protected void endDrag() {
        mIsDragging = false;

        if (mVelocityTracker != null) {
            mVelocityTracker.recycle();
            mVelocityTracker = null;
        }
    }
Called when a drag has been ended.
menudrawer/src/net/simonvt/menudrawer/DraggableDrawer.java