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      1 /*
      2  * Copyright (C) 2015 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.deskclock.data;
     18 
     19 import android.content.SharedPreferences;
     20 
     21 /**
     22  * This class encapsulates the transfer of data between widget objects and their permanent storage
     23  * in {@link SharedPreferences}.
     24  */
     25 final class WidgetDAO {
     26 
     27     /** Suffix for a key to a preference that stores the instance count for a given widget type. */
     28     private static final String WIDGET_COUNT = "_widget_count";
     29 
     30     private WidgetDAO() {}
     31 
     32     /**
     33      * @param widgetProviderClass indicates the type of widget being counted
     34      * @param count the number of widgets of the given type
     35      * @return the delta between the new count and the old count
     36      */
     37     static int updateWidgetCount(SharedPreferences prefs, Class widgetProviderClass, int count) {
     38         final String key = widgetProviderClass.getSimpleName() + WIDGET_COUNT;
     39         final int oldCount = prefs.getInt(key, 0);
     40         if (count == 0) {
     41             prefs.edit().remove(key).apply();
     42         } else {
     43             prefs.edit().putInt(key, count).apply();
     44         }
     45         return count - oldCount;
     46     }
     47 }