[Interest] [QtQuick] Interaction with user from C++

Sina Dogru sinadooru at gmail.com
Tue Apr 26 10:02:59 CEST 2016

Hello list,

Before watching this video
I was thinking the Qt-Declarative module is aiming to touch-screen and
mobile devices. And also after experiencing some QtQuick applications on
desktop my thought have totally changed. So I started a small desktop
application with QtQuick.

I had some problems with QML but also enthused :). If I come to the point,
my main problem is with C++ backend. I use some C++ classes with QML. I am
aware of that QML is natively seperates UI and business logic but sometimes
I need to interact with the user from my C++ classes. I am not sure if this
is about general architect problem of my design, I am not well exprienced
programmer. For example, on some points, qml sends some user interaction to
C++ classes, eg URL of a file. Class checks the url and responds to user
with QML(emitting a signal).

On the Widgets world, some of the static functions of QMessageBox and
QFileDialog (eg getSaveFileName
<http://doc.qt.io/qt-5/qfiledialog.html#getSaveFileName> and warning
<http://doc.qt.io/qt-5/qmessagebox.html#warning>) are so handy and
necessary, IMHO. I do mimic this behaviour with a QML function, which opens
a file dialog or a message box with the function arguments, connected to a
signal of a C++ class. So whenever I need to interact with the user from
C++ I just emit this signal with the proper arguments. For example when I
need to say to user that his/her input was incorrect, I just emit warning
signal. But the problem is when I need to get the user respond to this
warning box. Beauty of the QMessageBox and QFileDialog's static functions
are they creates their own event loop and they just returns the data that

My question is, I am not sure if this is originated from my design flaws,
is it possible to create an internal event loop in QML so the event loop
would return the necessary data?

Thank you,
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