/**
 * Determines if the current item is at the edge of a list by checking the
 * scrollable predecessors of the items on either or both sides.
 *
 * @param context The parent context.
 * @param node The node to check.
 * @param direction The direction in which to check, one of:
 *            <ul>
 *            <li>{@code -1} to check backward
 *            <li>{@code 0} to check both backward and forward
 *            <li>{@code 1} to check forward
 *            </ul>
 * @param filter (Optional) Filter used to validate list-type ancestors.
 * @return true if the current item is at the edge of a list.
 */
public static boolean isEdgeListItem(
        Context context, AccessibilityNodeInfoCompat node, int direction, NodeFilter filter) {
    if (node == null) {
        return false;
    }

    if ((direction <= 0) && isMatchingEdgeListItem(context, node,
            NodeFocusFinder.SEARCH_BACKWARD, FILTER_SCROLL_BACKWARD.and(filter))) {
        return true;
    }

    if ((direction >= 0) && isMatchingEdgeListItem(context, node,
            NodeFocusFinder.SEARCH_FORWARD, FILTER_SCROLL_FORWARD.and(filter))) {
        return true;
    }

    return false;
}
 

@Override
protected void onPopulateNodeForVirtualView(
        int virtualViewId, AccessibilityNodeInfoCompat node) {
    if (mVirtualViews == null || mVirtualViews.size() <= virtualViewId) {
        // TODO(clholgat): Remove this work around when the Android bug is fixed.
        // crbug.com/420177
        node.setBoundsInParent(mPlaceHolderRect);
        node.setContentDescription(PLACE_HOLDER_STRING);
        return;
    }
    VirtualView view = mVirtualViews.get(virtualViewId);
    view.getTouchTarget(mTouchTarget);

    node.setBoundsInParent(rectToPx(mTouchTarget));
    node.setContentDescription(view.getAccessibilityDescription());
    node.addAction(AccessibilityNodeInfoCompat.ACTION_CLICK);
    node.addAction(AccessibilityNodeInfoCompat.ACTION_FOCUS);
    node.addAction(AccessibilityNodeInfoCompat.ACTION_LONG_CLICK);
}
 

/**
 * This should really be in AccessibilityNodeInfoCompat, but there unfortunately
 * seem to be a few elements that are not easily cloneable using the underlying API.
 * Leave it private here as it's not general-purpose useful.
 */
private void copyNodeInfoNoChildren(AccessibilityNodeInfoCompat dest,
                                    AccessibilityNodeInfoCompat src) {
    final Rect rect = mTmpRect;

    src.getBoundsInParent(rect);
    dest.setBoundsInParent(rect);

    src.getBoundsInScreen(rect);
    dest.setBoundsInScreen(rect);

    dest.setVisibleToUser(src.isVisibleToUser());
    dest.setPackageName(src.getPackageName());
    dest.setClassName(src.getClassName());
    dest.setContentDescription(src.getContentDescription());

    dest.setEnabled(src.isEnabled());
    dest.setClickable(src.isClickable());
    dest.setFocusable(src.isFocusable());
    dest.setFocused(src.isFocused());
    dest.setAccessibilityFocused(src.isAccessibilityFocused());
    dest.setSelected(src.isSelected());
    dest.setLongClickable(src.isLongClickable());

    dest.addAction(src.getActions());
}
 

private boolean moveFocus(AccessibilityNodeInfoCompat from,
        int direction) {
    int searchDirection = (direction == DIRECTION_BACKWARD)
        ? FocusFinder.SEARCH_BACKWARD
        : FocusFinder.SEARCH_FORWARD;
    AccessibilityNodeInfoCompat next = null;
    next = mFocusFinder.linear(from, searchDirection);
    try {
        if (next != null) {
            return next.performAction(
                    AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS);
        }
    } finally {
        AccessibilityNodeInfoUtils.recycleNodes(next);
    }
    return false;
}
 

private boolean handleIncrementalSearchAction() {
    AccessibilityNodeInfoCompat currentNode = getFocusedNode(true);
    try {
        if (currentNode != null
                && WebInterfaceUtils.hasLegacyWebContent(currentNode)
                && mFeedbackManager.emitOnFailure(
                    WebInterfaceUtils.performSpecialAction(currentNode,
                        ACTION_TOGGLE_INCREMENTAL_SEARCH),
                    FeedbackManager.TYPE_COMMAND_FAILED)) {
            return true;
        }
        return false;
    } finally {
        AccessibilityNodeInfoUtils.recycleNodes(currentNode);
    }
}
 

