Postpone hover state resolution in DropDownListView (fb4cbc4a) · Commits · e / os / android_frameworks_base

core/java/android/widget/DropDownListView.java

+63 −8

Original line number	Diff line number	Diff line
		@@ -74,6 +74,12 @@ public class DropDownListView extends ListView {
		/** Helper for drag-to-open auto scrolling. */
		private AbsListViewAutoScroller mScrollHelper;

		/**
		* Runnable posted when we are awaiting hover event resolution. When set,
		* drawable state changes are postponed.
		*/
		private ResolveHoverRunnable mResolveHoverRunnable;

		/**
		* Creates a new list view wrapper.
		*
		@@ -100,19 +106,37 @@ public class DropDownListView extends ListView {
		return isHovered() \|\| super.shouldShowSelector();
		}

		@Override
		public boolean onTouchEvent(MotionEvent ev) {
		if (mResolveHoverRunnable != null) {
		// Resolved hover event as hover => touch transition.
		mResolveHoverRunnable.cancel();
		}

		return super.onTouchEvent(ev);
		}

		@Override
		public boolean onHoverEvent(@NonNull MotionEvent ev) {
		final int action = ev.getActionMasked();
		if (action == MotionEvent.ACTION_HOVER_EXIT && mResolveHoverRunnable == null) {
		// This may be transitioning to TOUCH_DOWN. Postpone drawable state
		// updates until either the next frame or the next touch event.
		mResolveHoverRunnable = new ResolveHoverRunnable();
		mResolveHoverRunnable.post();
		}

		// Allow the super class to handle hover state management first.
		final boolean handled = super.onHoverEvent(ev);

		final int action = ev.getActionMasked();
		if (action == MotionEvent.ACTION_HOVER_ENTER
		\|\| action == MotionEvent.ACTION_HOVER_MOVE) {
		final int position = pointToPosition((int) ev.getX(), (int) ev.getY());
		if (position != INVALID_POSITION && position != mSelectedPosition) {
		final View hoveredItem = getChildAt(position - getFirstVisiblePosition());
		if (hoveredItem.isEnabled()) {
		// Force a focus so that the proper selector state gets used when we update.
		// Force a focus so that the proper selector state gets
		// used when we update.
		requestFocus();

		positionSelector(position, hoveredItem);
		@@ -122,7 +146,8 @@ public class DropDownListView extends ListView {
		updateSelectorState();
		}
		} else {
		// Do not cancel the selected position if the selection is visible by other reasons.
		// Do not cancel the selected position if the selection is visible
		// by other means.
		if (!super.shouldShowSelector()) {
		setSelectedPositionInt(INVALID_POSITION);
		setNextSelectedPositionInt(INVALID_POSITION);
		@@ -132,6 +157,13 @@ public class DropDownListView extends ListView {
		return handled;
		}

		@Override
		protected void drawableStateChanged() {
		if (mResolveHoverRunnable == null) {
		super.drawableStateChanged();
		}
		}

		/**
		* Handles forwarded events.
		*
		@@ -196,12 +228,14 @@ public class DropDownListView extends ListView {
		}

		/**
		* Sets whether the list selection is hidden, as part of a workaround for a touch mode issue
		* (see the declaration for mListSelectionHidden).
		* @param listSelectionHidden
		* Sets whether the list selection is hidden, as part of a workaround for a
		* touch mode issue (see the declaration for mListSelectionHidden).
		*
		* @param hideListSelection {@code true} to hide list selection,
		* {@code false} to show
		*/
		public void setListSelectionHidden(boolean listSelectionHidden) {
		this.mListSelectionHidden = listSelectionHidden;
		public void setListSelectionHidden(boolean hideListSelection) {
		mListSelectionHidden = hideListSelection;
		}

		private void clearPressedItem() {
		@@ -312,4 +346,25 @@ public class DropDownListView extends ListView {
		public boolean hasFocus() {
		return mHijackFocus \|\| super.hasFocus();
		}

		/**
		* Runnable that forces hover event resolution and updates drawable state.
		*/
		private class ResolveHoverRunnable implements Runnable {
		@Override
		public void run() {
		// Resolved hover event as standard hover exit.
		mResolveHoverRunnable = null;
		drawableStateChanged();
		}

		public void cancel() {
		mResolveHoverRunnable = null;
		removeCallbacks(this);
		}

		public void post() {
		DropDownListView.this.post(this);
		}
		}
		}
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