Scroll accessibility focused nodes to make them visible.

Since nodes must be (at least partially) visible on screen for
double taps to work when touch exploration is enabled, we scroll the content
whenever accessibility focus is set.  During touch exploration, we delay scrolling
until the pointer goes up to avoid scrolling when the user is actually
exploring the screen.

BUG=335630

Review URL: https://codereview.chromium.org/137533014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247500 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 29 insertions, 1 deletions

diff --git a/content/browser/accessibility/browser_accessibility_manager_android.cc b/content/browser/accessibility/browser_accessibility_manager_android.cc
index 017afd1..d928258 100644
--- a/content/browser/accessibility/browser_accessibility_manager_android.cc
+++ b/content/browser/accessibility/browser_accessibility_manager_android.cc
@@ -379,6 +379,13 @@ void BrowserAccessibilityManagerAndroid::Blur(JNIEnv* env, jobject obj) {
   SetFocus(root_, true);
 }
 
+void BrowserAccessibilityManagerAndroid::ScrollToMakeNodeVisible(
+    JNIEnv* env, jobject obj, jint id) {
+  BrowserAccessibility* node = GetFromRendererID(id);
+  if (node)
+    ScrollToMakeVisible(*node, gfx::Rect(node->location().size()));
+}
+
 BrowserAccessibility* BrowserAccessibilityManagerAndroid::FuzzyHitTest(
     int x, int y, BrowserAccessibility* start_node) {
   BrowserAccessibility* nearest_node = NULL;
diff --git a/content/browser/accessibility/browser_accessibility_manager_android.h b/content/browser/accessibility/browser_accessibility_manager_android.h
index 921ca3a..53cb617 100644
--- a/content/browser/accessibility/browser_accessibility_manager_android.h
+++ b/content/browser/accessibility/browser_accessibility_manager_android.h
@@ -55,6 +55,7 @@ class CONTENT_EXPORT BrowserAccessibilityManagerAndroid
   void Click(JNIEnv* env, jobject obj, jint id);
   void Focus(JNIEnv* env, jobject obj, jint id);
   void Blur(JNIEnv* env, jobject obj);
+  void ScrollToMakeNodeVisible(JNIEnv* env, jobject obj, int id);
 
  protected:
   virtual void NotifyRootChanged() OVERRIDE;
diff --git a/content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java b/content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java
index 1a58d45..2327316 100644
--- a/content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java
+++ b/content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java
@@ -46,6 +46,7 @@ public class BrowserAccessibilityManager {
     private final int[] mTempLocation = new int[2];
     private final View mView;
     private boolean mUserHasTouchExplored;
+    private boolean mPendingScrollToMakeNodeVisible;
     private boolean mFrameInfoInitialized;
 
     // If this is true, enables an experimental feature that focuses the web page after it
@@ -168,6 +169,12 @@ public class BrowserAccessibilityManager {
                 mAccessibilityFocusId = virtualViewId;
                 sendAccessibilityEvent(mAccessibilityFocusId,
                         AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
+                if (mCurrentHoverId == View.NO_ID) {
+                    nativeScrollToMakeNodeVisible(
+                            mNativeObj, mAccessibilityFocusId);
+                } else {
+                    mPendingScrollToMakeNodeVisible = true;
+                }
                 return true;
             case AccessibilityNodeInfo.ACTION_CLEAR_ACCESSIBILITY_FOCUS:
                 if (mAccessibilityFocusId == virtualViewId) {
@@ -201,7 +208,18 @@ public class BrowserAccessibilityManager {
             return false;
         }
 
-        if (event.getAction() == MotionEvent.ACTION_HOVER_EXIT) return true;
+        if (event.getAction() == MotionEvent.ACTION_HOVER_EXIT) {
+            if (mCurrentHoverId != View.NO_ID) {
+                sendAccessibilityEvent(mCurrentHoverId, AccessibilityEvent.TYPE_VIEW_HOVER_EXIT);
+                mCurrentHoverId = View.NO_ID;
+            }
+            if (mPendingScrollToMakeNodeVisible) {
+                nativeScrollToMakeNodeVisible(
+                        mNativeObj, mAccessibilityFocusId);
+            }
+            mPendingScrollToMakeNodeVisible = false;
+            return true;
+        }
 
         mUserHasTouchExplored = true;
         float x = event.getX();
@@ -617,4 +635,6 @@ public class BrowserAccessibilityManager {
     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);
 }