android - 如何在 Robolectric 的 ViewPager 上模拟拖动事件？

Question

我是 Android 和 Robolectric 的新手。我正在尝试模拟(如主题所示)viewpager 上的拖动事件。

我曾经实现过这段代码并且它在模拟器上运行。

问题主要是:如何对它进行单元测试？

这是单元测试:

/** imports are skipped **/

@RunWith(RobolectricTestRunner.class)
@Config(manifest = "/src/main/AndroidManifest.xml")
public class TestImages {

private ImageActivity activity;

@InjectResource(R.drawable.ic_launcher)
private static Drawable image;

@Spy
private final PicturesModel picturesModel = spy(new PicturesModelImpl());

/**
 * Last touched view
 */
private View lastTouchView;

/**
 * Last touched X coordinate
 */
private float lastTouchX;
/**
 * Last touched Y coordinate
 */
private float lastTouchY;

@Before
public void setup() {
    MockitoAnnotations.initMocks(this);

    final Module roboGuiceModule = RoboGuice.newDefaultRoboModule(Robolectric.application);
    final Module pictureModule = Modules.override(roboGuiceModule).with(new PictureModule());
    final Module testModule = Modules.override(pictureModule).with(new TestPictureModule(picturesModel));

    RoboGuice.setBaseApplicationInjector(Robolectric.application, RoboGuice.DEFAULT_STAGE, testModule);
    RoboInjector injector = RoboGuice.getInjector(Robolectric.application);
    injector.injectMembersWithoutViews(this);
}

@Test
public void scroll_image() {
    final Intent intent = new Intent(Robolectric.getShadowApplication().getApplicationContext(), ImageActivity.class);
    final Album album = new Album(1, "album_1", image);
    intent.putExtra("album", album);
    intent.putExtra("position", 2);
    intent.putExtra("imageId", 2L);

    // Get the activity
    activity = Robolectric.buildActivity(ImageActivity.class).withIntent(intent).create().get();
    final Point point = new Point();
    activity.getWindowManager().getDefaultDisplay().getSize(point);

    // Get a spy viewer otherwise viewPager's width is always 0
    final ViewPager viewPager = spy((ViewPager) activity.findViewById(R.id.viewPager));
    viewPager.setVisibility(View.VISIBLE);
    when(viewPager.getWidth()).thenReturn(point.x - 50);

    // First item sent by viewPager before swipe
    final int firstItem = viewPager.getCurrentItem();

    // Swipe
    drag(viewPager, 10F, 10F, point.x - 60F, 10F);

    // Next item after swipe
    final int secondItem = viewPager.getCurrentItem();

    // Comparison
    assertThat(firstItem).isEqualTo(2);
    assertThat(secondItem).isEqualTo(3);
}

public void touchDown(View view, float x, float y) {
    lastTouchX = x;
    lastTouchY = y;
    lastTouchView = view;

    sendMotionEvent(view, MotionEvent.ACTION_DOWN, x, y);
}

public void touchMove(float x, float y) {
    lastTouchX = x;
    lastTouchY = y;

    sendMotionEvent(lastTouchView, MotionEvent.ACTION_MOVE, x, y);
}

public void touchUp() {
    sendMotionEvent(
            lastTouchView, MotionEvent.ACTION_UP, lastTouchX, lastTouchY);

    lastTouchView = null;
}

public void drag(View view, float xStart, float yStart,
                 float xEnd, float yEnd) {
    touchDown(view, xStart, yStart);
    touchMove(xEnd, yEnd);
    touchUp();
}

private void sendMotionEvent(View view, int action, float x, float y) {

    int[] screenOffset = new int[2];
    view.getLocationOnScreen(screenOffset);

    MotionEvent event = MotionEvent.obtain(100, 200, action,
            x + screenOffset[0], y + screenOffset[1], 0);

    shadowOf(event).setPointerIds(1, 2);
    shadowOf(event).setPointerIndex(1);

    view.onTouchEvent(event);
    view.dispatchTouchEvent(event);
}
}

和 Activity :

public class ImageActivity extends RoboActivity {

    @Inject
    private PicturesModel picturesModel;

    @InjectView(R.id.viewPager)
    private ViewPager viewPager;

    private PagerAdapter pagerAdapter;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.image);

        final Bundle bundle = getIntent().getExtras();
        if (bundle != null && !bundle.isEmpty()) {
            final long id = (long) bundle.get("imageId");
            final int position = (int) bundle.get("position");
            final Picture picture = picturesModel.getPicture(id);
            if (picture != null) {

                pagerAdapter = new ImageAdapter(this, picturesModel.getAllPictures((Album) bundle.get("album")));
                viewPager.setAdapter(pagerAdapter);
                viewPager.setCurrentItem(position, true);
            }
        }
    }
}

这是布局:

    <?xml version="1.0" encoding="utf-8"?>

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/viewPager" />

有人知道如何进行或告诉我我的错误在哪里吗？

Answer 1

我想你要找的是 Espresso图书馆。

它模拟 UI 事件，让您在抛出事件后检查 View 的状态，它非常易于使用。只是不要忘记在开发人员设置中关闭动画。