessibilityEvent(AccessibilityEvent)}, hence the event
289 * source {@link android.view.View} and the sub-tree rooted at it will not receive
290 * calls to {@link android.view.View#onPopulateAccessibilityEvent(AccessibilityEvent)
291 * View.onPopulateAccessibilityEvent(AccessibilityEvent)}. The preferred way to add
292 * text content to such events is by setting the
293 * {@link android.R.styleable#View_contentDescription contentDescription} of the source
294 * view.</br>
295 * </p>
296 * <p>
297 * <b>TRANSITION TYPES</b></br>
298 * </p>
299 * <p>
300 * <b>Window state changed</b> - represents the event of opening a
301 * {@link android.widget.PopupWindow}, {@link android.view.Menu},
302 * {@link android.app.Dialog}, etc.</br>
303 * <em>Type:</em> {@link #TYPE_WINDOW_STATE_CHANGED}</br>
304 * <em>Properties:</em></br>
305 * <ul>
306 *   <li>{@link #getEventType()} - The type of the event.</li>
307 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
308 *   <li>{@link #getClassName()} - The class name of the source.</li>
309 *   <li>{@link #getPackageName()} - The package name of the source.</li>
310 *   <li>{@link #getEventTime()}  - The event time.</li>
311 *   <li>{@link #getText()} - The text of the source's sub-tree.</li>
312 *   <li>{@link #isEnabled()} - Whether the source is enabled.</li>
313 * </ul>
314 * </p>
315 * <p>
316 * <b>Window content changed</b> - represents the event of change in the
317 * content of a window. This change can be adding/removing view, changing
318 * a view size, etc.</br>
319 * </p>
320 * <p>
321 * <strong>Note:</strong> This event is fired only for the window source of the
322 * last accessibility event different from {@link #TYPE_NOTIFICATION_STATE_CHANGED}
323 * and its purpose is to notify clients that the content of the user interaction
324 * window has changed.</br>
325 * <em>Type:</em> {@link #TYPE_WINDOW_CONTENT_CHANGED}</br>
326 * <em>Properties:</em></br>
327 * <ul>
328 *   <li>{@link #getEventType()} - The type of the event.</li>
329 *   <li>{@link #getContentChangeType()} - The type of content change.</li>
330 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
331 *   <li>{@link #getClassName()} - The class name of the source.</li>
332 *   <li>{@link #getPackageName()} - The package name of the source.</li>
333 *   <li>{@link #getEventTime()}  - The event time.</li>
334 * </ul>
335 * <em>Note:</em> This event type is not dispatched to descendants though
336 * {@link android.view.View#dispatchPopulateAccessibilityEvent(AccessibilityEvent)
337 * View.dispatchPopulateAccessibilityEvent(AccessibilityEvent)}, hence the event
338 * source {@link android.view.View} and the sub-tree rooted at it will not receive
339 * calls to {@link android.view.View#onPopulateAccessibilityEvent(AccessibilityEvent)
340 * View.onPopulateAccessibilityEvent(AccessibilityEvent)}. The preferred way to add
341 * text content to such events is by setting the
342 * {@link android.R.styleable#View_contentDescription contentDescription} of the source
343 * view.</br>
344 * </p>
345 * <p>
346 * <b>NOTIFICATION TYPES</b></br>
347 * </p>
348 * <p>
349 * <b>Notification state changed</b> - represents the event showing
350 * {@link android.app.Notification}.</br>
351 * <em>Type:</em> {@link #TYPE_NOTIFICATION_STATE_CHANGED}</br>
352 * <em>Properties:</em></br>
353 * <ul>
354 *   <li>{@link #getEventType()} - The type of the event.</li>
355 *   <li>{@link #getClassName()} - The class name of the source.</li>
356 *   <li>{@link #getPackageName()} - The package name of the source.</li>
357 *   <li>{@link #getEventTime()}  - The event time.</li>
358 *   <li>{@link #getText()} - The text of the source's sub-tree.</li>
359 *   <li>{@link #getParcelableData()} - The posted {@link android.app.Notification}.</li>
360 *   <li>{@link #getText()} - Text for providing more context.</li>
361 * </ul>
362 * <em>Note:</em> This event type is not dispatched to descendants though
363 * {@link android.view.View#dispatchPopulateAccessibilityEvent(AccessibilityEvent)
364 * View.dispatchPopulateAccessibilityEvent(AccessibilityEvent)}, hence the event
365 * source {@link android.view.View} and the sub-tree rooted at it will not receive
366 * calls to {@link android.view.View#onPopulateAccessibilityEvent(AccessibilityEvent)
367 * View.onPopulateAccessibilityEvent(AccessibilityEvent)}. The preferred way to add
368 * text content to such events is by setting the
369 * {@link android.R.styleable#View_contentDescription contentDescription} of the source
370 * view.</br>
371 * </p>
372 * <p>
373 * <b>EXPLORATION TYPES</b></br>
374 * </p>
375 * <p>
376 * <b>View hover enter</b> - represents the event of beginning to hover
377 * over a {@link android.view.View}. The hover may be generated via
378 * exploring the screen by touch or via a pointing device.</br>
379 * <em>Type:</em> {@link #TYPE_VIEW_HOVER_ENTER}</br>
380 * <em>Properties:</em></br>
381 * <ul>
382 *   <li>{@link #getEventType()} - The type of the event.</li>
383 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
384 *   <li>{@link #getClassName()} - The class name of the source.</li>
385 *   <li>{@link #getPackageName()} - The package name of the source.</li>
386 *   <li>{@link #getEventTime()}  - The event time.</li>
387 *   <li>{@link #getText()} - The text of the source's sub-tree.</li>
388 *   <li>{@link #isEnabled()} - Whether the source is enabled.</li>
