1 files changed, 233 insertions, 0 deletions
diff --git a/src/com/android/gallery3d/gadget/MediaSetSource.java b/src/com/android/gallery3d/gadget/MediaSetSource.java
new file mode 100644
index 000000000..458651c98
--- /dev/null
+++ b/src/com/android/gallery3d/gadget/MediaSetSource.java
@@ -0,0 +1,233 @@
+/*
+ * 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.gadget;
+
+import android.graphics.Bitmap;
+import android.net.Uri;
+import android.os.Binder;
+
+import com.android.gallery3d.common.Utils;
+import com.android.gallery3d.data.ContentListener;
+import com.android.gallery3d.data.DataManager;
+import com.android.gallery3d.data.MediaItem;
+import com.android.gallery3d.data.MediaObject;
+import com.android.gallery3d.data.MediaSet;
+import com.android.gallery3d.data.Path;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+
+public class MediaSetSource implements WidgetSource, ContentListener {
+    private static final String TAG = "MediaSetSource";
+
+    private DataManager mDataManager;
+    private Path mAlbumPath;
+
+    private WidgetSource mSource;
+
+    private MediaSet mRootSet;
+    private ContentListener mListener;
+
+    public MediaSetSource(DataManager manager, String albumPath) {
+        MediaSet mediaSet = (MediaSet) manager.getMediaObject(albumPath);
+        if (mediaSet != null) {
+            mSource = new CheckedMediaSetSource(mediaSet);
+            return;
+        }
+
+        // Initialize source to an empty source until the album path can be resolved
+        mDataManager = Utils.checkNotNull(manager);
+        mAlbumPath = Path.fromString(albumPath);
+        mSource = new EmptySource();
+        monitorRootPath();
+    }
+
+    @Override
+    public int size() {
+        return mSource.size();
+    }
+
+    @Override
+    public Bitmap getImage(int index) {
+        return mSource.getImage(index);
+    }
+
+    @Override
+    public Uri getContentUri(int index) {
+        return mSource.getContentUri(index);
+    }
+
+    @Override
+    public synchronized void setContentListener(ContentListener listener) {
+        if (mRootSet != null) {
+            mListener = listener;
+        } else {
+            mSource.setContentListener(listener);
+        }
+    }
+
+    @Override
+    public void reload() {
+        mSource.reload();
+    }
+
+    @Override
+    public void close() {
+        mSource.close();
+    }
+
+    @Override
+    public void onContentDirty() {
+        resolveAlbumPath();
+    }
+
+    private void monitorRootPath() {
+        String rootPath = mDataManager.getTopSetPath(DataManager.INCLUDE_ALL);
+        mRootSet = (MediaSet) mDataManager.getMediaObject(rootPath);
+        mRootSet.addContentListener(this);
+    }
+
+    private synchronized void resolveAlbumPath() {
+        if (mDataManager == null) return;
+        MediaSet mediaSet = (MediaSet) mDataManager.getMediaObject(mAlbumPath);
+        if (mediaSet != null) {
+            // Clear the reference instead of removing the listener
+            // to get around a concurrent modification exception.
+            mRootSet = null;
+
+            mSource = new CheckedMediaSetSource(mediaSet);
+            if (mListener != null) {
+                mListener.onContentDirty();
+                mSource.setContentListener(mListener);
+                mListener = null;
+            }
+            mDataManager = null;
+            mAlbumPath = null;
+        }
+    }
+
+    private static class CheckedMediaSetSource implements WidgetSource, ContentListener {
+        private static final int CACHE_SIZE = 32;
+
+        @SuppressWarnings("unused")
+        private static final String TAG = "CheckedMediaSetSource";
+
+        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 CheckedMediaSetSource(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();
+        }
+    }
+
+    private static class EmptySource implements WidgetSource {
+
+        @Override
+        public int size() {
+            return 0;
+        }
+
+        @Override
+        public Bitmap getImage(int index) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public Uri getContentUri(int index) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void setContentListener(ContentListener listener) {}
+
+        @Override
+        public void reload() {}
+
+        @Override
+        public void close() {}
+    }
+}