com.optimalorange.cooltechnologies.util.LruBitmapCache.java Source code

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Here is the source code for com.optimalorange.cooltechnologies.util.LruBitmapCache.java

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/**
 * Copyright (C) 2014 The Android Open Source Project
 *
 * 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.
 */
//stolen from http://developer.android.com/training/volley/request.html#lru-cache
package com.optimalorange.cooltechnologies.util;

import com.android.volley.toolbox.ImageLoader;

import android.content.Context;
import android.graphics.Bitmap;
import android.support.v4.util.LruCache;
import android.util.DisplayMetrics;

public class LruBitmapCache extends LruCache<String, Bitmap> implements ImageLoader.ImageCache {

    /**
     * @param maxSize the maximum sum of the sizes of the entries in this cache.
     */
    public LruBitmapCache(int maxSize) {
        super(maxSize);
    }

    /**
     * construct a {@link com.optimalorange.cooltechnologies.util.LruBitmapCache} with the maxSize
     * equal to approximately three screens worth of images.
     *
     * @see #LruBitmapCache(int maxSize)
     * @see #getCacheSize(android.content.Context context)
     */
    public LruBitmapCache(Context context) {
        this(getCacheSize(context));
    }

    @Override
    protected int sizeOf(String key, Bitmap value) {
        return value.getRowBytes() * value.getHeight();
    }

    @Override
    public Bitmap getBitmap(String url) {
        return get(url);
    }

    @Override
    public void putBitmap(String url, Bitmap bitmap) {
        put(url, bitmap);
    }

    /**
     * @return a cache size equal to approximately three screens worth of images.
     */
    public static int getCacheSize(Context context) {
        final DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
        final int screenWidth = displayMetrics.widthPixels;
        final int screenHeight = displayMetrics.heightPixels;
        // 4 bytes per pixel
        final int screenBytes = screenWidth * screenHeight * 4;

        return screenBytes * 3;
    }
}