Only activate FastScroller when it's needed (b9f2722f) · Commits · e / os / android_frameworks_base

core/java/android/widget/AbsListView.java

+12 −4

Original line number	Diff line number	Diff line
		@@ -1250,7 +1250,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		mFastScroller.setEnabled(true);
		}

		recomputePadding();
		resolvePadding();

		if (mFastScroller != null) {
		mFastScroller.updateLayout();
		@@ -1312,7 +1312,11 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		* @see #setFastScrollAlwaysVisible(boolean)
		*/
		public boolean isFastScrollAlwaysVisible() {
		if (mFastScroller == null) {
		return mFastScrollEnabled && mFastScrollAlwaysVisible;
		} else {
		return mFastScroller.isEnabled() && mFastScroller.isAlwaysShowEnabled();
		}
		}

		@Override
		@@ -1331,7 +1335,11 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		*/
		@ViewDebug.ExportedProperty
		public boolean isFastScrollEnabled() {
		if (mFastScroller == null) {
		return mFastScrollEnabled;
		} else {
		return mFastScroller.isEnabled();
		}
		}

		@Override
		@@ -1356,7 +1364,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		*/
		@Override
		protected boolean isVerticalScrollBarHidden() {
		return mFastScrollEnabled;
		return isFastScrollEnabled();
		}

		/**

core/java/android/widget/FastScroller.java

+51 −44

Original line number	Diff line number	Diff line
		@@ -152,9 +152,6 @@ class FastScroller {
		/** The number of headers at the top of the view. */
		private int mHeaderCount;

		/** The number of items in the list. */
		private int mItemCount = -1;

		/** The index of the current section. */
		private int mCurrentSection = -1;

		@@ -324,6 +321,7 @@ class FastScroller {

		getSectionsFromIndexer();
		refreshDrawablePressedState();
		updateLongList(listView.getChildCount(), listView.getCount());
		setScrollbarPosition(mList.getVerticalScrollbarPosition());
		postAutoHide();
		}
		@@ -343,14 +341,10 @@ class FastScroller {
		* @param enabled Whether the fast scroll thumb is enabled.
		*/
		public void setEnabled(boolean enabled) {
		if (mEnabled != enabled) {
		mEnabled = enabled;

		if (enabled) {
		if (mAlwaysShow) {
		setState(STATE_VISIBLE);
		}
		} else {
		stop();
		onStateDependencyChanged();
		}
		}

		@@ -358,19 +352,17 @@ class FastScroller {
		* @return Whether the fast scroll thumb is enabled.
		*/
		public boolean isEnabled() {
		return mEnabled;
		return mEnabled && (mLongList \|\| mAlwaysShow);
		}

		/**
		* @param alwaysShow Whether the fast scroll thumb should always be shown
		*/
		public void setAlwaysShow(boolean alwaysShow) {
		if (mAlwaysShow != alwaysShow) {
		mAlwaysShow = alwaysShow;

		if (alwaysShow) {
		setState(STATE_VISIBLE);
		} else if (mState == STATE_VISIBLE) {
		postAutoHide();
		onStateDependencyChanged();
		}
		}

		@@ -382,6 +374,23 @@ class FastScroller {
		return mAlwaysShow;
		}

		/**
		* Called when one of the variables affecting enabled state changes.
		*/
		private void onStateDependencyChanged() {
		if (isEnabled()) {
		if (isAlwaysShowEnabled()) {
		setState(STATE_VISIBLE);
		} else if (mState == STATE_VISIBLE) {
		postAutoHide();
		}
		} else {
		stop();
		}

		mList.resolvePadding();
		}

		public void setScrollBarStyle(int style) {
		if (mScrollBarStyle != style) {
		mScrollBarStyle = style;
		@@ -439,6 +448,18 @@ class FastScroller {
		final int firstVisibleItem = mList.getFirstVisiblePosition();
		setThumbPos(getPosFromItemCount(firstVisibleItem, visibleItemCount, totalItemCount));
		}

		updateLongList(visibleItemCount, totalItemCount);
		}

		private void updateLongList(int visibleItemCount, int totalItemCount) {
		final boolean longList = visibleItemCount > 0
		&& totalItemCount / visibleItemCount >= MIN_PAGES;
		if (mLongList != longList) {
		mLongList = longList;

		onStateDependencyChanged();
		}
		}

		/**
		@@ -795,19 +816,8 @@ class FastScroller {
		mList.postDelayed(mDeferHide, FADE_TIMEOUT);
		}

		private boolean isLongList(int visibleItemCount, int totalItemCount) {
		// Are there enough pages to require fast scroll? Recompute only if
		// total count changes.
		if (mItemCount != totalItemCount && visibleItemCount > 0) {
		mItemCount = totalItemCount;
		mLongList = mItemCount / visibleItemCount >= MIN_PAGES;
		}

		return mLongList;
		}

		public void onScroll(int firstVisibleItem, int visibleItemCount, int totalItemCount) {
		if (!mEnabled \|\| !mAlwaysShow && !isLongList(visibleItemCount, totalItemCount)) {
		if (!isEnabled()) {
		setState(STATE_NONE);
		return;
		}
		@@ -1221,7 +1231,7 @@ class FastScroller {
		}

		public boolean onInterceptTouchEvent(MotionEvent ev) {
		if (!mEnabled) {
		if (!isEnabled()) {
		return false;
		}

		@@ -1233,14 +1243,18 @@ class FastScroller {
		// need to allow the parent time to decide whether it wants
		// to intercept events. If it does, we will receive a CANCEL
		// event.
		if (mList.isInScrollingContainer()) {
		if (!mList.isInScrollingContainer()) {
		beginDrag();
		return true;
		}

		mInitialTouchY = ev.getY();
		startPendingDrag();
		return false;
		}

		beginDrag();
		return true;
		break;
		case MotionEvent.ACTION_MOVE:
		if (!isPointInside(ev.getX(), ev.getY())) {
		cancelPendingDrag();
		}
		break;
		case MotionEvent.ACTION_UP:
		@@ -1253,7 +1267,7 @@ class FastScroller {
		}

		public boolean onInterceptHoverEvent(MotionEvent ev) {
		if (!mEnabled) {
		if (!isEnabled()) {
		return false;
		}

		@@ -1269,18 +1283,11 @@ class FastScroller {
		}

		public boolean onTouchEvent(MotionEvent me) {
		if (!mEnabled) {
		if (!isEnabled()) {
		return false;
		}

		switch (me.getActionMasked()) {
		case MotionEvent.ACTION_DOWN: {
		if (isPointInside(me.getX(), me.getY())) {
		beginDrag();
		return true;
		}
		} break;

		case MotionEvent.ACTION_UP: {
		if (mHasPendingDrag) {
		// Allow a tap to scroll.