root/content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java

DEFINITIONS

1. JNINamespace
2. create
3. onNativeObjectDestroyed
4. getAccessibilityNodeProvider
5. createAccessibilityNodeInfo
6. findAccessibilityNodeInfosByText
7. performAction
8. onHoverEvent
9. notifyFrameInfoInitialized
10. jumpToElementType
11. sendAccessibilityEvent
12. getOrCreateBundleForAccessibilityEvent
13. createNodeForHost
14. handlePageLoaded
15. handleFocusChanged
16. handleCheckStateChanged
17. handleTextSelectionChanged
18. handleEditableTextChanged
19. handleContentChanged
20. handleNavigate
21. handleScrollPositionChanged
22. handleScrolledToAnchor
23. announceLiveRegionText
24. setAccessibilityNodeInfoParent
25. addAccessibilityNodeInfoChild
26. setAccessibilityNodeInfoBooleanAttributes
27. setAccessibilityNodeInfoClassName
28. setAccessibilityNodeInfoContentDescription
29. setAccessibilityNodeInfoLocation
30. setAccessibilityNodeInfoKitKatAttributes
31. setAccessibilityNodeInfoCollectionInfo
32. setAccessibilityNodeInfoCollectionItemInfo
33. setAccessibilityNodeInfoRangeInfo
34. setAccessibilityEventBooleanAttributes
35. setAccessibilityEventClassName
36. setAccessibilityEventListAttributes
37. setAccessibilityEventScrollAttributes
38. setAccessibilityEventTextChangedAttrs
39. setAccessibilityEventSelectionAttrs
40. setAccessibilityEventKitKatAttributes
41. setAccessibilityEventCollectionInfo
42. setAccessibilityEventCollectionItemInfo
43. setAccessibilityEventRangeInfo
44. nativeGetRootId
45. nativeIsNodeValid
46. nativeHitTest
47. nativePopulateAccessibilityNodeInfo
48. nativePopulateAccessibilityEvent
49. nativeClick
50. nativeFocus
51. nativeBlur
52. nativeScrollToMakeNodeVisible
53. nativeFindElementType

// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package org.chromium.content.browser.accessibility;

import android.content.Context;
import android.graphics.Rect;
import android.os.Build;
import android.os.Bundle;
import android.text.SpannableString;
import android.text.style.URLSpan;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewParent;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityManager;
import android.view.accessibility.AccessibilityNodeInfo;
import android.view.accessibility.AccessibilityNodeProvider;

import org.chromium.base.CalledByNative;
import org.chromium.base.JNINamespace;
import org.chromium.content.browser.ContentViewCore;
import org.chromium.content.browser.RenderCoordinates;

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

/**
 * Native accessibility for a {@link ContentViewCore}.
 *
 * This class is safe to load on ICS and can be used to run tests, but
 * only the subclass, JellyBeanBrowserAccessibilityManager, actually
 * has a AccessibilityNodeProvider implementation needed for native
 * accessibility.
 */
@JNINamespace("content")
public class BrowserAccessibilityManager {
    private static final String TAG = "BrowserAccessibilityManager";

    private ContentViewCore mContentViewCore;
    private final AccessibilityManager mAccessibilityManager;
    private final RenderCoordinates mRenderCoordinates;
    private long mNativeObj;
    private int mAccessibilityFocusId;
    private boolean mIsHovering;
    private int mCurrentRootId;
    private final int[] mTempLocation = new int[2];
    private final View mView;
    private boolean mUserHasTouchExplored;
    private boolean mPendingScrollToMakeNodeVisible;
    private boolean mFrameInfoInitialized;

