RoundedTransformation.java

package info.justaway.display;

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.Shader;

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) {
        try {
            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;
        } catch (OutOfMemoryError e) {
            return source;
        }
    }

    @Override
    public String key() {
        return "rounded(radius=" + radius + ", margin=" + margin + ")";
    }
}