Question

I’m wondering how to access parent class in my Qt application.
Lets say my project has following structure:

mainWindow: MainWindow
    tabWidget: QTabWidget
        tab1: MySubClass1
        tab2: MySubClass2
            tabWidget: QTabWidget
                xtab1: MySubSubClass1
                xtab2: MySubSubClass2

It is a little simplified.
What I want to do is to access mainWindows object from one of xtab2 slot functions.

(1) What would be the best method ?
I tried to pass the pointer to mainWindow along the tree but I get runtime errors.

(2) Should I include mainwindow.h in xtab.h file or should I do it in xtab.cpp file ?

Thanks for help 🙂

Answer 1

You could create a static method and object inside MainWindow that would return mainwindow object.

Something like this:

private:
     static MainWindow* _windowInstance

public:
     static MainWindow* windowInstance()
     {
          return _windowInstance;
     }

This seems to be the simples solution in most cases. Now you just have to include mainwindow.h whenever you need to access this object.

And don’t forget to initialize _windowInstance in the contructor, like this;

_windowInstance = this;