389 *   <li>{@link #getContentDescription()} - The content description of the source.</li>
390 *   <li>{@link #getScrollX()} - The offset of the source left edge in pixels
391 *       (without descendants of AdapterView).</li>
392 *   <li>{@link #getScrollY()} - The offset of the source top edge in pixels
393 *       (without descendants of AdapterView).</li>
394 *   <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
395 *       inclusive (for descendants of AdapterView).</li>
396 *   <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
397 *       inclusive (for descendants of AdapterView).</li>
398 *   <li>{@link #getItemCount()} - The total items of the source
399 *       (for descendants of AdapterView).</li>
400 * </ul>
401 * </p>
402 * <b>View hover exit</b> - represents the event of stopping to hover
403 * over a {@link android.view.View}. The hover may be generated via
404 * exploring the screen by touch or via a pointing device.</br>
405 * <em>Type:</em> {@link #TYPE_VIEW_HOVER_EXIT}</br>
406 * <em>Properties:</em></br>
407 * <ul>
408 *   <li>{@link #getEventType()} - The type of the event.</li>
409 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
410 *   <li>{@link #getClassName()} - The class name of the source.</li>
411 *   <li>{@link #getPackageName()} - The package name of the source.</li>
412 *   <li>{@link #getEventTime()}  - The event time.</li>
413 *   <li>{@link #getText()} - The text of the source's sub-tree.</li>
414 *   <li>{@link #isEnabled()} - Whether the source is enabled.</li>
415 *   <li>{@link #getContentDescription()} - The content description of the source.</li>
416 *   <li>{@link #getScrollX()} - The offset of the source left edge in pixels
417 *       (without descendants of AdapterView).</li>
418 *   <li>{@link #getScrollY()} - The offset of the source top edge in pixels
419 *       (without descendants of AdapterView).</li>
420 *   <li>{@link #getFromIndex()} - The zero based index of the first visible item of the source,
421 *       inclusive (for descendants of AdapterView).</li>
422 *   <li>{@link #getToIndex()} - The zero based index of the last visible item of the source,
423 *       inclusive (for descendants of AdapterView).</li>
424 *   <li>{@link #getItemCount()} - The total items of the source
425 *       (for descendants of AdapterView).</li>
426 * </ul>
427 * </p>
428 * <p>
429 * <b>Touch interaction start</b> - represents the event of starting a touch
430 * interaction, which is the user starts touching the screen.</br>
431 * <em>Type:</em> {@link #TYPE_TOUCH_INTERACTION_START}</br>
432 * <em>Properties:</em></br>
433 * <ul>
434 *   <li>{@link #getEventType()} - The type of the event.</li>
435 * </ul>
436 * <em>Note:</em> This event is fired only by the system and is not passed to the
437 * view tree to be populated.</br>
438 * </p>
439 * <p>
440 * <b>Touch interaction end</b> - represents the event of ending a touch
441 * interaction, which is the user stops touching the screen.</br>
442 * <em>Type:</em> {@link #TYPE_TOUCH_INTERACTION_END}</br>
443 * <em>Properties:</em></br>
444 * <ul>
445 *   <li>{@link #getEventType()} - The type of the event.</li>
446 * </ul>
447 * <em>Note:</em> This event is fired only by the system and is not passed to the
448 * view tree to be populated.</br>
449 * </p>
450 * <p>
451 * <b>Touch exploration gesture start</b> - represents the event of starting a touch
452 * exploring gesture.</br>
453 * <em>Type:</em> {@link #TYPE_TOUCH_EXPLORATION_GESTURE_START}</br>
454 * <em>Properties:</em></br>
455 * <ul>
456 *   <li>{@link #getEventType()} - The type of the event.</li>
457 * </ul>
458 * <em>Note:</em> This event is fired only by the system and is not passed to the
459 * view tree to be populated.</br>
460 * </p>
461 * <p>
462 * <b>Touch exploration gesture end</b> - represents the event of ending a touch
463 * exploring gesture.</br>
464 * <em>Type:</em> {@link #TYPE_TOUCH_EXPLORATION_GESTURE_END}</br>
465 * <em>Properties:</em></br>
466 * <ul>
467 *   <li>{@link #getEventType()} - The type of the event.</li>
468 * </ul>
469 * <em>Note:</em> This event is fired only by the system and is not passed to the
470 * view tree to be populated.</br>
471 * </p>
472 * <p>
473 * <b>Touch gesture detection start</b> - represents the event of starting a user
474 * gesture detection.</br>
475 * <em>Type:</em> {@link #TYPE_GESTURE_DETECTION_START}</br>
476 * <em>Properties:</em></br>
477 * <ul>
478 *   <li>{@link #getEventType()} - The type of the event.</li>
479 * </ul>
480 * <em>Note:</em> This event is fired only by the system and is not passed to the
481 * view tree to be populated.</br>
482 * </p>
483 * <p>
484 * <b>Touch gesture detection end</b> - represents the event of ending a user
485 * gesture detection.</br>
486 * <em>Type:</em> {@link #TYPE_GESTURE_DETECTION_END}</br>
487 * <em>Properties:</em></br>
488 * <ul>
489 *   <li>{@link #getEventType()} - The type of the event.</li>
490 * </ul>
491 * <em>Note:</em> This event is fired only by the system and is not passed to the
492 * view tree to be populated.</br>
493 * </p>
494 * <p>
495 * <b>MISCELLANEOUS TYPES</b></br>
496 * </p>
497 * <p>
498 * <b>Announcement</b> - represents the event of an application making an
499 * announcement. Usually this announcement is related to some sort of a context
500 * change for which none of the events representing UI transitions is a good fit.
