1 /* 2 * Copyright (C) 2014 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.camera.settings; 18 19 import java.util.HashMap; 20 21 /** 22 * A class for storing default values and possible values of 23 * SharedPreferences settings. It is optional to store defaults 24 * and possible values for a setting. If a default is not specified, 25 * the SettingsManager API chooses a default based on the type 26 * requested: 27 * 28 * <ul>getString: default is null</ul> 29 * <ul>getInteger: default is 0</ul> 30 * <ul>getBoolean: default is false</ul> 31 * 32 * If possible values aren't specified for a 33 * SharedPreferences key, then calling getIndexOfCurrentValue 34 * and setValueByIndex will throw an IllegalArgumentException. 35 */ 36 class DefaultsStore { 37 38 /** 39 * A class for storing a default value and set of possible 40 * values. Since all settings values are saved as Strings in 41 * SharedPreferences, the default and possible values are 42 * Strings. This simplifies default values management. 43 */ 44 private static class Defaults { 45 private String mDefaultValue; 46 private String[] mPossibleValues; 47 Defaults(String defaultValue, String[] possibleValues)48 public Defaults(String defaultValue, String[] possibleValues) { 49 mDefaultValue = defaultValue; 50 mPossibleValues = possibleValues; 51 } 52 getDefaultValue()53 public String getDefaultValue() { 54 return mDefaultValue; 55 } 56 getPossibleValues()57 public String[] getPossibleValues() { 58 return mPossibleValues; 59 } 60 } 61 62 /** Map of Defaults for SharedPreferences keys. */ 63 private static HashMap<String, Defaults> mDefaultsInternalStore = 64 new HashMap<String, Defaults>(); 65 66 /** 67 * Store a default value and a set of possible values 68 * for a SharedPreferences key. 69 */ storeDefaults(String key, String defaultValue, String[] possibleValues)70 public void storeDefaults(String key, String defaultValue, String[] possibleValues) { 71 Defaults defaults = new Defaults(defaultValue, possibleValues); 72 mDefaultsInternalStore.put(key, defaults); 73 } 74 75 /** 76 * Get the default value for a SharedPreferences key, 77 * if one has been stored. 78 */ getDefaultValue(String key)79 public String getDefaultValue(String key) { 80 Defaults defaults = mDefaultsInternalStore.get(key); 81 if (defaults == null) { 82 return null; 83 } 84 return defaults.getDefaultValue(); 85 } 86 87 /** 88 * Get the set of possible values for a SharedPreferences key, 89 * if a set has been stored. 90 */ getPossibleValues(String key)91 public String[] getPossibleValues(String key) { 92 Defaults defaults = mDefaultsInternalStore.get(key); 93 if (defaults == null) { 94 return null; 95 } 96 return defaults.getPossibleValues(); 97 } 98 }