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Commit b3e02c44 authored by Adam Powell's avatar Adam Powell
Browse files

Fix nested cross-scrolling for ScrollView/HorizontalScrollView 

Bug 6429006

Disallow intercepting touch events for parents of
ScrollView/HorizontalScrollView when scrolling begins. Properly
respect touch slop when the child of a ScrollView does not accept
touch events.

Change-Id: I2ce503ad5104d450829ed58cd2748c9163e020d3
parent fbbdbc2d

core/java/android/widget/HorizontalScrollView.java

+22 −5
Original line number Diff line number Diff line
@@ -536,10 +536,15 @@ public class HorizontalScrollView extends FrameLayout { 


        switch (action & MotionEvent.ACTION_MASK) {

            case MotionEvent.ACTION_DOWN: {

                mIsBeingDragged = getChildCount() != 0;

                if (!mIsBeingDragged) {

                if (getChildCount() == 0) {

                    return false;

                }

                if ((mIsBeingDragged = !mScroller.isFinished())) {

                    final ViewParent parent = getParent();

                    if (parent != null) {

                        parent.requestDisallowInterceptTouchEvent(true);

                    }

                }



                /*

                 * If being flinged and user touches, stop the fling. isFinished
@@ -555,11 +560,23 @@ public class HorizontalScrollView extends FrameLayout { 
                break;

            }

            case MotionEvent.ACTION_MOVE:

                if (mIsBeingDragged) {

                    // Scroll to follow the motion event

                final int activePointerIndex = ev.findPointerIndex(mActivePointerId);

                final int x = (int) ev.getX(activePointerIndex);

                    final int deltaX = (int) (mLastMotionX - x);

                int deltaX = mLastMotionX - x;

                if (!mIsBeingDragged && Math.abs(deltaX) > mTouchSlop) {

                    final ViewParent parent = getParent();

                    if (parent != null) {

                        parent.requestDisallowInterceptTouchEvent(true);

                    }

                    mIsBeingDragged = true;

                    if (deltaX > 0) {

                        deltaX -= mTouchSlop;

                    } else {

                        deltaX += mTouchSlop;

                    }

                }

                if (mIsBeingDragged) {

                    // Scroll to follow the motion event

                    mLastMotionX = x;



                    final int oldX = mScrollX;

core/java/android/widget/ScrollView.java

+26 −5
Original line number Diff line number Diff line
@@ -482,6 +482,10 @@ public class ScrollView extends FrameLayout { 
                    if (mScrollStrictSpan == null) {

                        mScrollStrictSpan = StrictMode.enterCriticalSpan("ScrollView-scroll");

                    }

                    final ViewParent parent = getParent();

                    if (parent != null) {

                        parent.requestDisallowInterceptTouchEvent(true);

                    }

                }

                break;

            }
@@ -546,10 +550,15 @@ public class ScrollView extends FrameLayout { 


        switch (action & MotionEvent.ACTION_MASK) {

            case MotionEvent.ACTION_DOWN: {

                mIsBeingDragged = getChildCount() != 0;

                if (!mIsBeingDragged) {

                if (getChildCount() == 0) {

                    return false;

                }

                if ((mIsBeingDragged = !mScroller.isFinished())) {

                    final ViewParent parent = getParent();

                    if (parent != null) {

                        parent.requestDisallowInterceptTouchEvent(true);

                    }

                }



                /*

                 * If being flinged and user touches, stop the fling. isFinished
@@ -569,11 +578,23 @@ public class ScrollView extends FrameLayout { 
                break;

            }

            case MotionEvent.ACTION_MOVE:

                if (mIsBeingDragged) {

                    // Scroll to follow the motion event

                final int activePointerIndex = ev.findPointerIndex(mActivePointerId);

                final int y = (int) ev.getY(activePointerIndex);

                    final int deltaY = mLastMotionY - y;

                int deltaY = mLastMotionY - y;

                if (!mIsBeingDragged && Math.abs(deltaY) > mTouchSlop) {

                    final ViewParent parent = getParent();

                    if (parent != null) {

                        parent.requestDisallowInterceptTouchEvent(true);

                    }

                    mIsBeingDragged = true;

                    if (deltaY > 0) {

                        deltaY -= mTouchSlop;

                    } else {

                        deltaY += mTouchSlop;

                    }

                }

                if (mIsBeingDragged) {

                    // Scroll to follow the motion event

                    mLastMotionY = y;



                    final int oldX = mScrollX;