ShapedImageView.java 文件源码

private Bitmap clippedRotatedOval(Bitmap bitmap) {
    Bitmap bmp;
    float width = bitmap.getWidth();
    float height = bitmap.getHeight();

    bmp = Bitmap.createBitmap((int) width, (int) height, Bitmap.Config.ARGB_8888);
    BitmapShader shader = new BitmapShader(bitmap, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP);

    Canvas canvas = new Canvas(bmp);
    Paint paint = new Paint();
    paint.setAntiAlias(true);
    paint.setShader(shader);

    Path oval = new Path();
    Matrix matrix = new Matrix();
    Region region = new Region();
    RectF ovalRect = new RectF(width / OVAL_FACTOR, 0, width - (width / OVAL_FACTOR), height);

    oval.addOval(ovalRect, Path.Direction.CW);
    matrix.postRotate(ROTATION, width / 2, height / 2);
    oval.transform(matrix, oval);
    region.setPath(oval, new Region((int) width / 2, 0, (int) width, (int) height));
    canvas.drawPath(region.getBoundaryPath(), paint);

    return bmp;
}