Get an item of an item in espresso

Issue

I am a beginner in Espresso. I have this menu.xml file:

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <item
        android:id="@+id/configuration"
        android:icon="@drawable/ic_settings"
        android:title="Configuration"
        app:showAsAction="ifRoom">

        <menu>
            <item
                android:id="@+id/add_sound"
                android:title="Add a sound"
                app:showAsAction="ifRoom" />

            <item
                android:id="@+id/takeof_sound"
                android:enabled="false"
                android:title="Take of the sound"
                app:showAsAction="ifRoom" />

            <item
                android:id="@+id/add_image"
                android:title="Add an image"
                app:showAsAction="ifRoom" />

            <item
                android:id="@+id/takeof_image"
                android:enabled="false"
                android:title="Take of the image"
                app:showAsAction="ifRoom" />
        </menu>

    </item>

    <item
        android:id="@+id/add"
        android:icon="@drawable/ic_add"
        android:title="Add"
        app:showAsAction="ifRoom" />
</menu>

I would like to perform a click on the item with id configuration and then a click on the sub-item with id add_sound. So, I have typed this code:

public void menuConfigurationTest()
    {
        onView(withId(R.id.configuration)).perform(click());
        onView(withId(R.id.add_sound)).perform(click());
    }

However I get this error:

android.support.test.espresso.NoMatchingViewException: No views in hierarchy found matching: with id: com.example.adrien.smartalarm:id/add_sound
If the target view is not part of the view hierarchy, you may need to use Espresso.onData to load it from one of the following AdapterViews:android.support.v7.widget.MenuPopupWindow$MenuDropDownListView{5a0c4d8 VFED.VC.. .F...... 0,0-686,672}

What is wrong with what I have done?

Solution

The problem is the submenu gets shown in a PopupWindow, which is not part of activity's view hierarchy. Therefore you have to add:

.inRoot(RootMatchers.isPlatformPopup())

The next thing is the items are displayed in a special ListView named MenuDropDownListView. So onView() will not work here, you have to use onData().

Therefore the complete expression is:

onData(CoreMatchers.anything())
        .inRoot(RootMatchers.isPlatformPopup()) // isPlatformPopup() == is in PopupWindow
        .inAdapterView(CoreMatchers.<View>instanceOf(MenuPopupWindow.MenuDropDownListView.class))
        .atPosition(0) // for the first submenu item, here: add_sound
        .perform(click());

Answered By - dankito