Add our own version of an lru memory cache

Allows us to remove our dependency on the
android support libs.

library/src/com/bumptech/glide/resize/ImageManager.java

@@ -23,7 +23,7 @@
 import com.bumptech.glide.resize.cache.DiskCache;
 import com.bumptech.glide.resize.cache.DiskCacheAdapter;
 import com.bumptech.glide.resize.cache.DiskLruCacheWrapper;
-import com.bumptech.glide.resize.cache.LruPhotoCache;
+import com.bumptech.glide.resize.cache.LruMemoryCache;
 import com.bumptech.glide.resize.cache.MemoryCache;
 import com.bumptech.glide.resize.cache.MemoryCacheAdapter;
 import com.bumptech.glide.util.Log;
@@ -294,7 +294,7 @@ public Thread newThread(Runnable runnable) {
             }
 
             if (memoryCache == null) {
-                memoryCache = new LruPhotoCache(getSafeMemoryCacheSize(context));
+                memoryCache = new LruMemoryCache(getSafeMemoryCacheSize(context));
             }
 
             if (diskCache == null) {

library/src/com/bumptech/glide/resize/cache/LruMemoryCache.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2012. Bump Technologies Inc. All Rights Reserved.
+ */
+
+package com.bumptech.glide.resize.cache;
+
+import android.graphics.Bitmap;
+
+import java.util.LinkedHashMap;
+
+/**
+ */
+public class LruMemoryCache implements MemoryCache {
+    private final LinkedHashMap<String, Bitmap> cache = new LinkedHashMap<String, Bitmap>(15, 0.75f, true);
+    private final int maxSize;
+    private ImageRemovedListener imageRemovedListener;
+    private int currentSize = 0;
+
+    private static int getSize(Bitmap bitmap) {
+        return bitmap.getHeight() * bitmap.getRowBytes();
+    }
+
+    public LruMemoryCache(int size) {
+        this.maxSize = size;
+    }
+
+    @Override
+    public boolean contains(String key) {
+        return cache.get(key) != null;
+    }
+
+    @Override
+    public Bitmap get(String key) {
+        return cache.get(key);
+    }
+
+    @Override
+    public Bitmap put(String key, Bitmap bitmap) {
+        currentSize += getSize(bitmap);
+        final Bitmap result = cache.put(key, bitmap);
+        evict();
+        return result;
+    }
+
+    @Override
+    public void setImageRemovedListener(ImageRemovedListener listener) {
+        this.imageRemovedListener = listener;
+    }
+
+    private void evict() {
+        LinkedHashMap.Entry<String, Bitmap> last;
+        while (currentSize > maxSize) {
+            last = cache.entrySet().iterator().next();
+            final Bitmap toRemove = last.getValue();
+            currentSize -= getSize(toRemove);
+            cache.remove(last.getKey());
+
+            if (imageRemovedListener != null) {
+                imageRemovedListener.onImageRemoved(toRemove);
+            }
+        }
+    }
+}