/* * Copyright (C) 2009 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.view.accessibility; import android.os.Parcel; import android.os.Parcelable; import android.text.TextUtils; import java.util.ArrayList; import java.util.List; /** *

* This class represents accessibility events that are sent by the system when * something notable happens in the user interface. For example, when a * {@link android.widget.Button} is clicked, a {@link android.view.View} is focused, etc. *

*

* 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. *

*

* 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) * 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 * accessibility service has not requested to retrieve the window content the event will * not contain reference to its source. Also for events of type * {@link #TYPE_NOTIFICATION_STATE_CHANGED} the source is never available. *

*

* This class represents various semantically different accessibility event * types. Each event type has an associated set of related properties. In other * words, each event type is characterized via a subset of the properties exposed * by this class. For each event type there is a corresponding constant defined * in this class. Follows a specification of the event types and their associated properties: *

*

* VIEW TYPES
*

*

* View clicked - represents the event of clicking on a {@link android.view.View} * like {@link android.widget.Button}, {@link android.widget.CompoundButton}, etc.
* Type:{@link #TYPE_VIEW_CLICKED}
* Properties:
*

*

*

* View long clicked - represents the event of long clicking on a {@link android.view.View} * like {@link android.widget.Button}, {@link android.widget.CompoundButton}, etc
* Type:{@link #TYPE_VIEW_LONG_CLICKED}
* Properties:
*

*

*

* View selected - represents the event of selecting an item usually in * the context of an {@link android.widget.AdapterView}.
* Type: {@link #TYPE_VIEW_SELECTED}
* Properties:
*

*

*

* View focused - represents the event of focusing a * {@link android.view.View}.
* Type: {@link #TYPE_VIEW_FOCUSED}
* Properties:
*

*

*

* View text changed - represents the event of changing the text of an * {@link android.widget.EditText}.
* Type: {@link #TYPE_VIEW_TEXT_CHANGED}
* Properties:
*

*

*

* View text selection changed - represents the event of changing the text * selection of an {@link android.widget.EditText}.
* Type: {@link #TYPE_VIEW_TEXT_SELECTION_CHANGED}
* Properties:
*

*

*

* View scrolled - 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.
* Type: {@link #TYPE_VIEW_SCROLLED}
* Properties:
*

* Note: 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.
*

*

* TRANSITION TYPES
*

*

* Window state changed - represents the event of opening a * {@link android.widget.PopupWindow}, {@link android.view.Menu}, * {@link android.app.Dialog}, etc.
* Type: {@link #TYPE_WINDOW_STATE_CHANGED}
* Properties:
*

*

*

* Window content changed - represents the event of change in the * content of a window. This change can be adding/removing view, changing * a view size, etc.
*

*

* Note: 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.
* Type: {@link #TYPE_WINDOW_CONTENT_CHANGED}
* Properties:
*

* Note: 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.
*

*

* NOTIFICATION TYPES
*

*

* Notification state changed - represents the event showing * {@link android.app.Notification}.
* Type: {@link #TYPE_NOTIFICATION_STATE_CHANGED}
* Properties:
*

* Note: 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.
*

*

* EXPLORATION TYPES
*

*

* View hover enter - represents the event of beginning to hover * over a {@link android.view.View}. The hover may be generated via * exploring the screen by touch or via a pointing device.
* Type: {@link #TYPE_VIEW_HOVER_ENTER}
* Properties:
*

*

* View hover exit - represents the event of stopping to hover * over a {@link android.view.View}. The hover may be generated via * exploring the screen by touch or via a pointing device.
* Type: {@link #TYPE_VIEW_HOVER_EXIT}
* Properties:
* *

*

* Touch exploration gesture start - represents the event of starting a touch * exploring gesture.
* Type: {@link #TYPE_TOUCH_EXPLORATION_GESTURE_START}
* Properties:
*

* Note: 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.
*

*

* Touch exploration gesture end - represents the event of ending a touch * exploring gesture.
* Type: {@link #TYPE_TOUCH_EXPLORATION_GESTURE_END}
* Properties:
*

