Fix ViewRootImpl handling of content changes, fix ViewPager parenting

Previously content changes were only handled if they came directly from
the focused host, which meant that changes that occurred higher in the
tree were ignored. As a result, scrolling in ViewPager that contained
virtual nodes would fail to update the focus position.

Change-Id: I028bd8c670f1210339da331626e1986c5b5d4b87
diff --git a/core/java/com/android/internal/widget/ViewPager.java b/core/java/com/android/internal/widget/ViewPager.java
index 8018942..8d66191 100644
--- a/core/java/com/android/internal/widget/ViewPager.java
+++ b/core/java/com/android/internal/widget/ViewPager.java
@@ -42,6 +42,7 @@
 import android.view.ViewParent;
 import android.view.accessibility.AccessibilityEvent;
 import android.view.accessibility.AccessibilityNodeInfo;
+import android.view.accessibility.AccessibilityNodeInfo.AccessibilityAction;
 import android.view.accessibility.AccessibilityRecord;
 import android.view.animation.Interpolator;
 import android.widget.EdgeEffect;
@@ -371,8 +372,6 @@
         mCloseEnough = (int) (CLOSE_ENOUGH * density);
         mDefaultGutterSize = (int) (DEFAULT_GUTTER_SIZE * density);
 
-        setAccessibilityDelegate(new MyAccessibilityDelegate());
-
         if (getImportantForAccessibility() == IMPORTANT_FOR_ACCESSIBILITY_AUTO) {
             setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_YES);
         }
@@ -2695,29 +2694,6 @@
     }
 
     @Override
-    public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) {
-        // Dispatch scroll events from this ViewPager.
-        if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_SCROLLED) {
-            return super.dispatchPopulateAccessibilityEvent(event);
-        }
-
-        // Dispatch all other accessibility events from the current page.
-        final int childCount = getChildCount();
-        for (int i = 0; i < childCount; i++) {
-            final View child = getChildAt(i);
-            if (child.getVisibility() == VISIBLE) {
-                final ItemInfo ii = infoForChild(child);
-                if (ii != null && ii.position == mCurItem &&
-                        child.dispatchPopulateAccessibilityEvent(event)) {
-                    return true;
-                }
-            }
-        }
-
-        return false;
-    }
-
-    @Override
     protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
         return new LayoutParams();
     }
@@ -2737,60 +2713,63 @@
         return new LayoutParams(getContext(), attrs);
     }
 
-    class MyAccessibilityDelegate extends AccessibilityDelegate {
 
-        @Override
-        public void onInitializeAccessibilityEvent(View host, AccessibilityEvent event) {
-            super.onInitializeAccessibilityEvent(host, event);
-            event.setClassName(ViewPager.class.getName());
-            final AccessibilityRecord record = AccessibilityRecord.obtain();
-            record.setScrollable(canScroll());
-            if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_SCROLLED
-                    && mAdapter != null) {
-                record.setItemCount(mAdapter.getCount());
-                record.setFromIndex(mCurItem);
-                record.setToIndex(mCurItem);
-            }
+    @Override
+    public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
+        super.onInitializeAccessibilityEvent(event);
+
+        event.setClassName(ViewPager.class.getName());
+        event.setScrollable(canScroll());
+
+        if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_SCROLLED && mAdapter != null) {
+            event.setItemCount(mAdapter.getCount());
+            event.setFromIndex(mCurItem);
+            event.setToIndex(mCurItem);
+        }
+    }
+
+    @Override
+    public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
+        super.onInitializeAccessibilityNodeInfo(info);
+
+        info.setClassName(ViewPager.class.getName());
+        info.setScrollable(canScroll());
+
+        if (canScrollHorizontally(1)) {
+            info.addAction(AccessibilityAction.ACTION_SCROLL_FORWARD);
         }
 
-        @Override
-        public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) {
-            super.onInitializeAccessibilityNodeInfo(host, info);
-            info.setClassName(ViewPager.class.getName());
-            info.setScrollable(canScroll());
-            if (canScrollHorizontally(1)) {
-                info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_FORWARD);
-            }
-            if (canScrollHorizontally(-1)) {
-                info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD);
-            }
+        if (canScrollHorizontally(-1)) {
+            info.addAction(AccessibilityAction.ACTION_SCROLL_BACKWARD);
+        }
+    }
+
+    @Override
+    public boolean performAccessibilityAction(int action, Bundle args) {
+        if (super.performAccessibilityAction(action, args)) {
+            return true;
         }
 
-        @Override
-        public boolean performAccessibilityAction(View host, int action, Bundle args) {
-            if (super.performAccessibilityAction(host, action, args)) {
-                return true;
-            }
-            switch (action) {
-                case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD: {
-                    if (canScrollHorizontally(1)) {
-                        setCurrentItem(mCurItem + 1);
-                        return true;
-                    }
-                } return false;
-                case AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD: {
-                    if (canScrollHorizontally(-1)) {
-                        setCurrentItem(mCurItem - 1);
-                        return true;
-                    }
-                } return false;
-            }
-            return false;
+        switch (action) {
+            case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD:
+                if (canScrollHorizontally(1)) {
+                    setCurrentItem(mCurItem + 1);
+                    return true;
+                }
+                return false;
+            case AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD:
+                if (canScrollHorizontally(-1)) {
+                    setCurrentItem(mCurItem - 1);
+                    return true;
+                }
+                return false;
         }
 
-        private boolean canScroll() {
-            return (mAdapter != null) && (mAdapter.getCount() > 1);
-        }
+        return false;
+    }
+
+    private boolean canScroll() {
+        return mAdapter != null && mAdapter.getCount() > 1;
     }
 
     private class PagerObserver extends DataSetObserver {