content: /*
   * Copyright (C) 2014 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.ui.app;
  
  import static androidx.test.espresso.Espresso.onView;
  import static androidx.test.espresso.Espresso.registerIdlingResources;
  import static androidx.test.espresso.Espresso.unregisterIdlingResources;
  import static androidx.test.espresso.action.ViewActions.click;
  import static androidx.test.espresso.assertion.ViewAssertions.matches;
  import static androidx.test.espresso.matcher.ViewMatchers.withId;
  import static androidx.test.espresso.matcher.ViewMatchers.withText;
  import static com.google.common.base.Preconditions.checkNotNull;
  import static org.junit.Assert.assertTrue;
  
  import androidx.test.core.app.ActivityScenario;
  import androidx.test.espresso.idling.CountingIdlingResource;
  import androidx.test.ext.junit.runners.AndroidJUnit4;
  import androidx.test.filters.LargeTest;
  import androidx.test.ui.app.SyncActivity.HelloWorldServer;
  import org.junit.After;
  import org.junit.Before;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  
  /**
   * Example for {@link CountingIdlingResource}. Demonstrates how to wait on a delayed response from
   * request before continuing with a test.
   */
  @RunWith(AndroidJUnit4.class)
  @LargeTest
  public class AdvancedSynchronizationTest {
    private CountingIdlingResource countingResource;
  
    private class DecoratedHelloWorldServer implements HelloWorldServer {
      private final HelloWorldServer realHelloWorldServer;
      private final CountingIdlingResource helloWorldServerIdlingResource;
  
      private DecoratedHelloWorldServer(HelloWorldServer realHelloWorldServer,
          CountingIdlingResource helloWorldServerIdlingResource) {
        this.realHelloWorldServer = checkNotNull(realHelloWorldServer);
        this.helloWorldServerIdlingResource = checkNotNull(helloWorldServerIdlingResource);
      }
  
      @Override
      public String getHelloWorld() {
        // Use CountingIdlingResource to track in-flight calls to getHelloWorld (a simulation of a
        // network call). Whenever the count goes to zero, Espresso will be notified that this
        // resource is idle and the test will be able to proceed.
        helloWorldServerIdlingResource.increment();
        try {
          return realHelloWorldServer.getHelloWorld();
        } finally {
          helloWorldServerIdlingResource.decrement();
        }
      }
    }
  
    @Before
    public void setUp() throws Exception {
      ActivityScenario<SyncActivity> activityScenario = ActivityScenario.launch(SyncActivity.class);
      activityScenario.onActivity(
          activity -> {
            HelloWorldServer realServer = activity.getHelloWorldServer();
            // Here, we use CountingIdlingResource - a common convenience class - to track the idle
            // state of
            // the server. You could also do this yourself, by implementing the IdlingResource
            // interface.
            countingResource = new CountingIdlingResource("HelloWorldServerCalls");
  
            activity.setHelloWorldServer(new DecoratedHelloWorldServer(realServer, countingResource));
            assertTrue(registerIdlingResources(countingResource));
          });
    }
  
    @After
    public void tearDown() throws Exception {
      assertTrue(unregisterIdlingResources(countingResource));
    }
  
    @Test
    public void testCountingIdlingResource() {
      // Request the "hello world!" text by clicking on the request button.
      onView(withId(R.id.request_button)).perform(click());
  
      // Espresso waits for the resource to go idle and then continues.
  
      // The check if the text is visible can pass now.
      onView(withId(R.id.status_text)).check(matches(withText(R.string.hello_world)));
    }
  }
  