| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License |
| */ |
| |
| package android.preference; |
| |
| import android.annotation.Nullable; |
| |
| import java.util.Set; |
| |
| /** |
| * A data store interface to be implemented and provided to the Preferences framework. This can be |
| * used to replace the default {@link android.content.SharedPreferences}, if needed. |
| * |
| * <p>In most cases you want to use {@link android.content.SharedPreferences} as it is automatically |
| * backed up and migrated to new devices. However, providing custom data store to preferences can be |
| * useful if your app stores its preferences in a local db, cloud or they are device specific like |
| * "Developer settings". It might be also useful when you want to use the preferences UI but |
| * the data are not supposed to be stored at all because they are valid per session only. |
| * |
| * <p>Once a put method is called it is full responsibility of the data store implementation to |
| * safely store the given values. Time expensive operations need to be done in the background to |
| * prevent from blocking the UI. You also need to have a plan on how to serialize the data in case |
| * the activity holding this object gets destroyed. |
| * |
| * <p>By default, all "put" methods throw {@link UnsupportedOperationException}. |
| * |
| * @see Preference#setPreferenceDataStore(PreferenceDataStore) |
| * @see PreferenceManager#setPreferenceDataStore(PreferenceDataStore) |
| */ |
| public interface PreferenceDataStore { |
| |
| /** |
| * Set a String value to the data store. |
| * |
| * <p>Once the value is set the data store is responsible for holding it. |
| * |
| * @param key The name of the preference to modify. |
| * @param value The new value for the preference. |
| * @see #getString(String, String) |
| */ |
| default void putString(String key, @Nullable String value) { |
| throw new UnsupportedOperationException("Not implemented on this data store"); |
| } |
| |
| /** |
| * Set a set of String value to the data store. |
| * |
| * <p>Once the value is set the data store is responsible for holding it. |
| * |
| * @param key The name of the preference to modify. |
| * @param values The set of new values for the preference. |
| * @see #getStringSet(String, Set) |
| */ |
| default void putStringSet(String key, @Nullable Set<String> values) { |
| throw new UnsupportedOperationException("Not implemented on this data store"); |
| } |
| |
| /** |
| * Set an int value to the data store. |
| * |
| * <p>Once the value is set the data store is responsible for holding it. |
| * |
| * @param key The name of the preference to modify. |
| * @param value The new value for the preference. |
| * @see #getInt(String, int) |
| */ |
| default void putInt(String key, int value) { |
| throw new UnsupportedOperationException("Not implemented on this data store"); |
| } |
| |
| /** |
| * Set a long value to the data store. |
| * |
| * <p>Once the value is set the data store is responsible for holding it. |
| * |
| * @param key The name of the preference to modify. |
| * @param value The new value for the preference. |
| * @see #getLong(String, long) |
| */ |
| default void putLong(String key, long value) { |
| throw new UnsupportedOperationException("Not implemented on this data store"); |
| } |
| |
| /** |
| * Set a float value to the data store. |
| * |
| * <p>Once the value is set the data store is responsible for holding it. |
| * |
| * @param key The name of the preference to modify. |
| * @param value The new value for the preference. |
| * @see #getFloat(String, float) |
| */ |
| default void putFloat(String key, float value) { |
| throw new UnsupportedOperationException("Not implemented on this data store"); |
| } |
| |
| /** |
| * Set a boolean value to the data store. |
| * |
| * <p>Once the value is set the data store is responsible for holding it. |
| * |
| * @param key The name of the preference to modify. |
| * @param value The new value for the preference. |
| * @see #getBoolean(String, boolean) |
| */ |
| default void putBoolean(String key, boolean value) { |
| throw new UnsupportedOperationException("Not implemented on this data store"); |
| } |
| |
| /** |
| * Retrieve a String value from the data store. |
| * |
| * @param key The name of the preference to retrieve. |
| * @param defValue Value to return if this preference does not exist. |
| * @see #putString(String, String) |
| */ |
| @Nullable |
| default String getString(String key, @Nullable String defValue) { |
| return defValue; |
| } |
| |
| /** |
| * Retrieve a set of String values from the data store. |
| * |
| * @param key The name of the preference to retrieve. |
| * @param defValues Values to return if this preference does not exist. |
| * @see #putStringSet(String, Set) |
| */ |
| @Nullable |
| default Set<String> getStringSet(String key, @Nullable Set<String> defValues) { |
| return defValues; |
| } |
| |
| /** |
| * Retrieve an int value from the data store. |
| * |
| * @param key The name of the preference to retrieve. |
| * @param defValue Value to return if this preference does not exist. |
| * @see #putInt(String, int) |
| */ |
| default int getInt(String key, int defValue) { |
| return defValue; |
| } |
| |
| /** |
| * Retrieve a long value from the data store. |
| * |
| * @param key The name of the preference to retrieve. |
| * @param defValue Value to return if this preference does not exist. |
| * @see #putLong(String, long) |
| */ |
| default long getLong(String key, long defValue) { |
| return defValue; |
| } |
| |
| /** |
| * Retrieve a float value from the data store. |
| * |
| * @param key The name of the preference to retrieve. |
| * @param defValue Value to return if this preference does not exist. |
| * @see #putFloat(String, float) |
| */ |
| default float getFloat(String key, float defValue) { |
| return defValue; |
| } |
| |
| /** |
| * Retrieve a boolean value from the data store. |
| * |
| * @param key The name of the preference to retrieve. |
| * @param defValue Value to return if this preference does not exist. |
| * @see #getBoolean(String, boolean) |
| */ |
| default boolean getBoolean(String key, boolean defValue) { |
| return defValue; |
| } |
| } |