core/java/android/view/accessibility/AccessibilityRecord.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2011 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.Parcelable;
 import android.view.View;

 import java.util.ArrayList;
 import java.util.List;

 /**
  * Represents a record in an {@link AccessibilityEvent} and contains information
  * about state change of its source {@link android.view.View}. When a view fires
  * an accessibility event it requests from its parent to dispatch the
  * constructed event. The parent may optionally append a record for itself
  * for providing more context to
  * {@link android.accessibilityservice.AccessibilityService}s. Hence,
  * accessibility services can facilitate additional accessibility records
  * to enhance feedback.
  * </p>
  * <p>
  * Once the accessibility event containing a record is dispatched the record is
  * made immutable and calling a state mutation method generates an error.
  * </p>
  * <p>
  * <strong>Note:</strong> Not all properties are applicable to all accessibility
  * event types. For detailed information please refer to {@link AccessibilityEvent}.
  * </p>
  *
  * <div class="special reference">
  * <h3>Developer Guides</h3>
  * <p>For more information about creating and processing AccessibilityRecords, read the
  * <a href="{@docRoot}guide/topics/ui/accessibility/index.html">Accessibility</a>
  * developer guide.</p>
  * </div>
  *
  * @see AccessibilityEvent
  * @see AccessibilityManager
  * @see android.accessibilityservice.AccessibilityService
  * @see AccessibilityNodeInfo
  */
 public class AccessibilityRecord {

     private static final int UNDEFINED = -1;

     private static final int PROPERTY_CHECKED = 0x00000001;
     private static final int PROPERTY_ENABLED = 0x00000002;
     private static final int PROPERTY_PASSWORD = 0x00000004;
     private static final int PROPERTY_FULL_SCREEN = 0x00000080;
     private static final int PROPERTY_SCROLLABLE = 0x00000100;
     private static final int PROPERTY_IMPORTANT_FOR_ACCESSIBILITY = 0x00000200;

     private static final int GET_SOURCE_PREFETCH_FLAGS =
         AccessibilityNodeInfo.FLAG_PREFETCH_PREDECESSORS
         | AccessibilityNodeInfo.FLAG_PREFETCH_SIBLINGS
         | AccessibilityNodeInfo.FLAG_PREFETCH_DESCENDANTS;

     // Housekeeping
     private static final int MAX_POOL_SIZE = 10;
     private static final Object sPoolLock = new Object();
     private static AccessibilityRecord sPool;
     private static int sPoolSize;
     private AccessibilityRecord mNext;
     private boolean mIsInPool;

     boolean mSealed;
     int mBooleanProperties = 0;
     int mCurrentItemIndex = UNDEFINED;
     int mItemCount = UNDEFINED;
     int mFromIndex = UNDEFINED;
     int mToIndex = UNDEFINED;
     int mScrollX = UNDEFINED;
     int mScrollY = UNDEFINED;
     int mMaxScrollX = UNDEFINED;
     int mMaxScrollY = UNDEFINED;

     int mAddedCount= UNDEFINED;
     int mRemovedCount = UNDEFINED;
     long mSourceNodeId = AccessibilityNodeInfo.makeNodeId(UNDEFINED, UNDEFINED);
     int mSourceWindowId = UNDEFINED;

     CharSequence mClassName;
     CharSequence mContentDescription;
     CharSequence mBeforeText;
     Parcelable mParcelableData;

     final List<CharSequence> mText = new ArrayList<CharSequence>();

     int mConnectionId = UNDEFINED;

     /*
      * Hide constructor.
      */
     AccessibilityRecord() {
     }

     /**
      * Sets the event source.
      *
      * @param source The source.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setSource(View source) {
         setSource(source, UNDEFINED);
     }

     /**
      * Sets the source to be a virtual descendant of the given <code>root</code>.
      * If <code>virtualDescendantId</code> equals to {@link View#NO_ID} the root
      * is set as the source.
      * <p>
      * A virtual descendant is an imaginary View that is reported as a part of the view
      * hierarchy for accessibility purposes. This enables custom views that draw complex
      * content to report them selves as a tree of virtual views, thus conveying their
      * logical structure.
      * </p>
      *
      * @param root The root of the virtual subtree.
      * @param virtualDescendantId The id of the virtual descendant.
      */
     public void setSource(View root, int virtualDescendantId) {
         enforceNotSealed();
         final boolean important;
         if (virtualDescendantId == UNDEFINED) {
             important = (root != null) ? root.isImportantForAccessibility() : true;
         } else {
             important = true;
         }
         setBooleanProperty(PROPERTY_IMPORTANT_FOR_ACCESSIBILITY, important);
         mSourceWindowId = (root != null) ? root.getAccessibilityWindowId() : UNDEFINED;
         final int rootViewId = (root != null) ? root.getAccessibilityViewId() : UNDEFINED;
         mSourceNodeId = AccessibilityNodeInfo.makeNodeId(rootViewId, virtualDescendantId);
     }

     /**
      * Gets the {@link AccessibilityNodeInfo} of the event source.
      * <p>
      *   <strong>Note:</strong> It is a client responsibility to recycle the received info
      *   by calling {@link AccessibilityNodeInfo#recycle() AccessibilityNodeInfo#recycle()}
      *   to avoid creating of multiple instances.
      * </p>
      * @return The info of the source.
      */
     public AccessibilityNodeInfo getSource() {
         enforceSealed();
         if (mConnectionId == UNDEFINED || mSourceWindowId == UNDEFINED
                 || AccessibilityNodeInfo.getAccessibilityViewId(mSourceNodeId) == UNDEFINED) {
             return null;
         }
         AccessibilityInteractionClient client = AccessibilityInteractionClient.getInstance();
         return client.findAccessibilityNodeInfoByAccessibilityId(mConnectionId, mSourceWindowId,
                 mSourceNodeId, false, GET_SOURCE_PREFETCH_FLAGS);
     }

