Component sidecar accessing protected property `children` when extending `javafx.scene.Parent`

[ruffrick]

Describe the bug The generated sidecar classes for components extending javafx.scene.Parent tries to access the components children property, which is protected in Parent. Only children of javafx.scene.layout.Pane, itself a child of Parent, have this property publicly accessible, resulting in an exception when creating components extending e.g. javafx.scene.control.ListView. The exception only occurrs if the component specifies a view resource (FXML).

To Reproduce Steps to reproduce the behavior:

1. Create a class extending ListView (a child of Parent but not of Pane)
2. Annotate the Class with @Component and specify the view argument
3. Create a corresponding FXML file
4. Compile & See error

Expected behavior The component is appropriately initialized and rendered.

Desktop

• OS: Windows 11
• Browser: N/A
• Version: 0.6.0

Additional context Relevant fulibFx snippet: https://github.com/fujaba/fulibFx/blob/master/annotation-processor/src/main/java/org/fulib/fx/FxClassGenerator.java#L306-L307

// javafx.scene.Parent
protected ObservableList<Node> getChildren() {
    return children;
}

// javafx.scene.layout.Pane
@Override public ObservableList<Node> getChildren() {
    return super.getChildren();
}

[LeStegii]

Thanks for the report, when not using the annotation processor, everything should work fine as then reflection is used to access the method:

if (root instanceof Parent parent) {
    ReflectionUtil.getChildrenList(instance.getClass(), parent).clear();
}

This should therefore be a relatively easy fix.

[Clashsoft]

@LeStegii We could statically check whether the component type extends Pane in the processor and have it decide whether to generate the efficient getChildren call or the ReflectionUtil fallback.

[LeStegii]

Yep, I'd have suggested the same thing. We could also implement this in the reflection sidecar.

[Clashsoft]

I will do that.