501 * For example, announcing a new page in a book.</br>
502 * <em>Type:</em> {@link #TYPE_ANNOUNCEMENT}</br>
503 * <em>Properties:</em></br>
504 * <ul>
505 *   <li>{@link #getEventType()} - The type of the event.</li>
506 *   <li>{@link #getSource()} - The source info (for registered clients).</li>
507 *   <li>{@link #getClassName()} - The class name of the source.</li>
508 *   <li>{@link #getPackageName()} - The package name of the source.</li>
509 *   <li>{@link #getEventTime()}  - The event time.</li>
510 *   <li>{@link #getText()} - The text of the announcement.</li>
511 *   <li>{@link #isEnabled()} - Whether the source is enabled.</li>
512 * </ul>
513 * </p>
514 * <p>
515 * <b>Security note</b>
516 * <p>
517 * Since an event contains the text of its source privacy can be compromised by leaking
518 * sensitive information such as passwords. To address this issue any event fired in response
519 * to manipulation of a PASSWORD field does NOT CONTAIN the text of the password.
520 * </p>
521 *
522 * @see android.view.accessibility.AccessibilityManager
523 * @see android.accessibilityservice.AccessibilityService
524 * @see AccessibilityNodeInfo
525 */
526public final class AccessibilityEvent extends AccessibilityRecord implements Parcelable {
527    private static final boolean DEBUG = false;
528
529    /**
530     * Invalid selection/focus position.
531     *
532     * @see #getCurrentItemIndex()
533     */
534    public static final int INVALID_POSITION = -1;
535
536    /**
537     * Maximum length of the text fields.
538     *
539     * @see #getBeforeText()
540     * @see #getText()
541     * </br>
542     * Note: This constant is no longer needed since there
543     *       is no limit on the length of text that is contained
544     *       in an accessibility event anymore.
545     */
546    @Deprecated
547    public static final int MAX_TEXT_LENGTH = 500;
548
549    /**
550     * Represents the event of clicking on a {@link android.view.View} like
551     * {@link android.widget.Button}, {@link android.widget.CompoundButton}, etc.
552     */
553    public static final int TYPE_VIEW_CLICKED = 0x00000001;
554
555    /**
556     * Represents the event of long clicking on a {@link android.view.View} like
557     * {@link android.widget.Button}, {@link android.widget.CompoundButton}, etc.
558     */
559    public static final int TYPE_VIEW_LONG_CLICKED = 0x00000002;
560
561    /**
562     * Represents the event of selecting an item usually in the context of an
563     * {@link android.widget.AdapterView}.
564     */
565    public static final int TYPE_VIEW_SELECTED = 0x00000004;
566
567    /**
568     * Represents the event of setting input focus of a {@link android.view.View}.
569     */
570    public static final int TYPE_VIEW_FOCUSED = 0x00000008;
571
572    /**
573     * Represents the event of changing the text of an {@link android.widget.EditText}.
574     */
575    public static final int TYPE_VIEW_TEXT_CHANGED = 0x00000010;
576
577    /**
578     * Represents the event of opening a {@link android.widget.PopupWindow},
579     * {@link android.view.Menu}, {@link android.app.Dialog}, etc.
580     */
581    public static final int TYPE_WINDOW_STATE_CHANGED = 0x00000020;
582
583    /**
584     * Represents the event showing a {@link android.app.Notification}.
585     */
586    public static final int TYPE_NOTIFICATION_STATE_CHANGED = 0x00000040;
587
588    /**
589     * Represents the event of a hover enter over a {@link android.view.View}.
590     */
591    public static final int TYPE_VIEW_HOVER_ENTER = 0x00000080;
592
593    /**
594     * Represents the event of a hover exit over a {@link android.view.View}.
595     */
596    public static final int TYPE_VIEW_HOVER_EXIT = 0x00000100;
597
598    /**
599     * Represents the event of starting a touch exploration gesture.
600     */
601    public static final int TYPE_TOUCH_EXPLORATION_GESTURE_START = 0x00000200;
602
603    /**
604     * Represents the event of ending a touch exploration gesture.
605     */
606    public static final int TYPE_TOUCH_EXPLORATION_GESTURE_END = 0x00000400;
607
608    /**
609     * Represents the event of changing the content of a window and more
610     * specifically the sub-tree rooted at the event's source.
611     */
612    public static final int TYPE_WINDOW_CONTENT_CHANGED = 0x00000800;
613
614    /**
615     * Represents the event of scrolling a view.
616     */
617    public static final int TYPE_VIEW_SCROLLED = 0x00001000;
618
619    /**
620     * Represents the event of changing the selection in an {@link android.widget.EditText}.