     /**
      * Sets the window id.
      *
      * @param windowId The window id.
      *
      * @hide
      */
     public void setWindowId(int windowId) {
         mSourceWindowId = windowId;
     }

     /**
      * Gets the id of the window from which the event comes from.
      *
      * @return The window id.
      */
     public int getWindowId() {
         return mSourceWindowId;
     }

     /**
      * Gets if the source is checked.
      *
      * @return True if the view is checked, false otherwise.
      */
     public boolean isChecked() {
         return getBooleanProperty(PROPERTY_CHECKED);
     }

     /**
      * Sets if the source is checked.
      *
      * @param isChecked True if the view is checked, false otherwise.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setChecked(boolean isChecked) {
         enforceNotSealed();
         setBooleanProperty(PROPERTY_CHECKED, isChecked);
     }

     /**
      * Gets if the source is enabled.
      *
      * @return True if the view is enabled, false otherwise.
      */
     public boolean isEnabled() {
         return getBooleanProperty(PROPERTY_ENABLED);
     }

     /**
      * Sets if the source is enabled.
      *
      * @param isEnabled True if the view is enabled, false otherwise.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setEnabled(boolean isEnabled) {
         enforceNotSealed();
         setBooleanProperty(PROPERTY_ENABLED, isEnabled);
     }

     /**
      * Gets if the source is a password field.
      *
      * @return True if the view is a password field, false otherwise.
      */
     public boolean isPassword() {
         return getBooleanProperty(PROPERTY_PASSWORD);
     }

     /**
      * Sets if the source is a password field.
      *
      * @param isPassword True if the view is a password field, false otherwise.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setPassword(boolean isPassword) {
         enforceNotSealed();
         setBooleanProperty(PROPERTY_PASSWORD, isPassword);
     }

     /**
      * Gets if the source is taking the entire screen.
      *
      * @return True if the source is full screen, false otherwise.
      */
     public boolean isFullScreen() {
         return getBooleanProperty(PROPERTY_FULL_SCREEN);
     }

     /**
      * Sets if the source is taking the entire screen.
      *
      * @param isFullScreen True if the source is full screen, false otherwise.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setFullScreen(boolean isFullScreen) {
         enforceNotSealed();
         setBooleanProperty(PROPERTY_FULL_SCREEN, isFullScreen);
     }

     /**
      * Gets if the source is scrollable.
      *
      * @return True if the source is scrollable, false otherwise.
      */
     public boolean isScrollable() {
         return getBooleanProperty(PROPERTY_SCROLLABLE);
     }

     /**
      * Sets if the source is scrollable.
      *
      * @param scrollable True if the source is scrollable, false otherwise.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setScrollable(boolean scrollable) {
         enforceNotSealed();
         setBooleanProperty(PROPERTY_SCROLLABLE, scrollable);
     }

     /**
      * Gets if the source is important for accessibility.
      *
      * <strong>Note:</strong> Used only internally to determine whether
      * to deliver the event to a given accessibility service since some
      * services may want to regard all views for accessibility while others
      * may want to regard only the important views for accessibility.
      *
      * @return True if the source is important for accessibility,
      *        false otherwise.
      *
      * @hide
      */
     public boolean isImportantForAccessibility() {
         return getBooleanProperty(PROPERTY_IMPORTANT_FOR_ACCESSIBILITY);
     }

     /**
      * Gets the number of items that can be visited.
      *
      * @return The number of items.
      */
     public int getItemCount() {
         return mItemCount;
     }

     /**
      * Sets the number of items that can be visited.
      *
      * @param itemCount The number of items.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setItemCount(int itemCount) {
         enforceNotSealed();
         mItemCount = itemCount;
     }

     /**
      * Gets the index of the source in the list of items the can be visited.
      *
      * @return The current item index.
      */
     public int getCurrentItemIndex() {
         return mCurrentItemIndex;
     }

     /**
      * Sets the index of the source in the list of items that can be visited.
      *
      * @param currentItemIndex The current item index.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setCurrentItemIndex(int currentItemIndex) {
         enforceNotSealed();
         mCurrentItemIndex = currentItemIndex;
     }

     /**
      * Gets the index of the first character of the changed sequence,
      * or the beginning of a text selection or the index of the first
      * visible item when scrolling.
      *
      * @return The index of the first character or selection
      *        start or the first visible item.
      */
     public int getFromIndex() {
         return mFromIndex;
     }

     /**
      * Sets the index of the first character of the changed sequence
      * or the beginning of a text selection or the index of the first
      * visible item when scrolling.
      *
      * @param fromIndex The index of the first character or selection
      *        start or the first visible item.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setFromIndex(int fromIndex) {
         enforceNotSealed();
         mFromIndex = fromIndex;
     }

     /**
      * Gets the index of text selection end or the index of the last
      * visible item when scrolling.
      *
      * @return The index of selection end or last item index.
      */
     public int getToIndex() {
         return mToIndex;
     }

     /**
      * Sets the index of text selection end or the index of the last
      * visible item when scrolling.
      *
      * @param toIndex The index of selection end or last item index.
      */
     public void setToIndex(int toIndex) {
         enforceNotSealed();
         mToIndex = toIndex;
     }

