[Qt-interest] QML signal connections

[Carl Snellman]

Hey,

I'm trying to use QML with C++ to create the GUI for my application,
but I bumped to a problem I havent' been able to solve after a day of
studying/trying.

I created a button in QML, and I'd like to connect its signal to a C++
class slot so that I get to react to the button press; Just like you
would connect QPushButton. However, I cannot figure out how to make
this connection. I tried to find the child object, but always return
null, so I cannot connect that way. I dont know how I would make the
connection in the QML file side (if it is possible)

I attached minimal app below to demonstrate what I've tried.
Any help is greatly appreciated!
Thanks,
Carl

main.cpp
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#include <QtGui/QApplication>
#include <QtDeclarative>
class MyType : public QObject {
    Q_OBJECT
public:
    MyType(QObject *parent = 0) : QObject(parent) {}
public slots:
    void doSomething() {
        qDebug() << "DoSomething!";
    }
};

int main(int argc, char *argv[]) {
    QApplication a(argc, argv);
    qmlRegisterType<MyType>("MyType", 1,0, "MyType");

    QGraphicsView *graphicsView = new QGraphicsView;
    graphicsView->setGeometry(QRect(0, 0, 500, 500));
    QGraphicsScene* scene = new QGraphicsScene(0, 0, 500, 500);
    graphicsView->setScene(scene);

    QDeclarativeEngine *engine = new QDeclarativeEngine;
    QDeclarativeComponent component(engine, QUrl("qrc:/myqml.qml"));
    QDeclarativeItem *root = qobject_cast<QDeclarativeItem
*>(component.create());
    scene->addItem(root);

    //QObject* rect = root->findChild<QObject*>("button");
    QObject* button = qFindChild<QObject*>(root, QString("button"));
    if(button) {
        MyType *mytype = new MyType;
        QObject::connect(button, SIGNAL(clicked()), mytype,
SLOT(doSomething()));
    }

    graphicsView->show();
    return a.exec();
}
#include "main.moc"
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res.qrc
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<RCC>
    <qresource prefix="/">
        <file>myqml.qml</file>
    </qresource>
</RCC>
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myqml.qml
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import Qt 4.7
//import MyType 1.0
 Item {
     id: screen
     width: 500; height: 500;
     Rectangle {
         id: button
         signal clicked
         width: 200; height: 200; color: "red"
         MouseArea {
             anchors.fill: parent
             onClicked: {
                 button.color = "blue";
                 button.clicked();
             }
         }
     }
//     MyType {
//         id: mytype1
//     }
//     Connections {
//         target: button
//         onClicked:  ??????
//     }
 }
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QMLConnectTest.pro
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QT       += core gui declarative
TARGET = QMLConnectTest
TEMPLATE = app
RESOURCES += res.qrc
SOURCES += main.cpp
OTHER_FILES += myqml.qml
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