621     */
622    public static final int TYPE_VIEW_TEXT_SELECTION_CHANGED = 0x00002000;
623
624    /**
625     * Represents the event of an application making an announcement.
626     */
627    public static final int TYPE_ANNOUNCEMENT = 0x00004000;
628
629    /**
630     * Represents the event of gaining accessibility focus.
631     */
632    public static final int TYPE_VIEW_ACCESSIBILITY_FOCUSED = 0x00008000;
633
634    /**
635     * Represents the event of clearing accessibility focus.
636     */
637    public static final int TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED = 0x00010000;
638
639    /**
640     * Represents the event of traversing the text of a view at a given movement granularity.
641     */
642    public static final int TYPE_VIEW_TEXT_TRAVERSED_AT_MOVEMENT_GRANULARITY = 0x00020000;
643
644    /**
645     * Represents the event of beginning gesture detection.
646     */
647    public static final int TYPE_GESTURE_DETECTION_START = 0x00040000;
648
649    /**
650     * Represents the event of ending gesture detection.
651     */
652    public static final int TYPE_GESTURE_DETECTION_END = 0x00080000;
653
654    /**
655     * Represents the event of the user starting to touch the screen.
656     */
657    public static final int TYPE_TOUCH_INTERACTION_START = 0x00100000;
658
659    /**
660     * Represents the event of the user ending to touch the screen.
661     */
662    public static final int TYPE_TOUCH_INTERACTION_END = 0x00200000;
663
664    /**
665     * Change type for {@link #TYPE_WINDOW_CONTENT_CHANGED} event:
666     * The subtree rooted at the source node changed.
667     */
668    public static final int CONTENT_CHANGE_TYPE_SUBTREE = 0;
669
670    /**
671     * Change type for {@link #TYPE_WINDOW_CONTENT_CHANGED} event:
672     * Only the source node changed.
673     */
674    public static final int CONTENT_CHANGE_TYPE_NODE = 1;
675
676    /**
677     * Mask for {@link AccessibilityEvent} all types.
678     *
679     * @see #TYPE_VIEW_CLICKED
680     * @see #TYPE_VIEW_LONG_CLICKED
681     * @see #TYPE_VIEW_SELECTED
682     * @see #TYPE_VIEW_FOCUSED
683     * @see #TYPE_VIEW_TEXT_CHANGED
684     * @see #TYPE_WINDOW_STATE_CHANGED
685     * @see #TYPE_NOTIFICATION_STATE_CHANGED
686     * @see #TYPE_VIEW_HOVER_ENTER
687     * @see #TYPE_VIEW_HOVER_EXIT
688     * @see #TYPE_TOUCH_EXPLORATION_GESTURE_START
689     * @see #TYPE_TOUCH_EXPLORATION_GESTURE_END
690     * @see #TYPE_WINDOW_CONTENT_CHANGED
691     * @see #TYPE_VIEW_SCROLLED
692     * @see #TYPE_VIEW_TEXT_SELECTION_CHANGED
693     * @see #TYPE_ANNOUNCEMENT
694     * @see #TYPE_VIEW_TEXT_TRAVERSED_AT_MOVEMENT_GRANULARITY
695     * @see #TYPE_GESTURE_DETECTION_START
696     * @see #TYPE_GESTURE_DETECTION_END
697     * @see #TYPE_TOUCH_INTERACTION_START
698     * @see #TYPE_TOUCH_INTERACTION_END
699     */
700    public static final int TYPES_ALL_MASK = 0xFFFFFFFF;
701
702    private static final int MAX_POOL_SIZE = 10;
703    private static final SynchronizedPool<AccessibilityEvent> sPool =
704            new SynchronizedPool<AccessibilityEvent>(MAX_POOL_SIZE);
705
706    private int mEventType;
707    private CharSequence mPackageName;
708    private long mEventTime;
709    int mMovementGranularity;
710    int mAction;
711    int mContentChangeType;
712
713    private final ArrayList<AccessibilityRecord> mRecords = new ArrayList<AccessibilityRecord>();
714
715    /*
716     * Hide constructor from clients.
717     */
718    private AccessibilityEvent() {
719    }
720
721    /**
722     * Initialize an event from another one.
723     *
724     * @param event The event to initialize from.
725     */
726    void init(AccessibilityEvent event) {
727        super.init(event);
728        mEventType = event.mEventType;
729        mMovementGranularity = event.mMovementGranularity;
730        mAction = event.mAction;
731        mContentChangeType = event.mContentChangeType;
732        mEventTime = event.mEventTime;
733        mPackageName = event.mPackageName;
734    }
735
736    /**
737     * Sets if this instance is sealed.
738     *
739     * @param sealed Whether is sealed.
740     *
741     * @hide
742     */
743    @Override
744    public void setSealed(boolean sealed) {
745        super.setSealed(sealed);
746        List<AccessibilityRecord> records = mRecords;
747        final int recordCount = records.size();
748        for (int i = 0; i < recordCount; i++) {
749            AccessibilityRecord record = records.get(i);
750            record.setSealed(sealed);
751        }
752    }
753
754    /**
755     * Gets the number of records contained in the event.
756     *
757     * @return The number of records.
758     */
759    public int getRecordCount() {
760        return mRecords.size();
761    }
762
763    /**
764     * Appends an {@link AccessibilityRecord} to the end of event records.