     /**
      * Gets the scroll offset of the source left edge in pixels.
      *
      * @return The scroll.
      */
     public int getScrollX() {
         return mScrollX;
     }

     /**
      * Sets the scroll offset of the source left edge in pixels.
      *
      * @param scrollX The scroll.
      */
     public void setScrollX(int scrollX) {
         enforceNotSealed();
         mScrollX = scrollX;
     }

     /**
      * Gets the scroll offset of the source top edge in pixels.
      *
      * @return The scroll.
      */
     public int getScrollY() {
         return mScrollY;
     }

     /**
      * Sets the scroll offset of the source top edge in pixels.
      *
      * @param scrollY The scroll.
      */
     public void setScrollY(int scrollY) {
         enforceNotSealed();
         mScrollY = scrollY;
     }

     /**
      * Gets the max scroll offset of the source left edge in pixels.
      *
      * @return The max scroll.
      */
     public int getMaxScrollX() {
         return mMaxScrollX;
     }

     /**
      * Sets the max scroll offset of the source left edge in pixels.
      *
      * @param maxScrollX The max scroll.
      */
     public void setMaxScrollX(int maxScrollX) {
         enforceNotSealed();
         mMaxScrollX = maxScrollX;
     }

     /**
      * Gets the max scroll offset of the source top edge in pixels.
      *
      * @return The max scroll.
      */
     public int getMaxScrollY() {
         return mMaxScrollY;
     }

     /**
      * Sets the max scroll offset of the source top edge in pixels.
      *
      * @param maxScrollY The max scroll.
      */
     public void setMaxScrollY(int maxScrollY) {
         enforceNotSealed();
         mMaxScrollY = maxScrollY;
     }

     /**
      * Gets the number of added characters.
      *
      * @return The number of added characters.
      */
     public int getAddedCount() {
         return mAddedCount;
     }

     /**
      * Sets the number of added characters.
      *
      * @param addedCount The number of added characters.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setAddedCount(int addedCount) {
         enforceNotSealed();
         mAddedCount = addedCount;
     }

     /**
      * Gets the number of removed characters.
      *
      * @return The number of removed characters.
      */
     public int getRemovedCount() {
         return mRemovedCount;
     }

     /**
      * Sets the number of removed characters.
      *
      * @param removedCount The number of removed characters.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setRemovedCount(int removedCount) {
         enforceNotSealed();
         mRemovedCount = removedCount;
     }

     /**
      * Gets the class name of the source.
      *
      * @return The class name.
      */
     public CharSequence getClassName() {
         return mClassName;
     }

     /**
      * Sets the class name of the source.
      *
      * @param className The lass name.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setClassName(CharSequence className) {
         enforceNotSealed();
         mClassName = className;
     }

     /**
      * Gets the text of the event. The index in the list represents the priority
      * of the text. Specifically, the lower the index the higher the priority.
      *
      * @return The text.
      */
     public List<CharSequence> getText() {
         return mText;
     }

     /**
      * Sets the text before a change.
      *
      * @return The text before the change.
      */
     public CharSequence getBeforeText() {
         return mBeforeText;
     }

     /**
      * Sets the text before a change.
      *
      * @param beforeText The text before the change.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setBeforeText(CharSequence beforeText) {
         enforceNotSealed();
         mBeforeText = beforeText;
     }

     /**
      * Gets the description of the source.
      *
      * @return The description.
      */
     public CharSequence getContentDescription() {
         return mContentDescription;
     }

     /**
      * Sets the description of the source.
      *
      * @param contentDescription The description.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setContentDescription(CharSequence contentDescription) {
         enforceNotSealed();
         mContentDescription = contentDescription;
     }

     /**
      * Gets the {@link Parcelable} data.
      *
      * @return The parcelable data.
      */
     public Parcelable getParcelableData() {
         return mParcelableData;
     }

     /**
      * Sets the {@link Parcelable} data of the event.
      *
      * @param parcelableData The parcelable data.
      *
      * @throws IllegalStateException If called from an AccessibilityService.
      */
     public void setParcelableData(Parcelable parcelableData) {
         enforceNotSealed();
         mParcelableData = parcelableData;
     }

     /**
      * Gets the id of the source node.
      *
      * @return The id.
      *
      * @hide
      */
     public long getSourceNodeId() {
         return mSourceNodeId;
     }

     /**
      * Sets the unique id of the IAccessibilityServiceConnection over which
      * this instance can send requests to the system.
      *
      * @param connectionId The connection id.
      *
      * @hide
      */
     public void setConnectionId(int connectionId) {
         enforceNotSealed();
         mConnectionId = connectionId;
     }

     /**
      * Sets if this instance is sealed.
      *
      * @param sealed Whether is sealed.
      *
      * @hide
      */
     public void setSealed(boolean sealed) {
         mSealed = sealed;
     }

     /**
      * Gets if this instance is sealed.
      *
      * @return Whether is sealed.
      */
     boolean isSealed() {
         return mSealed;
     }

     /**
      * Enforces that this instance is sealed.
      *
      * @throws IllegalStateException If this instance is not sealed.
      */
     void enforceSealed() {
         if (!isSealed()) {
             throw new IllegalStateException("Cannot perform this "
                     + "action on a not sealed instance.");
         }
     }

     /**
      * Enforces that this instance is not sealed.
      *
      * @throws IllegalStateException If this instance is sealed.
      */
     void enforceNotSealed() {
         if (isSealed()) {
             throw new IllegalStateException("Cannot perform this "
                     + "action on a sealed instance.");
         }
     }

