1/*
2 * Copyright (C) 2006-2011 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
17package com.android.server.am;
18
19import android.content.Context;
20import android.database.ContentObserver;
21import android.net.Uri;
22import android.os.Bundle;
23import android.provider.Settings;
24import android.provider.Settings.SettingNotFoundException;
25import android.util.Log;
26
27import java.util.HashMap;
28import java.util.Map;
29
30/**
31 * Helper class for watching a set of core settings which the framework
32 * propagates to application processes to avoid multiple lookups and potentially
33 * disk I/O operations. Note: This class assumes that all core settings reside
34 * in {@link Settings.Secure}.
35 */
36class CoreSettingsObserver extends ContentObserver {
37    private static final String LOG_TAG = CoreSettingsObserver.class.getSimpleName();
38
39    // mapping form property name to its type
40    private static final Map<String, Class<?>> sCoreSettingToTypeMap = new HashMap<
41            String, Class<?>>();
42    static {
43        sCoreSettingToTypeMap.put(Settings.Secure.LONG_PRESS_TIMEOUT, int.class);
44        // add other core settings here...
45    }
46
47    private final Bundle mCoreSettings = new Bundle();
48
49    private final ActivityManagerService mActivityManagerService;
50
51    public CoreSettingsObserver(ActivityManagerService activityManagerService) {
52        super(activityManagerService.mHandler);
53        mActivityManagerService = activityManagerService;
54        beginObserveCoreSettings();
55        sendCoreSettings();
56    }
57
58    public Bundle getCoreSettingsLocked() {
59        return (Bundle) mCoreSettings.clone();
60    }
61
62    @Override
63    public void onChange(boolean selfChange) {
64        synchronized (mActivityManagerService) {
65            sendCoreSettings();
66        }
67    }
68
69    private void sendCoreSettings() {
70        populateCoreSettings(mCoreSettings);
71        mActivityManagerService.onCoreSettingsChange(mCoreSettings);
72    }
73
74    private void beginObserveCoreSettings() {
75        for (String setting : sCoreSettingToTypeMap.keySet()) {
76            Uri uri = Settings.Secure.getUriFor(setting);
77            mActivityManagerService.mContext.getContentResolver().registerContentObserver(
78                    uri, false, this);
79        }
80    }
81
82    private void populateCoreSettings(Bundle snapshot) {
83        Context context = mActivityManagerService.mContext;
84        for (Map.Entry<String, Class<?>> entry : sCoreSettingToTypeMap.entrySet()) {
85            String setting = entry.getKey();
86            Class<?> type = entry.getValue();
87            try {
88                if (type == String.class) {
89                    String value = Settings.Secure.getString(context.getContentResolver(),
90                            setting);
91                    snapshot.putString(setting, value);
92                } else if (type == int.class) {
93                    int value = Settings.Secure.getInt(context.getContentResolver(),
94                            setting);
95                    snapshot.putInt(setting, value);
96                } else if (type == float.class) {
97                    float value = Settings.Secure.getFloat(context.getContentResolver(),
98                            setting);
99                    snapshot.putFloat(setting, value);
100                } else if (type == long.class) {
101                    long value = Settings.Secure.getLong(context.getContentResolver(),
102                            setting);
103                    snapshot.putLong(setting, value);
104                }
105            } catch (SettingNotFoundException snfe) {
106                Log.w(LOG_TAG, "Cannot find setting \"" + setting + "\"", snfe);
107            }
108        }
109    }
110}
111