RecyclerView update Idling Resource example code

01_RecyclerViewIdlingResourceTest.java

@RunWith(AndroidJUnit4.class)
public class RecyclerViewIdlingResourceTest {

  @Rule
  public ActivityRule<MainActivity> activityRule = new ActivityRule<MainActivity>(MainActivity.class);

  // number of items in the original list
  int allItemsCount = ...;
  
  // number of items after the list has been filtered
  int filteredItemsCount = ...;

  @Test
  public void testRecyclerviewFilter()
  {
    // verify all test items loaded
    // SUCCESS
    onView(withId(R.id.recyclerview)).check(withItemCount(allItemsCount));

    // since the search view is initially collapsed, open it first before tests are run
    onView(withId(R.id.action_search)).perform(click());

    // enter some text into the search view, and then press the action button.
    String searchText = "test"
    onView(withId(android.support.design.R.id.search_src_text)).perform(typeText(searchText), pressImeActionButton());

    // verify the number of items in the recyclerview list has been altered
    // FAIL!
    onView(withId(R.id.recyclerview)).check(withItemCount(filteredItemsCount));
  }
  
    @Test
  public void testRecyclerviewFilterWithPause()
  {
    // verify all test items loaded
    // SUCCESS
    onView(withId(R.id.recyclerview)).check(withItemCount(allItemsCount));

    // since the search view is initially collapsed, open it first before tests are run
    onView(withId(R.id.action_search)).perform(click());

    // enter some text into the search view, and then press the action button.
    String searchText = "test"
    onView(withId(android.support.design.R.id.search_src_text)).perform(typeText(searchText), pressImeActionButton());
    
    // pause for arbitrary period of time, InterruptedException handling left out to simplify example
    Thread.sleep(1000);

    // verify the number of items in the recyclerview list has been altered
    // SUCCESS - assuming the pause time was long enough
    onView(withId(R.id.recyclerview)).check(withItemCount(filteredItemsCount));
  }
  
  @Test
  public void testRecyclerviewFilterWithIdlingResource()
  {
    // verify all test items loaded
    // SUCCESS
    onView(withId(R.id.recyclerview)).check(withItemCount(allItemsCount));

    // since the search view is initially collapsed, open it first before tests are run
    onView(withId(R.id.action_search)).perform(click());

    // enter some text into the search view, and then press the action button.
    String searchText = "test"
    onView(withId(android.support.design.R.id.search_src_text)).perform(typeText(searchText), pressImeActionButton());

    // create the idling resource
    RecyclerViewLayoutCompleteIdlingResource idlingResource = new RecyclerViewLayoutCompleteIdlingResource((RecyclerViewCallbackContactsActivity) activityTestRule.getActivity());
    IdlingRegistry.getInstance().register(idlingResource);

    // verify the number of items in the recyclerview list has been altered
    // SUCCESS
    onView(withId(R.id.recyclerview)).check(withItemCount(filteredItemsCount));

    // clean up
    IdlingRegistry.getInstance().unregister(idlingResource);
  }
}

02_RecyclerViewLayoutCompleteListener.java

public interface RecyclerViewLayoutCompleteListener {
  
  // Callback to notify the idling resource that it can transition to the idle state
  public void onLayoutCompleted();
}

03_RecyclerViewIdlingCallback.java

public interface RecyclerViewIdlingCallback {

  public void setRecyclerViewLayoutCompleteListener(RecyclerViewLayoutCompleteListener listener);

  public void removeRecyclerViewLayoutCompleteListener(RecyclerViewLayoutCompleteListener listener);

  // Callback for the idling resource to check if the resource (in this example the activity containing the recyclerview)
  // is idle
  public boolean isRecyclerViewLayoutCompleted();
}

04_RecyclerViewLayoutCompleteIdlingResource.java

public class RecyclerViewLayoutCompleteIdlingResource implements IdlingResource {

  private ResourceCallback resourceCallback;
  
  // in this example the RecyclerViewIdlingCallback will be the activity containing the recyclerview
  private RecyclerViewIdlingCallback recyclerViewIdlingCallback;
  
  // the listener to add to the resource
  private RecyclerViewLayoutCompleteListener listener;

  public RecyclerViewLayoutCompleteIdlingResource(RecyclerViewIdlingCallback recyclerViewIdlingCallback){
    this.recyclerViewIdlingCallback = recyclerViewIdlingCallback;

    // create the listener
    listener = new RecyclerViewLayoutCompleteListener() {

      @Override
      public void onLayoutCompleted() {
        if (resourceCallback == null){
          return ;
        }

        //Called when the resource goes from busy to idle.
        resourceCallback.onTransitionToIdle();
      }
    };

    // add the listener to the view containing the recyclerview
    recyclerViewIdlingCallback.setRecyclerViewLayoutCompleteListener (listener);
  }
  @Override
  public String getName() {
    return "RecyclerViewLayoutCompleteIdlingResource";
  }

  @Override
  public boolean isIdleNow() {
    return recyclerViewIdlingCallback.isRecyclerViewLayoutCompleted();
  }

  @Override
  public void registerIdleTransitionCallback(ResourceCallback resourceCallback) {
    this.resourceCallback = resourceCallback;
  }
}

05_MainActivity.java

// An example activity to demonstrate using the RecyclerViewLayoutCompleteIdlingResource
public class MainActivity implements SearchView.OnQueryTextListener, ViewTreeObserver.OnGlobalLayoutListener,
    RecyclerViewIdlingCallback {
      
  /**
   * Flag to indicate if the layout for the recyclerview has complete. This should only be used
   * when the data in the recyclerview has been changed after the initial loading.
   */
  private boolean recyclerViewLayoutCompleted;

  /**
   * Listener to be set by the idling resource, so that it can be notified when recyclerview
   * layout has been done.
   */
  private RecyclerViewLayoutCompleteListener listener;
  
  @Override
  public void onCreate (Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.contact_list);

    // initialize the recyclerview with original data
    
    // YOUR CODE HERE
    
    setRecyclerViewLayoutCompleted(true);
    recyclerView.getViewTreeObserver().addOnGlobalLayoutListener(this);
  }

  @Override
  public boolean onQueryTextChange(String query) {
    // not used in this example
    return false;
  }
  
  @Override
  public boolean onQueryTextSubmit(String query) {
    // use the search query to filter the data in the recyclerview,
    // followed by a call of notifyDataSetChanged() for the adapter
    
    // YOUR CODE HERE

    // flag that a new layout will be required with the filtered data
    setRecyclerViewLayoutCompleted(false);
    return true;
  }

  @Override
  public void onGlobalLayout() {
    if (listener != null)
    {
      // set flag to let the idling resource know that processing has completed and is now idle
      setRecyclerViewLayoutCompleted(true);

      // notify the listener (should be in the idling resource)
      listener.onLayoutCompleted();
    }
  }

  @Override
  public void setRecyclerViewLayoutCompleteListener(RecyclerViewLayoutCompleteListener listener) {
    this.listener = listener;
  }

  @Override
  public void removeRecyclerViewLayoutCompleteListener(RecyclerViewLayoutCompleteListener listener) {
    if (this.listener != null && this.listener == listener)
    {
      this.listener = null;
    }
  }

  @Override
  public boolean isRecyclerViewLayoutCompleted() {
    return recyclerViewLayoutCompleted;
  }

  public void setRecyclerViewLayoutCompleted(boolean recyclerViewLayoutCompleted) {
    this.recyclerViewLayoutCompleted = recyclerViewLayoutCompleted;
  }
}