Fix some issues with smooth scrolling ListViews (37113317) · Commits · e / os / android_frameworks_base

core/java/android/widget/AbsListView.java

+16 −13

Original line number	Diff line number	Diff line
		@@ -2651,7 +2651,8 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		mMode = MOVE_OFFSET;

		final int firstPos = mFirstPosition;
		final int lastPos = firstPos + getChildCount() - 1;
		final int childCount = getChildCount();
		final int lastPos = firstPos + childCount - 1;

		int viewTravelCount = 0;
		if (position < firstPos) {
		@@ -2665,7 +2666,10 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		return;
		}

		mScrollDuration = SCROLL_DURATION / viewTravelCount;
		// Estimate how many screens we should travel
		final float screenTravelCount = viewTravelCount / childCount;
		mScrollDuration = (int) (SCROLL_DURATION / screenTravelCount);
		mLastSeenPos = INVALID_POSITION;
		post(this);
		}

		@@ -2674,6 +2678,10 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		}

		public void run() {
		if (mTouchMode != TOUCH_MODE_FLING && mLastSeenPos != INVALID_POSITION) {
		return;
		}

		final int listHeight = getHeight();
		final int firstPos = mFirstPosition;

		@@ -2799,23 +2807,17 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		}

		case MOVE_OFFSET: {
		if (firstPos == mLastSeenPos) {
		// No new views, let things keep going.
		post(this);
		}
		final int childCount = getChildCount();

		mLastSeenPos = firstPos;
		final int position = mTargetPos;
		final int lastPos = firstPos + getChildCount() - 1;
		final int lastPos = firstPos + childCount - 1;

		if (position < firstPos) {
		final View firstView = getChildAt(0);
		final int firstViewPixelsShowing = firstView.getHeight() + firstView.getTop();
		smoothScrollBy(-firstViewPixelsShowing, mScrollDuration);
		smoothScrollBy(-getHeight(), mScrollDuration);
		post(this);
		} else if (position > lastPos) {
		final View lastView = getChildAt(getChildCount() - 1);
		final int lastViewPixelsShowing = lastView.getBottom() - lastView.getHeight();
		smoothScrollBy(lastViewPixelsShowing, mScrollDuration);
		smoothScrollBy(getHeight(), mScrollDuration);
		post(this);
		} else {
		// On-screen, just scroll.
		@@ -3249,6 +3251,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te

		mResurrectToPosition = INVALID_POSITION;
		removeCallbacks(mFlingRunnable);
		removeCallbacks(mPositionScroller);
		mTouchMode = TOUCH_MODE_REST;
		clearScrollingCache();
		mSpecificTop = selectedTop;