@Override
public void onInitializeAccessibilityNodeInfoForItem(RecyclerView.Recycler recycler,
        RecyclerView.State state, View host, AccessibilityNodeInfoCompat info) {
    ViewGroup.LayoutParams lp = host.getLayoutParams();
    if (!(lp instanceof LayoutParams)) {
        super.onInitializeAccessibilityNodeInfoForItem(host, info);
        return;
    }
    LayoutParams glp = (LayoutParams) lp;
    int spanGroupIndex = getSpanGroupIndex(recycler, state, glp.getViewPosition());
    if (mOrientation == HORIZONTAL) {
        info.setCollectionItemInfo(AccessibilityNodeInfoCompat.CollectionItemInfoCompat.obtain(
                glp.getSpanIndex(), glp.getSpanSize(),
                spanGroupIndex, 1,
                mSpanCount > 1 && glp.getSpanSize() == mSpanCount, false));
    } else { // VERTICAL
        info.setCollectionItemInfo(AccessibilityNodeInfoCompat.CollectionItemInfoCompat.obtain(
                spanGroupIndex , 1,
                glp.getSpanIndex(), glp.getSpanSize(),
                mSpanCount > 1 && glp.getSpanSize() == mSpanCount, false));
    }
}
 

/**
 * This should really be in AccessibilityNodeInfoCompat, but there unfortunately
 * seem to be a few elements that are not easily cloneable using the underlying API.
 * Leave it private here as it's not general-purpose useful.
 */
private void copyNodeInfoNoChildren(AccessibilityNodeInfoCompat dest,
        AccessibilityNodeInfoCompat src) {
    final Rect rect = mTmpRect;

    src.getBoundsInParent(rect);
    dest.setBoundsInParent(rect);

    src.getBoundsInScreen(rect);
    dest.setBoundsInScreen(rect);

    dest.setVisibleToUser(src.isVisibleToUser());
    dest.setPackageName(src.getPackageName());
    dest.setClassName(src.getClassName());
    dest.setContentDescription(src.getContentDescription());

    dest.setEnabled(src.isEnabled());
    dest.setClickable(src.isClickable());
    dest.setFocusable(src.isFocusable());
    dest.setFocused(src.isFocused());
    dest.setAccessibilityFocused(src.isAccessibilityFocused());
    dest.setSelected(src.isSelected());
    dest.setLongClickable(src.isLongClickable());

    dest.addAction(src.getActions());
}
 

@Override
public void format(Editable result,
        Context context,
        AccessibilityNodeInfoCompat node) {
    boolean empty = (node.getChildCount() == 0);
    int res;
    if (AccessibilityNodeInfoUtils.nodeMatchesClassByType(context, node,
                    GridView.class)) {
        res = empty ? R.string.type_emptygridview : R.string.type_gridview;
    } else if (AccessibilityNodeInfoUtils.nodeMatchesClassByType(
        context, node, ScrollView.class)) {
        res = empty ? R.string.type_emptyscrollview
                : R.string.type_scrollview;
    } else {
        res = empty ? R.string.type_emptylistview : R.string.type_listview;
    }
    result.append(context.getString(res));
}
 

@Override
public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
    final AccessibilityNodeInfoCompat superNode = AccessibilityNodeInfoCompat.obtain(info);
    super.onInitializeAccessibilityNodeInfo(host, superNode);

    info.setSource(host);
    final ViewParent parent = ViewCompat.getParentForAccessibility(host);
    if (parent instanceof View) {
        info.setParent((View) parent);
    }
    copyNodeInfoNoChildren(info, superNode);

    superNode.recycle();

    addChildrenForAccessibility(info, (ViewGroup) host);
}
 

@Override
public boolean performAccessibilityAction(View host, int action, Bundle args) {
    if (super.performAccessibilityAction(host, action, args)) {
        return true;
    }
    switch (action) {
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD: {
            if (canScrollHorizontally(1)) {
                setCurrentItem(mCurItem + 1);
                return true;
            }
        } return false;
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD: {
            if (canScrollHorizontally(-1)) {
                setCurrentItem(mCurItem - 1);
                return true;
            }
        } return false;
    }
    return false;
}
 

