diff options
Diffstat (limited to 'core/java')
| -rw-r--r-- | core/java/android/widget/AbsListView.java | 34 |
1 files changed, 30 insertions, 4 deletions
diff --git a/core/java/android/widget/AbsListView.java b/core/java/android/widget/AbsListView.java index be47bf0..c308024 100644 --- a/core/java/android/widget/AbsListView.java +++ b/core/java/android/widget/AbsListView.java @@ -4924,11 +4924,37 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te * Scrolls the list items within the view by a specified number of pixels. * * @param y the amount of pixels to scroll by vertically - * @return true if the list is able to scroll, or false if the list is - * already at the beginning/end and unable to scroll any more. + * @see #canScrollList(int) */ - public boolean scrollListBy(int y) { - return !trackMotionScroll(-y, -y); + public void scrollListBy(int y) { + trackMotionScroll(-y, -y); + } + + /** + * Check if the items in the list can be scrolled in a certain direction. + * + * @param direction Negative to check scrolling up, positive to check + * scrolling down. + * @return true if the list can be scrolled in the specified direction, + * false otherwise. + * @see #scrollListBy(int) + */ + public boolean canScrollList(int direction) { + final int childCount = getChildCount(); + if (childCount == 0) { + return false; + } + + final int firstPosition = mFirstPosition; + final Rect listPadding = mListPadding; + if (direction > 0) { + final int lastBottom = getChildAt(childCount - 1).getBottom(); + final int lastPosition = firstPosition + childCount; + return lastPosition < mItemCount || lastBottom > getHeight() - listPadding.bottom; + } else { + final int firstTop = getChildAt(0).getTop(); + return firstPosition > 0 || firstTop < listPadding.top; + } } /** |