RectRoundedBordersTransformation.java

import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffColorFilter;
import android.os.Build;

import com.squareup.picasso.Transformation;

public class RectRoundedBordersTransformation implements Transformation{
    float radius = 10f;

    public RectRoundedBordersTransformation(float radius) {
        this.radius = radius;
    }

    @Override
    public Bitmap transform(final Bitmap source) {
        int size = Math.min(source.getWidth(), source.getHeight());

        int w = source.getWidth() / 2;
        int h = source.getHeight() / 2;

        Bitmap squaredBitmap = Bitmap.createBitmap(source, 0, 0, w, h);
        if (squaredBitmap != source) {
            source.recycle();
        }

        Bitmap bitmap = Bitmap.createBitmap(w, h, 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);
        paint.setColorFilter(new PorterDuffColorFilter(Color.WHITE, PorterDuff.Mode.DST_OVER));

        float sf = (float)size;
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP){
            canvas.drawRoundRect(0f, 0f, w, h, radius, radius, paint);
        }else{
            canvas.drawRect(0f, radius, w, h-radius, paint );
            canvas.drawRect(radius, 0f, w-radius, h, paint );
            canvas.drawCircle(radius, radius, radius, paint); // Upper-left
            canvas.drawCircle(w-radius, radius, radius, paint); // Upper-right
            canvas.drawCircle(radius, h-radius, radius, paint); // Bottom-left
            canvas.drawCircle(w-radius, h-radius, radius, paint); // Bottom-right
        }

        squaredBitmap.recycle();
        return bitmap;

    }

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