BitmapMemoryLruCache.java

/*******************************************************************************
 * Copyright (c) 2013 Chris Banes.
 *
 * 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 uk.co.senab.bitmapcache;

import android.support.v4.util.LruCache;

import java.util.Map.Entry;
import java.util.Set;

final class BitmapMemoryLruCache extends LruCache<String, CacheableBitmapDrawable> {

    BitmapMemoryLruCache(int maxSize) {
        super(maxSize);
    }

    CacheableBitmapDrawable put(CacheableBitmapDrawable value) {
        if (null != value) {
            value.setCached(true);
            return put(value.getUrl(), value);
        }

        return null;
    }

    @Override
    protected int sizeOf(String key, CacheableBitmapDrawable value) {
        return value.getMemorySize();
    }

    @Override
    protected void entryRemoved(boolean evicted, String key, CacheableBitmapDrawable oldValue,
            CacheableBitmapDrawable newValue) {
        // Notify the wrapper that it's no longer being cached
        oldValue.setCached(false);
    }

    void trimMemory() {
        final Set<Entry<String, CacheableBitmapDrawable>> values = snapshot().entrySet();

        for (Entry<String, CacheableBitmapDrawable> entry : values) {
            CacheableBitmapDrawable value = entry.getValue();
            if (null == value || !value.isBeingDisplayed()) {
                remove(entry.getKey());
            }
        }
    }

}