* Note: 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.
*

*

* Security note *

* Since an event contains the text of its source privacy can be compromised by leaking * sensitive information such as passwords. To address this issue any event fired in response * to manipulation of a PASSWORD field does NOT CONTAIN the text of the password. *

* * @see android.view.accessibility.AccessibilityManager * @see android.accessibilityservice.AccessibilityService * @see AccessibilityNodeInfo */ public final class AccessibilityEvent extends AccessibilityRecord implements Parcelable { private static final boolean DEBUG = false; /** * Invalid selection/focus position. * * @see #getCurrentItemIndex() */ public static final int INVALID_POSITION = -1; /** * Maximum length of the text fields. * * @see #getBeforeText() * @see #getText() *
* Note: This constant is no longer needed since there * is no limit on the length of text that is contained * in an accessibility event anymore. */ @Deprecated public static final int MAX_TEXT_LENGTH = 500; /** * Represents the event of clicking on a {@link android.view.View} like * {@link android.widget.Button}, {@link android.widget.CompoundButton}, etc. */ public static final int TYPE_VIEW_CLICKED = 0x00000001; /** * Represents the event of long clicking on a {@link android.view.View} like * {@link android.widget.Button}, {@link android.widget.CompoundButton}, etc. */ public static final int TYPE_VIEW_LONG_CLICKED = 0x00000002; /** * Represents the event of selecting an item usually in the context of an * {@link android.widget.AdapterView}. */ public static final int TYPE_VIEW_SELECTED = 0x00000004; /** * Represents the event of focusing a {@link android.view.View}. */ public static final int TYPE_VIEW_FOCUSED = 0x00000008; /** * Represents the event of changing the text of an {@link android.widget.EditText}. */ public static final int TYPE_VIEW_TEXT_CHANGED = 0x00000010; /** * Represents the event of opening a {@link android.widget.PopupWindow}, * {@link android.view.Menu}, {@link android.app.Dialog}, etc. */ public static final int TYPE_WINDOW_STATE_CHANGED = 0x00000020; /** * Represents the event showing a {@link android.app.Notification}. */ public static final int TYPE_NOTIFICATION_STATE_CHANGED = 0x00000040; /** * Represents the event of a hover enter over a {@link android.view.View}. */ public static final int TYPE_VIEW_HOVER_ENTER = 0x00000080; /** * Represents the event of a hover exit over a {@link android.view.View}. */ public static final int TYPE_VIEW_HOVER_EXIT = 0x00000100; /** * Represents the event of starting a touch exploration gesture. */ public static final int TYPE_TOUCH_EXPLORATION_GESTURE_START = 0x00000200; /** * Represents the event of ending a touch exploration gesture. */ public static final int TYPE_TOUCH_EXPLORATION_GESTURE_END = 0x00000400; /** * Represents the event of changing the content of a window. */ public static final int TYPE_WINDOW_CONTENT_CHANGED = 0x00000800; /** * Represents the event of scrolling a view. */ public static final int TYPE_VIEW_SCROLLED = 0x00001000; /** * Represents the event of changing the selection in an {@link android.widget.EditText}. */ public static final int TYPE_VIEW_TEXT_SELECTION_CHANGED = 0x00002000; /** * Mask for {@link AccessibilityEvent} all types. * * @see #TYPE_VIEW_CLICKED * @see #TYPE_VIEW_LONG_CLICKED * @see #TYPE_VIEW_SELECTED * @see #TYPE_VIEW_FOCUSED * @see #TYPE_VIEW_TEXT_CHANGED * @see #TYPE_WINDOW_STATE_CHANGED * @see #TYPE_NOTIFICATION_STATE_CHANGED * @see #TYPE_VIEW_HOVER_ENTER * @see #TYPE_VIEW_HOVER_EXIT * @see #TYPE_TOUCH_EXPLORATION_GESTURE_START * @see #TYPE_TOUCH_EXPLORATION_GESTURE_END * @see #TYPE_WINDOW_CONTENT_CHANGED * @see #TYPE_VIEW_SCROLLED * @see #TYPE_VIEW_TEXT_SELECTION_CHANGED */ public static final int TYPES_ALL_MASK = 0xFFFFFFFF; private static final int MAX_POOL_SIZE = 10; private static final Object sPoolLock = new Object(); private static AccessibilityEvent sPool; private static int sPoolSize; private