765     *
766     * @param record The record to append.
767     *
768     * @throws IllegalStateException If called from an AccessibilityService.
769     */
770    public void appendRecord(AccessibilityRecord record) {
771        enforceNotSealed();
772        mRecords.add(record);
773    }
774
775    /**
776     * Gets the record at a given index.
777     *
778     * @param index The index.
779     * @return The record at the specified index.
780     */
781    public AccessibilityRecord getRecord(int index) {
782        return mRecords.get(index);
783    }
784
785    /**
786     * Gets the event type.
787     *
788     * @return The event type.
789     */
790    public int getEventType() {
791        return mEventType;
792    }
793
794    /**
795     * Gets the type of node tree change signaled by an
796     * {@link #TYPE_WINDOW_CONTENT_CHANGED} event.
797     *
798     * @see #CONTENT_CHANGE_TYPE_NODE
799     * @see #CONTENT_CHANGE_TYPE_SUBTREE
800     *
801     * @return The change type.
802     */
803    public int getContentChangeType() {
804        return mContentChangeType;
805    }
806
807    /**
808     * Sets the type of node tree change signaled by an
809     * {@link #TYPE_WINDOW_CONTENT_CHANGED} event.
810     *
811     * @see #CONTENT_CHANGE_TYPE_NODE
812     * @see #CONTENT_CHANGE_TYPE_SUBTREE
813     *
814     * @param changeType The change type.
815     */
816    public void setContentChangeType(int changeType) {
817        enforceNotSealed();
818        mContentChangeType = changeType;
819    }
820
821    /**
822     * Sets the event type.
823     *
824     * @param eventType The event type.
825     *
826     * @throws IllegalStateException If called from an AccessibilityService.
827     */
828    public void setEventType(int eventType) {
829        enforceNotSealed();
830        mEventType = eventType;
831    }
832
833    /**
834     * Gets the time in which this event was sent.
835     *
836     * @return The event time.
837     */
838    public long getEventTime() {
839        return mEventTime;
840    }
841
842    /**
843     * Sets the time in which this event was sent.
844     *
845     * @param eventTime The event time.
846     *
847     * @throws IllegalStateException If called from an AccessibilityService.
848     */
849    public void setEventTime(long eventTime) {
850        enforceNotSealed();
851        mEventTime = eventTime;
852    }
853
854    /**
855     * Gets the package name of the source.
856     *
857     * @return The package name.
858     */
859    public CharSequence getPackageName() {
860        return mPackageName;
861    }
862
863    /**
864     * Sets the package name of the source.
865     *
866     * @param packageName The package name.
867     *
868     * @throws IllegalStateException If called from an AccessibilityService.
869     */
870    public void setPackageName(CharSequence packageName) {
871        enforceNotSealed();
872        mPackageName = packageName;
873    }
874
875    /**
876     * Sets the movement granularity that was traversed.
877     *
878     * @param granularity The granularity.
879     *
880     * @throws IllegalStateException If called from an AccessibilityService.
881     */
882    public void setMovementGranularity(int granularity) {
883        enforceNotSealed();
884        mMovementGranularity = granularity;
885    }
886
887    /**
888     * Gets the movement granularity that was traversed.
889     *
890     * @return The granularity.
891     */
892    public int getMovementGranularity() {
893        return mMovementGranularity;
894    }
895
896    /**
897     * Sets the performed action that triggered this event.
898     *
899     * @param action The action.
900     *
901     * @throws IllegalStateException If called from an AccessibilityService.
902     */
903    public void setAction(int action) {
904        enforceNotSealed();
905        mAction = action;
906    }
907
908    /**
909     * Gets the performed action that triggered this event.
910     *
911     * @return The action.
912     */
913    public int getAction() {
914        return mAction;
915    }
916
917    /**
918     * Returns a cached instance if such is available or a new one is
919     * instantiated with its type property set.
920     *
921     * @param eventType The event type.
922     * @return An instance.
923     */
924    public static AccessibilityEvent obtain(int eventType) {
925        AccessibilityEvent event = AccessibilityEvent.obtain();
926        event.setEventType(eventType);
927        return event;
928    }
929
930    /**
931     * Returns a cached instance if such is available or a new one is
932     * created. The returned instance is initialized from the given
933     * <code>event</code>.
934     *
935     * @param event The other event.
936     * @return An instance.
937     */
938    public static AccessibilityEvent obtain(AccessibilityEvent event) {
939        AccessibilityEvent eventClone = AccessibilityEvent.obtain();
940        eventClone.init(event);
941
942        final int recordCount = event.mRecords.size();
943        for (int i = 0; i < recordCount; i++) {
944            AccessibilityRecord record = event.mRecords.get(i);
945            AccessibilityRecord recordClone = AccessibilityRecord.obtain(record);
946            eventClone.mRecords.add(recordClone);
947        }
948
949        return eventClone;
950    }
951
952    /**
953     * Returns a cached instance if such is available or a new one is
954     * instantiated.
955     *
956     * @return An instance.
957     */
958    public static AccessibilityEvent obtain() {
959        AccessibilityEvent event = sPool.acquire();
960        return (event != null) ? event : new AccessibilityEvent();
961    }
962
963    /**
964     * Recycles an instance back to be reused.
965     * <p>
966     *   <b>Note: You must not touch the object after calling this function.</b>
967     * </p>
968     *
969     * @throws IllegalStateException If the event is already recycled.
