| /* |
| * Copyright 2018 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.viewpager.widget; |
| |
| import static org.junit.Assert.assertFalse; |
| import static org.junit.Assert.assertTrue; |
| |
| import android.app.Activity; |
| import android.os.Bundle; |
| import android.view.View; |
| import android.view.ViewGroup; |
| |
| import androidx.annotation.NonNull; |
| import androidx.annotation.Nullable; |
| import androidx.test.filters.MediumTest; |
| import androidx.test.platform.app.InstrumentationRegistry; |
| import androidx.test.rule.ActivityTestRule; |
| |
| import org.junit.Rule; |
| import org.junit.Test; |
| |
| @MediumTest |
| public final class ViewPagerTest { |
| @Rule |
| public final ActivityTestRule<ViewPagerActivity> activityRule = new ActivityTestRule<>( |
| ViewPagerActivity.class); |
| |
| public static final class ViewPagerActivity extends Activity { |
| public ViewPager pager; |
| |
| @Override |
| protected void onCreate(@Nullable Bundle savedInstanceState) { |
| super.onCreate(savedInstanceState); |
| pager = new ViewPager(this); |
| setContentView(pager); |
| } |
| } |
| |
| @Test |
| public void setPrimaryItemNotCalledWhenAdapterIsEmpty() { |
| ViewPager pager = activityRule.getActivity().pager; |
| final PrimaryItemPagerAdapter adapter = new PrimaryItemPagerAdapter(); |
| pager.setAdapter(adapter); |
| |
| InstrumentationRegistry.getInstrumentation().waitForIdleSync(); |
| assertFalse(adapter.primaryCalled); |
| |
| InstrumentationRegistry.getInstrumentation().runOnMainSync(new Runnable() { |
| @Override |
| public void run() { |
| adapter.count = 1; |
| adapter.notifyDataSetChanged(); |
| } |
| }); |
| |
| InstrumentationRegistry.getInstrumentation().waitForIdleSync(); |
| assertTrue(adapter.primaryCalled); |
| } |
| |
| static final class PrimaryItemPagerAdapter extends PagerAdapter { |
| public volatile int count; |
| public volatile boolean primaryCalled; |
| |
| @Override |
| public int getCount() { |
| return count; |
| } |
| |
| @Override |
| public void setPrimaryItem(@NonNull ViewGroup container, int position, |
| @NonNull Object object) { |
| primaryCalled = true; |
| } |
| |
| @Override |
| public boolean isViewFromObject(@NonNull View view, @NonNull Object object) { |
| return view == object; |
| } |
| |
| @NonNull |
| @Override |
| public Object instantiateItem(@NonNull ViewGroup container, int position) { |
| View view = new View(container.getContext()); |
| container.addView(view); |
| return view; |
| } |
| |
| @Override |
| public void destroyItem(@NonNull ViewGroup container, int position, |
| @NonNull Object object) { |
| container.removeView((View) object); |
| } |
| } |
| } |