    /**
     * Create a BrowserAccessibilityManager object, which is owned by the C++
     * BrowserAccessibilityManagerAndroid instance, and connects to the content view.
     * @param nativeBrowserAccessibilityManagerAndroid A pointer to the counterpart native
     *     C++ object that owns this object.
     * @param contentViewCore The content view that this object provides accessibility for.
     */
    @CalledByNative
    private static BrowserAccessibilityManager create(long nativeBrowserAccessibilityManagerAndroid,
            ContentViewCore contentViewCore) {
        // A bug in the KitKat framework prevents us from using these new APIs.
        // http://crbug.com/348088/
        // if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        //     return new KitKatBrowserAccessibilityManager(
        //             nativeBrowserAccessibilityManagerAndroid, contentViewCore);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
            return new JellyBeanBrowserAccessibilityManager(
                    nativeBrowserAccessibilityManagerAndroid, contentViewCore);
        } else {
            return new BrowserAccessibilityManager(
                    nativeBrowserAccessibilityManagerAndroid, contentViewCore);
        }
    }

    protected BrowserAccessibilityManager(long nativeBrowserAccessibilityManagerAndroid,
            ContentViewCore contentViewCore) {
        mNativeObj = nativeBrowserAccessibilityManagerAndroid;
        mContentViewCore = contentViewCore;
        mContentViewCore.setBrowserAccessibilityManager(this);
        mAccessibilityFocusId = View.NO_ID;
        mIsHovering = false;
        mCurrentRootId = View.NO_ID;
        mView = mContentViewCore.getContainerView();
        mRenderCoordinates = mContentViewCore.getRenderCoordinates();
        mAccessibilityManager =
            (AccessibilityManager) mContentViewCore.getContext()
            .getSystemService(Context.ACCESSIBILITY_SERVICE);
    }

    @CalledByNative
    private void onNativeObjectDestroyed() {
        if (mContentViewCore.getBrowserAccessibilityManager() == this) {
            mContentViewCore.setBrowserAccessibilityManager(null);
        }
        mNativeObj = 0;
        mContentViewCore = null;
    }

    /**
     * @return An AccessibilityNodeProvider on JellyBean, and null on previous versions.
     */
    public AccessibilityNodeProvider getAccessibilityNodeProvider() {
        return null;
    }

    /**
     * @see AccessibilityNodeProvider#createAccessibilityNodeInfo(int)
     */
    protected AccessibilityNodeInfo createAccessibilityNodeInfo(int virtualViewId) {
        if (!mAccessibilityManager.isEnabled() || mNativeObj == 0) {
            return null;
        }

        int rootId = nativeGetRootId(mNativeObj);

        if (virtualViewId == View.NO_ID) {
            return createNodeForHost(rootId);
        }

        if (!mFrameInfoInitialized) {
            return null;
        }

        final AccessibilityNodeInfo info = AccessibilityNodeInfo.obtain(mView);
        info.setPackageName(mContentViewCore.getContext().getPackageName());
        info.setSource(mView, virtualViewId);

        if (virtualViewId == rootId) {
            info.setParent(mView);
        }

        if (nativePopulateAccessibilityNodeInfo(mNativeObj, info, virtualViewId)) {
            return info;
        } else {
            info.recycle();
            return null;
        }
    }

    /**
     * @see AccessibilityNodeProvider#findAccessibilityNodeInfosByText(String, int)
     */
    protected List<AccessibilityNodeInfo> findAccessibilityNodeInfosByText(String text,
            int virtualViewId) {
        return new ArrayList<AccessibilityNodeInfo>();
    }

    /**
     * @see AccessibilityNodeProvider#performAction(int, int, Bundle)
     */
    protected boolean performAction(int virtualViewId, int action, Bundle arguments) {
        // We don't support any actions on the host view or nodes
        // that are not (any longer) in the tree.
        if (!mAccessibilityManager.isEnabled() || mNativeObj == 0
                || !nativeIsNodeValid(mNativeObj, virtualViewId)) {
            return false;
        }

        switch (action) {
            case AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS:
                if (mAccessibilityFocusId == virtualViewId) {
                    return true;
                }

