BlurTransformation.java

package com.jp.wasabeef.glide.transformations;

/**
 * Copyright (C) 2015 Wasabeef
 * <p>
 * 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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.bumptech.glide.Glide;
import com.bumptech.glide.load.Transformation;
import com.bumptech.glide.load.engine.Resource;
import com.bumptech.glide.load.engine.bitmap_recycle.BitmapPool;
import com.bumptech.glide.load.resource.bitmap.BitmapResource;
import com.jp.wasabeef.glide.transformations.internal.FastBlur;
import com.jp.wasabeef.glide.transformations.internal.RSBlur;

public class BlurTransformation implements Transformation<Bitmap> {

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

    private Context mContext;
    private BitmapPool mBitmapPool;

    private int mRadius;
    private int mSampling;

    public BlurTransformation(Context context) {
        this(context, Glide.get(context).getBitmapPool(), MAX_RADIUS, DEFAULT_DOWN_SAMPLING);
    }

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

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

    public BlurTransformation(Context context, int radius) {
        this(context, Glide.get(context).getBitmapPool(), radius, DEFAULT_DOWN_SAMPLING);
    }

    public BlurTransformation(Context context, int radius, int sampling) {
        this(context, Glide.get(context).getBitmapPool(), radius, sampling);
    }

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

    @Override
    public Resource<Bitmap> transform(Resource<Bitmap> resource, int outWidth, int outHeight) {
        Bitmap source = resource.get();

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

        Bitmap bitmap = mBitmapPool.get(scaledWidth, scaledHeight, Bitmap.Config.ARGB_8888);
        if (bitmap == null) {
            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_MR1) {
            try {
                bitmap = RSBlur.getInstance().blur(bitmap, mRadius);
            } catch (RSRuntimeException e) {
                bitmap = FastBlur.blur(bitmap, mRadius, true);
            }
        } else {
            bitmap = FastBlur.blur(bitmap, mRadius, true);
        }

        return BitmapResource.obtain(bitmap, mBitmapPool);
    }

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