1 files changed, 113 insertions, 0 deletions
diff --git a/src/com/android/gallery3d/widget/MediaSetSource.java b/src/com/android/gallery3d/widget/MediaSetSource.java
new file mode 100644
index 000000000..1677f69f1
--- /dev/null
+++ b/src/com/android/gallery3d/widget/MediaSetSource.java
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2011 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.
+ */
+
+package com.android.gallery3d.widget;
+
+import com.android.gallery3d.common.Utils;
+import com.android.gallery3d.data.ContentListener;
+import com.android.gallery3d.data.MediaItem;
+import com.android.gallery3d.data.MediaObject;
+import com.android.gallery3d.data.MediaSet;
+
+import android.graphics.Bitmap;
+import android.net.Uri;
+import android.os.Binder;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+
+public class MediaSetSource implements WidgetSource, ContentListener {
+    private static final int CACHE_SIZE = 32;
+
+    private static final String TAG = "MediaSetSource";
+
+    private MediaSet mSource;
+    private MediaItem mCache[] = new MediaItem[CACHE_SIZE];
+    private int mCacheStart;
+    private int mCacheEnd;
+    private long mSourceVersion = MediaObject.INVALID_DATA_VERSION;
+
+    private ContentListener mContentListener;
+
+    public MediaSetSource(MediaSet source) {
+        mSource = Utils.checkNotNull(source);
+        mSource.addContentListener(this);
+    }
+
+    @Override
+    public void close() {
+        mSource.removeContentListener(this);
+    }
+
+    private void ensureCacheRange(int index) {
+        if (index >= mCacheStart && index < mCacheEnd) return;
+
+        long token = Binder.clearCallingIdentity();
+        try {
+            mCacheStart = index;
+            ArrayList<MediaItem> items = mSource.getMediaItem(mCacheStart, CACHE_SIZE);
+            mCacheEnd = mCacheStart + items.size();
+            items.toArray(mCache);
+        } finally {
+            Binder.restoreCallingIdentity(token);
+        }
+    }
+
+    @Override
+    public synchronized Uri getContentUri(int index) {
+        ensureCacheRange(index);
+        if (index < mCacheStart || index >= mCacheEnd) return null;
+        return mCache[index - mCacheStart].getContentUri();
+    }
+
+    @Override
+    public synchronized Bitmap getImage(int index) {
+        ensureCacheRange(index);
+        if (index < mCacheStart || index >= mCacheEnd) return null;
+        return WidgetUtils.createWidgetBitmap(mCache[index - mCacheStart]);
+    }
+
+    @Override
+    public void reload() {
+        long version = mSource.reload();
+        if (mSourceVersion != version) {
+            mSourceVersion = version;
+            mCacheStart = 0;
+            mCacheEnd = 0;
+            Arrays.fill(mCache, null);
+        }
+    }
+
+    @Override
+    public void setContentListener(ContentListener listener) {
+        mContentListener = listener;
+    }
+
+    @Override
+    public int size() {
+        long token = Binder.clearCallingIdentity();
+        try {
+            return mSource.getMediaItemCount();
+        } finally {
+            Binder.restoreCallingIdentity(token);
+        }
+    }
+
+    @Override
+    public void onContentDirty() {
+        if (mContentListener != null) mContentListener.onContentDirty();
+    }
+}