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.quicksearchbox.util;
18 
19 import android.database.DataSetObservable;
20 import android.os.Handler;
21 
22 /**
23  * A version of {@link DataSetObservable} that performs callbacks on given {@link Handler}.
24  */
25 public class AsyncDataSetObservable extends DataSetObservable {
26 
27     private final Handler mHandler;
28 
29     private final Runnable mChangedRunnable = new Runnable() {
30         public void run() {
31             AsyncDataSetObservable.super.notifyChanged();
32         }
33     };
34 
35     private final Runnable mInvalidatedRunnable = new Runnable() {
36         public void run() {
37             AsyncDataSetObservable.super.notifyInvalidated();
38         }
39     };
40 
41     /**
42      * @param handler Handler to run callbacks on.
43      */
AsyncDataSetObservable(Handler handler)44     public AsyncDataSetObservable(Handler handler) {
45         mHandler = handler;
46     }
47 
48     @Override
notifyChanged()49     public void notifyChanged() {
50         if (mHandler == null) {
51             super.notifyChanged();
52         } else {
53             mHandler.post(mChangedRunnable);
54         }
55     }
56 
57     @Override
notifyInvalidated()58     public void notifyInvalidated() {
59         if (mHandler == null) {
60             super.notifyInvalidated();
61         } else {
62             mHandler.post(mInvalidatedRunnable);
63         }
64     }
65 
66 }
67