Adjust talkback focus rect to stay within viewport size

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

 // 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.annotation.SuppressLint;
 import android.content.Context;
 import android.graphics.Rect;
 import android.os.Build;
@@ skipping 812 matching lines @@
 
         // 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]);
 
+        // Clip the node's bounding rect to the viewport bounds.
+        int viewportRectTop = viewLocation[1] + (int) mRenderCoordinates.getContentOffsetYPix();
+        int viewportRectBottom = viewportRectTop + mContentViewCore.getViewportHeightPix();
+        if (rect.top < viewportRectTop) rect.top = viewportRectTop;
+        if (rect.bottom > viewportRectBottom) rect.bottom = viewportRectBottom;
+
         node.setBoundsInScreen(rect);
 
         // Work around a bug in the Android framework where if the object with accessibility
         // focus moves, the accessibility focus rect is not updated - both the visual highlight,
         // and the location on the screen that's clicked if you double-tap. To work around this,
         // when we know the object with accessibility focus moved, move focus away and then
         // move focus right back to it, which tricks Android into updating its bounds.
         if (virtualViewId == mAccessibilityFocusId && virtualViewId != mCurrentRootId) {
             if (mAccessibilityFocusRect == null) {
                 mAccessibilityFocusRect = rect;
@@ skipping 185 matching lines @@
             int selectionGranularity, boolean extendSelection, int id, int cursorIndex);
     private native boolean nativeAdjustSlider(
             long nativeBrowserAccessibilityManagerAndroid, int id, boolean increment);
     private native void nativeSetAccessibilityFocus(
             long nativeBrowserAccessibilityManagerAndroid, int id);
     private native boolean nativeIsSlider(
             long nativeBrowserAccessibilityManagerAndroid, int id);
     private native boolean nativeScroll(
             long nativeBrowserAccessibilityManagerAndroid, int id, int direction);
 }