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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.gallery3d.data;
     18 
     19 import android.net.Uri;
     20 
     21 import com.android.gallery3d.app.GalleryApp;
     22 
     23 import java.util.concurrent.atomic.AtomicBoolean;
     24 
     25 // This handles change notification for media sets.
     26 public class ChangeNotifier {
     27 
     28     private MediaSet mMediaSet;
     29     private AtomicBoolean mContentDirty = new AtomicBoolean(true);
     30 
     31     public ChangeNotifier(MediaSet set, Uri uri, GalleryApp application) {
     32         mMediaSet = set;
     33         application.getDataManager().registerChangeNotifier(uri, this);
     34     }
     35 
     36     // Returns the dirty flag and clear it.
     37     public boolean isDirty() {
     38         return mContentDirty.compareAndSet(true, false);
     39     }
     40 
     41     // For debugging only.
     42     public void fakeChange() {
     43         onChange(false);
     44     }
     45 
     46     protected void onChange(boolean selfChange) {
     47         if (mContentDirty.compareAndSet(false, true)) {
     48             mMediaSet.notifyContentChanged();
     49         }
     50     }
     51 }