question: private void updateArrow ( ) { path1 . reset ( ) ; path2 . reset ( ) ; path3 . reset ( ) ; path1 . moveTo ( mRealLeft + radius , mArrowStart ) ; path1 . lineTo ( mRealLeft + radius , mArrowStart + radius ) ; path2 . moveTo ( mRealLeft + radius , mArrowStart + radius ) ; path2 . lineTo ( ( float ) ( mRealLeft + radius - Math . tan ( Math . toRadians ( 40 ) ) * radius * 0.46f ) , mArrowStart + radius - radius * .46f ) ; path3 . moveTo ( mRealLeft + radius , mArrowStart + radius ) ; path3 . lineTo ( ( float ) ( mRealLeft + radius + Math . tan ( Math . toRadians ( 40 ) ) * radius * 0.46f ) , mArrowStart + radius - radius * .46f ) ; pathMeasure1 . setPath ( path1 , false ) ; pathMeasure2 . setPath ( path2 , false ) ; pathMeasure3 . setPath ( path3 , false ) ; mArrow_center_length = pathMeasure1 . getLength ( ) ; mArrow_left_length = pathMeasure2 . getLength ( ) ; mArrow_right_length = pathMeasure3 . getLength ( ) ; }
target:  update the Arrow's Status