[SailfishDevel] Accessing C++ properties from QML

[Petr Vytovtov]

You can try to use signals and slots like this:



Header

class // ...

{

// ...



signals:

void somethingWasDone();



// ....

}



Source

// ...



someMethod() {

// Do something ....

emit somethingWasDone();

}



// ...



QML

// ...



Connections {

target: // Your module

onSomethingWasDone: // Change properties

}



// ...



More about this you can see at the video: https://www.youtube.com/watch?v=R59lpwNy9WE



Regards,

Petr

[Linux User Group Udmurtia](https://udmlug.wordpress.com/)






-------- Original Message --------

Subject: Re: [SailfishDevel] Accessing C++ properties from QML

Time (UTC): August 13 2015 5:26 pm

From: ziobilly94 at gmail.com

To: devel at lists.sailfishos.org

CC:



for properties system you should use Q_PROPERTY macro inside your class.



Since i have to access properties of a class declared inside another class i find using the macro Q_PROPERTY a little confusing.

Actually, I think you're creating a new instance of the FirstPage.qml component using this code. But, Sailfish should have already created its own instance of that page when it started up.

You might instead try retrieving a view of the Sailfish instance and going from there, something like this:

QQuickView *view = SailfishApp::createView();
QObject *object = view->rootObject();
QObject *label = object->findChild<QObject *>("label");

--John


I tried this, it compiles, after including <sailfishapp.h> and <QQuickItem>, but now there's no output, as it can't find the proper object or the SailfishApp::createView() creates a new, empty view



The code is this:

...
QQuickView *view = SailfishApp::createView();
QObject *object = view->rootObject();
QObject *label = object->findChild<QObject*>("label");
QQmlProperty property(label, "text");

cout << "Read before: " << property.read().toString() << endl;

if (label) {
cout << "true";
property.write(active.name);
} else
cout << "false" << endl;

cout << "Read after: " << property.read().toString() << endl;

fetchMonsterDone();
...




the output is:


Read before:


false


Read after:


[D] onFetchMonsterDone:51 - Fetch done
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