     /**
      * Gets the value of a boolean property.
      *
      * @param property The property.
      * @return The value.
      */
     private boolean getBooleanProperty(int property) {
         return (mBooleanProperties & property) == property;
     }

     /**
      * Sets a boolean property.
      *
      * @param property The property.
      * @param value The value.
      */
     private void setBooleanProperty(int property, boolean value) {
         if (value) {
             mBooleanProperties |= property;
         } else {
             mBooleanProperties &= ~property;
         }
     }

     /**
      * Returns a cached instance if such is available or a new one is
      * instantiated. The instance is initialized with data from the
      * given record.
      *
      * @return An instance.
      */
     public static AccessibilityRecord obtain(AccessibilityRecord record) {
        AccessibilityRecord clone = AccessibilityRecord.obtain();
        clone.init(record);
        return clone;
     }

     /**
      * Returns a cached instance if such is available or a new one is
      * instantiated.
      *
      * @return An instance.
      */
     public static AccessibilityRecord obtain() {
         synchronized (sPoolLock) {
             if (sPool != null) {
                 AccessibilityRecord record = sPool;
                 sPool = sPool.mNext;
                 sPoolSize--;
                 record.mNext = null;
                 record.mIsInPool = false;
                 return record;
             }
             return new AccessibilityRecord();
         }
     }

     /**
      * Return an instance back to be reused.
      * <p>
      * <strong>Note:</strong> You must not touch the object after calling this function.
      *
      * @throws IllegalStateException If the record is already recycled.
      */
     public void recycle() {
         if (mIsInPool) {
             throw new IllegalStateException("Record already recycled!");
         }
         clear();
         synchronized (sPoolLock) {
             if (sPoolSize <= MAX_POOL_SIZE) {
                 mNext = sPool;
                 sPool = this;
                 mIsInPool = true;
                 sPoolSize++;
             }
         }
     }

     /**
      * Initialize this record from another one.
      *
      * @param record The to initialize from.
      */
     void init(AccessibilityRecord record) {
         mSealed = record.mSealed;
         mBooleanProperties = record.mBooleanProperties;
         mCurrentItemIndex = record.mCurrentItemIndex;
         mItemCount = record.mItemCount;
         mFromIndex = record.mFromIndex;
         mToIndex = record.mToIndex;
         mScrollX = record.mScrollX;
         mScrollY = record.mScrollY;
         mMaxScrollX = record.mMaxScrollX;
         mMaxScrollY = record.mMaxScrollY;
         mAddedCount = record.mAddedCount;
         mRemovedCount = record.mRemovedCount;
         mClassName = record.mClassName;
         mContentDescription = record.mContentDescription;
         mBeforeText = record.mBeforeText;
         mParcelableData = record.mParcelableData;
         mText.addAll(record.mText);
         mSourceWindowId = record.mSourceWindowId;
         mSourceNodeId = record.mSourceNodeId;
         mConnectionId = record.mConnectionId;
     }

     /**
      * Clears the state of this instance.
      */
     void clear() {
         mSealed = false;
         mBooleanProperties = 0;
         mCurrentItemIndex = UNDEFINED;
         mItemCount = UNDEFINED;
         mFromIndex = UNDEFINED;
         mToIndex = UNDEFINED;
         mScrollX = UNDEFINED;
         mScrollY = UNDEFINED;
         mMaxScrollX = UNDEFINED;
         mMaxScrollY = UNDEFINED;
         mAddedCount = UNDEFINED;
         mRemovedCount = UNDEFINED;
         mClassName = null;
         mContentDescription = null;
         mBeforeText = null;
         mParcelableData = null;
         mText.clear();
         mSourceNodeId = AccessibilityNodeInfo.makeNodeId(UNDEFINED, UNDEFINED);
         mSourceWindowId = UNDEFINED;
         mConnectionId = UNDEFINED;
     }

     @Override
     public String toString() {
         StringBuilder builder = new StringBuilder();
         builder.append(" [ ClassName: " + mClassName);
         builder.append("; Text: " + mText);
         builder.append("; ContentDescription: " + mContentDescription);
         builder.append("; ItemCount: " + mItemCount);
         builder.append("; CurrentItemIndex: " + mCurrentItemIndex);
         builder.append("; IsEnabled: " + getBooleanProperty(PROPERTY_ENABLED));
         builder.append("; IsPassword: " + getBooleanProperty(PROPERTY_PASSWORD));
         builder.append("; IsChecked: " + getBooleanProperty(PROPERTY_CHECKED));
         builder.append("; IsFullScreen: " + getBooleanProperty(PROPERTY_FULL_SCREEN));
         builder.append("; Scrollable: " + getBooleanProperty(PROPERTY_SCROLLABLE));
         builder.append("; BeforeText: " + mBeforeText);
         builder.append("; FromIndex: " + mFromIndex);
         builder.append("; ToIndex: " + mToIndex);
         builder.append("; ScrollX: " + mScrollX);
         builder.append("; ScrollY: " + mScrollY);
         builder.append("; MaxScrollX: " + mMaxScrollX);
         builder.append("; MaxScrollY: " + mMaxScrollY);
         builder.append("; AddedCount: " + mAddedCount);
         builder.append("; RemovedCount: " + mRemovedCount);
         builder.append("; ParcelableData: " + mParcelableData);
         builder.append(" ]");
         return builder.toString();
     }
 }
	/*
	* Copyright (C) 2011 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.Parcelable;
	import android.view.View;

	import java.util.ArrayList;
	import java.util.List;