                mAccessibilityFocusId = virtualViewId;
                sendAccessibilityEvent(mAccessibilityFocusId,
                        AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
                if (!mIsHovering) {
                    nativeScrollToMakeNodeVisible(
                            mNativeObj, mAccessibilityFocusId);
                } else {
                    mPendingScrollToMakeNodeVisible = true;
                }
                return true;
            case AccessibilityNodeInfo.ACTION_CLEAR_ACCESSIBILITY_FOCUS:
                if (mAccessibilityFocusId == virtualViewId) {
                    sendAccessibilityEvent(mAccessibilityFocusId,
                            AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED);
                    mAccessibilityFocusId = View.NO_ID;
                }
                return true;
            case AccessibilityNodeInfo.ACTION_CLICK:
                nativeClick(mNativeObj, virtualViewId);
                sendAccessibilityEvent(virtualViewId,
                        AccessibilityEvent.TYPE_VIEW_CLICKED);
                return true;
            case AccessibilityNodeInfo.ACTION_FOCUS:
                nativeFocus(mNativeObj, virtualViewId);
                return true;
            case AccessibilityNodeInfo.ACTION_CLEAR_FOCUS:
                nativeBlur(mNativeObj);
                return true;

            case AccessibilityNodeInfo.ACTION_NEXT_HTML_ELEMENT: {
                if (arguments == null)
                    return false;
                String elementType = arguments.getString(
                    AccessibilityNodeInfo.ACTION_ARGUMENT_HTML_ELEMENT_STRING);
                if (elementType == null)
                    return false;
                elementType = elementType.toUpperCase(Locale.US);
                return jumpToElementType(elementType, true);
            }
            case AccessibilityNodeInfo.ACTION_PREVIOUS_HTML_ELEMENT: {
                if (arguments == null)
                    return false;
                String elementType = arguments.getString(
                    AccessibilityNodeInfo.ACTION_ARGUMENT_HTML_ELEMENT_STRING);
                if (elementType == null)
                    return false;
                elementType = elementType.toUpperCase(Locale.US);
                return jumpToElementType(elementType, false);
            }

            default:
                break;
        }
        return false;
    }

    /**
     * @see View#onHoverEvent(MotionEvent)
     */
    public boolean onHoverEvent(MotionEvent event) {
        if (!mAccessibilityManager.isEnabled() || mNativeObj == 0) {
            return false;
        }

        if (event.getAction() == MotionEvent.ACTION_HOVER_EXIT) {
            mIsHovering = false;
            if (mPendingScrollToMakeNodeVisible) {
                nativeScrollToMakeNodeVisible(
                        mNativeObj, mAccessibilityFocusId);
            }
            mPendingScrollToMakeNodeVisible = false;
            return true;
        }

        mIsHovering = true;
        mUserHasTouchExplored = true;
        float x = event.getX();
        float y = event.getY();

        // Convert to CSS coordinates.
        int cssX = (int) (mRenderCoordinates.fromPixToLocalCss(x) +
                          mRenderCoordinates.getScrollX());
        int cssY = (int) (mRenderCoordinates.fromPixToLocalCss(y) +
                          mRenderCoordinates.getScrollY());
        int id = nativeHitTest(mNativeObj, cssX, cssY);
        if (mAccessibilityFocusId != id) {
            sendAccessibilityEvent(mAccessibilityFocusId, AccessibilityEvent.TYPE_VIEW_HOVER_EXIT);
            sendAccessibilityEvent(id, AccessibilityEvent.TYPE_VIEW_HOVER_ENTER);
        }

        return true;
    }

    /**
     * Called by ContentViewCore to notify us when the frame info is initialized,
     * the first time, since until that point, we can't use mRenderCoordinates to transform
     * web coordinates to screen coordinates.
     */
    public void notifyFrameInfoInitialized() {
        if (mFrameInfoInitialized) return;

        mFrameInfoInitialized = true;
        // Invalidate the host, since the chrome accessibility tree is now
        // ready and listed as the child of the host.
        mView.sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED);

