1 /*
2  * Copyright (C) 2017 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.internal.telephony;
18 
19 import android.content.ContentResolver;
20 import android.content.Context;
21 import android.database.ContentObserver;
22 import android.net.Uri;
23 import android.os.Handler;
24 
25 import com.android.telephony.Rlog;
26 
27 import java.util.HashMap;
28 import java.util.Map;
29 
30 /**
31  * The class to describe settings observer
32  */
33 public class SettingsObserver extends ContentObserver {
34     private final Map<Uri, Integer> mUriEventMap;
35     private final Context mContext;
36     private final Handler mHandler;
37     private static final String TAG = "SettingsObserver";
38 
SettingsObserver(Context context, Handler handler)39     public SettingsObserver(Context context, Handler handler) {
40         super(null);
41         mUriEventMap = new HashMap<>();
42         mContext = context;
43         mHandler = handler;
44     }
45 
46     /**
47      * Start observing a content.
48      * @param uri Content URI
49      * @param what The event to fire if the content changes
50      */
observe(Uri uri, int what)51     public void observe(Uri uri, int what) {
52         mUriEventMap.put(uri, what);
53         final ContentResolver resolver = mContext.getContentResolver();
54         resolver.registerContentObserver(uri, false, this);
55     }
56 
57     /**
58      * Stop observing a content.
59      */
unobserve()60     public void unobserve() {
61         final ContentResolver resolver = mContext.getContentResolver();
62         resolver.unregisterContentObserver(this);
63     }
64 
65     @Override
onChange(boolean selfChange)66     public void onChange(boolean selfChange) {
67         Rlog.e(TAG, "Should never be reached.");
68     }
69 
70     @Override
onChange(boolean selfChange, Uri uri)71     public void onChange(boolean selfChange, Uri uri) {
72         final Integer what = mUriEventMap.get(uri);
73         if (what != null) {
74             mHandler.obtainMessage(what.intValue()).sendToTarget();
75         } else {
76             Rlog.e(TAG, "No matching event to send for URI=" + uri);
77         }
78     }
79 }
80