Using QQuickView in separate thread problems

[binaural]

Hi,

thanks for hint. I did update code accordingly and it start working:

MyThread::MyThread() {
	m_view = new QQuickView();
	connect(this, SIGNAL(show()), m_view, SLOT(show()));
	connect(this, SIGNAL(qmlSetSource(QUrl)), m_view, SLOT(setSource(QUrl)));
}
 
void MyThread::run() {
 
	qDebug() << "thread() " << currentThread();
	emit qmlSetSource(QUrl(QStringLiteral("qrc:/test/loadingView.qml")));
	emit show();
	exec();
 
}

MyThread::MyThread() {
	m_view = new QQuickView();
	connect(this, SIGNAL(show()), m_view, SLOT(show()));
	connect(this, SIGNAL(qmlSetSource(QUrl)), m_view, SLOT(setSource(QUrl)));
}

void MyThread::run() {

	qDebug() << "thread() " << currentThread();
	emit qmlSetSource(QUrl(QStringLiteral("qrc:/test/loadingView.qml")));
	emit show();
	exec();

}

To copy to clipboard, switch view to plain text mode 

class MyThread : public QThread {
 
	Q_OBJECT
public:
	MyThread();
 
public slots:
	void run();
 
private:
 
	QQuickView *m_view;
 
signals:
	void show();
	void qmlSetSource(QUrl url);
 
};

class MyThread : public QThread {

	Q_OBJECT
public:
	MyThread();

public slots:
	void run();

private:

	QQuickView *m_view;

signals:
	void show();
	void qmlSetSource(QUrl url);

};

To copy to clipboard, switch view to plain text mode 

One thing which remain is warning printed in console when run example:

13:26:30.192 WARNING: QObject::setParent: Cannot set parent, new parent is in a different thread
13:26:30.416 WARNING: Updates can only be scheduled from GUI thread or from QQuickItem::updatePaintNode()

Thanks

[anda_skoa]

Might be caused by some other code that you haven't posted yet.

The first one for example could be caused by creating an instance of a QObject derived class in run() and passing "this" as the parent.

Cheers,
_

[binaural]

Attaching full source (qml remains unchanged):

main.cpp

#include <iostream>
#include <QGuiApplication>
#include <QQuickView>
#include "mythread.h"
#include <qdebug.h>
 
using namespace std;
 
int main(int argc, char ** argv)
{
	QGuiApplication app(argc, argv);
	qDebug() << "app.thread() " << QGuiApplication::instance()->thread();
 
	MyThread thread;
	thread.start();
 
	return app.exec();
}

#include <iostream>
#include <QGuiApplication>
#include <QQuickView>
#include "mythread.h"
#include <qdebug.h>

using namespace std;

int main(int argc, char ** argv)
{
	QGuiApplication app(argc, argv);
	qDebug() << "app.thread() " << QGuiApplication::instance()->thread();

	MyThread thread;
	thread.start();

	return app.exec();
}

To copy to clipboard, switch view to plain text mode 

mytheread.cpp

#include "mythread.h"
#include <QDebug>
#include <QString>
#include <QMutexLocker>
#include <QTime>
 
 
MyThread::MyThread() {
	m_view = new QQuickView();
	connect(this, SIGNAL(show()), m_view, SLOT(show()));
	connect(this, SIGNAL(qmlSetSource(QUrl)), m_view, SLOT(setSource(QUrl)));
}
 
void MyThread::run() {
 
	qDebug() << "thread() " << currentThread();
	emit qmlSetSource(QUrl(QStringLiteral("qrc:/test/loadingView.qml")));
	emit show();
	exec();
 
}

#include "mythread.h"
#include <QDebug>
#include <QString>
#include <QMutexLocker>
#include <QTime>


MyThread::MyThread() {
	m_view = new QQuickView();
	connect(this, SIGNAL(show()), m_view, SLOT(show()));
	connect(this, SIGNAL(qmlSetSource(QUrl)), m_view, SLOT(setSource(QUrl)));
}

void MyThread::run() {

	qDebug() << "thread() " << currentThread();
	emit qmlSetSource(QUrl(QStringLiteral("qrc:/test/loadingView.qml")));
	emit show();
	exec();

}

To copy to clipboard, switch view to plain text mode 

mythread.h

#ifndef MYTHREAD_H
#define MYTHREAD_H
 
#include <QThread>
#include <QMutex>
#include <QQuickView>
#include <QQmlApplicationEngine>
 
class MyThread : public QThread {
 
	Q_OBJECT
public:
	MyThread();
 
public slots:
	void run();
 
private:
 
	QQuickView *m_view;
 
signals:
	void show();
	void qmlSetSource(QUrl url);
 
};
 
#endif // MYTHREAD_H

#ifndef MYTHREAD_H
#define MYTHREAD_H

#include <QThread>
#include <QMutex>
#include <QQuickView>
#include <QQmlApplicationEngine>

class MyThread : public QThread {

	Q_OBJECT
public:
	MyThread();

public slots:
	void run();

private:

	QQuickView *m_view;

signals:
	void show();
	void qmlSetSource(QUrl url);

};

#endif // MYTHREAD_H

To copy to clipboard, switch view to plain text mode 

[anda_skoa]

Works for me.

I copied the QML content from the thread start and modified it to use a Rectangle as the top level element as QQuickView expects an Item.
I also change the URL to the local file.

Cheers,
_