@Override
public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
    final AccessibilityNodeInfoCompat superNode = AccessibilityNodeInfoCompat.obtain(info);
    super.onInitializeAccessibilityNodeInfo(host, superNode);

    info.setSource(host);
    final ViewParent parent = ViewCompat.getParentForAccessibility(host);
    if (parent instanceof View) {
        info.setParent((View) parent);
    }
    copyNodeInfoNoChildren(info, superNode);

    superNode.recycle();

    addChildrenForAccessibility(info, (ViewGroup) host);
}
 

@Override
public boolean performAccessibilityAction(View host, int action, Bundle args) {
    if (super.performAccessibilityAction(host, action, args)) {
        return true;
    }
    switch (action) {
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD: {
            if (canScrollHorizontally(1)) {
                setCurrentItem(mCurItem + 1);
                return true;
            }
        } return false;
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD: {
            if (canScrollHorizontally(-1)) {
                setCurrentItem(mCurItem - 1);
                return true;
            }
        } return false;
    }
    return false;
}
 

/**
 * Necessary for accessibility, to ensure we support "scrolling" forward and backward
 * in the circle.
 */
@Override
@SuppressWarnings("deprecation")
public void onInitializeAccessibilityNodeInfo(@NonNull AccessibilityNodeInfo info) {
    super.onInitializeAccessibilityNodeInfo(info);
    if (Build.VERSION.SDK_INT >= 21) {
        info.addAction(AccessibilityNodeInfo.AccessibilityAction.ACTION_SCROLL_BACKWARD);
        info.addAction(AccessibilityNodeInfo.AccessibilityAction.ACTION_SCROLL_FORWARD);
    }
    else if (Build.VERSION.SDK_INT >= 16) {
        info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_FORWARD);
        info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD);
    } else {
        info.addAction(AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD);
        info.addAction(AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD);
    }
}
 

public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
    super.onInitializeAccessibilityNodeInfo(host, info);
    NestedScrollView nsvHost = (NestedScrollView) host;
    info.setClassName(ScrollView.class.getName());
    if (nsvHost.isEnabled()) {
        int scrollRange = nsvHost.getScrollRange();
        if (scrollRange > 0) {
            info.setScrollable(true);
            if (nsvHost.getScrollY() > 0) {
                info.addAction(8192);
            }
            if (nsvHost.getScrollY() < scrollRange) {
                info.addAction(4096);
            }
        }
    }
}
 

public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
    if (DrawerLayout.CAN_HIDE_DESCENDANTS) {
        super.onInitializeAccessibilityNodeInfo(host, info);
    } else {
        AccessibilityNodeInfoCompat superNode = AccessibilityNodeInfoCompat.obtain(info);
        super.onInitializeAccessibilityNodeInfo(host, superNode);
        info.setSource(host);
        ViewParent parent = ViewCompat.getParentForAccessibility(host);
        if (parent instanceof View) {
            info.setParent((View) parent);
        }
        copyNodeInfoNoChildren(info, superNode);
        superNode.recycle();
        addChildrenForAccessibility(info, (ViewGroup) host);
    }
    info.setClassName(DrawerLayout.class.getName());
    info.setFocusable(false);
    info.setFocused(false);
    info.removeAction(AccessibilityActionCompat.ACTION_FOCUS);
    info.removeAction(AccessibilityActionCompat.ACTION_CLEAR_FOCUS);
}
 

/**
 * Returns whether a node is actionable. That is, the node supports one of
 * the following actions:
 * <ul>
 * <li>{@link AccessibilityNodeInfoCompat#isClickable()}
 * <li>{@link AccessibilityNodeInfoCompat#isFocusable()}
 * <li>{@link AccessibilityNodeInfoCompat#isLongClickable()}
 * </ul>
 * This parities the system method View#isActionableForAccessibility(), which
 * was added in JellyBean.
 *
 * @param node The node to examine.
 * @return {@code true} if node is actionable.
 */
public static boolean isActionableForAccessibility(AccessibilityNodeInfoCompat node) {
    if (node == null) {
        return false;
    }

