I'm writing a custom view to be used inside `Andro...

# compose

[Justin Yue]

I'm writing a custom view to be used inside AndroidView, but when I run my app, my custom view does not appear. I was thinking perhaps passing in null for the root paramater might be problematic for LayoutInflater.from(context).finflate(R.layout.view_visualization, null, false). Normally, I would call rootView instead, but that just returns my custom view. Is there a way to instead have the root be the composable that calls this custom view?

[mattinger]

Some code would be helpful here. I’ve had no issues using custom views inside of AndroidView.

[mattinger]

I would look at the AndroidViewBinding API to do what you want.

[mattinger]

Some code would be helpful here, but I suspect you really need to use the AndroidViewBinding API here. It supports inflation from an xml file

[mattinger]

Something like this

AndroidViewBinding(
   factory = { inflater, parent, attachToParent ->
     inflater.inflate(R.layout.view_visualization, parent, attachToParent)
   }
)

[mattinger]

If you’re using view binding, it’s even sipler:

AndroidViewBinding(factory=ViewVisualization::inflate)

[Justin Yue]

Gotcha, I initially did try this view binding approach but encountered the error, Error inflating class androix.fragment.app.FragmentContainerView . Perhaps it's because I didn't insert the FragmentContainerView properly in my xml file?

Here's the relevant code.

@Composable
fun VizSection(onBack: () -> Unit) {
    val TAG = "VizSection"
    val fragmentContainerView = FragmentContainerView(LocalContext.current)
    Column(modifier = Modifier.fillMaxWidth()) {
        HomeNavBar(title = R.string.visualization_title, false, { onBack() }) {
            onBack()
        }
        AndroidViewBinding(FragmentVisualizationBinding::inflate) {
            Log.d(TAG, "compose: Viz Section is called")
            val vizFragment = fragmentContainerView.getFragment<VisualizationFragment>()
        }
    }
}

XML File:

<RelativeLayout xmlns:android="<http://schemas.android.com/apk/res/android>"
    xmlns:tools="<http://schemas.android.com/tools>"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ui.visualization.VisualizationFragment"
    android:name="com.radgard.lara.ui.visualization.VisualizationFragment">
        <androidx.fragment.app.FragmentContainerView
            xmlns:android="<http://schemas.android.com/apk/res/android>"
            android:id="@+id/fragment_container_view"
            android:layout_height="match_parent"
            android:layout_width="match_parent"
            android:name="com.radgard.lara.ui.visualization.VisualizationFragment">
        </androidx.fragment.app.FragmentContainerView>


    <android.opengl.GLSurfaceView
        android:id="@+id/surfaceview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_gravity="top"/>

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Plz work"
                android:layout_alignParentTop="true"
                android:layout_alignParentLeft="true"
                android:layout_margin="25dp"/>

    <ImageButton
        android:id="@+id/settings_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:layout_alignParentTop="true"
        android:layout_margin="25dp"
        android:src="@drawable/ic_settings"
        android:background="@android:color/transparent"/>
</RelativeLayout>

[mattinger]

I’ve never tried this approach with fragments, but i suspect it might cause issues because the compose world doesn’t really deal in fragments, so it’s kind of unclear to me how the inflater it gives you would handle it.

[mattinger]

One thing i notice in your code is this:

val fragmentContainerView = FragmentContainerView(LocalContext.current)

[mattinger]

any reason that is there?

[Justin Yue]

The stack trace points to line 7 of the XML file, not the line here. I use fragmentContainerView to create my fragment bc that's where I would run my ARCore-related code

[mattinger]

So it sounds maybe like there’s some issue with the fragment itself. Try replacing your fragment with just a standard androidx.fragment.app.Fragment and see if it works.

[mattinger]

I tried a basic example with an empty fragment and it worked fine.

[mattinger]

Do you have a longer stack trace? One thing to watch out for is that your Activity has to extend FragmentActivity. In most cases in compose, people may end up extending ComponentActivity to avoid the overhead of the fragment manager.

[mattinger]

I changed my example from FragmentActivity to ComponentActivity and this is what i got

android.view.InflateException: Binary XML file line #12 in com.example.material3test:layout/layout_test: Binary XML file line #12 in com.example.material3test:layout/layout_test: Error inflating class androidx.fragment.app.FragmentContainerView
    Caused by: android.view.InflateException: Binary XML file line #12 in com.example.material3test:layout/layout_test: Error inflating class androidx.fragment.app.FragmentContainerView
    Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Constructor.newInstance0(Native Method)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:343)
        at android.view.LayoutInflater.createView(LayoutInflater.java:852)

[mattinger]

Caused by: java.lang.UnsupportedOperationException: FragmentContainerView must be within a FragmentActivity to use android:name="androidx.fragment.app.Fragment"

[Justin Yue]

Ah, I just got the stack trace that says I need a FragmentActivity. I'm assuming you mean the MainActivity should extend a FragmentActivity? I also use Hilt in this project, and it crashes if the MainActivity is a FragmentActivity...

[Ian Lake]

Error inflating class androix.fragment.app.FragmentContainerView always, always, always points to another exception farther down. You'll need to include that stack trace for anyone to be able to help