MediaUtils.java 文件源码

public static Bitmap modifyTrackCellArtworkBitmap(Bitmap source){
    if (source == null)
        return null;

    int w = source.getWidth();
    int h = source.getHeight();

    Bitmap scaled = Bitmap.createScaledBitmap(source, w, h, true);

    w = scaled.getWidth();
    h = scaled.getHeight();

    Bitmap overlay = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);

    Canvas canvas = new Canvas(overlay);
    final Paint paint = new Paint();

    canvas.drawBitmap(scaled, 0, 0, null);

    Shader shader = new LinearGradient(
            0, 0, h, 0,
            0x00FFFFFF, 0x77FFFFFF,
            Shader.TileMode.CLAMP
    );

    paint.setShader(shader);
    paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));

    canvas.drawRect(0, 0, w, h, paint);

    return overlay;
}