    // Nodes that are clickable are always actionable.
    if (isClickable(node) || isLongClickable(node)) {
        return true;
    }

    if (node.isFocusable()) {
        return true;
    }

    return supportsAnyAction(node, AccessibilityNodeInfoCompat.ACTION_FOCUS,
            AccessibilityNodeInfoCompat.ACTION_NEXT_HTML_ELEMENT,
            AccessibilityNodeInfoCompat.ACTION_PREVIOUS_HTML_ELEMENT);
}
 

private CharSequence getFallbackText(
    Context context,
    AccessibilityNodeInfoCompat node) {
    // Order is important below because of class inheritance.
    if (matchesAny(context, node, Button.class, ImageButton.class)) {
        return context.getString(R.string.type_button);
    }
    if (matchesAny(context, node, QuickContactBadge.class)) {
        return context.getString(R.string.type_quickcontact);
    }
    if (matchesAny(context, node, ImageView.class)) {
        return context.getString(R.string.type_image);
    }
    if (matchesAny(context, node, EditText.class)) {
        return context.getString(R.string.type_edittext);
    }
    if (matchesAny(context, node, AbsSeekBar.class)) {
        return context.getString(R.string.type_seekbar);
    }
    return "";
}
 

@Override
public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
    final AccessibilityNodeInfoCompat superNode = AccessibilityNodeInfoCompat.obtain(info);
    super.onInitializeAccessibilityNodeInfo(host, superNode);

    info.setSource(host);
    final ViewParent parent = ViewCompat.getParentForAccessibility(host);
    if (parent instanceof View) {
        info.setParent((View) parent);
    }
    copyNodeInfoNoChildren(info, superNode);

    superNode.recycle();

    addChildrenForAccessibility(info, (ViewGroup) host);
}
 

/**
 * Returns whether a node matches the class specified by
 * {@code className} and exactly match the text or content description
 * specified by {@code text}.
 */
private static boolean nodeMatchesFilter(Context context, AccessibilityNodeInfoCompat node,
        CharSequence referenceClassName, String findText) {
    final ClassLoadingManager loader = ClassLoadingManager.getInstance();
    final CharSequence nodeClass = node.getClassName();
    final CharSequence nodePackage = node.getPackageName();

    if (!loader.checkInstanceOf(context, nodeClass, nodePackage, referenceClassName)) {
        return false;
    }

    final CharSequence nodeText = node.getText();
    if (TextUtils.equals(findText, nodeText)) {
        return true;
    }

    final CharSequence nodeDesc = node.getContentDescription();
    if (TextUtils.equals(findText, nodeDesc)) {
        return true;
    }

    return false;
}
 

/**
 * This should really be in AccessibilityNodeInfoCompat, but there unfortunately
 * seem to be a few elements that are not easily cloneable using the underlying API.
 * Leave it private here as it's not general-purpose useful.
 */
private void copyNodeInfoNoChildren(AccessibilityNodeInfoCompat dest,
                                    AccessibilityNodeInfoCompat src) {
    final Rect rect = mTmpRect;

    src.getBoundsInParent(rect);
    dest.setBoundsInParent(rect);

    src.getBoundsInScreen(rect);
    dest.setBoundsInScreen(rect);

    dest.setVisibleToUser(src.isVisibleToUser());
    dest.setPackageName(src.getPackageName());
    dest.setClassName(src.getClassName());
    dest.setContentDescription(src.getContentDescription());

    dest.setEnabled(src.isEnabled());
    dest.setClickable(src.isClickable());
    dest.setFocusable(src.isFocusable());
    dest.setFocused(src.isFocused());
    dest.setAccessibilityFocused(src.isAccessibilityFocused());
    dest.setSelected(src.isSelected());
    dest.setLongClickable(src.isLongClickable());

    dest.addAction(src.getActions());
}
 

@Override
public boolean performAccessibilityAction(View host, int action, Bundle args) {
    if (super.performAccessibilityAction(host, action, args)) {
        return true;
    }
    switch (action) {
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD: {
            if (internalCanScrollVertically(1)) {
                setCurrentItem(mCurItem + 1);
                return true;
            }
        }
        return false;
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD: {
            if (internalCanScrollVertically(-1)) {
                setCurrentItem(mCurItem - 1);
                return true;
            }
        }
        return false;
    }
    return false;
}
 

@Override
public boolean performAccessibilityAction(View host, int action, Bundle args) {
    if (super.performAccessibilityAction(host, action, args)) {
        return true;
    }
    switch (action) {
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD: {
            if (canScrollHorizontally(1)) {
                setCurrentItem(mCurItem + 1);
                return true;
            }
        } return false;
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD: {
            if (canScrollHorizontally(-1)) {
                setCurrentItem(mCurItem - 1);
                return true;
            }
        } return false;
    }
    return false;
}
 

