RxImageTool.java 文件源码

/**
 * 可以对该图的非透明区域着色
 * <p>
 * 有多种使用场景，常见如 Button 的 pressed 状态，View 的阴影状态等
 *
 * @param iv
 * @param src
 * @param radius
 * @param color
 * @return
 */
private static Bitmap getDropShadow(ImageView iv, Bitmap src, float radius, int color) {

    final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
    paint.setColor(color);

    final int width = src.getWidth(), height = src.getHeight();
    final Bitmap dest = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    final Canvas canvas = new Canvas(dest);
    final Bitmap alpha = src.extractAlpha();
    canvas.drawBitmap(alpha, 0, 0, paint);

    final BlurMaskFilter filter = new BlurMaskFilter(radius, BlurMaskFilter.Blur.OUTER);
    paint.setMaskFilter(filter);
    canvas.drawBitmap(alpha, 0, 0, paint);
    iv.setImageBitmap(dest);

    return dest;
}