CODEWITHSUNDEEP
c++qtqmlqtquick2signals-slots
Ignas J
Ignas J

Reputation: 13

MessageDialog freezes when created from Slot qt

I am trying to show message dialog from worker thread. Using slots and signals is standard way of communicating with/calling QML objects, but when dialog appears it's button is unclickable/not responding.

main.cpp

tester* test = new tester;
QtConcurrent::run(test,tester::testFunction);

tester.cpp

#include "tester.h"
#include <QQmlEngine>
#include <QQmlComponent>

tester::tester(QObject *parent) : QObject(parent) {
    QObject::connect(this,SIGNAL(show()),this,SLOT(showSlot()));
}
void tester::testFunction() {
    emit show();
}
void tester::showSlot(){
    QQmlEngine engine;
    QQmlComponent component(&engine, QUrl(QLatin1String("qrc:/BlockingDialog.qml")));
    QObject *object = component.create();
    QMetaObject::invokeMethod(object, "open");
}

tester.h

#include <QObject>

class tester : public QObject{
    Q_OBJECT
public:
    explicit tester(QObject *parent = 0);
    void testFunction();
signals:
    void show();
public slots:
    void showSlot();
};

BlockingDialog.qml

import QtQuick 2.7
import QtQuick.Dialogs 1.2

MessageDialog {
    id:dialog    
}

Upvotes: 0

Views: 93

Answers (1)

Mitch
Mitch

Reputation: 24386

You're creating the QML engine on the stack in showSlot(), so it will be destroyed when the function finishes. The typical approach to loading QML files is to create the QML engine on the stack in main().

Upvotes: 2

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