	/**
	* Represents a record in an {@link AccessibilityEvent} and contains information
	* about state change of its source {@link android.view.View}. When a view fires
	* an accessibility event it requests from its parent to dispatch the
	* constructed event. The parent may optionally append a record for itself
	* for providing more context to
	* {@link android.accessibilityservice.AccessibilityService}s. Hence,
	* accessibility services can facilitate additional accessibility records
	* to enhance feedback.
	* </p>
	* <p>
	* Once the accessibility event containing a record is dispatched the record is
	* made immutable and calling a state mutation method generates an error.
	* </p>
	* <p>
	* <strong>Note:</strong> Not all properties are applicable to all accessibility
	* event types. For detailed information please refer to {@link AccessibilityEvent}.
	* </p>
	*
	* <div class="special reference">
	* <h3>Developer Guides</h3>
	* <p>For more information about creating and processing AccessibilityRecords, read the
	* <a href="{@docRoot}guide/topics/ui/accessibility/index.html">Accessibility</a>
	* developer guide.</p>
	* </div>
	*
	* @see AccessibilityEvent
	* @see AccessibilityManager
	* @see android.accessibilityservice.AccessibilityService
	* @see AccessibilityNodeInfo
	*/
	public class AccessibilityRecord {

	private static final int UNDEFINED = -1;

	private static final int PROPERTY_CHECKED = 0x00000001;
	private static final int PROPERTY_ENABLED = 0x00000002;
	private static final int PROPERTY_PASSWORD = 0x00000004;
	private static final int PROPERTY_FULL_SCREEN = 0x00000080;
	private static final int PROPERTY_SCROLLABLE = 0x00000100;
	private static final int PROPERTY_IMPORTANT_FOR_ACCESSIBILITY = 0x00000200;

	private static final int GET_SOURCE_PREFETCH_FLAGS =
	AccessibilityNodeInfo.FLAG_PREFETCH_PREDECESSORS
	\| AccessibilityNodeInfo.FLAG_PREFETCH_SIBLINGS
	\| AccessibilityNodeInfo.FLAG_PREFETCH_DESCENDANTS;

	// Housekeeping
	private static final int MAX_POOL_SIZE = 10;
	private static final Object sPoolLock = new Object();
	private static AccessibilityRecord sPool;
	private static int sPoolSize;
	private AccessibilityRecord mNext;
	private boolean mIsInPool;

	boolean mSealed;
	int mBooleanProperties = 0;
	int mCurrentItemIndex = UNDEFINED;
	int mItemCount = UNDEFINED;
	int mFromIndex = UNDEFINED;
	int mToIndex = UNDEFINED;
	int mScrollX = UNDEFINED;
	int mScrollY = UNDEFINED;
	int mMaxScrollX = UNDEFINED;
	int mMaxScrollY = UNDEFINED;

	int mAddedCount= UNDEFINED;
	int mRemovedCount = UNDEFINED;
	long mSourceNodeId = AccessibilityNodeInfo.makeNodeId(UNDEFINED, UNDEFINED);
	int mSourceWindowId = UNDEFINED;

	CharSequence mClassName;
	CharSequence mContentDescription;
	CharSequence mBeforeText;
	Parcelable mParcelableData;

	final List<CharSequence> mText = new ArrayList<CharSequence>();

	int mConnectionId = UNDEFINED;

	/*
	* Hide constructor.
	*/
	AccessibilityRecord() {
	}

	/**
	* Sets the event source.
	*
	* @param source The source.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setSource(View source) {
	setSource(source, UNDEFINED);
	}

	/**
	* Sets the source to be a virtual descendant of the given <code>root</code>.
	* If <code>virtualDescendantId</code> equals to {@link View#NO_ID} the root
	* is set as the source.
	* <p>
	* A virtual descendant is an imaginary View that is reported as a part of the view
	* hierarchy for accessibility purposes. This enables custom views that draw complex
	* content to report them selves as a tree of virtual views, thus conveying their
	* logical structure.
	* </p>
	*
	* @param root The root of the virtual subtree.
	* @param virtualDescendantId The id of the virtual descendant.
	*/
	public void setSource(View root, int virtualDescendantId) {
	enforceNotSealed();
	final boolean important;
	if (virtualDescendantId == UNDEFINED) {
	important = (root != null) ? root.isImportantForAccessibility() : true;
	} else {
	important = true;
	}
	setBooleanProperty(PROPERTY_IMPORTANT_FOR_ACCESSIBILITY, important);
	mSourceWindowId = (root != null) ? root.getAccessibilityWindowId() : UNDEFINED;
	final int rootViewId = (root != null) ? root.getAccessibilityViewId() : UNDEFINED;
	mSourceNodeId = AccessibilityNodeInfo.makeNodeId(rootViewId, virtualDescendantId);
	}

	/**
	* Gets the {@link AccessibilityNodeInfo} of the event source.
	* <p>
	* <strong>Note:</strong> It is a client responsibility to recycle the received info
	* by calling {@link AccessibilityNodeInfo#recycle() AccessibilityNodeInfo#recycle()}
	* to avoid creating of multiple instances.
	* </p>
	* @return The info of the source.
	*/
	public AccessibilityNodeInfo getSource() {
	enforceSealed();
	if (mConnectionId == UNDEFINED \|\| mSourceWindowId == UNDEFINED
	\|\| AccessibilityNodeInfo.getAccessibilityViewId(mSourceNodeId) == UNDEFINED) {
	return null;
	}
	AccessibilityInteractionClient client = AccessibilityInteractionClient.getInstance();
	return client.findAccessibilityNodeInfoByAccessibilityId(mConnectionId, mSourceWindowId,
	mSourceNodeId, false, GET_SOURCE_PREFETCH_FLAGS);
	}

