Android Espresso：按住按钮时进行断言

Question

我对 Android 上的 Espresso 还很陌生，我遇到了以下问题： 我希望 Espresso 对按钮执行长按（或其他操作），并且在按住按钮的同时，我想检查不同视图的状态。

在（或多或少）伪代码中：

onView(withId(button_id)).perform(pressButtonDown());
onView(withId(textBox_id)).check(matches(withText("Button is pressed")));
onView(withId(button_id)).perform(releaseButton());

我尝试使用 MotionEvents.sendDown() 和 .sendUp() 编写 2 个自定义 Taps，PRESS 和 RELEASE，但没有成功。 如果这是正确的路径，我可以发布到目前为止的代码。

编辑：

public class PressViewActions
{
    public static ViewAction pressDown(){
        return new GeneralClickAction(HoldTap.DOWN, GeneralLocation.CENTER, Press.THUMB);
    }

    public static ViewAction release() {
        return new GeneralClickAction(HoldTap.UP, GeneralLocation.CENTER, Press.THUMB);
    }
}

以及 Tappers 的代码：

public enum HoldTap implements Tapper {

    DOWN {
        @Override
        public Tapper.Status sendTap(UiController uiController, float[] coordinates, float[] precision)
        {
            checkNotNull(uiController);
            checkNotNull(coordinates);
            checkNotNull(precision);

            DownResultHolder res = MotionEvents.sendDown(uiController, coordinates, precision);

            ResultHolder.setController(uiController);
            ResultHolder.setResult(res);

            return Status.SUCCESS;
        }
    },

    UP{
        @Override
        public Tapper.Status sendTap(UiController uiController, float[] coordinates, float[] precision)
        {
            DownResultHolder res = ResultHolder.getResult();
            UiController controller = ResultHolder.getController();

            try {
                if(!MotionEvents.sendUp(controller, res.down))
                {
                    MotionEvents.sendCancel(controller, res.down);
                    return Status.FAILURE;
                }

            }
            finally {
                //res.down.recycle();
            }

            return Status.SUCCESS;
        }
    }
}

我得到的错误如下：

android.support.test.espresso.PerformException: Error performing 'up click' on view 'with id: de.test.app:id/key_ptt'.
...
...
Caused by: java.lang.RuntimeException: Couldn't click at: 281.5,1117.5 precision: 25.0, 25.0 . Tapper: UP coordinate provider: CENTER precision describer: THUMB. Tried 3 times. With Rollback? false

我希望，这会有所帮助。

我们将不胜感激任何帮助和想法！

提前坦克很多！

Answer 1

Android 中的点击由两个事件组成，一个向下事件和一个向上/取消事件。如果您想将这两者分开，则不能进行“点击”，因为它们已经包含了两者。

也就是说，你的想法可行，你只需要使用较低级别的 api，即UiController 以及 MotionEvents 中的辅助方法。但请注意：由于“释放”视图需要首先持有它，如果您不进行适当的清理，您的测试将相互依赖。

示例：在一个测试中，您按下一个视图，您的测试失败，然后在另一个测试中您在一个未单击的视图上发布：您的第二个测试会通过，而它不应该通过。

我在my github 上上传了一个完整的样本。这里是关键点。首先是测试代码：

@Before
public void setUp() throws Exception {
    super.setUp();
    injectInstrumentation(InstrumentationRegistry.getInstrumentation());
    getActivity();
}

@After
public void tearDown() throws Exception {
    super.tearDown();
    LowLevelActions.tearDown();
}

@Test
public void testAssertWhilePressed() {
    onView(withId(R.id.button)).perform(pressAndHold());
    onView(withId(R.id.text)).check(matches(withText("Button is held down")));
    onView(withId(R.id.button)).perform(release());
}

然后是 LowLevelActions：

public class LowLevelActions {
    static MotionEvent sMotionEventDownHeldView = null;

    public static PressAndHoldAction pressAndHold() {
        return new PressAndHoldAction();
    }

    public static ReleaseAction release() {
        return new ReleaseAction();
    }

    public static void tearDown() {
        sMotionEventDownHeldView = null;
    }

    static class PressAndHoldAction implements ViewAction {
        @Override
        public Matcher<View> getConstraints() {
            return isDisplayingAtLeast(90); // Like GeneralClickAction
        }

        @Override
        public String getDescription() {
            return "Press and hold action";
        }

        @Override
        public void perform(final UiController uiController, final View view) {
            if (sMotionEventDownHeldView != null) {
                throw new AssertionError("Only one view can be held at a time");
            }

            float[] precision = Press.FINGER.describePrecision();
            float[] coords = GeneralLocation.CENTER.calculateCoordinates(view);
            sMotionEventDownHeldView = MotionEvents.sendDown(uiController, coords, precision).down;
            // TODO: save view information and make sure release() is on same view
        }
    }

    static class ReleaseAction implements ViewAction {
        @Override
        public Matcher<View> getConstraints() {
            return isDisplayingAtLeast(90);  // Like GeneralClickAction
        }

        @Override
        public String getDescription() {
            return "Release action";
        }

        @Override
        public void perform(final UiController uiController, final View view) {
            if (sMotionEventDownHeldView == null) {
                throw new AssertionError("Before calling release(), you must call pressAndHold() on a view");
            }

            float[] coords = GeneralLocation.CENTER.calculateCoordinates(view);
            MotionEvents.sendUp(uiController, sMotionEventDownHeldView, coords);
        }
    }
}