What is "Must not specify @QtPropertyConstant in combination with writer and/or notifier signal." since version 5.15.18?

[paul35621]

Since QtJambi 5.15.18 (also tested with 5.15.20 and 6.7.0), I get an exception somewhere in my application during the construction of a subclass of QStackedWidget:

Apr 28, 2024 1:44:37 PM QTreeView::mouseDoubleClickEvent(QMouseEvent*) 
SEVERE: io.qt.QPropertyDeclarationException has been thrown in QTreeView::mouseDoubleClickEvent(QMouseEvent*)
io.qt.QPropertyDeclarationException: Property editor in class appgui.ProjectNotes: Must not specify @QtPropertyConstant in combination with writer and/or notifier signal.
	at io.qt.internal.MetaObjectUtility.analyze(MetaObjectUtility.java:1763)
	at io.qt.widgets.QStackedWidget.initialize_native(Native Method)
	at io.qt.widgets.QStackedWidget.<init>(QStackedWidget.java:35)
	at io.qt.widgets.QStackedWidget.<init>(QStackedWidget.java:189)
	at appgui.ProjectNotes.<init>(project-main.kt:25)
	at appgui.ProjectMain.<init>(project-main.kt:147)
	at appgui.TabDocumentProject$pageMain$2.invoke(tab-document-project.kt:54)
	at appgui.TabDocumentProject$pageMain$2.invoke(tab-document-project.kt:54)
	at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74)
	at appgui.TabDocumentProject.getPageMain(tab-document-project.kt:54)
	at appgui.TabDocumentProject$2.invoke(tab-document-project.kt:80)
	at appgui.TabDocumentProject$2.invoke(tab-document-project.kt:76)
	at generalqt.ConnectKt.connect$lambda$2(connect.kt:14)
	at io.qt.internal.JavaMethodHandles.lambda$getSlotInvoker$6(JavaMethodHandles.java:398)
	at io.qt.internal.SignalUtility$AbstractReflectiveConnection.invoke(SignalUtility.java:4479)
	at io.qt.core.QItemSelectionModel.select_native_cref_QModelIndex_QItemSelectionModel_SelectionFlags(Native Method)
	at io.qt.core.QItemSelectionModel.select(QItemSelectionModel.java:482)
	at io.qt.core.QItemSelectionModel.select(QItemSelectionModel.java:636)
	at appgui.TabDocumentProject.<init>(tab-document-project.kt:113)
	at appgui.Window.openProject(window.kt:63)
	at appgui.RecentProjectListView.mouseDoubleClickEvent(page-projects.kt:26)
	at io.qt.widgets.QApplication.exec(Native Method)
	at appgui.MainKt.main(main.kt:42)

As far as I know I'm not doing anything special and I have no clue what causes this exception. Is this a bug in QtJambi or should I write my code in a different way?

Is it clear from the stack trace what is happening or do I need to produce a minimal reproducable example?

[omix]

Does your class appgui.ProjectNotes have a property called "editor"? A property with annotation @QtPropertyConstant must not have a setter or notify signal. As QtJambi autodetects properties, even the appearance of a method setEditor is enough to cause this issue. You can hide the setter method by annotation @QtPropertyWriter(enabled=false).

[omix]

Oh, it was public member? Public members are also autodetected as property. But was there a constant annotation?

[paul35621]

Yes, a public member. I'm not using annotations anywhere in my code. This is the relevant code when I decompile to Java:

public final class ProjectNotes extends QStackedWidget {
	public QPlainTextEdit editor;
	
	@NotNull
	public final QPlainTextEdit getEditor() {
		QPlainTextEdit var1 = this.editor;
		if (var1 != null) {
			return var1;
		}
		else {
			Intrinsics.throwUninitializedPropertyAccessException("editor");
			return null;
		}
	}
	
	public final void setEditor(@NotNull QPlainTextEdit var1) {
		Intrinsics.checkNotNullParameter(var1, "<set-?>");
		this.editor = var1;
	}
}

[omix]

Thanks! I'll try to figure out why this causes the exception.

[omix]

This was a bug. I've fixed it.

[omix]

The bug has been fixed in the upcoming release QtJambi 6.7.1.