Details
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Bug
-
Resolution: Invalid
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P1: Critical
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6.5.3
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None
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Android,
macOS
Description
I have installed version Qt 6.5.3 on Ubuntu with an additional Android package. I'm building and debugging an application on a desktop and cross-compiling it to a target Android device.
My application includes the QML CppClasses plugin, which registers C++ classes as QML types:
// myqmltype.h class MyQmlType : public QObject { Q_OBJECT QML_ELEMENT ... // myqmlcontroller.h class MyQmlController : public QObject { Q_OBJECT QML_ELEMENT QML_UNCREATABLE("MyQmlController type cannot be created") ...
qmltypes file contains:
...
Component {
file: "myqmltype.h"
name: "MyQmlType"
accessSemantics: "reference"
prototype: "QObject"
exports: ["CppClasses/MyQmlType 1.0"]
exportMetaObjectRevisions: [256]
}
Component {
file: "myqmlcontroller.h"
name: "MyQmlController"
accessSemantics: "reference"
prototype: "QObject"
exports: ["CppClasses/MyQmlController 1.0"]
isCreatable: false
exportMetaObjectRevisions: [256]
}
...
The problematic QML file looks like this:
// MyComponent.qml import QtQuick import CppClasses as CPP Item { id: _control required property CPP.MyQmlController controller CPP.MyQmlType { id: _child anyProperty: controller.anyProperty // for example } }
This component is perfect from a qmllint point of view, there are no `unqualified access` warnings. But I have two problems.
In the application the component is created as follows:
QVariantMap MyQmlController::defaultInitialProperties() const { QVariantMap initialProperties; initialProperties["controller"] = QVariant::fromValue(this); return initialProperties; } void MyQmlController::appendComponentWithInitialProperties( const QUrl &source, QQmlEngine *engine) { QQmlComponent component(engine, source, QQmlComponent::PreferSynchronous); auto item = qobject_cast<QQuickItem *>(component.createWithInitialProperties(defaultInitialProperties())); // [1] if (item) { auto child = item->findChild<MyQmlType *>("", Qt::FindDirectChildrenOnly); // [2] } }
- Line [1] shows a warning "Could not set initial property controller".
- In line [2] the variable child is always nullptr.
On Ubuntu (gcc_64) there are no such problems and everything works correctly. We managed to find out that everything magically depends on whether QT_BOOTSTRAPPED is enabled or not.