Filip Pavlis | 0b0c6cb | 2016-11-16 15:58:28 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2016 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 android.preference; |
| 18 | |
| 19 | import android.annotation.Nullable; |
| 20 | |
| 21 | import java.util.Set; |
| 22 | |
| 23 | /** |
Filip Pavlis | fd59645 | 2017-03-01 18:50:00 +0000 | [diff] [blame] | 24 | * A data store interface to be implemented and provided to the Preferences framework. This can be |
| 25 | * used to replace the default {@link android.content.SharedPreferences}, if needed. |
Filip Pavlis | 0b0c6cb | 2016-11-16 15:58:28 +0000 | [diff] [blame] | 26 | * |
Filip Pavlis | fd59645 | 2017-03-01 18:50:00 +0000 | [diff] [blame] | 27 | * <p>In most cases you want to use {@link android.content.SharedPreferences} as it is automatically |
| 28 | * backed up and migrated to new devices. However, providing custom data store to preferences can be |
| 29 | * useful if your app stores its preferences in a local db, cloud or they are device specific like |
| 30 | * "Developer settings". It might be also useful when you want to use the preferences UI but |
| 31 | * the data are not supposed to be stored at all because they are valid per session only. |
| 32 | * |
| 33 | * <p>Once a put method is called it is full responsibility of the data store implementation to |
| 34 | * safely store the given values. Time expensive operations need to be done in the background to |
| 35 | * prevent from blocking the UI. You also need to have a plan on how to serialize the data in case |
| 36 | * the activity holding this object gets destroyed. |
| 37 | * |
| 38 | * <p>By default, all "put" methods throw {@link UnsupportedOperationException}. |
| 39 | * |
| 40 | * @see Preference#setPreferenceDataStore(PreferenceDataStore) |
| 41 | * @see PreferenceManager#setPreferenceDataStore(PreferenceDataStore) |
Filip Pavlis | 0b0c6cb | 2016-11-16 15:58:28 +0000 | [diff] [blame] | 42 | */ |
| 43 | public interface PreferenceDataStore { |
| 44 | |
| 45 | /** |
| 46 | * Set a String value to the data store. |
| 47 | * |
Filip Pavlis | fd59645 | 2017-03-01 18:50:00 +0000 | [diff] [blame] | 48 | * <p>Once the value is set the data store is responsible for holding it. |
| 49 | * |
Filip Pavlis | 0b0c6cb | 2016-11-16 15:58:28 +0000 | [diff] [blame] | 50 | * @param key The name of the preference to modify. |
| 51 | * @param value The new value for the preference. |
| 52 | * @see #getString(String, String) |
| 53 | */ |
| 54 | default void putString(String key, @Nullable String value) { |
| 55 | throw new UnsupportedOperationException("Not implemented on this data store"); |
| 56 | } |
| 57 | |
| 58 | /** |
| 59 | * Set a set of String value to the data store. |
| 60 | * |
Filip Pavlis | fd59645 | 2017-03-01 18:50:00 +0000 | [diff] [blame] | 61 | * <p>Once the value is set the data store is responsible for holding it. |
| 62 | * |
Filip Pavlis | 0b0c6cb | 2016-11-16 15:58:28 +0000 | [diff] [blame] | 63 | * @param key The name of the preference to modify. |
| 64 | * @param values The set of new values for the preference. |
| 65 | * @see #getStringSet(String, Set) |
| 66 | */ |
| 67 | default void putStringSet(String key, @Nullable Set<String> values) { |
| 68 | throw new UnsupportedOperationException("Not implemented on this data store"); |
| 69 | } |
| 70 | |
| 71 | /** |
| 72 | * Set an int value to the data store. |
| 73 | * |
Filip Pavlis | fd59645 | 2017-03-01 18:50:00 +0000 | [diff] [blame] | 74 | * <p>Once the value is set the data store is responsible for holding it. |
| 75 | * |
Filip Pavlis | 0b0c6cb | 2016-11-16 15:58:28 +0000 | [diff] [blame] | 76 | * @param key The name of the preference to modify. |
| 77 | * @param value The new value for the preference. |
| 78 | * @see #getInt(String, int) |
| 79 | */ |
| 80 | default void putInt(String key, int value) { |
| 81 | throw new UnsupportedOperationException("Not implemented on this data store"); |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Set a long value to the data store. |
| 86 | * |
Filip Pavlis | fd59645 | 2017-03-01 18:50:00 +0000 | [diff] [blame] | 87 | * <p>Once the value is set the data store is responsible for holding it. |
