will Qt delete all dynamic data?

[Lykurg]

in main create the widget on the stack, then it will be deleted when you leave the scope. Since Qt uses pimpl the main part of the object is allocated dynamically. but if you want to create your main window on the heap use:

int returnValue = app.exec();
delete widget;
return returnValue;

int returnValue = app.exec();
delete widget;
return returnValue;

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[somename]

Ok, and please, give me some small utility, that can show to me memory leaks..(for windows)

[graeme]

Try the following:

#ifndef WIDGET_H
#define WIDGET_H
 
#include <QtGui>
 
class Widget : public QWidget
{
    Q_OBJECT
 
public:
    Widget(QWidget *parent = 0) : QWidget(parent) {}
 
    ~Widget()
    {
        qDebug() << "I AM IN DESTRUCTOR OF WIDGET!";
    }
};
 
#endif // WIDGET_H

#ifndef WIDGET_H
#define WIDGET_H

#include <QtGui>
 
class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = 0) : QWidget(parent) {}

    ~Widget()
    {
        qDebug() << "I AM IN DESTRUCTOR OF WIDGET!";
    }
};

#endif // WIDGET_H

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#include "widget.h"
 
 
int main(int argc, char **argv)
{
    QApplication app(argc, argv);
 
    QMainWindow mainWin;
    Widget *widget = new Widget(&mainWin);
    mainWin.show();
 
    return app.exec();
};

#include "widget.h"


int main(int argc, char **argv)
{
    QApplication app(argc, argv);

    QMainWindow mainWin;
    Widget *widget = new Widget(&mainWin);
    mainWin.show();

    return app.exec();
};

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See that whilst in the mainWindow I've not set up a parent when the app closes it gets deleted (because it's on the stack) and then the widget which is a child of mainWindow is deleted. (Or at least the destructor is called!)

[somename]

Ok, and one more question.
I have mainWidget, that contain several other widget (window),
and when I do following code, on my mainWidget I see other widget... I don't want that it show on mainWidget..

class MainWidget : public QMainWidget
{
    Q_OBJECT
public:
    MainWidget()
    {
        myForm = new MyForm(this);
    }
 
private:
    MyForm *myForm;
 
}

class MainWidget : public QMainWidget
{
    Q_OBJECT
public:
    MainWidget()
    {
        myForm = new MyForm(this);
    }
    
private:
    MyForm *myForm;

}

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How to do myForm as a child without showing on MainWidget?

[Lykurg]

where do you want to show it?
Inside your main window: use layouts.
outside your main widnow: use QDialog as a base class for example. or set the modal widget attribute.

[somename]

aa.. QDialog..
Ok, thanks!

[somename]

hmm.. I have one problem.
My app has one QMainWindow, and several other QWidget that can be show on QMainWindow(one at the time, and it is not QTabWidget!!).

There are several situations:

class Widget : public QWidget
{
     Widget(QWidget *parent) : QWidget(parent) {};
}
//In this situation, on my QMainWindow are showing several widget at the time
 
 
class Widget : public QDialog
{
     Widget(QWidget *parent) : QDialog(parent) {};
}
//In this situation, widget show as a dialog, on other window (not in QMainWindow)
 
class Widget : public QWidget
{
     Widget() {};
}
//In this situation all works fine, only this widget are showing on QMainWindow at the time. But it brings memory leaks, 
// because this widget has no parent, and i need to delete it by it self..
 
//In my QMainWindow I do this:
setCurrentWidget(widget)

class Widget : public QWidget
{
     Widget(QWidget *parent) : QWidget(parent) {};
}
//In this situation, on my QMainWindow are showing several widget at the time


class Widget : public QDialog
{
     Widget(QWidget *parent) : QDialog(parent) {};
}
//In this situation, widget show as a dialog, on other window (not in QMainWindow)

class Widget : public QWidget
{
     Widget() {};
}
//In this situation all works fine, only this widget are showing on QMainWindow at the time. But it brings memory leaks, 
// because this widget has no parent, and i need to delete it by it self..

//In my QMainWindow I do this:
setCurrentWidget(widget)

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[Lykurg]

Have a look at QStackedWidget!