        // (Re-) focus focused element, since we weren't able to create an
        // AccessibilityNodeInfo for this element before.
        if (mAccessibilityFocusId != View.NO_ID) {
            sendAccessibilityEvent(mAccessibilityFocusId,
                                   AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
        }
    }

    private boolean jumpToElementType(String elementType, boolean forwards) {
        int id = nativeFindElementType(mNativeObj, mAccessibilityFocusId, elementType, forwards);
        if (id == 0)
            return false;

        mAccessibilityFocusId = id;
        sendAccessibilityEvent(id, AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
        return true;
    }

    private void sendAccessibilityEvent(int virtualViewId, int eventType) {
        // If mFrameInfoInitialized is false, then the virtual hierarchy
        // doesn't exist in the view of the Android framework, so should
        // never send any events.
        if (!mAccessibilityManager.isEnabled() || mNativeObj == 0
                || !mFrameInfoInitialized) {
            return;
        }

        final AccessibilityEvent event = AccessibilityEvent.obtain(eventType);
        event.setPackageName(mContentViewCore.getContext().getPackageName());
        event.setSource(mView, virtualViewId);
        if (!nativePopulateAccessibilityEvent(mNativeObj, event, virtualViewId, eventType)) {
            event.recycle();
            return;
        }

        // This is currently needed if we want Android to draw the yellow box around
        // the item that has accessibility focus. In practice, this doesn't seem to slow
        // things down, because it's only called when the accessibility focus moves.
        // TODO(dmazzoni): remove this if/when Android framework fixes bug.
        mContentViewCore.getContainerView().postInvalidate();

        mContentViewCore.getContainerView().requestSendAccessibilityEvent(mView, event);
    }

    private Bundle getOrCreateBundleForAccessibilityEvent(AccessibilityEvent event) {
        Bundle bundle = (Bundle) event.getParcelableData();
        if (bundle == null) {
            bundle = new Bundle();
            event.setParcelableData(bundle);
        }
        return bundle;
    }

    private AccessibilityNodeInfo createNodeForHost(int rootId) {
        // Since we don't want the parent to be focusable, but we can't remove
        // actions from a node, copy over the necessary fields.
        final AccessibilityNodeInfo result = AccessibilityNodeInfo.obtain(mView);
        final AccessibilityNodeInfo source = AccessibilityNodeInfo.obtain(mView);
        mView.onInitializeAccessibilityNodeInfo(source);

        // Copy over parent and screen bounds.
        Rect rect = new Rect();
        source.getBoundsInParent(rect);
        result.setBoundsInParent(rect);
        source.getBoundsInScreen(rect);
        result.setBoundsInScreen(rect);

        // Set up the parent view, if applicable.
        final ViewParent parent = mView.getParentForAccessibility();
        if (parent instanceof View) {
            result.setParent((View) parent);
        }

        // Populate the minimum required fields.
        result.setVisibleToUser(source.isVisibleToUser());
        result.setEnabled(source.isEnabled());
        result.setPackageName(source.getPackageName());
        result.setClassName(source.getClassName());

        // Add the Chrome root node.
        if (mFrameInfoInitialized) {
            result.addChild(mView, rootId);
        }

        return result;
    }

    @CalledByNative
    private void handlePageLoaded(int id) {
        if (mUserHasTouchExplored) return;

        mAccessibilityFocusId = id;
        sendAccessibilityEvent(id, AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
    }

    @CalledByNative
    private void handleFocusChanged(int id) {
        sendAccessibilityEvent(id, AccessibilityEvent.TYPE_VIEW_FOCUSED);

        // Update accessibility focus if not already set to this node.
        if (mAccessibilityFocusId != id) {
            sendAccessibilityEvent(id, AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
            mAccessibilityFocusId = id;
        }
    }

    @CalledByNative
    private void handleCheckStateChanged(int id) {
        sendAccessibilityEvent(id, AccessibilityEvent.TYPE_VIEW_CLICKED);
    }

    @CalledByNative
    private void handleTextSelectionChanged(int id) {
        sendAccessibilityEvent(id, AccessibilityEvent.TYPE_VIEW_TEXT_SELECTION_CHANGED);
    }

    @CalledByNative
    private void handleEditableTextChanged(int id) {
        sendAccessibilityEvent(id, AccessibilityEvent.TYPE_VIEW_TEXT_CHANGED);
    }

    @CalledByNative
    private void handleContentChanged(int id) {
        int rootId = nativeGetRootId(mNativeObj);
        if (rootId != mCurrentRootId) {
            mCurrentRootId = rootId;
            mView.sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED);
        } else {
            sendAccessibilityEvent(id, AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED);
        }
    }

