Adding QML element from C++

[emppu]

Hello, I am trying to add QML elements in C++ but it doesn't work.

I have tried to (1) find a parent, (2) create QQmlComponent, (3) create an object, and (4) setParent.

1. QObject *parent = engine.rootObjects().first()->findChild<QObject*>("row1");;

QQmlEngine *engine2 = new QQmlEngine;
QQmlComponent component(engine, QUrl("qrc:/Abc.qml"), QQmlComponent::PreferSynchronous);

3. QObject *rect = component.create();
4. rect->setParent(parent);

I added objectName: "parent" to a QML element and Abc.qml is simple:

Rectangle {
	width: 100
	height: 62
	color: green
}

What is wrong?

[JKSH]

Hi @emppu,

First, you need to understand the difference between object parent and visual parent (see http://doc.qt.io/qt-5/qtquick-visualcanvas-visualparent.html ).

Qt Quick components are shown based on their visual parent.

3. QObject *rect = component.create();
4. rect->setParent(parent);

This sets the object parent, not the visual parent.

Instead, you need to use QQuickItem::setVisualParent() QQuickItem::setParentItem(). [EDIT: Typo]

[emppu]

@JKSH Thanks!
In Qt 5.4, the following sets the visual parent.
child->setParentItem((QQuickItem*)parent);

[emppu]

The follow-up question:
Is it possbie to specify the index of insertion? Or change the existing order of children?

[JKSH]

You're welcome!

@emppu said:

Is it possbie to specify the index of insertion? Or change the existing order of children?

Yes. Set the "z" property (similar to "x" and "y").