BlurTransform.java

/*
 * Copyright 2014 Google Inc. All rights reserved.
 *
 * 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.android.example.leanback;

import android.content.Context;
import android.graphics.Bitmap;
import android.renderscript.Allocation;
import android.renderscript.Element;
import android.renderscript.RenderScript;
import android.renderscript.ScriptIntrinsicBlur;

import com.squareup.picasso.Transformation;

public class BlurTransform implements Transformation {

    RenderScript rs;

    static BlurTransform blurTransform;

    protected BlurTransform() {
        // Exists only to defeat instantiation.
    }

    private BlurTransform(Context context) {
        super();
        rs = RenderScript.create(context);
    }

    public static BlurTransform getInstance(Context context) {
        if (blurTransform == null) {
            blurTransform = new BlurTransform(context);
        }
        return blurTransform;
    }

    @Override
    public Bitmap transform(Bitmap bitmap) {
        // Create another bitmap that will hold the results of the filter.
        Bitmap blurredBitmap = Bitmap.createBitmap(bitmap);

        // Allocate memory for Renderscript to work with
        Allocation input = Allocation.createFromBitmap(rs, bitmap, Allocation.MipmapControl.MIPMAP_FULL, Allocation.USAGE_SHARED);
        Allocation output = Allocation.createTyped(rs, input.getType());

        // Load up an instance of the specific script that we want to use.
        ScriptIntrinsicBlur script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
        script.setInput(input);

        // Set the blur radius
        script.setRadius(20);

        // Start the ScriptIntrinisicBlur
        script.forEach(output);

        // Copy the output to the blurred bitmap
        output.copyTo(blurredBitmap);

        bitmap.recycle();

        return blurredBitmap;
    }

    @Override
    public String key() {
        return "blur";
    }

}