    @CalledByNative
    private void handleNavigate() {
        mAccessibilityFocusId = View.NO_ID;
        mUserHasTouchExplored = false;
        mFrameInfoInitialized = false;
        // Invalidate the host, since its child is now gone.
        mView.sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED);
    }

    @CalledByNative
    private void handleScrollPositionChanged(int id) {
        sendAccessibilityEvent(id, AccessibilityEvent.TYPE_VIEW_SCROLLED);
    }

    @CalledByNative
    private void handleScrolledToAnchor(int id) {
        if (mAccessibilityFocusId == id) {
            return;
        }

        mAccessibilityFocusId = id;
        sendAccessibilityEvent(id, AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
    }

    @CalledByNative
    private void announceLiveRegionText(String text) {
        mView.announceForAccessibility(text);
    }

    @CalledByNative
    private void setAccessibilityNodeInfoParent(AccessibilityNodeInfo node, int parentId) {
        node.setParent(mView, parentId);
    }

    @CalledByNative
    private void addAccessibilityNodeInfoChild(AccessibilityNodeInfo node, int childId) {
        node.addChild(mView, childId);
    }

    @CalledByNative
    private void setAccessibilityNodeInfoBooleanAttributes(AccessibilityNodeInfo node,
            int virtualViewId, boolean checkable, boolean checked, boolean clickable,
            boolean enabled, boolean focusable, boolean focused, boolean password,
            boolean scrollable, boolean selected, boolean visibleToUser) {
        node.setCheckable(checkable);
        node.setChecked(checked);
        node.setClickable(clickable);
        node.setEnabled(enabled);
        node.setFocusable(focusable);
        node.setFocused(focused);
        node.setPassword(password);
        node.setScrollable(scrollable);
        node.setSelected(selected);
        node.setVisibleToUser(visibleToUser);

        node.addAction(AccessibilityNodeInfo.ACTION_NEXT_HTML_ELEMENT);
        node.addAction(AccessibilityNodeInfo.ACTION_PREVIOUS_HTML_ELEMENT);

        if (focusable) {
            if (focused) {
                node.addAction(AccessibilityNodeInfo.ACTION_CLEAR_FOCUS);
            } else {
                node.addAction(AccessibilityNodeInfo.ACTION_FOCUS);
            }
        }

        if (mAccessibilityFocusId == virtualViewId) {
            node.setAccessibilityFocused(true);
            node.addAction(AccessibilityNodeInfo.ACTION_CLEAR_ACCESSIBILITY_FOCUS);
        } else {
            node.setAccessibilityFocused(false);
            node.addAction(AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS);
        }

        if (clickable) {
            node.addAction(AccessibilityNodeInfo.ACTION_CLICK);
        }
    }

    @CalledByNative
    private void setAccessibilityNodeInfoClassName(AccessibilityNodeInfo node,
            String className) {
        node.setClassName(className);
    }

    @CalledByNative
    private void setAccessibilityNodeInfoContentDescription(
            AccessibilityNodeInfo node, String contentDescription, boolean annotateAsLink) {
        if (annotateAsLink) {
            SpannableString spannable = new SpannableString(contentDescription);
            spannable.setSpan(new URLSpan(""), 0, spannable.length(), 0);
            node.setContentDescription(spannable);
        } else {
            node.setContentDescription(contentDescription);
        }
    }

    @CalledByNative
    private void setAccessibilityNodeInfoLocation(AccessibilityNodeInfo node,
            int absoluteLeft, int absoluteTop, int parentRelativeLeft, int parentRelativeTop,
            int width, int height, boolean isRootNode) {
        // First set the bounds in parent.
        Rect boundsInParent = new Rect(parentRelativeLeft, parentRelativeTop,
                parentRelativeLeft + width, parentRelativeTop + height);
        if (isRootNode) {
            // Offset of the web content relative to the View.
            boundsInParent.offset(0, (int) mRenderCoordinates.getContentOffsetYPix());
        }
        node.setBoundsInParent(boundsInParent);

        // Now set the absolute rect, which requires several transformations.
        Rect rect = new Rect(absoluteLeft, absoluteTop, absoluteLeft + width, absoluteTop + height);

