LayoutRipple.java 文件源码

/**
 * @param bitmap
 * @return 设置涟漪的边界，涟漪在这个区域里面可见。这里可以设置四角的弧度数
 */
public Bitmap cropRoundRect(Bitmap bitmap) {
    Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
    bitmap.getHeight(), Config.ARGB_8888);
    Canvas canvas = new Canvas(output);

    final int color = 0xff424242;
    final Paint paint = new Paint();
    final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());

    paint.setAntiAlias(true);
    canvas.drawARGB(0, 0, 0, 0);
    paint.setColor(color);
    RectF rectF = new RectF(0, 0, bitmap.getWidth(), bitmap.getHeight());
    canvas.drawRoundRect(rectF, rippleBorderRadius, rippleBorderRadius, paint);

    paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
    canvas.drawBitmap(bitmap, rect, rect, paint);
    return output;
}