Can't execute new UI or setModel.

Brownies

@yoavmil Sorry for being unclear.
I want the pushbutton to open another UI and then hide the original UI.

Ex: You're on form One.ui. You press a button and Two.ui opens while One.ui disappears. Hope I was clear.

Brownies

@SGaist I'm really embarrassed for making such a mistake; Yes, I did mean setModal instead of setModel.
Though I changed my mistake to setModal and I added #include <QDialog> but that didn't work either. I thought that perhaps I was including the library in the wrong file, so I included it in all the files for testing but that didn't work either. I received the following errors on every try:

mainwindow.cpp:38: error: C2039: 'setModal' : is not a member of 'MainMenu'
mainmenu.h:11: see declaration of 'MainMenu'
mainwindow.cpp:39: error: C2039: 'exec' : is not a member of 'MainMenu'
mainmenu.h:11: see declaration of 'MainMenu'

The following is the code for mainmenu.h:11

class MainMenu : public QMainWindow
{
    Q_OBJECT
public:
    explicit MainMenu(QWidget *parent = 0);
    ~MainMenu();
private slots:
        void showTime(); /*For Time*/
private:
    Ui::MainMenu *ui;
};

Nothing unusual and to me, everything seems in order.

SGaist

Except that your MainMenu is a QMainWindow not a QDialog

Brownies

@SGaist I sorta noticed that after I peered through my own stupidity.
I made the following changes, and it works fine.

MainWindow.cpp

void MainWindow::on_MyPushButton_clicked()
{
   MainMenuWin = new MainMenu();
   MainMenuWin -> show();

}

MainWindow.h
Added as a private data member of class 'MainWindow'

private:
   MainMenu *MainMenuWin;

After that, I just went to the MainMenu UI, selected the form and changed the windowModality as can be seen below:
http://s1.postimg.org/6se84xv5b/Help.png

Thanks for your help and sorry for being a bother :P
I will definetly use @yoavmil 's advice for hiding a UI.
Thanks!

SGaist

Beware, you have a memory leak, each time on_MyPushButton_clicked is called you create a new MainMenu object

Brownies

Oh right, I forgot to mention that you have to delete the pointer MainMenuWin as such:

If the mainwindow.cpp file already referances the deconstructor, then add this to the deconsturctor:

MainWindow::~MainWindow()
{
    delete ui;
    delete MainMenuWin; //Add this to delete the dynamically created pointer ( new MainMenu(); )
}

If you don't have the deconstructor referance in mainwindow.cpp, go to mainwindow.h and look for the deconstructor in the public part of the class:

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

Just convert it to the following:

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow()
          {
               delete MainMenuWin; //Delete pointer
          }

Sorry if this seems like trivial baby talk to most of you; I just like explaining it step-by-step in case a beginner reads this thread.
Thanks again for your help!

SGaist

That doesn't solve the problem, you are still creating a new MainMenuWin each time on_MyPushButton_clicked is called. So either add a check in the slot to only construct it once, or do it in the constructor.

Brownies

I understand what you're saying. But in my program, the user can only call the function once and then the program will close, running the deoconstructor. So I don't think I will face the problem of having the button pressed multiple times and having MainMenuWin created more than once.
But I guess I will implement a check to make sure that if the function is called more than once (for any possible reason), MainMenuWin will not be dynamically created again.
Thank you again!

if ( MainMenuWin != &MainMenu() ) {MainMenuWin = new MainMenu();}
/* If Pointer MainMenuWin points to the address of MainMenu, then MainMenu has already been dynamically created
and there is no need to create it once more. */

Hope I'm on the right track :D

Chris Kawa

To avoid having to worry about duplicates or deleting pointers (or even storing them) you might want to simply create the thing and set a Qt::WA_DeleteOnClose flag to let Qt delete the object for you when you close the window:

void MainWindow::on_MyPushButton_clicked()
{
   auto mm = new MainMenu();
   mm->setAttribute(Qt::WA_DeleteOnClose);
   mm->show();
}

Unless of course you don't want multiple copies of the window to be shown at the same time.

Brownies

@Chris-Kawa Oh wow. I didn't even know about that! Thanks! :D