ListView now tries to keep the position containing focused child views on-screen. (9bf3c128) · Commits · e / os / android_frameworks_base

core/java/android/widget/AbsListView.java

+5 −0

Original line number	Diff line number	Diff line
		@@ -4017,6 +4017,10 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		* View type for this view, as returned by
		* {@link android.widget.Adapter#getItemViewType(int) }
		*/
		@ViewDebug.ExportedProperty(mapping = {
		@ViewDebug.IntToString(from = ITEM_VIEW_TYPE_IGNORE, to = "ITEM_VIEW_TYPE_IGNORE"),
		@ViewDebug.IntToString(from = ITEM_VIEW_TYPE_HEADER_OR_FOOTER, to = "ITEM_VIEW_TYPE_HEADER_OR_FOOTER")
		})
		int viewType;

		/**
		@@ -4025,6 +4029,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		* been added to the list view and whether they should be treated as
		* recycled views or not.
		*/
		@ViewDebug.ExportedProperty
		boolean recycledHeaderFooter;

		public LayoutParams(Context c, AttributeSet attrs) {

+36 −0

Original line number	Diff line number	Diff line
		@@ -140,6 +140,9 @@ public class ListView extends AbsListView {
		// allocating these thingies too often.
		private final ArrowScrollFocusResult mArrowScrollFocusResult = new ArrowScrollFocusResult();

		// Keeps focused children visible through resizes
		private FocusSelector mFocusSelector;

		public ListView(Context context) {
		this(context, null);
		}
		@@ -1017,6 +1020,39 @@ public class ListView extends AbsListView {
		return sel;
		}

		private class FocusSelector implements Runnable {
		private int mPosition;
		private int mPositionTop;

		public FocusSelector setup(int position, int top) {
		mPosition = position;
		mPositionTop = top;
		return this;
		}

		public void run() {
		setSelectionFromTop(mPosition, mPositionTop);
		}
		}

		@Override
		protected void onSizeChanged(int w, int h, int oldw, int oldh) {
		if (getChildCount() > 0) {
		View focusedChild = getFocusedChild();
		if (focusedChild != null) {
		final int childPosition = mFirstPosition + indexOfChild(focusedChild);
		final int childBottom = focusedChild.getBottom();
		final int offset = Math.max(0, childBottom - (h - mPaddingTop));
		final int top = focusedChild.getTop() - offset;
		if (mFocusSelector == null) {
		mFocusSelector = new FocusSelector();
		}
		post(mFocusSelector.setup(childPosition, top));
		}
		}
		super.onSizeChanged(w, h, oldw, oldh);
		}

		@Override
		protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		// Sets up mListPadding