How to Show GUI and work on background

[roseicollis]

Hi,

Since you have fixed sequence of functions, dervice from QThread and implement that sequence in its run() method.

Ok so you mean to do :

class MainWindow : public QMainWindow, QThread
{
    Q_OBJECT
...
}

class MainWindow : public QMainWindow, QThread
{
    Q_OBJECT
...
}

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Then it says In member function 'virtual const QMetaObject* MainWindow::metaObject() const':/home/sg/Docs/.../moc_mainwindow.cpp:62: error: 'QObject' is an ambiguous base of 'MainWindow'

You could also create a second, non-UI program and start that from the UI program using QProcess.

Ok here I'm completly lost ^^'' can you explain that better please?

Thanks,

[anda_skoa]

Ok so you mean to do :

class MainWindow : public QMainWindow, QThread
{
    Q_OBJECT
...
}

class MainWindow : public QMainWindow, QThread
{
    Q_OBJECT
...
}

To copy to clipboard, switch view to plain text mode 

Then it says In member function 'virtual const QMetaObject* MainWindow::metaObject() const':/home/sg/Docs/.../moc_mainwindow.cpp:62: error: 'QObject' is an ambiguous base of 'MainWindow'

You can only derive from one QObject based class.

Ok here I'm completly lost ^^'' can you explain that better please?

QProcess is a Qt class that allows you to run other programs/executables.
So one parallel processing approach is to have a task program that can be blocking/sequential and have the main program run it via QProcess.

Cheers,
_

[roseicollis]

You can only derive from one QObject based class.

Then? How can I derive from both?

QProcess is a Qt class that allows you to run other programs/executables.
So one parallel processing approach is to have a task program that can be blocking/sequential and have the main program run it via QProcess.

Do you mean that I have to make 2 projects and then unify them with a process?? If yes can you put the code or the idea more or less of it? I can't understand how can the code be.
Sorry for all, I'm really newbie with Qt and developing with threads/process/etc. I've been looking for some written examples to try to understand it more but can't find any for that, so could you please write it?

Thank you!

[Lesiok]

Then? How can I derive from both?

GUI can't be used outside main thread.

[anda_skoa]

Then? How can I derive from both?

Didn't I just write that this is not possible?
How does asking how to do it make any sense?
Obviously there is no "how".

Do you mean that I have to make 2 projects and then unify them with a process??

That is an option.
You can also have a project that contains two exectuables.
The template for a multi target project is called "subdirs".

If yes can you put the code or the idea more or less of it? I can't understand how can the code be.

The idea is two have two programs:
1) a GUI that needs to be event driven to stay responive
2) a simple non-GUI worker program that can block until it is done

Then have the GUI program run the non-GUI program using QProcess.

Multi-Process is an alternative to multithreading with slightly different properties.

Depends a lot on what that parallel task is, how much it needs to share data with the UI and how often it needs to communicate.

Cheers,
_

[roseicollis]

Didn't I just write that this is not possible?
How does asking how to do it make any sense?
Obviously there is no "how".

As you said: "Since you have fixed sequence of functions, dervice from QThread and implement that sequence in its run() method."
Though you meant I had to inherit from it too.

I'll search more about what you think of exes Thank you!

[anda_skoa]

As you said: "Since you have fixed sequence of functions, dervice from QThread and implement that sequence in its run() method."
Though you meant I had to inherit from it too.

Yes, you thought correctly.
The way to reimplement a virtual method in C++ is to overwrite it, meaning you derive from the class and implement the method again in that new class.

Cheers,
_