QtQuick2 does not find .h files with new classes - c++

Question

I'm trying to learn how to connect Qt quick object signals to slots in classes in the c++ code. When I add the class definitions to the "qtquick2applicationviewer.h" file that is created by the system, everything works.
But I can't find a way to add my own .h file (I should do this as indicated in the .h file: "It is recommended not to modify this file, since newer versions of Qt Creator may offer an updated version of it.")
I tried adding the source to the .pro file (HEADERS += classes.h), also tried to add it to the .pri file (HEADERS += $$PWD/../classes.h) but no luck.
The Error I get is a linker error:
LNK2001: unresolved external sybol "public: virtual struct QMetaObject const * __thiscall MyClass::metaObject(void)const " (?metaObject#Myclass##UBEPBUQMetaObject##XZ)
and two more similar.
Any inputs on what I'm doing wrong is highly appreciated :)
Can probably help many others as well as it is a general question bases on the QTQuick tutorial application.
//classes.h
#ifndef CLASSES_H
#define CLASSES_H
#include <QObject>
#include <QVariant>
class MyClass : public QObject
{
Q_OBJECT
public:
MyClass(QObject *QMLObject) : m_QMLObject(QMLObject) {}
public slots:
void handleClick() {
m_QMLObject->setProperty("text", "Qt was here");
}
protected:
QObject *m_QMLObject;
};
#endif // CLASSES_H
//main.cpp
#include <QtGui/QGuiApplication>
#include "qtquick2applicationviewer.h"
#include "classes.h"
#include <QtQuick>
#include <QtDebug>
void MyClassInQtQhfile::cppSlot(const QString &msg) {
qDebug() << "Called the C++ slot with message:" << msg;
}
int main(int argc, char *argv[])
{
QTextStream out(stdout);
QGuiApplication app(argc, argv);
QtQuick2ApplicationViewer viewer;
viewer.setMainQmlFile(QStringLiteral("qml/Transitions/main.qml"));
viewer.showExpanded();
QObject *rectangle = viewer.rootObject()->findChild<QObject*>("rectangle");
QObject *text = viewer.rootObject()->findChild<QObject*>("text");
MyClassInQtQhfile *myClassInQtQhfile = new MyClassInQtQhfile();
MyClass *myclass = new MyClass(text);
QObject::connect(rectangle, SIGNAL(qmlSignal(QString)),
myClassInQtQhfile, SLOT(cppSlot(QString)));
QObject::connect(rectangle, SIGNAL(qmlSignal(QString)),
myclass, SLOT(handleClick()));
//rectangle is the object name, which needs to be define in qml for the component.e.g. objectName: "rectangle"
return app.exec();
}
//QML object sending signal
Rectangle {
objectName: "rectangle"
id: bottomLeftRect
width: 64
height: 64
color: "#00000000"
radius: 6
anchors.left: parent.left
anchors.leftMargin: 10
anchors.bottom: parent.bottom
anchors.bottomMargin: 20
border.color: "#808080"
signal qmlSignal(string msg)
MouseArea {
id: mousearea3
anchors.fill: parent
onClicked:{
bottomLeftRect.qmlSignal("Hello from QML")
onClicked: page.state = 'State2'
}
}
}
Beginning of qtquick2applicationviewer.pri
# checksum 0x21c9 version 0x90005
# This file was generated by the Qt Quick 2 Application wizard of Qt Creator.
# The code below adds the QtQuick2ApplicationViewer to the project and handles
# the activation of QML debugging.
# It is recommended not to modify this file, since newer versions of Qt Creator
# may offer an updated version of it.
QT += qml quick
SOURCES += $$PWD/qtquick2applicationviewer.cpp
HEADERS += $$PWD/qtquick2applicationviewer.h
HEADERS += $$PWD/../classes.h
INCLUDEPATH += $$PWD
...
.pro file
# Add more folders to ship with the application, here
folder_01.source = qml/Transitions
folder_01.target = qml
DEPLOYMENTFOLDERS = folder_01
# Additional import path used to resolve QML modules in Creator's code model
QML_IMPORT_PATH =
# The .cpp file which was generated for your project. Feel free to hack it.
SOURCES += main.cpp
# Installation path
# target.path =
# Please do not modify the following two lines. Required for deployment.
include(qtquick2applicationviewer/qtquick2applicationviewer.pri)
qtcAddDeployment()
HEADERS += \
classes.h