Resize MDI subwindows

Hi,

I want to resize subwindows of simple MDI application:

Code:

---

#include "MainWindow.h"
#include "ui_MainWindow.h"
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
 
    m_firstWindow = new FirstWindow;
    m_secondWindow = new SecondWindow;
    m_thirdWindow = new ThirdWindow;
 
    m_firstWindow->resize( 500, 500 );
 
    ui->mdiArea->addSubWindow( m_firstWindow );
    ui->mdiArea->addSubWindow( m_secondWindow );
    ui->mdiArea->addSubWindow( m_thirdWindow );
}
 
MainWindow::~MainWindow()
{
    delete ui;
}

---

But it doesn't work:
Attachment 10559

It is the project: https://github.com/8Observer8/SimpleMDIApplication

Thank you!

If you want to resize the MdiSubWindow then you should call resize() on that object, not the widget it contains:

Code:

---

#include "MainWindow.h"
#include "ui_MainWindow.h"
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
 
    m_firstWindow = new FirstWindow;
    m_secondWindow = new SecondWindow;
    m_thirdWindow = new ThirdWindow;
 
    QMdiSubWindow *w1 = ui->mdiArea->addSubWindow( m_firstWindow );
    ui->mdiArea->addSubWindow( m_secondWindow );
    ui->mdiArea->addSubWindow( m_thirdWindow );
 
    w1->resize( 500, 500 );
}

---

If your widgets actually contained anything then the containing QMdiSubWindow would get a preferred size from the layout and you probably would not need to resize at all.

Thank you very much :)

I've created my first useful MDI application :D

Matrix Operations

Attachment 10563

Source code: https://github.com/8Observer8/MatrixOperations

When I run my MDI application I see:
Attachment 10564

But I want to see:
Attachment 10565

Source code: https://github.com/8Observer8/SingleTriangleEditor

How will I be able to do it? Where can I read about layout the MdiSubWindows on the mdiArea?

Thank you!

MDI sub windows are basically like windows, they are not layouted among themselved other than the simple things that QMdiArea::WindowOrder does.

Which is one of the reasons why this sort of MDI applications is not used very often anymore.

Cheers,
_

There are also tileSubwindows() and cascadeSubWindows() slots to arrange the windows. If you want a layout that is generally fixed then you are better off doing that yourself with a layout inside a widget rather than with QMdiArea.

Agreed.
The screenshot does not look like multiple documents at all, more like a single document and editing tool.

Which would more likely be served better by using QDockWidget

Cheers,
_