QtQuick: create component from C++ - c++

Question

I have a problem with QQuickView instantiating components from C++... Here is my code:
Class definition (vviewerqml.h):
class VViewerQml : public QObject
{
Q_OBJECT
public:
explicit VViewerQml(QSettings &systemSettings, QObject *parent = 0);
~VViewerQml();
protected slots:
void onViewStatusChanged(QQuickView::Status status);
protected:
QString _qmlFolder;
QQuickView _view;
};
Class implementation (vviewerqml.cpp):
#include "vviewerqml.h"
VViewerQml::VViewerQml(QSettings &systemSettings, QObject *parent) :
QObject(parent)
{
// Initialize viewer reading from settings file
_qmlFolder = "/my/path/to/qml/files";
// Initialize the source
connect(&_view, SIGNAL(statusChanged(QQuickView::Status)),
this, SLOT(onViewStatusChanged(QQuickView::Status)));
_view.setSource(QUrl::fromLocalFile(QDir(_qmlFolder).filePath("Main.qml")));
// Show the viewer
_view.show();
}
VViewerQml::~VViewerQml()
{
// Close the viewer
_view.close();
}
void VViewerQml::onViewStatusChanged(QQuickView::Status status)
{
if(status == QQuickView::Ready)
{
QQmlComponent *c =
new QQmlComponent(_view.engine(),
QDir(_qmlFolder).filePath("TextLegacy.qml"));
QQuickItem *i = qobject_cast<QQuickItem*>(c->create());
QQmlEngine::setObjectOwnership(i, QQmlEngine::CppOwnership);
i->setParent(_view.rootObject());
i->setVisible(true);
}
}
Here is my Main.qml:
import QtQuick 2.0
Rectangle {
width: 1024
height: 768
color: "#000000"
Text {
x: 0
y: 0
color: "#ffffff"
text: "Main page"
}
}
And here is my TextLegacy.qml:
import QtQuick 2.0
Item {
Rectangle {
x: 0
y: 0
width: 100
height: 50
color: "#ff0000"
}
}
My code works fine until the load of Main.qml: the QML viewer opens on the screen and I can read the text "Main page" (white on black) on my screen... But unluckily I am not able to load the TextLegacy.qml... if I put a breakpoint in onViewStatusChanged function, the execution reaches that point... no visible errors are shown in the debug console... but I am not able to see on the screen the red rectangle provided by TextLegacy.qml...
What am I missing? Can somebody give some help?

Answer 1

Ok, I found the solution on my own: I have confused setParent with setParentItem... The correct code is:
void VViewerQml::onViewStatusChanged(QQuickView::Status status)
{
if(status == QQuickView::Ready)
{
QQmlComponent *c = new QQmlComponent(_view.engine(),
QUrl::fromLocalFile(QDir(_qmlFolder).filePath("TextLegacy.qml")));
QQuickItem *i = qobject_cast<QQuickItem*>(c->create());
QQmlEngine::setObjectOwnership(i, QQmlEngine::CppOwnership);
i->setParent(this);
i->setVisible(true);
i->setParentItem(_view.rootObject());
}
}
Actually i->setParent(this); defines the parent of i as a QObject (for deleting purposes, for example) while i->setParentItem(_view.rootObject()); actually adds the object to the scene, as a child of the scene root object.