AccessibilityEvent mNext; private boolean mIsInPool; private int mEventType; private CharSequence mPackageName; private long mEventTime; private final ArrayList mRecords = new ArrayList(); /* * Hide constructor from clients. */ private AccessibilityEvent() { } /** * Initialize an event from another one. * * @param event The event to initialize from. */ void init(AccessibilityEvent event) { super.init(event); mEventType = event.mEventType; mEventTime = event.mEventTime; mPackageName = event.mPackageName; } /** * Sets if this instance is sealed. * * @param sealed Whether is sealed. * * @hide */ @Override public void setSealed(boolean sealed) { super.setSealed(sealed); List records = mRecords; final int recordCount = records.size(); for (int i = 0; i < recordCount; i++) { AccessibilityRecord record = records.get(i); record.setSealed(sealed); } } /** * Gets the number of records contained in the event. * * @return The number of records. */ public int getRecordCount() { return mRecords.size(); } /** * Appends an {@link AccessibilityRecord} to the end of event records. * * @param record The record to append. * * @throws IllegalStateException If called from an AccessibilityService. */ public void appendRecord(AccessibilityRecord record) { enforceNotSealed(); mRecords.add(record); } /** * Gets the record at a given index. * * @param index The index. * @return The record at the specified index. */ public AccessibilityRecord getRecord(int index) { return mRecords.get(index); } /** * Gets the event type. * * @return The event type. */ public int getEventType() { return mEventType; } /** * Sets the event type. * * @param eventType The event type. * * @throws IllegalStateException If called from an AccessibilityService. */ public void setEventType(int eventType) { enforceNotSealed(); mEventType = eventType; } /** * Gets the time in which this event was sent. * * @return The event time. */ public long getEventTime() { return mEventTime; } /** * Sets the time in which this event was sent. * * @param eventTime The event time. * * @throws IllegalStateException If called from an AccessibilityService. */ public void setEventTime(long eventTime) { enforceNotSealed(); mEventTime = eventTime; } /** * Gets the package name of the source. * * @return The package name. */ public CharSequence getPackageName() { return mPackageName; } /** * Sets the package name of the source. * * @param packageName The package name. * * @throws IllegalStateException If called from an AccessibilityService. */ public void setPackageName(CharSequence packageName) { enforceNotSealed(); mPackageName = packageName; } /** * Returns a cached instance if such is available or a new one is * instantiated with its type property set. * * @param eventType The event type. * @return An instance. */ public static AccessibilityEvent obtain(int eventType) { AccessibilityEvent event = AccessibilityEvent.obtain(); event.setEventType(eventType); return event; } /** * Returns a cached instance if such is available or a new one is * created. The returned instance is initialized from the given * event. * * @param event The other event. * @return An instance. */ public static AccessibilityEvent obtain(AccessibilityEvent event) { AccessibilityEvent eventClone = AccessibilityEvent.obtain(); eventClone.init(event); final int recordCount = event.mRecords.size(); for (int i = 0; i < recordCount; i++) { AccessibilityRecord record = event.mRecords.get(i); AccessibilityRecord recordClone = AccessibilityRecord.obtain(record); eventClone.mRecords.add(recordClone); } return eventClone; } /** * Returns a cached instance if such is available or a new one is * instantiated. * * @return An instance. */ public static AccessibilityEvent obtain() { synchronized (sPoolLock) { if (sPool != null) { AccessibilityEvent event = sPool; sPool = sPool.mNext; sPoolSize--; event.mNext = null; event.mIsInPool = false; return event; } return new AccessibilityEvent(); } } /** * Recycles an instance back to be reused. *

