Child widget problem

[poporacer]

I am trying to lear QT creator and have searched and read the forum and several areas but I must be missing something. But first I have a question. I am writing a program that will have a main window and then widgets (dialog forms) that I want to display in the main window. I read about stacked widgets but am concerned that if all the widgets are loaded then this could create a resource issue. Is that thought process correct? I am able to create the forms and have the button open the second form. The problem is that the form does not open as a child of the main window. I am using QT Creator 1.2.1 based on QT 4.5.2. What am I missing? Here is the code!

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

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

protected:
void changeEvent(QEvent *e);

private:
Ui::MainWindow *ui;

private slots:
void on_btnNextPage_clicked();

};

#endif // MAINWINDOW_H


mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "page2.h"

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

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

void MainWindow::changeEvent(QEvent *e)
{
QMainWindow::changeEvent(e);
switch (e->type()) {
case QEvent::LanguageChange:
ui->retranslateUi(this);
break;
default:
break;
}
}

void MainWindow::on_btnNextPage_clicked()
{

Page2* page2 = new Page2 () ;
page2->exec();
}



page2.h

#ifndef PAGE2_H
#define PAGE2_H

#include <QDialog>

namespace Ui {
class Page2;
}

class Page2 : public QDialog
{
Q_OBJECT

public:
explicit Page2(QWidget *parent = 0);
~Page2();

protected:
void changeEvent(QEvent *e);

private:
Ui::Page2 *ui;
};

#endif // PAGE2_H


page2.cpp

#include "page2.h"
#include "ui_page2.h"

Page2::Page2(QWidget *parent) :
QDialog(parent),
ui(new Ui::Page2)
{
ui->setupUi(this);
}

Page2::~Page2()
{
delete ui;
}

void Page2::changeEvent(QEvent *e)
{
QDialog::changeEvent(e);
switch (e->type()) {
case QEvent::LanguageChange:
ui->retranslateUi(this);
break;
default:
break;
}
}

Thanks for your assistance

Rick

[Lykurg]

Ok, do you want to use QStackedWidget? then your code is absolutely wrong:) add your widget in the constructor to the stackwidget and in the slot change the current index of your stackwidget. If you don't want use a stack widget, then you have to add your widget to the layout of your main class. Furthermore it is better to create the widget with a parent, so better always use
Page2* page2 = new Page2 (this) ;

And normally QStackedWidget wont be a resource problem.

[poporacer]

I didn't use a stacked widget because of my concerns with resources as several widgets will be connected to databases, so I was going to load and unload each widget as needed. Which way is better?

I think I am missing something because I tried

1.Page2* page2 = new Page2 (this) ;
and Page2 still opened as its own window, not a window within mainwindow. What did I miss?
Thanks for taking your time!
Rick

[Lykurg]

As told, you have to put that widget into the layout of your mainwindow. (See layout() to get it, or use setCentralWidget(), but that depends on your needs)

[poporacer]

I am not sure how to add the widget into the layout of my window dynamically. I looked at the QLayout* QWidget::layout()const class and couldn't figure it out. I think I might need to place some sort of placeholder widget in the mainwindow widget and then somehow load and unload the widgets as needed. could you give me a little more information? Thanks
Rick