        // Offset by the scroll position.
        rect.offset(-(int) mRenderCoordinates.getScrollX(),
                    -(int) mRenderCoordinates.getScrollY());

        // Convert CSS (web) pixels to Android View pixels
        rect.left = (int) mRenderCoordinates.fromLocalCssToPix(rect.left);
        rect.top = (int) mRenderCoordinates.fromLocalCssToPix(rect.top);
        rect.bottom = (int) mRenderCoordinates.fromLocalCssToPix(rect.bottom);
        rect.right = (int) mRenderCoordinates.fromLocalCssToPix(rect.right);

        // Offset by the location of the web content within the view.
        rect.offset(0,
                    (int) mRenderCoordinates.getContentOffsetYPix());

        // Finally offset by the location of the view within the screen.
        final int[] viewLocation = new int[2];
        mView.getLocationOnScreen(viewLocation);
        rect.offset(viewLocation[0], viewLocation[1]);

        node.setBoundsInScreen(rect);
    }

    @CalledByNative
    protected void setAccessibilityNodeInfoKitKatAttributes(AccessibilityNodeInfo node,
            boolean canOpenPopup,
            boolean contentInvalid,
            boolean dismissable,
            boolean multiLine,
            int inputType,
            int liveRegion) {
        // Requires KitKat or higher.
    }

    @CalledByNative
    protected void setAccessibilityNodeInfoCollectionInfo(AccessibilityNodeInfo node,
            int rowCount, int columnCount, boolean hierarchical) {
        // Requires KitKat or higher.
    }

    @CalledByNative
    protected void setAccessibilityNodeInfoCollectionItemInfo(AccessibilityNodeInfo node,
            int rowIndex, int rowSpan, int columnIndex, int columnSpan, boolean heading) {
        // Requires KitKat or higher.
    }

    @CalledByNative
    protected void setAccessibilityNodeInfoRangeInfo(AccessibilityNodeInfo node,
            int rangeType, float min, float max, float current) {
        // Requires KitKat or higher.
    }

    @CalledByNative
    private void setAccessibilityEventBooleanAttributes(AccessibilityEvent event,
            boolean checked, boolean enabled, boolean password, boolean scrollable) {
        event.setChecked(checked);
        event.setEnabled(enabled);
        event.setPassword(password);
        event.setScrollable(scrollable);
    }

    @CalledByNative
    private void setAccessibilityEventClassName(AccessibilityEvent event, String className) {
        event.setClassName(className);
    }

    @CalledByNative
    private void setAccessibilityEventListAttributes(AccessibilityEvent event,
            int currentItemIndex, int itemCount) {
        event.setCurrentItemIndex(currentItemIndex);
        event.setItemCount(itemCount);
    }

    @CalledByNative
    private void setAccessibilityEventScrollAttributes(AccessibilityEvent event,
            int scrollX, int scrollY, int maxScrollX, int maxScrollY) {
        event.setScrollX(scrollX);
        event.setScrollY(scrollY);
        event.setMaxScrollX(maxScrollX);
        event.setMaxScrollY(maxScrollY);
    }

    @CalledByNative
    private void setAccessibilityEventTextChangedAttrs(AccessibilityEvent event,
            int fromIndex, int addedCount, int removedCount, String beforeText, String text) {
        event.setFromIndex(fromIndex);
        event.setAddedCount(addedCount);
        event.setRemovedCount(removedCount);
        event.setBeforeText(beforeText);
        event.getText().add(text);
    }

    @CalledByNative
    private void setAccessibilityEventSelectionAttrs(AccessibilityEvent event,
            int fromIndex, int addedCount, int itemCount, String text) {
        event.setFromIndex(fromIndex);
        event.setAddedCount(addedCount);
        event.setItemCount(itemCount);
        event.getText().add(text);
    }

