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