multiple inheritance

[Natural_Bugger]

i would like to add the Thread class to my customButton class

thread-basics

custombutton.h file

#ifndef CUSTOMBUTTON_H
#define CUSTOMBUTTON_H

#include <QPushButton>
#include <QThread>

class CustomButton : public QPushButton, public QThread
{
public:
    CustomButton( const QString& text, QWidget* parent = 0 );

    // Enhancement, it will reverse the button text
    void reverseText();
private:
    void run();
};

#endif // CUSTOMBUTTON_H

customButton.cpp file

#include "CustomButton.h"
#include "algorithm"
#include <QDebug>
#include "CustomButton.h"
#include "algorithm"
#include <QDebug>
#include <QApplication>

CustomButton::CustomButton( const QString& text, QWidget* parent )
    : QPushButton( text, parent )
{
    //this->set
    const QSize btnSize = QSize(150, 150);
    this->setFixedSize(btnSize);
    this->move(1000, 10);

}

void CustomButton::reverseText()
{
    QString buttonText = text();
    std::reverse(buttonText.begin(), buttonText.end());
    setText( buttonText );
}

void CustomButton::run(){
    int randomNumber = rand();
    setText(  QString::number(randomNumber) );
}

main.cpp

.
..
...
CustomButton *mybutton = new CustomButton( QString::number(size.width()) + " abc " + QString::number(size.height()));
    mybutton->show();
    mybutton->start(); // <---
    mybutton->reverseText();
...
..
.

how do i make random numbers appear on the button every x time?

if you comment out:

//mybutton->start();

the "run" method doesn't get executed.

does the thread class only apply to private methods?

[JonB]

@Natural_Bugger said in multiple inheritance:

class CustomButton : public QPushButton, public QThread

How does it make sense to create an object which inherits from a QPushButton and from QThread?

I do not see any connection. Keep any threading quite separate.

[Natural_Bugger]

@JonB

well, i wanna try to give that button some properties.
i need to access the button properties.
just trying some stuff.

what do you suggest?

[JonB]

@Natural_Bugger
It's difficult to know, because I have no idea what you are thinking of conceptually....

Why are you going anywhere near threads at all? They add a lot of complexity, what use case do you have here for threads?

how do i make random numbers appear on the button every x time?

Maybe use a QTimer to change the text on the button over time??

Or, if you really, really have a thread generating random numbers all the time and you want to display them, use the pattern that the worker thread raises signals with the desired number/text and the main UI thread has a slot for the signal which updates whatever on the UI.

[Bonnie]

Well, just want to say that multiple inheritance of classes which inherit QObject is not allowed.

[Natural_Bugger]

@JonB

i would like to make the button fall at a rate of 9.81 pixels per second and if i lift it up again.
so my guess: is that my button needs to check autonomously where it resides.

[JonB]

@Bonnie raises a good point: you cannot inherit twice from anything inheriting from QObject. So you won't get class CustomButton : public QPushButton, public QThread to work anyway, which is just as well! :)

[JonB]

@Natural_Bugger said in multiple inheritance:

i would like to make the button fall at a rate of 9.81 pixels per second and if i lift it up again.

Not that I know what this means, but it sounds like you want a 1-second repeating QTimer in which you do some update to the UI?

[J.Hilk]

@Natural_Bugger I'm surprised this compiled

https://doc.qt.io/qt-5/moc.html#multiple-inheritance-requires-qobject-to-be-first

Inheriting from multiple QObjects is not allowed/supported

[Natural_Bugger]

@J-Hilk

it actually runs.

mybutton->start(); // <---

if i comment out "mybutton->start(); // <---", the run function doesn't work, otherwise it does.

[Natural_Bugger]

@JonB

it's just an experiment.
trying to give the button some "life"

[JonB]

@Natural_Bugger
Well, it's the wrong experiment! Conceptually widgets and threads have nothing to do with each other. What's wrong with a QTimer, which sounds like all you are looking for?

[mrjj]

Hi
For such animations, you can also use
https://doc.qt.io/qt-5/qpropertyanimation.html