970     */
971    @Override
972    public void recycle() {
973        clear();
974        sPool.release(this);
975    }
976
977    /**
978     * Clears the state of this instance.
979     *
980     * @hide
981     */
982    @Override
983    protected void clear() {
984        super.clear();
985        mEventType = 0;
986        mMovementGranularity = 0;
987        mAction = 0;
988        mContentChangeType = 0;
989        mPackageName = null;
990        mEventTime = 0;
991        while (!mRecords.isEmpty()) {
992            AccessibilityRecord record = mRecords.remove(0);
993            record.recycle();
994        }
995    }
996
997    /**
998     * Creates a new instance from a {@link Parcel}.
999     *
1000     * @param parcel A parcel containing the state of a {@link AccessibilityEvent}.
1001     */
1002    public void initFromParcel(Parcel parcel) {
1003        mSealed = (parcel.readInt() == 1);
1004        mEventType = parcel.readInt();
1005        mMovementGranularity = parcel.readInt();
1006        mAction = parcel.readInt();
1007        mContentChangeType = parcel.readInt();
1008        mPackageName = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel);
1009        mEventTime = parcel.readLong();
1010        mConnectionId = parcel.readInt();
1011        readAccessibilityRecordFromParcel(this, parcel);
1012
1013        // Read the records.
1014        final int recordCount = parcel.readInt();
1015        for (int i = 0; i < recordCount; i++) {
1016            AccessibilityRecord record = AccessibilityRecord.obtain();
1017            readAccessibilityRecordFromParcel(record, parcel);
1018            record.mConnectionId = mConnectionId;
1019            mRecords.add(record);
1020        }
1021    }
1022
1023    /**
1024     * Reads an {@link AccessibilityRecord} from a parcel.
1025     *
1026     * @param record The record to initialize.
1027     * @param parcel The parcel to read from.
1028     */
1029    private void readAccessibilityRecordFromParcel(AccessibilityRecord record,
1030            Parcel parcel) {
1031        record.mBooleanProperties = parcel.readInt();
1032        record.mCurrentItemIndex = parcel.readInt();
1033        record.mItemCount = parcel.readInt();
1034        record.mFromIndex = parcel.readInt();
1035        record.mToIndex = parcel.readInt();
1036        record.mScrollX = parcel.readInt();
1037        record.mScrollY =  parcel.readInt();
1038        record.mMaxScrollX = parcel.readInt();
1039        record.mMaxScrollY =  parcel.readInt();
1040        record.mAddedCount = parcel.readInt();
1041        record.mRemovedCount = parcel.readInt();
1042        record.mClassName = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel);
1043        record.mContentDescription = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel);
1044        record.mBeforeText = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel);
1045        record.mParcelableData = parcel.readParcelable(null);
1046        parcel.readList(record.mText, null);
1047        record.mSourceWindowId = parcel.readInt();
1048        record.mSourceNodeId = parcel.readLong();
1049        record.mSealed = (parcel.readInt() == 1);
1050    }
1051
1052    /**
1053     * {@inheritDoc}
1054     */
1055    public void writeToParcel(Parcel parcel, int flags) {
1056        parcel.writeInt(isSealed() ? 1 : 0);
1057        parcel.writeInt(mEventType);
1058        parcel.writeInt(mMovementGranularity);
1059        parcel.writeInt(mAction);
1060        parcel.writeInt(mContentChangeType);
1061        TextUtils.writeToParcel(mPackageName, parcel, 0);
1062        parcel.writeLong(mEventTime);
1063        parcel.writeInt(mConnectionId);
1064        writeAccessibilityRecordToParcel(this, parcel, flags);
1065
1066        // Write the records.
1067        final int recordCount = getRecordCount();
1068        parcel.writeInt(recordCount);
1069        for (int i = 0; i < recordCount; i++) {
1070            AccessibilityRecord record = mRecords.get(i);
1071            writeAccessibilityRecordToParcel(record, parcel, flags);
1072        }
1073    }
1074
1075    /**
1076     * Writes an {@link AccessibilityRecord} to a parcel.
1077     *
1078     * @param record The record to write.
1079     * @param parcel The parcel to which to write.
