how do you calling a function from MainWindow from a widget.

[parsnips146]

Hello,

I have only just started programming both C++ and Qt and have a question about accessing functions in classes.

I have a main function with a MDI and have a widget i created for the documents to open. I also have a Wizard called newWizard which currently opens shows some labels and is supposed to create a default child object in the Mdi.

the MainWindow code used to create the Mdi and the children is shown below,

#include <QtGui>
 
#include "mainwindow.h"
#include "newwizard.h"
#include "groupbox.h"
 
MainWindow::MainWindow()
{
    mdiArea = new QMdiArea;
    mdiArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAsNeeded);
    mdiArea->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
    mdiArea->setViewMode(QMdiArea::TabbedView);
    setCentralWidget(mdiArea);
 
    createActions();
    createMenu();
    createToolbars();
 
    readSetting();
 
    setWindowIcon(QIcon(":images/images/cegu.ico"));
    //setCurrentFile("");
 
    createchild();
}
 
void MainWindow::createchild()
{
    GroupBox *child = new GroupBox;
    mdiArea->addSubWindow(child);
    child->show();
}
 
 
void MainWindow::fileNew()
{
    newWizard wizard;
    wizard.exec();
}

#include <QtGui>

#include "mainwindow.h"
#include "newwizard.h"
#include "groupbox.h"

MainWindow::MainWindow()
{
    mdiArea = new QMdiArea;
    mdiArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAsNeeded);
    mdiArea->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
    mdiArea->setViewMode(QMdiArea::TabbedView);
    setCentralWidget(mdiArea);

    createActions();
    createMenu();
    createToolbars();

    readSetting();

    setWindowIcon(QIcon(":images/images/cegu.ico"));
    //setCurrentFile("");

    createchild();
}

void MainWindow::createchild()
{
    GroupBox *child = new GroupBox;
    mdiArea->addSubWindow(child);
    child->show();
}


void MainWindow::fileNew()
{
    newWizard wizard;
    wizard.exec();
}

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the headerfile for mainwindow is shown below:

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QMainWindow>
 
class QAction;
class QLabel;
class QMdiArea;
class newWizard;
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow();
    void createchild();
...
private:
    void createActions();
    void createMenu();
    void createToolbars();
    void readSetting();
    void writeSetting();
    void loadFile(const QString &fileName);
    bool saveFile(const QString &fileName);
    void setCurrentFile(const QString &fileName);
    QString strippedName(const QString &fullFileName);
 
    QStringList recentFiles;
    QMdiArea *mdiArea;

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

class QAction;
class QLabel;
class QMdiArea;
class newWizard;

class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow();
    void createchild();
...
private:
    void createActions();
    void createMenu();
    void createToolbars();
    void readSetting();
    void writeSetting();
    void loadFile(const QString &fileName);
    bool saveFile(const QString &fileName);
    void setCurrentFile(const QString &fileName);
    QString strippedName(const QString &fullFileName);

    QStringList recentFiles;
    QMdiArea *mdiArea;

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The newWizard code is shown below

#include <QtGui>
#include "newwizard.h"
#include "mainwindow.h"
 
 
newWizard::newWizard(QWidget *parent) :
    QWizard(parent)
{
    addPage(new introPage);
    addPage(new fileTypePage);
    addPage(new whichVariablesPage);
    addPage(new conclusionPage);
 
 
    setWindowTitle(tr("New File Wizard"));
}
 
void newWizard::accept(QWidget *parent) : QMainWindow(parent)
{
    parent->
    createchild();
 
}
 
introPage::introPage(QWidget *parent) : QWizardPage(parent)
{
    setTitle(tr("Introduction"));
 
    label = new QLabel(tr("This wizard will create a new"
			  "File either header or Footer"
			  "with the variable you choose"
			  ));
    label->setWordWrap(true);
 
    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(label);
    setLayout(layout);
}
 
fileTypePage::fileTypePage(QWidget *parent) : QWizardPage(parent)
{
    setTitle(tr("File Type Selection"));
    setSubTitle(tr("Specify which File type either"
		   "header or footer and the name."));
 
    headerRadioButton = new QRadioButton(tr("&Header File: "));
    headerNameLineEdit = new QLineEdit;
    connect(headerRadioButton, SIGNAL(toggled(bool)), headerNameLineEdit, SLOT(setEnabled(bool)));
    headerRadioButton->setChecked(true);
 
    footerRadioButton = new QRadioButton(tr("&Footer File: "));
    footerNameLineEdit = new QLineEdit;
    connect(footerRadioButton, SIGNAL(toggled(bool)), footerNameLineEdit, SLOT(setEnabled(bool)));
    footerRadioButton->setChecked(false);
    footerNameLineEdit->setEnabled(false);
 
    registerField("HeaderName", headerNameLineEdit);
    registerField("headerSelect", headerRadioButton);
    registerField("FooterName", footerNameLineEdit);
    registerField("footerSelect", footerRadioButton);
 
    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(headerRadioButton);
    layout->addWidget(headerNameLineEdit);
    layout->addWidget(footerRadioButton);
    layout->addWidget(footerNameLineEdit);
    setLayout(layout);
}
 
whichVariablesPage::whichVariablesPage(QWidget *parent) : QWizardPage(parent)
{
    setTitle(tr("Variables Selection"));
    setSubTitle(tr("Specify which Variables you would like to include."));
 
