Interacting with QML Objects from C++

[p3c0]

@Khachatur How did you check whether they are 2 separate instance ?

[Khachatur]

@p3c0

I don't know the way how to check directly whether they are 2 separate instances, but I was relying on logic.

In QML slots onColorChanged and onVisibleChanged of test_rect I am printing the 'color' and 'visible' values.

        onColorChanged: {
            console.log(color)
        }

        onVisibleChanged: {
            console.log(visible)
        }

When I am changing property of QML objects from C++ code:

          aRect->setProperty("color", "green");
          aRect->setVisible(false);

In output console I get the correct values of color and visibility (green and false respectively), but rectangle still remains red and visible.

Therefore I make decision that I am working with another instance of main.qml and I was right.

[p3c0]

@Khachatur No they are exactly the same objects.
Consider the following example:
main.qml

import QtQuick 2.4
import QtQuick.Window 2.2

Window {
    visible: true
    width: 150
    height: 150

    Rectangle {
        anchors.fill: parent
    }

    Component.onCompleted: console.log("From QML: ",this) // prints the root object
}

your main.cpp

QQmlApplicationEngine anEngine;
anEngine.load(QUrl(QStringLiteral("qrc:/main.qml")));

QObject *aRoot = anEngine.rootObjects()[0];
qDebug() << "From C++: " << aRoot;

After running if you look at the outputs you can see the same address on both sides which indicates it is the same object.
I think there is some other problem in your code.
Can you post or upload an updated complete minimal working example which will show the problem ?

[Khachatur]

@p3c0

I have checked.

This code I am using at the first time in file main.cpp when I am launching the application

QQmlApplicationEngine anEngine;
anEngine.load(QUrl(QStringLiteral("qrc:/main.qml")));

QObject *aRoot = anEngine.rootObjects()[0];
qDebug() << "From C++: " << aRoot;

Then I am using the same code in my OperationCreatePoint.cpp class and I get the different address of aRoot.

The output is:
From main.cpp: ApplicationWindow_QMLTYPE_57_QML_74(0x4711600)
From OperationCreatePoint.cpp: ApplicationWindow_QMLTYPE_143_QML_160(0x8478fc0)

[p3c0]

@Khachatur Some confusion. Do you mean you load main.qml twice ? One is main.cpp and another in OperationCreatePoint.cpp ?
Atleast from the output it seems.

[Khachatur]

@p3c0

English is not my native language, may be you misunderstood me... Anyway thank you for your response and sorry for misunderstood

[p3c0]

@Khachatur That's fine :)
If you still have the problem you can post the updated complete minimal working example so that it would be more helpful in finding the problem.

[Khachatur]

@p3c0

Yes, I meant I was loading main.qml twice in main.cpp and OperationCreatePoint.cpp. Currently, I have not any problem, Thanks :)

I just have another question about QML FileDialog component, but I guess... should I create new thread?

I am using the FileDialog to load and save files. When I am saving file I want to pass to my FileDialog the default file name, but unfortunately FileDialog have not such property, only fileUrl property which is ReadOnly. I don't want to implement my own file dialog component...

[p3c0]

@Khachatur AFAIK it is still not implemented. Taking this into consideration some one has already implemented their own. See here.

[Khachatur]

@p3c0

That is exactly what I need. Thank you :)