* Note: You must not touch the object after calling this function. *

* * @throws IllegalStateException If the event is already recycled. */ @Override public void recycle() { if (mIsInPool) { throw new IllegalStateException("Event already recycled!"); } clear(); synchronized (sPoolLock) { if (sPoolSize <= MAX_POOL_SIZE) { mNext = sPool; sPool = this; mIsInPool = true; sPoolSize++; } } } /** * Clears the state of this instance. * * @hide */ @Override protected void clear() { super.clear(); mEventType = 0; mPackageName = null; mEventTime = 0; while (!mRecords.isEmpty()) { AccessibilityRecord record = mRecords.remove(0); record.recycle(); } } /** * Creates a new instance from a {@link Parcel}. * * @param parcel A parcel containing the state of a {@link AccessibilityEvent}. */ public void initFromParcel(Parcel parcel) { mSealed = (parcel.readInt() == 1); mEventType = parcel.readInt(); mPackageName = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel); mEventTime = parcel.readLong(); mConnectionId = parcel.readInt(); readAccessibilityRecordFromParcel(this, parcel); // Read the records. final int recordCount = parcel.readInt(); for (int i = 0; i < recordCount; i++) { AccessibilityRecord record = AccessibilityRecord.obtain(); readAccessibilityRecordFromParcel(record, parcel); record.mConnectionId = mConnectionId; mRecords.add(record); } } /** * Reads an {@link AccessibilityRecord} from a parcel. * * @param record The record to initialize. * @param parcel The parcel to read from. */ private void readAccessibilityRecordFromParcel(AccessibilityRecord record, Parcel parcel) { record.mBooleanProperties = parcel.readInt(); record.mCurrentItemIndex = parcel.readInt(); record.mItemCount = parcel.readInt(); record.mFromIndex = parcel.readInt(); record.mToIndex = parcel.readInt(); record.mScrollX = parcel.readInt(); record.mScrollY = parcel.readInt(); record.mMaxScrollX = parcel.readInt(); record.mMaxScrollY = parcel.readInt(); record.mAddedCount = parcel.readInt(); record.mRemovedCount = parcel.readInt(); record.mClassName = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel); record.mContentDescription = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel); record.mBeforeText = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel); record.mParcelableData = parcel.readParcelable(null); parcel.readList(record.mText, null); record.mSourceWindowId = parcel.readInt(); record.mSourceViewId = parcel.readInt(); record.mSealed = (parcel.readInt() == 1); } /** * {@inheritDoc} */ public void writeToParcel(Parcel parcel, int flags) { parcel.writeInt(isSealed() ? 1 : 0); parcel.writeInt(mEventType); TextUtils.writeToParcel(mPackageName, parcel, 0); parcel.writeLong(mEventTime); parcel.writeInt(mConnectionId); writeAccessibilityRecordToParcel(this, parcel, flags); // Write the records. final int recordCount = getRecordCount(); parcel.writeInt(recordCount); for (int i = 0; i < recordCount; i++) { AccessibilityRecord record = mRecords.get(i); writeAccessibilityRecordToParcel(record, parcel, flags); } } /** * Writes an {@link AccessibilityRecord} to a parcel. * * @param record The record to write. * @param parcel The parcel to which to write. */ private void writeAccessibilityRecordToParcel(AccessibilityRecord record, Parcel parcel, int flags) { parcel.writeInt(record.mBooleanProperties); parcel.writeInt(record.mCurrentItemIndex); parcel.writeInt(record.mItemCount); parcel.writeInt(record.mFromIndex); parcel.writeInt(record.mToIndex); parcel.writeInt(record.mScrollX); parcel.writeInt(record.mScrollY); parcel.writeInt(record.mMaxScrollX); parcel.writeInt(record.mMaxScrollY); parcel.writeInt(record.mAddedCount); parcel.writeInt(record.mRemovedCount); TextUtils.writeToParcel(record.mClassName, parcel, flags); TextUtils.writeToParcel(record.mContentDescription, parcel, flags); TextUtils.writeToParcel(record.mBeforeText, parcel, flags); parcel.writeParcelable(record.mParcelableData, flags); parcel.writeList(record.mText); parcel.writeInt(record.mSourceWindowId); parcel.writeInt(record.mSourceViewId); parcel.writeInt(record.mSealed ? 