android - Rounded corners with Picasso

Question

Is there a reasonable way to do rounded corners with Picasso that

1. Doesn't significantly slow down drawing
2. Works with hardware layers
3. Doesn't create an extra bitmap for each image
4. Allows resizing the downloaded bitmap into the size of the destination imageview

Most of the picasso advice on rounded corners suggests that a transformation be used, but I haven't seen an example that doesn't create an extra bitmap as part of the transformation.

This seems to be because Picasso only uses bitmaps, while the tricks to do rounded corners use the fact that you can dynamically draw the rounded corners on reasonably efficiently (most solutions use something along the lines of http://www.curious-creature.org/2012/12/11/android-recipe-1-image-with-rounded-corners/).

Doing this with Volley was a bit hacky but possible, by just changing the type of ImageView to something that took a custom drawable, which drew rounded corners. Since Picasso needs bitmaps (at least, there's only a bitmap -> bitmap transformation), this is out, since the conversion of the drawable to bitmap creates a bitmap in the process.

One solution would be to do the work to modify picasso in a branch on my own that added a bitmap -> drawable transform, but I'd imagine there's a better way to go about this.

I do not want to draw a 9-patch on top of a view to give the appearance of rounded corners.

Answer 1

1. This code works fine for me
   

   Picasso.with(getApplicationContext())
           .load(sp.getString("image_url", ""))
           .transform(new RoundedTransformation(100, 0))
           .fit()
           .into(userProfileImg);
   

// here is the class for make

    public class RoundedTransformation implements
        com.squareup.picasso.Transformation {
    private final int radius;
    private final int margin; // dp

    // radius is corner radii in dp
    // margin is the board in dp
    public RoundedTransformation(final int radius, final int margin) {
        this.radius = radius;
        this.margin = margin;
    }

    @Override
    public Bitmap transform(final Bitmap source) {
        final Paint paint = new Paint();
        paint.setAntiAlias(true);
        paint.setShader(new BitmapShader(source, Shader.TileMode.CLAMP,
                Shader.TileMode.CLAMP));

        Bitmap output = Bitmap.createBitmap(source.getWidth(),
                source.getHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(output);
        canvas.drawRoundRect(new RectF(margin, margin, source.getWidth()
                - margin, source.getHeight() - margin), radius, radius, paint);

        if (source != output) {
            source.recycle();
        }

        return output;
    }

    @Override
    public String key() {
        return "rounded";
    }
}