I'm trying to test drive the QQmlPropertyMap
class. It seems like it might work well for what I want, if I can subclass it. The documentation here even gives some rudimentary instructions on what to do for subclassing it. Said documentation also indicates that this class derives from QObject
.
For what it's worth, I'm using QtCreator 2.6.1 on Qt 5.0.0 with QtQuick 2.0.
My main.qml:
import QtQuick 2.0
Rectangle {
width: 360
height: 360
Text {
text: owner.field
anchors.centerIn: parent
}
MouseArea {
anchors.fill: parent
onClicked: {
owner.testFunc();
}
}
}
My main.cpp:
#include <QtGui/QGuiApplication>
#include "qtquick2applicationviewer.h"
#include "TestMap.h"
#include <QQmlContext>
int main(int argc, char *argv[])
{
TestMap* map = new TestMap();
QGuiApplication app(argc, argv);
QtQuick2ApplicationViewer viewer;
QQmlContext* ctxt = viewer.rootContext();
ctxt->setContextProperty("owner", map);
viewer.setMainQmlFile(QStringLiteral("qml/TestMap/main.qml"));
viewer.showExpanded();
return app.exec();
}
My TestMap.h
#ifndef TESTMAP_H
#define TESTMAP_H
#include <QObject>
#include <QQmlPropertyMap>
#include <QDebug>
class TestMap: public QQmlPropertyMap // QObject
{
Q_OBJECT
public:
TestMap(QObject* parent = 0): QQmlPropertyMap(this, parent) // QObject(parent)
{
insert("field", "value"); // Comment this out
}
TestMap(const TestMap& value) { }
virtual ~TestMap() {}
public slots:
void testFunc()
{
qDebug() << "Success!";
}
};
Q_DECLARE_METATYPE(TestMap)
#endif
When I run, I get a window saying "value", as I'd expect. But when I click on the window, I get a console output saying
TypeError: Property 'testFunc' of object TestMap(0xaaa0b8) is not a function
I've looked for similar problems, but all the search results are about people that forgot to include the Q_OBJECT
macro. It must be something I'm doing wrong in the code, because if I make all the changes indicated in the comments of the TestMap file (and leave the main.cpp and main.qml exactly as is), I get the qDebug
message I expect.
I'm not sure whether I'm supposed to Q_DECLARE_METATYPE
or not (I think the 2-arg protected constructor is supposed to do it for me), but it doesn't work either way.
For the record, the only things I have to change to get it to work are:
1) Derive from QObject
instead of QQmlPropertyMap
.
2) Change the constructor to:
TestMap(QObject* parent = 0): QObject(parent) {}
And that's it. Since it works when I don't change anything about the main.cpp, main.qml, or the slot itself, I have to conclude it's nothing wrong with those. Can anyone tell me what I'm doing wrong?
This is now fixed in Qt 5.1.0 and onwards. See the following codereview url for details:
https://codereview.qt-project.org/#change,57418