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

Dmitry Volosnykh dmitry.volosnykh at gmail.com
Tue Apr 26 12:07:17 CEST 2016

> Well the problem is ... while using QFileDialog's and QMessageBox's
static functions, program can continue to flow from where those functions

This is declarative language. Spaghetti code is unavoidable %) You'll have
to do a mind-shift to use QML as it was designed.

On Tue, Apr 26, 2016 at 1:03 PM Dmitry Volosnykh <dmitry.volosnykh at gmail.com>

> > FileDialog's open function would not return the file URL while
> QFileDialog::getSaveFileName would return it
> While FileDialog.open() does not return anythying, you still able to get
> file's URL via fileUrl property of FileDialog instance like follows:
> FileDialog {
>   id: fileDialog
>   onAccepted: console.log("User selected file:", fileUrl)
> }
> Situation with MessageBox is mostly the same. This QML type provides,
> basically, the same functionality as its C++ counterpart. So you may
> perform different actions upon receiving different signals which correspond
> to buttons that user may press (Not suprisingly that these signals are
> named exactly the same as button enum's that are returned as an int result
> of QMessageBox::exec() method). So, here you are:
> MessageBox {
>   id: messageBox
>   onYes: console.log("User pressed Yes button")
>   onNo: console.log("User pressed No button")
>   onApply: console.log("User pressed Apply button")
>   // etc ...
> }
> On Tue, Apr 26, 2016 at 12:36 PM Sina Dogru <sinadooru at gmail.com> wrote:
>> Hi, Sina. You may try to wrap those C++-side static methods with
>>> intermediary class that is exposed to QML in a usual way. As far as I
>>> remember there should be some API for opening files as well as for message
>>> notifications. But that will require you to import QtQuick.Controls module.
>>> Please, refer to official documentation for more precise name of the module.
>> Hello Dmitry, thank you for respond. I think you are talking about the
>> FileDialog QML type and MessageBox. But my problem is, when I call a static
>> method of the intermediary class which calls FileDialog's open function
>> would not return the file URL while QFileDialog::getSaveFileName would
>> return it. So to do it, QML would need to call another function onAccepted
>> handler and it would need to know which function it needs to call.
>> I mean, for example consider a situation where a C++ class process a user
>> input carried from QML to C++. If the user input is incorrect, I would need
>> to ask the user some options. So I pop up a message box which presents the
>> options to the user with this intermediary class. But when I do this, I
>> would lose the flow of the program. So when the user responds to the
>> message box, I would need to call another C++ function to process. But
>> since QMessageBox's and QFileDialog's static functions create their own
>> event loop and returns the data, I would be able to process new data
>> without loosing the current stack and flow of the program.
>> So QMessageBox and QFileDialog's static functions are not need to know on
>> their event handlers, because they just returns the information that is
>> needed so program can continue from the same stack.
>> Like I said, I am not so exprienced with programming. I might be
>> misjudging your advice or QML and C++ seperation.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20160426/07a3b919/attachment.html>

More information about the Interest mailing list