BlurTransformation.java

package jp.wasabeef.picasso.transformations;

/**
 * Copyright (C) 2017 Wasabeef
 *
 * 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.
 */

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.os.Build;
import android.renderscript.RSRuntimeException;
import com.squareup.picasso.Transformation;
import jp.wasabeef.picasso.transformations.internal.FastBlur;
import jp.wasabeef.picasso.transformations.internal.RSBlur;

public class BlurTransformation implements Transformation {

  private static int MAX_RADIUS = 25;
  private static int DEFAULT_DOWN_SAMPLING = 1;

  private Context mContext;

  private int mRadius;
  private int mSampling;

  public BlurTransformation(Context context) {
    this(context, MAX_RADIUS, DEFAULT_DOWN_SAMPLING);
  }

  public BlurTransformation(Context context, int radius) {
    this(context, radius, DEFAULT_DOWN_SAMPLING);
  }

  public BlurTransformation(Context context, int radius, int sampling) {
    mContext = context.getApplicationContext();
    mRadius = radius;
    mSampling = sampling;
  }

  @Override public Bitmap transform(Bitmap source) {

    int scaledWidth = source.getWidth() / mSampling;
    int scaledHeight = source.getHeight() / mSampling;

    Bitmap bitmap = Bitmap.createBitmap(scaledWidth, scaledHeight, Bitmap.Config.ARGB_8888);

    Canvas canvas = new Canvas(bitmap);
    canvas.scale(1 / (float) mSampling, 1 / (float) mSampling);
    Paint paint = new Paint();
    paint.setFlags(Paint.FILTER_BITMAP_FLAG);
    canvas.drawBitmap(source, 0, 0, paint);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
      try {
        bitmap = RSBlur.blur(mContext, bitmap, mRadius);
      } catch (RSRuntimeException e) {
        bitmap = FastBlur.blur(bitmap, mRadius, true);
      }
    } else {
      bitmap = FastBlur.blur(bitmap, mRadius, true);
    }

    source.recycle();

    return bitmap;
  }

  @Override public String key() {
    return "BlurTransformation(radius=" + mRadius + ", sampling=" + mSampling + ")";
  }
}