private void updateDragging(MotionEvent ev) {
        setHotspot(ev.getX(), ev.getY());
        int x = (int) ev.getX();

        int left = getPaddingLeft();
        int right = getWidth() - getPaddingRight();

        int posX = x - mDragOffset;
        if (posX < left) {
            posX = left;
        } else if (posX > right) {
            posX = right;
        }

        int available = right - left;
        float scale = (float) (posX - left) / (float) available;

        if (isRtl()) {
            scale = 1f - scale;
        }
        int progress = Math.round((scale * (mMax - mMin)) + mMin);
        setProgress(progress, true, scale);
    }
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