content: package com.lib.bitmap;
  
  import android.graphics.Bitmap;
  import android.graphics.BitmapShader;
  import android.graphics.Canvas;
  import android.graphics.Paint;
  
  import com.squareup.picasso.Transformation;
  
  /**
   * Created by robi on 2016-06-06 15:20.
   */
  public class CircleTransform implements Transformation {
      @Override
      public Bitmap transform(Bitmap source) {
          int size = Math.min(source.getWidth(), source.getHeight());
  
          int x = (source.getWidth() - size) / 2;
          int y = (source.getHeight() - size) / 2;
  
          Bitmap squaredBitmap = Bitmap.createBitmap(source, x, y, size, size);
          if (squaredBitmap != source) {
              source.recycle();
          }
  
          Bitmap bitmap = Bitmap.createBitmap(size, size, source.getConfig());
  
          Canvas canvas = new Canvas(bitmap);
          Paint paint = new Paint();
          BitmapShader shader = new BitmapShader(squaredBitmap,
                  BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP);
          paint.setShader(shader);
          paint.setAntiAlias(true);
  
          float r = size / 2f;
          canvas.drawCircle(r, r, r, paint);
  
          squaredBitmap.recycle();
          return bitmap;
      }
  
      @Override
      public String key() {
          return "circle";
      }
  }
  