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      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 
     17 package com.android.server.am;
     18 
     19 import android.content.Context;
     20 import android.database.ContentObserver;
     21 import android.net.Uri;
     22 import android.os.Bundle;
     23 import android.provider.Settings;
     24 import android.provider.Settings.SettingNotFoundException;
     25 import android.util.Log;
     26 
     27 import java.util.HashMap;
     28 import 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  */
     36 class 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