1080     */
1081    private void writeAccessibilityRecordToParcel(AccessibilityRecord record, Parcel parcel,
1082            int flags) {
1083        parcel.writeInt(record.mBooleanProperties);
1084        parcel.writeInt(record.mCurrentItemIndex);
1085        parcel.writeInt(record.mItemCount);
1086        parcel.writeInt(record.mFromIndex);
1087        parcel.writeInt(record.mToIndex);
1088        parcel.writeInt(record.mScrollX);
1089        parcel.writeInt(record.mScrollY);
1090        parcel.writeInt(record.mMaxScrollX);
1091        parcel.writeInt(record.mMaxScrollY);
1092        parcel.writeInt(record.mAddedCount);
1093        parcel.writeInt(record.mRemovedCount);
1094        TextUtils.writeToParcel(record.mClassName, parcel, flags);
1095        TextUtils.writeToParcel(record.mContentDescription, parcel, flags);
1096        TextUtils.writeToParcel(record.mBeforeText, parcel, flags);
1097        parcel.writeParcelable(record.mParcelableData, flags);
1098        parcel.writeList(record.mText);
1099        parcel.writeInt(record.mSourceWindowId);
1100        parcel.writeLong(record.mSourceNodeId);
1101        parcel.writeInt(record.mSealed ? 1 : 0);
1102    }
1103
1104    /**
1105     * {@inheritDoc}
1106     */
1107    public int describeContents() {
1108        return 0;
1109    }
1110
1111    @Override
1112    public String toString() {
1113        StringBuilder builder = new StringBuilder();
1114        builder.append("EventType: ").append(eventTypeToString(mEventType));
1115        builder.append("; EventTime: ").append(mEventTime);
1116        builder.append("; PackageName: ").append(mPackageName);
1117        builder.append("; MovementGranularity: ").append(mMovementGranularity);
1118        builder.append("; Action: ").append(mAction);
1119        builder.append(super.toString());
1120        if (DEBUG) {
1121            builder.append("\n");
1122            builder.append("; ContentChangeType: ").append(mContentChangeType);
1123            builder.append("; sourceWindowId: ").append(mSourceWindowId);
1124            builder.append("; mSourceNodeId: ").append(mSourceNodeId);
1125            for (int i = 0; i < mRecords.size(); i++) {
1126                AccessibilityRecord record = mRecords.get(i);
1127                builder.append("  Record ");
1128                builder.append(i);
1129                builder.append(":");
1130                builder.append(" [ ClassName: " + record.mClassName);
1131                builder.append("; Text: " + record.mText);
1132                builder.append("; ContentDescription: " + record.mContentDescription);
1133                builder.append("; ItemCount: " + record.mItemCount);
1134                builder.append("; CurrentItemIndex: " + record.mCurrentItemIndex);
1135                builder.append("; IsEnabled: " + record.isEnabled());
1136                builder.append("; IsPassword: " + record.isPassword());
1137                builder.append("; IsChecked: " + record.isChecked());
1138                builder.append("; IsFullScreen: " + record.isFullScreen());
1139                builder.append("; Scrollable: " + record.isScrollable());
1140                builder.append("; BeforeText: " + record.mBeforeText);
1141                builder.append("; FromIndex: " + record.mFromIndex);
1142                builder.append("; ToIndex: " + record.mToIndex);
1143                builder.append("; ScrollX: " + record.mScrollX);
1144                builder.append("; ScrollY: " + record.mScrollY);
1145                builder.append("; AddedCount: " + record.mAddedCount);
1146                builder.append("; RemovedCount: " + record.mRemovedCount);
1147                builder.append("; ParcelableData: " + record.mParcelableData);
1148                builder.append(" ]");
1149                builder.append("\n");
1150            }
1151        } else {
1152            builder.append("; recordCount: ").append(getRecordCount());
1153        }
1154        return builder.toString();
1155    }
1156
1157    /**
1158     * Returns the string representation of an event type. For example,
1159     * {@link #TYPE_VIEW_CLICKED} is represented by the string TYPE_VIEW_CLICKED.
1160     *
1161     * @param eventType The event type
1162     * @return The string representation.
1163     */
1164    public static String eventTypeToString(int eventType) {
1165        if (eventType == TYPES_ALL_MASK) {
1166            return "TYPES_ALL_MASK";
1167        }
1168        StringBuilder builder = new StringBuilder();
1169        int eventTypeCount = 0;
1170        while (eventType != 0) {
1171            final int eventTypeFlag = 1 << Integer.numberOfTrailingZeros(eventType);
1172            eventType &= ~eventTypeFlag;
1173            switch (eventTypeFlag) {
1174                case TYPE_VIEW_CLICKED: {
1175                    if (eventTypeCount > 0) {
1176                        builder.append(", ");
1177                    }
1178                    builder.append("TYPE_VIEW_CLICKED");
1179                    eventTypeCount++;
1180                } break;
1181                case TYPE_VIEW_LONG_CLICKED: {
1182                    if (eventTypeCount > 0) {
1183                        builder.append(", ");
1184                    }
1185                    builder.append("TYPE_VIEW_LONG_CLICKED");
1186                    eventTypeCount++;
1187                } break;
1188                case TYPE_VIEW_SELECTED: {
1189                    if (eventTypeCount > 0) {
1190                        builder.append(", ");
1191                    }
1192                    builder.append("TYPE_VIEW_SELECTED");
1193                    eventTypeCount++;
1194                } break;
1195                case TYPE_VIEW_FOCUSED: {
1196                    if (eventTypeCount > 0) {
1197                        builder.append(", ");
1198                    }
1199                    builder.append("TYPE_VIEW_FOCUSED");
1200                    eventTypeCount++;
1201                } break;
1202                case TYPE_VIEW_TEXT_CHANGED: {
1203                    if (eventTypeCount > 0) {
1204                        builder.append(", ");
1205                    }
1206                    builder.append("TYPE_VIEW_TEXT_CHANGED");
1207                    eventTypeCount++;
1208                } break;
1209                case TYPE_WINDOW_STATE_CHANGED: {
