src/test/java/com/google/android/libraries/feed/sharedstream/logging/VisibilityMonitorTest.java

// Copyright 2018 The Feed Authors.
//
// 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.google.android.libraries.feed.sharedstream.logging;

import static org.mockito.Mockito.never;
import static org.mockito.Mockito.reset;
import static org.mockito.Mockito.verify;
import static org.mockito.MockitoAnnotations.initMocks;

import android.app.Activity;
import android.graphics.Point;
import android.graphics.Rect;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
import android.widget.FrameLayout.LayoutParams;
import com.google.android.libraries.feed.api.host.config.Configuration;
import com.google.android.libraries.feed.api.host.config.Configuration.ConfigKey;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.robolectric.Robolectric;
import org.robolectric.RobolectricTestRunner;

/** Tests for {@link VisibilityMonitor}. */
@RunWith(RobolectricTestRunner.class)
public class VisibilityMonitorTest {

  private static final Configuration CONFIGURATION =
      new Configuration.Builder().put(ConfigKey.VIEW_LOG_THRESHOLD, .50).build();
  private static final int VIEW_HEIGHT = 100;
  private static final int VIEW_WIDTH = 50;

  @Mock private VisibilityListener visibilityListener;

  private Activity context;
  private ViewGroup parentView;
  private View view;
  private VisibilityMonitor visibilityMonitor;

  @Before
  public void setUp() {
    initMocks(this);
    context = Robolectric.setupActivity(Activity.class);

    setUpViews(
        ((child, r, offset) -> {
          r.set(0, 0, VIEW_WIDTH, VIEW_HEIGHT);
          return true;
        }));
  }

  @Test
  public void testPreDraw_notifiesListener() {
    context.setContentView(parentView);

    visibilityMonitor.onPreDraw();

    verify(visibilityListener).onViewVisible();
  }

  @Test
  public void testPreDraw_notifiesListenerIfVisibleViewHeightIsAtThreshold() {
    setUpViews(
        (child, r, offset) -> {
          r.set(0, 0, VIEW_WIDTH, 50);
          return true;
        });
    context.setContentView(parentView);

    visibilityMonitor.onPreDraw();

    verify(visibilityListener).onViewVisible();
  }

  @Test
  public void testPreDraw_doesNotNotifyListenerIfAlreadyVisible() {
    context.setContentView(parentView);
    visibilityMonitor.onPreDraw();
    reset(visibilityListener);

    visibilityMonitor.onPreDraw();

    verify(visibilityListener, never()).onViewVisible();
  }

  @Test
  public void testPreDraw_doesNotNotifyListenerIfVisibleViewHeightIsBelowThreshold() {
    setUpViews(
        (child, r, offset) -> {
          r.set(0, 0, VIEW_WIDTH, 49);
          return true;
        });
    context.setContentView(parentView);

    visibilityMonitor.onPreDraw();

    verify(visibilityListener, never()).onViewVisible();
  }

  @Test
  public void testPreDraw_doesNotNotifyListenerIfViewNotAttached() {
    setUpViews((child, r, offset) -> false);

    visibilityMonitor.onPreDraw();

    verify(visibilityListener, never()).onViewVisible();
  }

  @Test
  public void testPreDraw_doesNotNotifyListenerIfParentIsNull() {
    visibilityMonitor = new VisibilityMonitor(new FrameLayout(context), CONFIGURATION);
    visibilityMonitor.setListener(null);

    visibilityMonitor.onPreDraw();

    verify(visibilityListener, never()).onViewVisible();
  }

  private void setUpViews(ChildVisibleRectMock childVisibleRectMock) {
    view = new FrameLayout(context);
    view.setLayoutParams(new LayoutParams(VIEW_WIDTH, VIEW_HEIGHT));
    parentView =
        new FrameLayout(context) {
          @Override
          public boolean getChildVisibleRect(View child, Rect r, Point offset) {
            return childVisibleRectMock.getChildVisibleRect(child, r, offset);
          }
        };

    parentView.addView(view);
    visibilityMonitor = new VisibilityMonitor(view, CONFIGURATION);
    visibilityMonitor.setListener(visibilityListener);
  }

  interface ChildVisibleRectMock {
    boolean getChildVisibleRect(View child, Rect r, Point offset);
  }
}