midi child does not close when I call close()

[qlands]

Hi,

I have a Mdi child with a close button. I connected the signal clicked() of the button to the slot close() of the Mdi child.

But when I click close the button disappears and the window does not close!

The MdiChild is based on a QMainWindow.

Any idea why?!!!

Thanks.
Carlos

[FelixB]

show the code of the connection. you probably connected wrong objects.

[qlands]

Hi,

#include "documentwindow.h"
#include "ui_documentwindow.h"
 
documentWindow::documentWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::documentWindow)
{
    ui->setupUi(this);
    connect(ui->pushButton,SIGNAL(clicked()),this,SLOT(close()));
}
 
documentWindow::~documentWindow()
{
}

#include "documentwindow.h"
#include "ui_documentwindow.h"

documentWindow::documentWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::documentWindow)
{
    ui->setupUi(this);
    connect(ui->pushButton,SIGNAL(clicked()),this,SLOT(close()));
}

documentWindow::~documentWindow()
{
}

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So when I click in the pushButton the window does not close!

[FelixB]

Hi,

the code looks good to me. the problem might be related to the mdi-stuff you are doing. can you show the mdi-code?

Felix

[qlands]

Hi,

the MdiChild is declared as:

#include <QMainWindow>
#include <impgenmaint.h>
 
namespace Ui {
    class documentWindow;
}
 
class documentWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit documentWindow(QWidget *parent = 0);
    ~documentWindow();
 
private:
    Ui::documentWindow *ui;
};

#include <QMainWindow>
#include <impgenmaint.h>

namespace Ui {
    class documentWindow;
}

class documentWindow : public QMainWindow
{
    Q_OBJECT

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

private:
    Ui::documentWindow *ui;
};

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The implementation is the same I previously posted.

I copied the QT mdi example, thus the code the created the mdi child is:

documentWindow *MainWindow::createMdiChild()
{
    documentWindow *child = new documentWindow;
    mdiArea->addSubWindow(child);
    return child;
}

documentWindow *MainWindow::createMdiChild()
{
    documentWindow *child = new documentWindow;
    mdiArea->addSubWindow(child);
    return child;
}

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I call createMdiChild as:

documentWindow *child = createMdiChild();
child->show();

documentWindow *child = createMdiChild();
child->show();

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Thanks.
Carlos.

[ChrisW67]

I find it annoying that closing the widget contained by a QMdiSubWindow does not close the sub window itself, but that's the way it works.

Try connecting to the close() slot of the QMDiSubWindow returned by QMdiArea::addSubWindow(). You will need to give documentWindow a closeMe() signal that is exposed so that you can make the connection in MainWindow::createMdiChild(). Then connect your push button signal to the new closeMe() signal to have it repeated outside documentWindow (yes I mean connect a signal to a signal).

#include <QtGui>
#include <QDebug>
 
class docWindow: public QMainWindow {
    Q_OBJECT
 
public:
    docWindow(QWidget *p = 0): QMainWindow(p) { 
        QPushButton *b = new QPushButton("Close", this);
        connect(b, SIGNAL(clicked()), this, SIGNAL(closeMe()));
        setCentralWidget(b);
    }
    ~docWindow() { }
 
signals:
    void closeMe();
 
};
 
 
class MainWindow: public QMainWindow {
    Q_OBJECT
public:
    MainWindow(QWidget *p = 0): QMainWindow(p) {
        m_mdiArea = new QMdiArea(this);
        setCentralWidget(m_mdiArea);
 
        docWindow *dw = new docWindow(this);
        QMdiSubWindow *sw = m_mdiArea->addSubWindow(dw);
        connect(dw, SIGNAL(closeMe()), sw, SLOT(close()));
    }
private:
    QMdiArea *m_mdiArea;
};
 
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
 
    MainWindow m;
    m.show();
 
    return app.exec();
}
#include "main.moc"

#include <QtGui>
#include <QDebug>

class docWindow: public QMainWindow {
    Q_OBJECT

public:
    docWindow(QWidget *p = 0): QMainWindow(p) { 
        QPushButton *b = new QPushButton("Close", this);
        connect(b, SIGNAL(clicked()), this, SIGNAL(closeMe()));
        setCentralWidget(b);
    }
    ~docWindow() { }

signals:
    void closeMe();

};


class MainWindow: public QMainWindow {
    Q_OBJECT
public:
    MainWindow(QWidget *p = 0): QMainWindow(p) {
        m_mdiArea = new QMdiArea(this);
        setCentralWidget(m_mdiArea);

        docWindow *dw = new docWindow(this);
        QMdiSubWindow *sw = m_mdiArea->addSubWindow(dw);
        connect(dw, SIGNAL(closeMe()), sw, SLOT(close()));
    }
private:
    QMdiArea *m_mdiArea;
};

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

    MainWindow m;
    m.show();

    return app.exec();
}
#include "main.moc"

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[qlands]

Thanks... What I did instead of calling this.close() I call this->parentWidget.close() because as you said close will close the widget but not the parent window.

[ChrisW67]

As long as you never use docWindow without a parent, or check for that circumstance, that will be fine. You could do something like:

public slots:
void closeMe() {
  QMdiSubWindows *sw = qobject_cast<QMdiSubWindow*>(parentWidget());
  if (sw)
    sw->close();
  else
    close();
}

public slots:
void closeMe() {
  QMdiSubWindows *sw = qobject_cast<QMdiSubWindow*>(parentWidget());
  if (sw)
    sw->close();
  else
    close();
}

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The app I borrowed from used the window either as an MDI child, a top-level window, or buried in a more complex UI and connected closeMe() accordingly.