	/**
	* Sets the window id.
	*
	* @param windowId The window id.
	*
	* @hide
	*/
	public void setWindowId(int windowId) {
	mSourceWindowId = windowId;
	}

	/**
	* Gets the id of the window from which the event comes from.
	*
	* @return The window id.
	*/
	public int getWindowId() {
	return mSourceWindowId;
	}

	/**
	* Gets if the source is checked.
	*
	* @return True if the view is checked, false otherwise.
	*/
	public boolean isChecked() {
	return getBooleanProperty(PROPERTY_CHECKED);
	}

	/**
	* Sets if the source is checked.
	*
	* @param isChecked True if the view is checked, false otherwise.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setChecked(boolean isChecked) {
	enforceNotSealed();
	setBooleanProperty(PROPERTY_CHECKED, isChecked);
	}

	/**
	* Gets if the source is enabled.
	*
	* @return True if the view is enabled, false otherwise.
	*/
	public boolean isEnabled() {
	return getBooleanProperty(PROPERTY_ENABLED);
	}

	/**
	* Sets if the source is enabled.
	*
	* @param isEnabled True if the view is enabled, false otherwise.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setEnabled(boolean isEnabled) {
	enforceNotSealed();
	setBooleanProperty(PROPERTY_ENABLED, isEnabled);
	}

	/**
	* Gets if the source is a password field.
	*
	* @return True if the view is a password field, false otherwise.
	*/
	public boolean isPassword() {
	return getBooleanProperty(PROPERTY_PASSWORD);
	}

	/**
	* Sets if the source is a password field.
	*
	* @param isPassword True if the view is a password field, false otherwise.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setPassword(boolean isPassword) {
	enforceNotSealed();
	setBooleanProperty(PROPERTY_PASSWORD, isPassword);
	}

	/**
	* Gets if the source is taking the entire screen.
	*
	* @return True if the source is full screen, false otherwise.
	*/
	public boolean isFullScreen() {
	return getBooleanProperty(PROPERTY_FULL_SCREEN);
	}

	/**
	* Sets if the source is taking the entire screen.
	*
	* @param isFullScreen True if the source is full screen, false otherwise.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setFullScreen(boolean isFullScreen) {
	enforceNotSealed();
	setBooleanProperty(PROPERTY_FULL_SCREEN, isFullScreen);
	}

	/**
	* Gets if the source is scrollable.
	*
	* @return True if the source is scrollable, false otherwise.
	*/
	public boolean isScrollable() {
	return getBooleanProperty(PROPERTY_SCROLLABLE);
	}

	/**
	* Sets if the source is scrollable.
	*
	* @param scrollable True if the source is scrollable, false otherwise.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setScrollable(boolean scrollable) {
	enforceNotSealed();
	setBooleanProperty(PROPERTY_SCROLLABLE, scrollable);
	}

	/**
	* Gets if the source is important for accessibility.
	*
	* <strong>Note:</strong> Used only internally to determine whether
	* to deliver the event to a given accessibility service since some
	* services may want to regard all views for accessibility while others
	* may want to regard only the important views for accessibility.
	*
	* @return True if the source is important for accessibility,
	* false otherwise.
	*
	* @hide
	*/
	public boolean isImportantForAccessibility() {
	return getBooleanProperty(PROPERTY_IMPORTANT_FOR_ACCESSIBILITY);
	}

	/**
	* Gets the number of items that can be visited.
	*
	* @return The number of items.
	*/
	public int getItemCount() {
	return mItemCount;
	}

	/**
	* Sets the number of items that can be visited.
	*
	* @param itemCount The number of items.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setItemCount(int itemCount) {
	enforceNotSealed();
	mItemCount = itemCount;
	}

	/**
	* Gets the index of the source in the list of items the can be visited.
	*
	* @return The current item index.
	*/
	public int getCurrentItemIndex() {
	return mCurrentItemIndex;
	}

	/**
	* Sets the index of the source in the list of items that can be visited.
	*
	* @param currentItemIndex The current item index.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setCurrentItemIndex(int currentItemIndex) {
	enforceNotSealed();
	mCurrentItemIndex = currentItemIndex;
	}

	/**
	* Gets the index of the first character of the changed sequence,
	* or the beginning of a text selection or the index of the first
	* visible item when scrolling.
	*
	* @return The index of the first character or selection
	* start or the first visible item.
	*/
	public int getFromIndex() {
	return mFromIndex;
	}

	/**
	* Sets the index of the first character of the changed sequence
	* or the beginning of a text selection or the index of the first
	* visible item when scrolling.
	*
	* @param fromIndex The index of the first character or selection
	* start or the first visible item.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setFromIndex(int fromIndex) {
	enforceNotSealed();
	mFromIndex = fromIndex;
	}

	/**
	* Gets the index of text selection end or the index of the last
	* visible item when scrolling.
	*
	* @return The index of selection end or last item index.
	*/
	public int getToIndex() {
	return mToIndex;
	}

	/**
	* Sets the index of text selection end or the index of the last
	* visible item when scrolling.
	*
	* @param toIndex The index of selection end or last item index.
	*/
	public void setToIndex(int toIndex) {
	enforceNotSealed();
	mToIndex = toIndex;
	}

