Enabling accessibility focus only if explore by touch is on.

1. Now we will enable the accessibility focus only if Explore by
   Touch is enabled. Enabling this feature allows a blind user to
   touch the screen and set the accessibility focus at this
   location as well as get spoken feedback. Also an accessibility
   service can move the accessibility as a result of user gestures
   detected only if Explore by Touch is enabled. Since we will
   handle some gestures by default if not accessibility service
   does so to provide reasonable built-in navigation of the UI
   by "objects" we need the accessibility focus functionality.

bug:6383361

Change-Id: I13ce6072a90f5838c7656379788144c99a772bf0

Author: sganov

core/java/android/view/View.java

@@ -5942,7 +5942,8 @@ boolean isAccessibilityFocused() {
      * @hide
      */
     public boolean requestAccessibilityFocus() {
-        if (!AccessibilityManager.getInstance(mContext).isEnabled()) {
+        AccessibilityManager manager = AccessibilityManager.getInstance(mContext);
+        if (!manager.isEnabled() || !manager.isTouchExplorationEnabled()) {
             return false;
         }
         if ((mViewFlags & VISIBILITY_MASK) != VISIBLE) {

core/java/android/view/ViewRootImpl.java

@@ -2316,7 +2316,8 @@ private boolean drawSoftware(Surface surface, AttachInfo attachInfo, int yoff,
      * @param canvas The canvas on which to draw.
      */
     private void drawAccessibilityFocusedDrawableIfNeeded(Canvas canvas) {
-        if (!AccessibilityManager.getInstance(mView.mContext).isEnabled()) {
+        AccessibilityManager manager = AccessibilityManager.getInstance(mView.mContext);
+        if (!manager.isEnabled() || !manager.isTouchExplorationEnabled()) {
             return;
         }
         if (mAccessibilityFocusedHost == null || mAccessibilityFocusedHost.mAttachInfo == null) {