@Override
public boolean performAccessibilityAction(View host, int action, Bundle args) {
    if (super.performAccessibilityAction(host, action, args)) {
        return true;
    }
    switch (action) {
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD: {
            if (canScrollHorizontally(1)) {
                setCurrentItem(mCurItem + 1);
                return true;
            }
        } return false;
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD: {
            if (canScrollHorizontally(-1)) {
                setCurrentItem(mCurItem - 1);
                return true;
            }
        } return false;
    }
    return false;
}
 

private static AccessibilityNodeInfoCompat refreshFromChild(
        AccessibilityNodeInfoCompat node) {
    if (node.getChildCount() > 0) {
        AccessibilityNodeInfoCompat firstChild = node.getChild(0);
        if (firstChild != null) {
            AccessibilityNodeInfoCompat parent = firstChild.getParent();
            firstChild.recycle();
            if (node.equals(parent)) {
                return parent;
            } else {
                recycleNodes(parent);
            }
        }
    }
    return null;
}
 

@Override
public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
    super.onInitializeAccessibilityNodeInfo(host, info);
    info.setClassName(ViewPager.class.getName());
    info.setScrollable(canScroll());
    if (canScrollHorizontally(1)) {
        info.addAction(AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD);
    }
    if (canScrollHorizontally(-1)) {
        info.addAction(AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD);
    }
}
 

/**
 * Logs the tree using the input node as the root.
 */
public static void logNodeTree(AccessibilityNodeInfoCompat node) {
    if (node == null) {
        return;
    }

    HashSet<AccessibilityNodeInfoCompat> seen = new HashSet<AccessibilityNodeInfoCompat>();
    logNodeTree(AccessibilityNodeInfoCompat.obtain(node), "", seen);
    for (AccessibilityNodeInfoCompat n : seen) {
        n.recycle();
    }
}
 

@Override
public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
    super.onInitializeAccessibilityNodeInfo(host, info);
    if (!mRecyclerViewDelegate.shouldIgnore()
            && mRecyclerViewDelegate.mRecyclerView.getLayoutManager() != null) {
        mRecyclerViewDelegate.mRecyclerView.getLayoutManager()
                .onInitializeAccessibilityNodeInfoForItem(host, info);
    }
}
 

@Override
public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
    super.onInitializeAccessibilityNodeInfo(host, info);
    info.setClassName(ViewPager.class.getName());
    info.setScrollable(canScroll());
    if (canScrollHorizontally(1)) {
        info.addAction(AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD);
    }
    if (canScrollHorizontally(-1)) {
        info.addAction(AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD);
    }
}
 

/**
 * Returns the result of applying a filter using breadth-first traversal.
 *
 * @param context The parent context.
 * @param node The root node to traverse from.
 * @param filter The filter to satisfy.
 * @return The first node reached via BFS traversal that satisfies the
 *         filter.
 */
public static AccessibilityNodeInfoCompat searchFromBfs(
        Context context, AccessibilityNodeInfoCompat node, NodeFilter filter) {
    if (node == null) {
        return null;
    }

    final LinkedList<AccessibilityNodeInfoCompat> queue =
            new LinkedList<AccessibilityNodeInfoCompat>();

    queue.add(AccessibilityNodeInfoCompat.obtain(node));

    while (!queue.isEmpty()) {
        final AccessibilityNodeInfoCompat item = queue.removeFirst();

        if (filter.accept(context, item)) {
            return AccessibilityNodeInfoCompat.obtain(item);
        }

        final int childCount = item.getChildCount();

        for (int i = 0; i < childCount; i++) {
            final AccessibilityNodeInfoCompat child = item.getChild(i);

            if (child != null) {
                queue.addLast(child);
            }
        }
    }

    return null;
}
 

private void addChildrenForAccessibility(AccessibilityNodeInfoCompat info, ViewGroup v) {
    final int childCount = v.getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = v.getChildAt(i);
        if (filter(child)) {
            continue;
        }

        // Adding children that are marked as not important for
        // accessibility will break the hierarchy, so we need to check
        // that value and re-parent views if necessary.
        final int importance = ViewCompat.getImportantForAccessibility(child);
        switch (importance) {
            case ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS:
                // Always skip NO_HIDE views and their descendants.
                break;
            case ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO:
                // Re-parent children of NO view groups, skip NO views.
                if (child instanceof ViewGroup) {
                    addChildrenForAccessibility(info, (ViewGroup) child);
                }
                break;
            case ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_AUTO:
                // Force AUTO views to YES and add them.
                ViewCompat.setImportantForAccessibility(
                        child, ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_YES);
            case ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_YES:
                info.addChild(child);
                break;
        }
    }
}