Expose whether a scroll is active via ContentViewCore

Track the active fling count in addition to whether touch scrolling is active.
This is useful for transient GestureStateListeners to precisely determine the
current state of scroll activity.

BUG=354599

Review URL: https://codereview.chromium.org/202253002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@258481 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 10 insertions, 0 deletions

diff --git a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
index 1e20730..88f798d 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
+++ b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
@@ -415,6 +415,10 @@ public class ContentViewCore
     // sequence, so this will also be true for the duration of a pinch gesture.
     private boolean mTouchScrollInProgress;
 
+    // The outstanding fling start events that hasn't got fling end yet. It may be > 1 because
+    // onNativeFlingStopped() is called asynchronously.
+    private int mPotentiallyActiveFlingCount;
+
     private ViewAndroid mViewAndroid;
 
     private SmartClipDataListener mSmartClipDataListener = null;
@@ -1203,10 +1207,15 @@ public class ContentViewCore
         nativeIgnoreRemainingTouchEvents(mNativeContentViewCore);
     }
 
+    public boolean isScrollInProgress() {
+        return mTouchScrollInProgress || mPotentiallyActiveFlingCount > 0;
+    }
+
     @SuppressWarnings("unused")
     @CalledByNative
     private void onFlingStartEventConsumed(int vx, int vy) {
         mTouchScrollInProgress = false;
+        mPotentiallyActiveFlingCount++;
         temporarilyHideTextHandles();
         for (mGestureStateListenersIterator.rewind();
                     mGestureStateListenersIterator.hasNext();) {
@@ -3112,6 +3121,7 @@ public class ContentViewCore
         // Note that mTouchScrollInProgress should normally be false at this
         // point, but we reset it anyway as another failsafe.
         mTouchScrollInProgress = false;
+        if (mPotentiallyActiveFlingCount > 0) mPotentiallyActiveFlingCount--;
         updateGestureStateListener(GestureEventType.FLING_END);
     }