 
}
 
conclusionPage::conclusionPage(QWidget *parent) :QWizardPage(parent)
{
 
}

#include <QtGui>
#include "newwizard.h"
#include "mainwindow.h"


newWizard::newWizard(QWidget *parent) :
    QWizard(parent)
{
    addPage(new introPage);
    addPage(new fileTypePage);
    addPage(new whichVariablesPage);
    addPage(new conclusionPage);


    setWindowTitle(tr("New File Wizard"));
}

void newWizard::accept(QWidget *parent) : QMainWindow(parent)
{
    parent->
    createchild();

}

introPage::introPage(QWidget *parent) : QWizardPage(parent)
{
    setTitle(tr("Introduction"));

    label = new QLabel(tr("This wizard will create a new"
			  "File either header or Footer"
			  "with the variable you choose"
			  ));
    label->setWordWrap(true);

    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(label);
    setLayout(layout);
}

fileTypePage::fileTypePage(QWidget *parent) : QWizardPage(parent)
{
    setTitle(tr("File Type Selection"));
    setSubTitle(tr("Specify which File type either"
		   "header or footer and the name."));

    headerRadioButton = new QRadioButton(tr("&Header File: "));
    headerNameLineEdit = new QLineEdit;
    connect(headerRadioButton, SIGNAL(toggled(bool)), headerNameLineEdit, SLOT(setEnabled(bool)));
    headerRadioButton->setChecked(true);

    footerRadioButton = new QRadioButton(tr("&Footer File: "));
    footerNameLineEdit = new QLineEdit;
    connect(footerRadioButton, SIGNAL(toggled(bool)), footerNameLineEdit, SLOT(setEnabled(bool)));
    footerRadioButton->setChecked(false);
    footerNameLineEdit->setEnabled(false);

    registerField("HeaderName", headerNameLineEdit);
    registerField("headerSelect", headerRadioButton);
    registerField("FooterName", footerNameLineEdit);
    registerField("footerSelect", footerRadioButton);

    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(headerRadioButton);
    layout->addWidget(headerNameLineEdit);
    layout->addWidget(footerRadioButton);
    layout->addWidget(footerNameLineEdit);
    setLayout(layout);
}

whichVariablesPage::whichVariablesPage(QWidget *parent) : QWizardPage(parent)
{
    setTitle(tr("Variables Selection"));
    setSubTitle(tr("Specify which Variables you would like to include."));


}

conclusionPage::conclusionPage(QWidget *parent) :QWizardPage(parent)
{

}

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and the header file for that is

#ifndef NEWWIZARD_H
#define NEWWIZARD_H
 
#include <QWizard>
 
QT_BEGIN_NAMESPACE
class QCheckBox;
class QGroupBox;
class QLabel;
class QLineEdit;
class QRadioButton;
class QMdiArea;
QT_END_NAMESPACE
 
 
class newWizard : public QWizard
{
    Q_OBJECT
 
public:
    newWizard(QWidget *parent = 0);
 
 
    void accept();
 
};
 
class introPage : public QWizardPage
{
    Q_OBJECT
 
public:
    introPage(QWidget *parent = 0);
 
private:
    QLabel *label;
};
 
class fileTypePage : public QWizardPage
{
    Q_OBJECT
 
public:
    fileTypePage(QWidget *parent = 0);
 
private:
    QLabel *headerNameLabel;
    QLabel *footerNameLabel;
    QLineEdit *headerNameLineEdit;
    QLineEdit *footerNameLineEdit;
    QRadioButton *headerRadioButton;
    QRadioButton *footerRadioButton;
 
};
 
class whichVariablesPage : public QWizardPage
{
    Q_OBJECT
 
public:
    whichVariablesPage(QWidget *parent = 0);
 
private:
    QLabel *label;
};
 
 
class conclusionPage : public QWizardPage
{
    Q_OBJECT
 
public:
    conclusionPage(QWidget *parent = 0);
 
private:
    QLabel *label;
};
 
#endif // NEWWIZARD_H

#ifndef NEWWIZARD_H
#define NEWWIZARD_H

#include <QWizard>

QT_BEGIN_NAMESPACE
class QCheckBox;
class QGroupBox;
class QLabel;
class QLineEdit;
class QRadioButton;
class QMdiArea;
QT_END_NAMESPACE


class newWizard : public QWizard
{
    Q_OBJECT

public:
    newWizard(QWidget *parent = 0);


    void accept();

};

class introPage : public QWizardPage
{
    Q_OBJECT

public:
    introPage(QWidget *parent = 0);

private:
    QLabel *label;
};

class fileTypePage : public QWizardPage
{
    Q_OBJECT

public:
    fileTypePage(QWidget *parent = 0);

private:
    QLabel *headerNameLabel;
    QLabel *footerNameLabel;
    QLineEdit *headerNameLineEdit;
    QLineEdit *footerNameLineEdit;
    QRadioButton *headerRadioButton;
    QRadioButton *footerRadioButton;

};

class whichVariablesPage : public QWizardPage
{
    Q_OBJECT

public:
    whichVariablesPage(QWidget *parent = 0);

private:
    QLabel *label;
};


class conclusionPage : public QWizardPage
{
    Q_OBJECT

public:
    conclusionPage(QWidget *parent = 0);

private:
    QLabel *label;
};

#endif // NEWWIZARD_H

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This code is not the finished article and is still a work in progress. As can be seen in the newWizard code at lines 18 to 23 i am trying to access the createchild() function from the mainwindow in that function when the wizard closes.

Any help on this would be great.

Thanks

James Parsons

[Lykurg]

This question was asked several times, so please use the search function of this board.

Short answer: use signal and slots mechanism or pass a pointer of your main window to the dialog. Better use the first version.

[parsnips146]

Thank you for the quick reply.

The hint to use signal and slot mechanism was extreamly useful and enabled me to get this part of the code to work.