	/**
	* Gets the scroll offset of the source left edge in pixels.
	*
	* @return The scroll.
	*/
	public int getScrollX() {
	return mScrollX;
	}

	/**
	* Sets the scroll offset of the source left edge in pixels.
	*
	* @param scrollX The scroll.
	*/
	public void setScrollX(int scrollX) {
	enforceNotSealed();
	mScrollX = scrollX;
	}

	/**
	* Gets the scroll offset of the source top edge in pixels.
	*
	* @return The scroll.
	*/
	public int getScrollY() {
	return mScrollY;
	}

	/**
	* Sets the scroll offset of the source top edge in pixels.
	*
	* @param scrollY The scroll.
	*/
	public void setScrollY(int scrollY) {
	enforceNotSealed();
	mScrollY = scrollY;
	}

	/**
	* Gets the max scroll offset of the source left edge in pixels.
	*
	* @return The max scroll.
	*/
	public int getMaxScrollX() {
	return mMaxScrollX;
	}

	/**
	* Sets the max scroll offset of the source left edge in pixels.
	*
	* @param maxScrollX The max scroll.
	*/
	public void setMaxScrollX(int maxScrollX) {
	enforceNotSealed();
	mMaxScrollX = maxScrollX;
	}

	/**
	* Gets the max scroll offset of the source top edge in pixels.
	*
	* @return The max scroll.
	*/
	public int getMaxScrollY() {
	return mMaxScrollY;
	}

	/**
	* Sets the max scroll offset of the source top edge in pixels.
	*
	* @param maxScrollY The max scroll.
	*/
	public void setMaxScrollY(int maxScrollY) {
	enforceNotSealed();
	mMaxScrollY = maxScrollY;
	}

	/**
	* Gets the number of added characters.
	*
	* @return The number of added characters.
	*/
	public int getAddedCount() {
	return mAddedCount;
	}

	/**
	* Sets the number of added characters.
	*
	* @param addedCount The number of added characters.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setAddedCount(int addedCount) {
	enforceNotSealed();
	mAddedCount = addedCount;
	}

	/**
	* Gets the number of removed characters.
	*
	* @return The number of removed characters.
	*/
	public int getRemovedCount() {
	return mRemovedCount;
	}

	/**
	* Sets the number of removed characters.
	*
	* @param removedCount The number of removed characters.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setRemovedCount(int removedCount) {
	enforceNotSealed();
	mRemovedCount = removedCount;
	}

	/**
	* Gets the class name of the source.
	*
	* @return The class name.
	*/
	public CharSequence getClassName() {
	return mClassName;
	}

	/**
	* Sets the class name of the source.
	*
	* @param className The lass name.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setClassName(CharSequence className) {
	enforceNotSealed();
	mClassName = className;
	}

	/**
	* Gets the text of the event. The index in the list represents the priority
	* of the text. Specifically, the lower the index the higher the priority.
	*
	* @return The text.
	*/
	public List<CharSequence> getText() {
	return mText;
	}

	/**
	* Sets the text before a change.
	*
	* @return The text before the change.
	*/
	public CharSequence getBeforeText() {
	return mBeforeText;
	}

	/**
	* Sets the text before a change.
	*
	* @param beforeText The text before the change.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setBeforeText(CharSequence beforeText) {
	enforceNotSealed();
	mBeforeText = beforeText;
	}

	/**
	* Gets the description of the source.
	*
	* @return The description.
	*/
	public CharSequence getContentDescription() {
	return mContentDescription;
	}

	/**
	* Sets the description of the source.
	*
	* @param contentDescription The description.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setContentDescription(CharSequence contentDescription) {
	enforceNotSealed();
	mContentDescription = contentDescription;
	}

	/**
	* Gets the {@link Parcelable} data.
	*
	* @return The parcelable data.
	*/
	public Parcelable getParcelableData() {
	return mParcelableData;
	}

	/**
	* Sets the {@link Parcelable} data of the event.
	*
	* @param parcelableData The parcelable data.
	*
	* @throws IllegalStateException If called from an AccessibilityService.
	*/
	public void setParcelableData(Parcelable parcelableData) {
	enforceNotSealed();
	mParcelableData = parcelableData;
	}

	/**
	* Gets the id of the source node.
	*
	* @return The id.
	*
	* @hide
	*/
	public long getSourceNodeId() {
	return mSourceNodeId;
	}

	/**
	* Sets the unique id of the IAccessibilityServiceConnection over which
	* this instance can send requests to the system.
	*
	* @param connectionId The connection id.
	*
	* @hide
	*/
	public void setConnectionId(int connectionId) {
	enforceNotSealed();
	mConnectionId = connectionId;
	}

	/**
	* Sets if this instance is sealed.
	*
	* @param sealed Whether is sealed.
	*
	* @hide
	*/
	public void setSealed(boolean sealed) {
	mSealed = sealed;
	}

	/**
	* Gets if this instance is sealed.
	*
	* @return Whether is sealed.
	*/
	boolean isSealed() {
	return mSealed;
	}

	/**
	* Enforces that this instance is sealed.
	*
	* @throws IllegalStateException If this instance is not sealed.
	*/
	void enforceSealed() {
	if (!isSealed()) {
	throw new IllegalStateException("Cannot perform this "
	+ "action on a not sealed instance.");
	}
	}

