content: /*
   * 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)
   *
   * @deprecated Use the <a href="{@docRoot}jetpack/androidx.html">AndroidX</a>
   *      <a href="{@docRoot}reference/androidx/preference/package-summary.html">
   *      Preference Library</a> for consistent behavior across all devices. For more information on
   *      using the AndroidX Preference Library see
   *      <a href="{@docRoot}guide/topics/ui/settings.html">Settings</a>.
   */
  @Deprecated
  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;
      }
  }
  