Merge "Fix bug 3324981 - Inconsistent/buggy FastScroll behavior" into honeycomb (8b50495d) · Commits · e / os / android_frameworks_base

core/java/android/widget/FastScroller.java

+49 −4

Original line number	Diff line number	Diff line
		@@ -18,7 +18,6 @@ package android.widget;

		import android.content.Context;
		import android.content.res.ColorStateList;
		import android.content.res.Resources;
		import android.content.res.TypedArray;
		import android.graphics.Canvas;
		import android.graphics.Paint;
		@@ -407,7 +406,10 @@ class FastScroller {
		// Are there enough pages to require fast scroll? Recompute only if total count changes
		if (mItemCount != totalItemCount && visibleItemCount > 0) {
		mItemCount = totalItemCount;
		mLongList = mAlwaysShow \|\| mItemCount / visibleItemCount >= MIN_PAGES;
		mLongList = mItemCount / visibleItemCount >= MIN_PAGES;
		}
		if (mAlwaysShow) {
		mLongList = true;
		}
		if (!mLongList) {
		if (mState != STATE_NONE) {
		@@ -416,8 +418,8 @@ class FastScroller {
		return;
		}
		if (totalItemCount - visibleItemCount > 0 && mState != STATE_DRAGGING ) {
		mThumbY = ((mList.getHeight() - mThumbH) * firstVisibleItem)
		/ (totalItemCount - visibleItemCount);
		mThumbY = getThumbPositionForListPosition(firstVisibleItem, visibleItemCount,
		totalItemCount);
		if (mChangedBounds) {
		resetThumbPos();
		mChangedBounds = false;
		@@ -579,6 +581,49 @@ class FastScroller {
		}
		}

		private int getThumbPositionForListPosition(int firstVisibleItem, int visibleItemCount,
		int totalItemCount) {
		if (mSectionIndexer == null) {
		getSectionsFromIndexer();
		}
		if (mSectionIndexer == null) {
		return ((mList.getHeight() - mThumbH) * firstVisibleItem)
		/ (totalItemCount - visibleItemCount);
		}

		firstVisibleItem -= mListOffset;
		if (firstVisibleItem < 0) {
		return 0;
		}
		totalItemCount -= mListOffset;

		final int trackHeight = mList.getHeight() - mThumbH;

		final int section = mSectionIndexer.getSectionForPosition(firstVisibleItem);
		final int sectionPos = mSectionIndexer.getPositionForSection(section);
		final int nextSectionPos = mSectionIndexer.getPositionForSection(section + 1);
		final int sectionCount = mSectionIndexer.getSections().length;
		final int positionsInSection = nextSectionPos - sectionPos;

		final View child = mList.getChildAt(0);
		final float incrementalPos = firstVisibleItem +
		(float) (mList.getPaddingTop() - child.getTop()) / child.getHeight();
		final float posWithinSection = (incrementalPos - sectionPos) / positionsInSection;
		int result = (int) ((section + posWithinSection) / sectionCount * trackHeight);

		// Fake out the scrollbar for the last item. Since the section indexer won't
		// ever actually move the list in this end space, make scrolling across the last item
		// account for whatever space is remaining.
		if (firstVisibleItem > 0 && firstVisibleItem + visibleItemCount == totalItemCount) {
		final View lastChild = mList.getChildAt(visibleItemCount - 1);
		final float lastItemVisible = (float) (mList.getHeight() - mList.getPaddingBottom()
		- lastChild.getTop()) / lastChild.getHeight();
		result += (trackHeight - result) * lastItemVisible;
		}

		return result;
		}

		private void cancelFling() {
		// Cancel the list fling
		MotionEvent cancelFling = MotionEvent.obtain(0, 0, MotionEvent.ACTION_CANCEL, 0, 0, 0);