    @CalledByNative
    protected void setAccessibilityEventKitKatAttributes(AccessibilityEvent event,
            boolean canOpenPopup,
            boolean contentInvalid,
            boolean dismissable,
            boolean multiLine,
            int inputType,
            int liveRegion) {
        // Backwards compatibility for KitKat AccessibilityNodeInfo fields.
        Bundle bundle = getOrCreateBundleForAccessibilityEvent(event);
        bundle.putBoolean("AccessibilityNodeInfo.canOpenPopup", canOpenPopup);
        bundle.putBoolean("AccessibilityNodeInfo.contentInvalid", contentInvalid);
        bundle.putBoolean("AccessibilityNodeInfo.dismissable", dismissable);
        bundle.putBoolean("AccessibilityNodeInfo.multiLine", multiLine);
        bundle.putInt("AccessibilityNodeInfo.inputType", inputType);
        bundle.putInt("AccessibilityNodeInfo.liveRegion", liveRegion);
    }

    @CalledByNative
    protected void setAccessibilityEventCollectionInfo(AccessibilityEvent event,
            int rowCount, int columnCount, boolean hierarchical) {
        // Backwards compatibility for KitKat AccessibilityNodeInfo fields.
        Bundle bundle = getOrCreateBundleForAccessibilityEvent(event);
        bundle.putInt("AccessibilityNodeInfo.CollectionInfo.rowCount", rowCount);
        bundle.putInt("AccessibilityNodeInfo.CollectionInfo.columnCount", columnCount);
        bundle.putBoolean("AccessibilityNodeInfo.CollectionInfo.hierarchical", hierarchical);
    }

    @CalledByNative
    protected void setAccessibilityEventCollectionItemInfo(AccessibilityEvent event,
            int rowIndex, int rowSpan, int columnIndex, int columnSpan, boolean heading) {
        // Backwards compatibility for KitKat AccessibilityNodeInfo fields.
        Bundle bundle = getOrCreateBundleForAccessibilityEvent(event);
        bundle.putInt("AccessibilityNodeInfo.CollectionItemInfo.rowIndex", rowIndex);
        bundle.putInt("AccessibilityNodeInfo.CollectionItemInfo.rowSpan", rowSpan);
        bundle.putInt("AccessibilityNodeInfo.CollectionItemInfo.columnIndex", columnIndex);
        bundle.putInt("AccessibilityNodeInfo.CollectionItemInfo.columnSpan", columnSpan);
        bundle.putBoolean("AccessibilityNodeInfo.CollectionItemInfo.heading", heading);
    }

    @CalledByNative
    protected void setAccessibilityEventRangeInfo(AccessibilityEvent event,
            int rangeType, float min, float max, float current) {
        // Backwards compatibility for KitKat AccessibilityNodeInfo fields.
        Bundle bundle = getOrCreateBundleForAccessibilityEvent(event);
        bundle.putInt("AccessibilityNodeInfo.RangeInfo.type", rangeType);
        bundle.putFloat("AccessibilityNodeInfo.RangeInfo.min", min);
        bundle.putFloat("AccessibilityNodeInfo.RangeInfo.max", max);
        bundle.putFloat("AccessibilityNodeInfo.RangeInfo.current", current);
    }

    private native int nativeGetRootId(long nativeBrowserAccessibilityManagerAndroid);
    private native boolean nativeIsNodeValid(long nativeBrowserAccessibilityManagerAndroid, int id);
    private native int nativeHitTest(long nativeBrowserAccessibilityManagerAndroid, int x, int y);
    private native boolean nativePopulateAccessibilityNodeInfo(
        long nativeBrowserAccessibilityManagerAndroid, AccessibilityNodeInfo info, int id);
    private native boolean nativePopulateAccessibilityEvent(
        long nativeBrowserAccessibilityManagerAndroid, AccessibilityEvent event, int id,
        int eventType);
    private native void nativeClick(long nativeBrowserAccessibilityManagerAndroid, int id);
    private native void nativeFocus(long nativeBrowserAccessibilityManagerAndroid, int id);
    private native void nativeBlur(long nativeBrowserAccessibilityManagerAndroid);
    private native void nativeScrollToMakeNodeVisible(
            long nativeBrowserAccessibilityManagerAndroid, int id);
    private native int nativeFindElementType(long nativeBrowserAccessibilityManagerAndroid,
            int startId, String elementType, boolean forwards);
}