	/**
	* Enforces that this instance is not sealed.
	*
	* @throws IllegalStateException If this instance is sealed.
	*/
	void enforceNotSealed() {
	if (isSealed()) {
	throw new IllegalStateException("Cannot perform this "
	+ "action on a sealed instance.");
	}
	}

	/**
	* Gets the value of a boolean property.
	*
	* @param property The property.
	* @return The value.
	*/
	private boolean getBooleanProperty(int property) {
	return (mBooleanProperties & property) == property;
	}

	/**
	* Sets a boolean property.
	*
	* @param property The property.
	* @param value The value.
	*/
	private void setBooleanProperty(int property, boolean value) {
	if (value) {
	mBooleanProperties \|= property;
	} else {
	mBooleanProperties &= ~property;
	}
	}

	/**
	* Returns a cached instance if such is available or a new one is
	* instantiated. The instance is initialized with data from the
	* given record.
	*
	* @return An instance.
	*/
	public static AccessibilityRecord obtain(AccessibilityRecord record) {
	AccessibilityRecord clone = AccessibilityRecord.obtain();
	clone.init(record);
	return clone;
	}

	/**
	* Returns a cached instance if such is available or a new one is
	* instantiated.
	*
	* @return An instance.
	*/
	public static AccessibilityRecord obtain() {
	synchronized (sPoolLock) {
	if (sPool != null) {
	AccessibilityRecord record = sPool;
	sPool = sPool.mNext;
	sPoolSize--;
	record.mNext = null;
	record.mIsInPool = false;
	return record;
	}
	return new AccessibilityRecord();
	}
	}

	/**
	* Return an instance back to be reused.
	* <p>
	* <strong>Note:</strong> You must not touch the object after calling this function.
	*
	* @throws IllegalStateException If the record is already recycled.
	*/
	public void recycle() {
	if (mIsInPool) {
	throw new IllegalStateException("Record already recycled!");
	}
	clear();
	synchronized (sPoolLock) {
	if (sPoolSize <= MAX_POOL_SIZE) {
	mNext = sPool;
	sPool = this;
	mIsInPool = true;
	sPoolSize++;
	}
	}
	}

	/**
	* Initialize this record from another one.
	*
	* @param record The to initialize from.
	*/
	void init(AccessibilityRecord record) {
	mSealed = record.mSealed;
	mBooleanProperties = record.mBooleanProperties;
	mCurrentItemIndex = record.mCurrentItemIndex;
	mItemCount = record.mItemCount;
	mFromIndex = record.mFromIndex;
	mToIndex = record.mToIndex;
	mScrollX = record.mScrollX;
	mScrollY = record.mScrollY;
	mMaxScrollX = record.mMaxScrollX;
	mMaxScrollY = record.mMaxScrollY;
	mAddedCount = record.mAddedCount;
	mRemovedCount = record.mRemovedCount;
	mClassName = record.mClassName;
	mContentDescription = record.mContentDescription;
	mBeforeText = record.mBeforeText;
	mParcelableData = record.mParcelableData;
	mText.addAll(record.mText);
	mSourceWindowId = record.mSourceWindowId;
	mSourceNodeId = record.mSourceNodeId;
	mConnectionId = record.mConnectionId;
	}

	/**
	* Clears the state of this instance.
	*/
	void clear() {
	mSealed = false;
	mBooleanProperties = 0;
	mCurrentItemIndex = UNDEFINED;
	mItemCount = UNDEFINED;
	mFromIndex = UNDEFINED;
	mToIndex = UNDEFINED;
	mScrollX = UNDEFINED;
	mScrollY = UNDEFINED;
	mMaxScrollX = UNDEFINED;
	mMaxScrollY = UNDEFINED;
	mAddedCount = UNDEFINED;
	mRemovedCount = UNDEFINED;
	mClassName = null;
	mContentDescription = null;
	mBeforeText = null;
	mParcelableData = null;
	mText.clear();
	mSourceNodeId = AccessibilityNodeInfo.makeNodeId(UNDEFINED, UNDEFINED);
	mSourceWindowId = UNDEFINED;
	mConnectionId = UNDEFINED;
	}

	@Override
	public String toString() {
	StringBuilder builder = new StringBuilder();
	builder.append(" [ ClassName: " + mClassName);
	builder.append("; Text: " + mText);
	builder.append("; ContentDescription: " + mContentDescription);
	builder.append("; ItemCount: " + mItemCount);
	builder.append("; CurrentItemIndex: " + mCurrentItemIndex);
	builder.append("; IsEnabled: " + getBooleanProperty(PROPERTY_ENABLED));
	builder.append("; IsPassword: " + getBooleanProperty(PROPERTY_PASSWORD));
	builder.append("; IsChecked: " + getBooleanProperty(PROPERTY_CHECKED));
	builder.append("; IsFullScreen: " + getBooleanProperty(PROPERTY_FULL_SCREEN));
	builder.append("; Scrollable: " + getBooleanProperty(PROPERTY_SCROLLABLE));
	builder.append("; BeforeText: " + mBeforeText);
	builder.append("; FromIndex: " + mFromIndex);
	builder.append("; ToIndex: " + mToIndex);
	builder.append("; ScrollX: " + mScrollX);
	builder.append("; ScrollY: " + mScrollY);
	builder.append("; MaxScrollX: " + mMaxScrollX);
	builder.append("; MaxScrollY: " + mMaxScrollY);
	builder.append("; AddedCount: " + mAddedCount);
	builder.append("; RemovedCount: " + mRemovedCount);
	builder.append("; ParcelableData: " + mParcelableData);
	builder.append(" ]");
	return builder.toString();
	}
	}