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 com.example.android.testing.espresso.IdlingResourceSample;
  
  import android.os.Handler;
  import androidx.annotation.Nullable;
  import androidx.test.espresso.IdlingResource;
  
  import com.example.android.testing.espresso.IdlingResourceSample.IdlingResource.SimpleIdlingResource;
  
  /**
   * Takes a String and returns it after a while via a callback.
   * <p>
   * This executes a long-running operation on a different thread that results in problems with
   * Espresso if an {@link IdlingResource} is not implemented and registered.
   */
  class MessageDelayer {
  
      private static final int DELAY_MILLIS = 3000;
  
      interface DelayerCallback {
          void onDone(String text);
      }
  
      /**
       * Takes a String and returns it after {@link #DELAY_MILLIS} via a {@link DelayerCallback}.
       * @param message the String that will be returned via the callback
       * @param callback used to notify the caller asynchronously
       */
      static void processMessage(final String message, final DelayerCallback callback,
              @Nullable final SimpleIdlingResource idlingResource) {
          // The IdlingResource is null in production.
          if (idlingResource != null) {
              idlingResource.setIdleState(false);
          }
  
          // Delay the execution, return message via callback.
          Handler handler = new Handler();
          handler.postDelayed(new Runnable() {
              @Override
              public void run() {
                  if (callback != null) {
                      callback.onDone(message);
                      if (idlingResource != null) {
                          idlingResource.setIdleState(true);
                      }
                  }
              }
          }, DELAY_MILLIS);
      }
  }
  