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 androidx.test.multiprocess.app.idling;
  
  import android.os.Handler;
  import androidx.annotation.Nullable;
  import androidx.test.espresso.IdlingResource;
  
  /**
   * Takes a String and passes it back 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.
   */
  public class MessageDelayer {
  
    private static final int DELAY_MILLIS = 3000;
  
    /**
     * Callback interface for clients to use.
     */
    public 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
     */
    public 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);
    }
  }
  