CODEWITHSUNDEEP
c++qt
JavaRunner
JavaRunner

Reputation: 2545

Can't access my UI's widgets

I have a MainWindow class which contains all widgets and I have a MyClass class where I want to access to all widgets placed in the main window (MainWindow class). How can I do this? I try to do it like this (code below) - but it gives me a bunch of errors:

MyClass.h:4: error: 'Ui' has not been declared
MyClass.h:4: error: expected `)' before '*' token
MyClass.h:6: error: 'Ui' has not been declared
MyClass.h:6: error: ISO C++ forbids declaration of 'MainWindow' with no type
MyClass.h:6: error: expected ';' before '*' token

This MainWindow created by QtCreator - it's a standart GUI window created by Qt Creator.

// -=-=-=-=-=-=-=-=-=-=[ MyClass.h ]=-=-=-=-=-=-=-=-=-=-=-=-=-
#include "MainWindow.h"
class MyClass {
    public:
        MyClass( Ui::MainWindow *ui );
    private:
        Ui::MainWindow *ui;
};

// -=-=-=-=-=-=-=-=-=-=[ MyClass.cpp ]=-=-=-=-=-=-=-=-=-=-=-=-=-

#include "MyClass.h"

MyClass::MyClass( Ui::MainWindow *ui ){
    this->myUI = ui; // myUI is desclared as: Ui::MainWindow *myUI
}

// -=-=-=-=-=-=-=-=-=-=[ MainWindow.h ]=-=-=-=-=-=-=-=-=-=-=-=-=-
....
namespace Ui {
    class MainWindow;
}
class MainWindow : public QMainWindow {
    Q_OBJECT    
    private:
        Ui::MainWindow *ui; // this has done by Qt Creator
    public:
        MyClass *myClass;
}
// -=-=-=-=-=-=-=-=-=-=[ MainWindow.cpp ]=-=-=-=-=-=-=-=-=-=-=-=-=-
#include "MainWindow.h"
MainWindow::MainWindow( QWidget *parent ): QMainWindow( parent ), ui( new Ui::MainWindow ) {
    ui->setupUi( this );
    myClass = new MyClass( ui ); // my attempt
}

Update: There's useful code in the comment below by beige. It works fine. But not in my case :( When I try to declare MyClass from any class (not from MainWindow.h):

// -=-=-=-=-=-=-=-=-=-=[ MyGLWidget.h ]=-=-=-=-=-=-=-=-=-=-=-=-=-

#include "MyClass.h"
class MyGLWidget : public QGLWidget {
   Q_OBJECT
   public:
     MyClass *myClass;
}

it doesn't work:

myclass.h:9: error: 'Ui' has not been declared
myclass.h:9: error: expected `)' before '*' token
myclass.h:12: error: 'Ui' has not been declared
myclass.h:12: error: ISO C++ forbids declaration of 'MainWindow' with no type
myclass.h:12: error: expected ';' before '*' token

but why? I have declaration of the "ui_mainwindow.h" in my MyClass.h.

Upvotes: 0

Views: 6701

Answers (1)

tomvodi
tomvodi

Reputation: 5897

The MyClass header has to include the generated headerfile from the user interface compiler. In your case, it is called ui_mainwindow.h. The constructor of MyClass will take the Ui::MainWindow parameter and save it in a private member variable.

In the constructor of MainWindow you can initialize your MyClass member variable with the MainWindow ui.

// -=-=-=-=-=-=-=-=-=-=[ myclass.h ]=-=-=-=-=-=-=-=-=-=-=-=-=-

#include <ui_mainwindow.h>

class MyClass
{
public:
    MyClass(Ui::MainWindow *ui);

private:
    Ui::MainWindow *myUi;
};

// -=-=-=-=-=-=-=-=-=-=[ myclass.cpp ]=-=-=-=-=-=-=-=-=-=-=-=-=-

MyClass::MyClass(Ui::MainWindow *ui)
{
    // Save the MainWindow-ui as private member of MyClass
    this->myUi = ui;
}

// -=-=-=-=-=-=-=-=-=-=[ MainWindow.h ]=-=-=-=-=-=-=-=-=-=-=-=-=-

#include <QMainWindow>
#include "myclass.h"

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
    MyClass *myClass; // myClass member dont't has to be public
};

// -=-=-=-=-=-=-=-=-=-=[ MainWindow.cpp ]=-=-=-=-=-=-=-=-=-=-=-=-=-

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    // Initialize MyClass with the MainWindow-ui
    myClass = new MyClass(ui);
}

MainWindow::~MainWindow()
{
    delete myClass;
    delete ui;
}

Upvotes: 3

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