question: private void drawBackground ( Canvas canvas ) { RectF rect = mCropWindowHandler . getRect ( ) ; float left = Math . max ( BitmapUtils . getRectLeft ( mBoundsPoints ) , 0 ) ; float top = Math . max ( BitmapUtils . getRectTop ( mBoundsPoints ) , 0 ) ; float right = Math . min ( BitmapUtils . getRectRight ( mBoundsPoints ) , getWidth ( ) ) ; float bottom = Math . min ( BitmapUtils . getRectBottom ( mBoundsPoints ) , getHeight ( ) ) ; if ( mCropShape == CropImageView . CropShape . RECTANGLE ) { if ( ! isNonStraightAngleRotated ( ) || Build . VERSION . SDK_INT <= 17 ) { canvas . drawRect ( left , top , right , rect . top , mBackgroundPaint ) ; canvas . drawRect ( left , rect . bottom , right , bottom , mBackgroundPaint ) ; canvas . drawRect ( left , rect . top , rect . left , rect . bottom , mBackgroundPaint ) ; canvas . drawRect ( rect . right , rect . top , right , rect . bottom , mBackgroundPaint ) ; } else { mPath . reset ( ) ; mPath . moveTo ( mBoundsPoints [ 0 ] , mBoundsPoints [ 1 ] ) ; mPath . lineTo ( mBoundsPoints [ 2 ] , mBoundsPoints [ 3 ] ) ; mPath . lineTo ( mBoundsPoints [ 4 ] , mBoundsPoints [ 5 ] ) ; mPath . lineTo ( mBoundsPoints [ 6 ] , mBoundsPoints [ 7 ] ) ; mPath . close ( ) ; canvas . save ( ) ; canvas . clipPath ( mPath , Region . Op . INTERSECT ) ; canvas . clipRect ( rect , Region . Op . XOR ) ; canvas . drawRect ( left , top , right , bottom , mBackgroundPaint ) ; canvas . restore ( ) ; } } else { mPath . reset ( ) ; if ( Build . VERSION . SDK_INT >= 11 && Build . VERSION . SDK_INT <= 17 && mCropShape == CropImageView . CropShape . OVAL ) { mDrawRect . set ( rect . left + 2 , rect . top + 2 , rect . right - 2 , rect . bottom - 2 ) ; } else { mDrawRect . set ( rect . left , rect . top , rect . right , rect . bottom ) ; } mPath . addOval ( mDrawRect , Path . Direction . CW ) ; canvas . save ( ) ; canvas . clipPath ( mPath , Region . Op . XOR ) ; canvas . drawRect ( left , top , right , bottom , mBackgroundPaint ) ; canvas . restore ( ) ; } }
target:  Draw shadow background over the image not including the crop area.