private void startDragging(MotionEvent ev, boolean ignoreTrackIfInScrollContainer) {
        final Rect bounds = mTempRect;

        mSeekBarDrawable.copyTouchBounds(bounds);

        //Grow the current thumb rect for a bigger touch area
        boolean isDragging = (bounds.contains((int) ev.getX(), (int) ev.getY()));
        if (!isDragging && mAllowTrackClick && !ignoreTrackIfInScrollContainer) {
            //If the user clicked outside the thumb, we compute the current position
            //and force an immediate drag to it.
            isDragging = true;
            mDragOffset = bounds.width() / 2;
            updateDragging(ev);
            //As the thumb may have moved, get the bounds again
            mSeekBarDrawable.setHotScale(mSeekBarDrawable.getHotScale());
        }
        if (isDragging) {
            onStartTrackingTouch();
            setHotspot(ev.getX(), ev.getY());
            mDragOffset = (int) (ev.getX() - bounds.centerX());
        }
    }
Sets the color of the SeekBar scrubber

@param color The color the track will be changed to
caprice/ui/src/main/java/net/qiujuer/genius/ui/widget/AbsSeekBar.java