Question

this is a simple OOP QT question.
my app consists of main window (QMainWindow) and a table (QTableWidget).
in the main window i have arguments and variables which i would like to pass to the table class, and to access methods in main widnow class from the table class, how should i do it ?

mainwindow.h

class MainWindow : public QMainWindow {
    Q_OBJECT
private:
    int a;
    int b;
    Spreadsheet *spreadsheet;

public:
    void set_a(int);
    void set_b(int);

spreadsheet.h

class Spreadsheet : public QTableWidget {
    Q_OBJECT

public:
    Spreadsheet(QWidget *parent = 0);

atm i define Spreadsheet like this:

spreadsheet = new Spreadsheet(this);

and i’d like to access set_a() from spreadsheet.cpp…

Answer 1

You can use the parent() method in the Spreadsheet object to get a pointer to your MainWindow.

For example,

// spreadsheet.cpp
MainWindow* mainWindow = (MainWindow*) this->parent();
mainWindow->set_a(123);

Of course, the parent object passed to Spreadsheet‘s constructor should be your MainWindow instance for this to work.

However, you should seriously consider oscode’s suggestion, since it also points you towards creating a more Qt-like API.