1210                    if (eventTypeCount > 0) {
1211                        builder.append(", ");
1212                    }
1213                    builder.append("TYPE_WINDOW_STATE_CHANGED");
1214                    eventTypeCount++;
1215                } break;
1216                case TYPE_VIEW_HOVER_ENTER: {
1217                    if (eventTypeCount > 0) {
1218                        builder.append(", ");
1219                    }
1220                    builder.append("TYPE_VIEW_HOVER_ENTER");
1221                    eventTypeCount++;
1222                } break;
1223                case TYPE_VIEW_HOVER_EXIT: {
1224                    if (eventTypeCount > 0) {
1225                        builder.append(", ");
1226                    }
1227                    builder.append("TYPE_VIEW_HOVER_EXIT");
1228                    eventTypeCount++;
1229                } break;
1230                case TYPE_NOTIFICATION_STATE_CHANGED: {
1231                    if (eventTypeCount > 0) {
1232                        builder.append(", ");
1233                    }
1234                    builder.append("TYPE_NOTIFICATION_STATE_CHANGED");
1235                    eventTypeCount++;
1236                } break;
1237                case TYPE_TOUCH_EXPLORATION_GESTURE_START: {
1238                    if (eventTypeCount > 0) {
1239                        builder.append(", ");
1240                    }
1241                    builder.append("TYPE_TOUCH_EXPLORATION_GESTURE_START");
1242                    eventTypeCount++;
1243                } break;
1244                case TYPE_TOUCH_EXPLORATION_GESTURE_END: {
1245                    if (eventTypeCount > 0) {
1246                        builder.append(", ");
1247                    }
1248                    builder.append("TYPE_TOUCH_EXPLORATION_GESTURE_END");
1249                    eventTypeCount++;
1250                } break;
1251                case TYPE_WINDOW_CONTENT_CHANGED: {
1252                    if (eventTypeCount > 0) {
1253                        builder.append(", ");
1254                    }
1255                    builder.append("TYPE_WINDOW_CONTENT_CHANGED");
1256                    eventTypeCount++;
1257                } break;
1258                case TYPE_VIEW_TEXT_SELECTION_CHANGED: {
1259                    if (eventTypeCount > 0) {
1260                        builder.append(", ");
1261                    }
1262                    builder.append("TYPE_VIEW_TEXT_SELECTION_CHANGED");
1263                    eventTypeCount++;
1264                } break;
1265                case TYPE_VIEW_SCROLLED: {
1266                    if (eventTypeCount > 0) {
1267                        builder.append(", ");
1268                    }
1269                    builder.append("TYPE_VIEW_SCROLLED");
1270                    eventTypeCount++;
1271                } break;
1272                case TYPE_ANNOUNCEMENT: {
1273                    if (eventTypeCount > 0) {
1274                        builder.append(", ");
1275                    }
1276                    builder.append("TYPE_ANNOUNCEMENT");
1277                    eventTypeCount++;
1278                } break;
1279                case TYPE_VIEW_ACCESSIBILITY_FOCUSED: {
1280                    if (eventTypeCount > 0) {
1281                        builder.append(", ");
1282                    }
1283                    builder.append("TYPE_VIEW_ACCESSIBILITY_FOCUSED");
1284                    eventTypeCount++;
1285                } break;
1286                case TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED: {
1287                    if (eventTypeCount > 0) {
1288                        builder.append(", ");
1289                    }
1290                    builder.append("TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED");
1291                    eventTypeCount++;
1292                } break;
1293                case TYPE_VIEW_TEXT_TRAVERSED_AT_MOVEMENT_GRANULARITY: {
1294                    if (eventTypeCount > 0) {
1295                        builder.append(", ");
1296                    }
1297                    builder.append("TYPE_VIEW_TEXT_TRAVERSED_AT_MOVEMENT_GRANULARITY");
1298                    eventTypeCount++;
1299                } break;
1300                case TYPE_GESTURE_DETECTION_START: {
1301                    if (eventTypeCount > 0) {
1302                        builder.append(", ");
1303                    }
1304                    builder.append("TYPE_GESTURE_DETECTION_START");
1305                    eventTypeCount++;
1306                } break;
1307                case TYPE_GESTURE_DETECTION_END: {
1308                    if (eventTypeCount > 0) {
1309                        builder.append(", ");
1310                    }
1311                    builder.append("TYPE_GESTURE_DETECTION_END");
1312                    eventTypeCount++;
1313                } break;
1314                case TYPE_TOUCH_INTERACTION_START: {
1315                    if (eventTypeCount > 0) {
1316                        builder.append(", ");
1317                    }
1318                    builder.append("TYPE_TOUCH_INTERACTION_START");
1319                    eventTypeCount++;
1320                } break;
1321                case TYPE_TOUCH_INTERACTION_END: {
1322                    if (eventTypeCount > 0) {
1323                        builder.append(", ");
1324                    }
1325                    builder.append("TYPE_TOUCH_INTERACTION_END");
1326                    eventTypeCount++;
1327                } break;
1328            }
1329        }
1330        if (eventTypeCount > 1) {
1331            builder.insert(0, '[');
1332            builder.append(']');
1333        }
1334        return builder.toString();
1335    }
1336
1337    /**
1338     * @see Parcelable.Creator
1339     */
1340    public static final Parcelable.Creator<AccessibilityEvent> CREATOR =
1341            new Parcelable.Creator<AccessibilityEvent>() {
1342        public AccessibilityEvent createFromParcel(Parcel parcel) {
1343            AccessibilityEvent event = AccessibilityEvent.obtain();
1344            event.initFromParcel(parcel);
1345            return event;
1346        }
1347
1348        public AccessibilityEvent[] newArray(int size) {
1349            return new AccessibilityEvent[size];
1350        }
1351    };
1352}
1353