| 88 | * |
Filip Pavlis | 0b0c6cb | 2016-11-16 15:58:28 +0000 | [diff] [blame] | 89 | * @param key The name of the preference to modify. |
| 90 | * @param value The new value for the preference. |
| 91 | * @see #getLong(String, long) |
| 92 | */ |
| 93 | default void putLong(String key, long value) { |
| 94 | throw new UnsupportedOperationException("Not implemented on this data store"); |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * Set a float value to the data store. |
| 99 | * |
Filip Pavlis | fd59645 | 2017-03-01 18:50:00 +0000 | [diff] [blame] | 100 | * <p>Once the value is set the data store is responsible for holding it. |
| 101 | * |
Filip Pavlis | 0b0c6cb | 2016-11-16 15:58:28 +0000 | [diff] [blame] | 102 | * @param key The name of the preference to modify. |
| 103 | * @param value The new value for the preference. |
| 104 | * @see #getFloat(String, float) |
| 105 | */ |
| 106 | default void putFloat(String key, float value) { |
| 107 | throw new UnsupportedOperationException("Not implemented on this data store"); |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * Set a boolean value to the data store. |
| 112 | * |
Filip Pavlis | fd59645 | 2017-03-01 18:50:00 +0000 | [diff] [blame] | 113 | * <p>Once the value is set the data store is responsible for holding it. |
| 114 | * |
Filip Pavlis | 0b0c6cb | 2016-11-16 15:58:28 +0000 | [diff] [blame] | 115 | * @param key The name of the preference to modify. |
| 116 | * @param value The new value for the preference. |
| 117 | * @see #getBoolean(String, boolean) |
| 118 | */ |
| 119 | default void putBoolean(String key, boolean value) { |
| 120 | throw new UnsupportedOperationException("Not implemented on this data store"); |
| 121 | } |
| 122 | |
| 123 | /** |
| 124 | * Retrieve a String value from the data store. |
| 125 | * |
| 126 | * @param key The name of the preference to retrieve. |
| 127 | * @param defValue Value to return if this preference does not exist. |
| 128 | * @see #putString(String, String) |
| 129 | */ |
| 130 | @Nullable |
| 131 | default String getString(String key, @Nullable String defValue) { |
| 132 | return defValue; |
| 133 | } |
| 134 | |
| 135 | /** |
| 136 | * Retrieve a set of String values from the data store. |
| 137 | * |
| 138 | * @param key The name of the preference to retrieve. |
| 139 | * @param defValues Values to return if this preference does not exist. |
| 140 | * @see #putStringSet(String, Set) |
| 141 | */ |
| 142 | @Nullable |
| 143 | default Set<String> getStringSet(String key, @Nullable Set<String> defValues) { |
| 144 | return defValues; |
| 145 | } |
| 146 | |
| 147 | /** |
| 148 | * Retrieve an int value from the data store. |
| 149 | * |
| 150 | * @param key The name of the preference to retrieve. |
| 151 | * @param defValue Value to return if this preference does not exist. |
| 152 | * @see #putInt(String, int) |
| 153 | */ |
| 154 | default int getInt(String key, int defValue) { |
| 155 | return defValue; |
| 156 | } |
| 157 | |
| 158 | /** |
| 159 | * Retrieve a long value from the data store. |
| 160 | * |
| 161 | * @param key The name of the preference to retrieve. |
| 162 | * @param defValue Value to return if this preference does not exist. |
| 163 | * @see #putLong(String, long) |
| 164 | */ |
| 165 | default long getLong(String key, long defValue) { |
| 166 | return defValue; |
| 167 | } |
| 168 | |
| 169 | /** |
| 170 | * Retrieve a float value from the data store. |
| 171 | * |
| 172 | * @param key The name of the preference to retrieve. |
| 173 | * @param defValue Value to return if this preference does not exist. |
| 174 | * @see #putFloat(String, float) |
| 175 | */ |
| 176 | default float getFloat(String key, float defValue) { |
| 177 | return defValue; |
| 178 | } |
| 179 | |
| 180 | /** |
| 181 | * Retrieve a boolean value from the data store. |
| 182 | * |
| 183 | * @param key The name of the preference to retrieve. |
| 184 | * @param defValue Value to return if this preference does not exist. |
| 185 | * @see #getBoolean(String, boolean) |
| 186 | */ |
| 187 | default boolean getBoolean(String key, boolean defValue) { |
| 188 | return defValue; |
| 189 | } |
| 190 | } |