Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 32c3a692 authored by Adam Powell's avatar Adam Powell
Browse files

Fix bug 3324981 - Inconsistent/buggy FastScroll behavior 

The fast scroller now always positions by index position.

Fixed a bug with always-show fast scrollers.

Change-Id: I08586ab2aae9733e78aa823aff711bcc14d2d44d
parent ac0f347e

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);