invoking qml from cpp

[Coy0ty]

Hi everyone,

i've been reading the forums for some time but now i need some help

I tried to boil it down to the most simples case to show it here:

I have a qml file simply taken from one of the official tutorials.
It's a simple button. lets call it button2.

I have a cpp code, that generates a window and a button, button1.
Once the button1 is pressed, QDeclarativeView is used to view the qml file and a window pops up showing button1.

Pressing button2 (the qml button) should connect to a cpp slot that will show a message on terminal.

Everything works fine, but when i click on button2 i get a segfault.

Here is the code.
I was not sure if i'm supposed to post the entire code (with all the indcludes and stuff).
I hope its ok to post the code in such a way.

//Button.qml
import QtQuick 1.0
 
Rectangle
{
    id: button
    width: 75; height: 50
 
    Text
    {
        id: buttonLabel
        anchors.centerIn: parent
        text: "click here"
    }
 
    MouseArea
    { 
        id: buttonMouseArea
        anchors.fill: parent
        onClicked: buttonClick()
    }   
 
    signal buttonClick()
    onButtonClick: 
    {
        qmlSlot.cppMethod("Hello from QML") //this is the cpp slot i whant to call
    }
}

//Button.qml
import QtQuick 1.0

Rectangle
{
    id: button
    width: 75; height: 50
    
    Text
    {
        id: buttonLabel
        anchors.centerIn: parent
        text: "click here"
    }
  
    MouseArea
    { 
        id: buttonMouseArea
        anchors.fill: parent
        onClicked: buttonClick()
    }   
             
    signal buttonClick()
    onButtonClick: 
    {
        qmlSlot.cppMethod("Hello from QML") //this is the cpp slot i whant to call
    }
}

To copy to clipboard, switch view to plain text mode 

//myqml.h
 
class MyClass : public QWidget
{
  Q_OBJECT
 
  public:
    MyClass(QWidget *parent = 0);
 
  private slots:
	void showQmlSlot(); //this is the slot to view the qml file
    Q_INVOKABLE void cppMethod(const QString &msg) {
         qDebug() << "Called the C++ method with" << msg;
     }//this is the cpp slot to be called within the qml file
 
  private:
    QPushButton *click;
};

//myqml.h

class MyClass : public QWidget
{
  Q_OBJECT

  public:
    MyClass(QWidget *parent = 0);
    
  private slots:
	void showQmlSlot(); //this is the slot to view the qml file
    Q_INVOKABLE void cppMethod(const QString &msg) {
         qDebug() << "Called the C++ method with" << msg;
     }//this is the cpp slot to be called within the qml file
    
  private:
    QPushButton *click;
};

To copy to clipboard, switch view to plain text mode 

//myqml.cpp
 
MyClass::MyClass(QWidget *parent)
    : QWidget(parent)
{
  click = new QPushButton("Click me", this);
  click->setGeometry(50, 40, 75, 30);
 
  connect(click, SIGNAL(clicked()), 
      this, SLOT(showQmlSlot()));
}
 
 
void MyClass::showQmlSlot()
{  
	MyClass myClass;
 
	QDeclarativeView *view = new QDeclarativeView();
 
	view->setSource(QUrl::fromLocalFile("Button.qml"));
	view->rootContext()->setContextProperty("qmlSlot", &myClass);
 
    view->setResizeMode(QDeclarativeView::SizeRootObjectToView);
    view->show();
 }

//myqml.cpp

MyClass::MyClass(QWidget *parent)
    : QWidget(parent)
{
  click = new QPushButton("Click me", this);
  click->setGeometry(50, 40, 75, 30);

  connect(click, SIGNAL(clicked()), 
      this, SLOT(showQmlSlot()));
}


void MyClass::showQmlSlot()
{  
	MyClass myClass;

	QDeclarativeView *view = new QDeclarativeView();
	
	view->setSource(QUrl::fromLocalFile("Button.qml"));
	view->rootContext()->setContextProperty("qmlSlot", &myClass);

    view->setResizeMode(QDeclarativeView::SizeRootObjectToView);
    view->show();
 }

To copy to clipboard, switch view to plain text mode 

I just dont get where the error comes from.
Funny enought, if i use the QDeclarativeView within the main.cpp,
like shown for instance here
http://www.developer.nokia.com/Commu...ation_from_QML
it works fine...

Thanks for helping me

[Urthas]

Disclaimer: I am a total QML newb. That said: your invokable function is a private slot. Can you call a private cpp function from qml? Somehow, I doubt it...