content: /*
   * Copyright 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 <%= appPackage %>.data.source;
  
  import android.support.annotation.NonNull;
  
  import <%= appPackage %>.data.Task;
  
  import java.util.List;
  
  /**
   * Main entry point for accessing tasks data.
   * <p>
   * For simplicity, only getTasks() and getTask() have callbacks. Consider adding callbacks to other
   * methods to inform the user of network/database errors or successful operations.
   * For example, when a new task is created, it's synchronously stored in cache but usually every
   * operation on database or network should be executed in a different thread.
   */
  public interface TasksDataSource {
  
      interface GetTasksCallback {
  
          void onTasksLoaded(List<Task> tasks);
  
          void onDataNotAvailable();
      }
  
      interface GetTaskCallback {
  
          void onTaskLoaded(Task task);
  
          void onDataNotAvailable();
      }
  
      void getTasks(@NonNull GetTasksCallback callback);
  
      void getTask(@NonNull String taskId, @NonNull GetTaskCallback callback);
  
      void saveTask(@NonNull Task task);
  
      void completeTask(@NonNull Task task);
  
      void completeTask(@NonNull String taskId);
  
      void activateTask(@NonNull Task task);
  
      void activateTask(@NonNull String taskId);
  
      void clearCompletedTasks();
  
      void deleteAllTasks();
  
      void deleteTask(@NonNull String taskId);
  }