RoundedCornersTransform for Picasso

RoundedCornersTransform.java

/*
 * Copyright 2016 Juan Pablo Prado
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.picassodemo;

import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import com.squareup.picasso.Transformation;

public class RoundedCornersTransform implements Transformation {
  private final int radius;

  public RoundedCornersTransform(int radius) {
    this.radius = radius;
  }

  @Override public Bitmap transform(Bitmap source) {

    Bitmap result = Bitmap.createBitmap(source.getWidth(), source.getHeight(), Bitmap.Config.ARGB_8888);

    Canvas canvas = new Canvas(result);
    Paint shaderPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    BitmapShader shader = new BitmapShader(source, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP);
    shaderPaint.setShader(shader);

    canvas.drawRoundRect(new RectF(0, 0, source.getWidth(), source.getHeight()), radius, radius, shaderPaint);

    if (source != result) {
      source.recycle();
    }
    return result;
  }

  @Override public String key() {
    return RoundedCornersTransform.class.getCanonicalName();
  }
}