am ef793669: Merge "Fix a stability regression in ListView arrow scrolling" into jb-mr2-dev (6338eb11) · Commits · e / os / android_frameworks_base

core/java/android/widget/ListView.java

+29 −3

Original line number	Diff line number	Diff line
		@@ -2416,6 +2416,34 @@ public class ListView extends AbsListView {
		}
		}

		/**
		* Used by {@link #arrowScrollImpl(int)} to help determine the next selected position
		* to move to. This can return a position currently not represented by a view on screen
		* but only in the direction given.
		*
		* @param selectedPos Current selected position to move from
		* @param direction Direction to move in
		* @return Desired selected position after moving in the given direction
		*/
		private final int nextSelectedPositionForDirection(int selectedPos, int direction) {
		int nextSelected;
		if (direction == View.FOCUS_DOWN) {
		nextSelected = selectedPos != INVALID_POSITION && selectedPos >= mFirstPosition ?
		selectedPos + 1 :
		mFirstPosition;
		} else {
		final int lastPos = mFirstPosition + getChildCount() - 1;
		nextSelected = selectedPos != INVALID_POSITION && selectedPos < lastPos?
		selectedPos - 1 :
		lastPos;
		}

		if (nextSelected < 0 \|\| nextSelected >= mAdapter.getCount()) {
		return INVALID_POSITION;
		}
		return lookForSelectablePosition(nextSelected, direction == View.FOCUS_DOWN);
		}

		/**
		* Handle an arrow scroll going up or down. Take into account whether items are selectable,
		* whether there are focusable items etc.
		@@ -2431,9 +2459,7 @@ public class ListView extends AbsListView {
		View selectedView = getSelectedView();
		int selectedPos = mSelectedPosition;

		int nextSelectedPosition = (direction == View.FOCUS_DOWN) ?
		lookForSelectablePosition(selectedPos + 1, true) :
		lookForSelectablePosition(selectedPos - 1, false);
		int nextSelectedPosition = nextSelectedPositionForDirection(selectedPos, direction);
		int amountToScroll = amountToScroll(direction, nextSelectedPosition);

		// if we are moving focus, we may OVERRIDE the default behavior