1 : 0); } /** * {@inheritDoc} */ public int describeContents() { return 0; } @Override public String toString() { StringBuilder builder = new StringBuilder(); builder.append("EventType: ").append(eventTypeToString(mEventType)); builder.append("; EventTime: ").append(mEventTime); builder.append("; PackageName: ").append(mPackageName); builder.append(super.toString()); if (DEBUG) { builder.append("\n"); builder.append("; sourceWindowId: ").append(mSourceWindowId); builder.append("; sourceViewId: ").append(mSourceViewId); for (int i = 0; i < mRecords.size(); i++) { AccessibilityRecord record = mRecords.get(i); builder.append(" Record "); builder.append(i); builder.append(":"); builder.append(" [ ClassName: " + record.mClassName); builder.append("; Text: " + record.mText); builder.append("; ContentDescription: " + record.mContentDescription); builder.append("; ItemCount: " + record.mItemCount); builder.append("; CurrentItemIndex: " + record.mCurrentItemIndex); builder.append("; IsEnabled: " + record.isEnabled()); builder.append("; IsPassword: " + record.isPassword()); builder.append("; IsChecked: " + record.isChecked()); builder.append("; IsFullScreen: " + record.isFullScreen()); builder.append("; Scrollable: " + record.isScrollable()); builder.append("; BeforeText: " + record.mBeforeText); builder.append("; FromIndex: " + record.mFromIndex); builder.append("; ToIndex: " + record.mToIndex); builder.append("; ScrollX: " + record.mScrollX); builder.append("; ScrollY: " + record.mScrollY); builder.append("; AddedCount: " + record.mAddedCount); builder.append("; RemovedCount: " + record.mRemovedCount); builder.append("; ParcelableData: " + record.mParcelableData); builder.append(" ]"); builder.append("\n"); } } else { builder.append("; recordCount: ").append(getRecordCount()); } return builder.toString(); } /** * Returns the string representation of an event type. For example, * {@link #TYPE_VIEW_CLICKED} is represented by the string TYPE_VIEW_CLICKED. * * @param eventType The event type * @return The string representation. */ public static String eventTypeToString(int eventType) { switch (eventType) { case TYPE_VIEW_CLICKED: return "TYPE_VIEW_CLICKED"; case TYPE_VIEW_LONG_CLICKED: return "TYPE_VIEW_LONG_CLICKED"; case TYPE_VIEW_SELECTED: return "TYPE_VIEW_SELECTED"; case TYPE_VIEW_FOCUSED: return "TYPE_VIEW_FOCUSED"; case TYPE_VIEW_TEXT_CHANGED: return "TYPE_VIEW_TEXT_CHANGED"; case TYPE_WINDOW_STATE_CHANGED: return "TYPE_WINDOW_STATE_CHANGED"; case TYPE_VIEW_HOVER_ENTER: return "TYPE_VIEW_HOVER_ENTER"; case TYPE_VIEW_HOVER_EXIT: return "TYPE_VIEW_HOVER_EXIT"; case TYPE_NOTIFICATION_STATE_CHANGED: return "TYPE_NOTIFICATION_STATE_CHANGED"; case TYPE_TOUCH_EXPLORATION_GESTURE_START: return "TYPE_TOUCH_EXPLORATION_GESTURE_START"; case TYPE_TOUCH_EXPLORATION_GESTURE_END: return "TYPE_TOUCH_EXPLORATION_GESTURE_END"; case TYPE_WINDOW_CONTENT_CHANGED: return "TYPE_WINDOW_CONTENT_CHANGED"; case TYPE_VIEW_TEXT_SELECTION_CHANGED: return "TYPE_VIEW_TEXT_SELECTION_CHANGED"; case TYPE_VIEW_SCROLLED: return "TYPE_VIEW_SCROLLED"; default: return null; } } /** * @see Parcelable.Creator */ public static final Parcelable.Creator CREATOR = new Parcelable.Creator() { public AccessibilityEvent createFromParcel(Parcel parcel) { AccessibilityEvent event = AccessibilityEvent.obtain(); event.initFromParcel(parcel); return event; } public AccessibilityEvent[] newArray(int size) { return new AccessibilityEvent[size]; } }; }