v1/src/test/java/com/xtremelabs/robolectric/shadows/ViewPagerTest.java

package com.xtremelabs.robolectric.shadows;

import android.app.Activity;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
import com.xtremelabs.robolectric.WithTestDefaultsRunner;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

import static junit.framework.Assert.*;

@RunWith(WithTestDefaultsRunner.class)
public class ViewPagerTest {

    private ViewPager pager;
    private TestPagerAdapter adapter;

    @Before
    public void setUp() throws Exception {
        pager = new ViewPager(new Activity());
        adapter = new TestPagerAdapter();
    }

    @Test
    public void shouldSetAndGetAdapter() throws Exception {
        assertNull(pager.getAdapter());

        pager.setAdapter(adapter);
        assertSame(adapter, pager.getAdapter());
    }

    @Test
    public void test_getAndSetCurrentItem() throws Exception {
        pager.setCurrentItem(2);
        assertEquals(2, pager.getCurrentItem());
    }

    @Test
    public void setCurrentItem_shouldInvokeListener() throws Exception {
        TestOnPageChangeListener listener = new TestOnPageChangeListener();
        pager.setOnPageChangeListener(listener);
        assertFalse(listener.onPageSelectedCalled);
        pager.setCurrentItem(2);
        assertTrue(listener.onPageSelectedCalled);
    }

    private static class TestPagerAdapter extends PagerAdapter {
        @Override
        public int getCount() {
            return 0;
        }

        @Override
        public boolean isViewFromObject(View view, Object object) {
            return false;
        }
    }

    private static class TestOnPageChangeListener extends ViewPager.SimpleOnPageChangeListener {
        public boolean onPageSelectedCalled;

        @Override
        public void onPageSelected(int position) {
            onPageSelectedCalled = true;
        }
    }
}