Connecting custom signal and slot

[DmitryNik]

Hello!

I have a small problem with connecting the custom signal and the custom slot(Object::connect: No such signal)

Here is the code, what I have:

datedialog.h:

#ifndef DATEDIALOG_H
#define DATEDIALOG_H
 
#include <QDialog>
class QPushButton;
class QLineEdit;
class QCalendarWidget;
 
class DateDialog:public QDialog
{
    Q_OBJECT
 
public:
    DateDialog(QWidget *parent = 0);
signals:
    void SendText(const QString &text);
 
private:
    void Initialization();
    void PlacingElements();
 
private slots:
    void EnableOKButton(const QString &text);
    void GetDateToLine();
    void BeforeShowMsg();
    void ShowMessageBox(const QString &text);
 
private:
QCalendarWidget *calendar;
QLineEdit *line;
QPushButton *OkButton;
 
};
 
#endif // DATEDIALOG_H

#ifndef DATEDIALOG_H
#define DATEDIALOG_H

#include <QDialog>
class QPushButton;
class QLineEdit;
class QCalendarWidget;

class DateDialog:public QDialog
{
    Q_OBJECT

public:
    DateDialog(QWidget *parent = 0);
signals:
    void SendText(const QString &text);

private:
    void Initialization();
    void PlacingElements();

private slots:
    void EnableOKButton(const QString &text);
    void GetDateToLine();
    void BeforeShowMsg();
    void ShowMessageBox(const QString &text);

private:
QCalendarWidget *calendar;
QLineEdit *line;
QPushButton *OkButton;

};

#endif // DATEDIALOG_H

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datedialog.cpp

#include "datedialog.h"
#include <QHBoxLayout>
#include <QCalendarWidget>
#include <QLineEdit>
#include <QPushButton>
#include <QIcon>
#include <QString>
#include <QMessageBox>
 
DateDialog::DateDialog(QWidget *parent):QDialog(parent)
{
    Initialization();
}
 
void DateDialog::Initialization()
{
    calendar = new QCalendarWidget();
    line = new QLineEdit();
    line->setFocus();
    OkButton = new QPushButton(QObject::tr("Press me!"));
    OkButton->setDefault(true);
    OkButton->setEnabled(false);
    connect(this->calendar, SIGNAL(selectionChanged()),
            this, SLOT(GetDateToLine()));
    connect(this->line, SIGNAL(textChanged(const QString &)),
            this, SLOT(EnableOKButton(const QString &)));
    connect(this->OkButton, SIGNAL(clicked()),
            this, SLOT(BeforeShowMsg()));
   connect(this, SIGNAL(SendText(cosnt QString &)),
            this, SLOT(ShowMessageBox(const QString &)));
    PlacingElements();
}
 
void DateDialog::PlacingElements()
{
    QHBoxLayout *leftTop = new QHBoxLayout;
    leftTop->addWidget(this->line);
    QHBoxLayout *leftDown = new QHBoxLayout;
    leftDown->addWidget(OkButton);
 
    QVBoxLayout *left = new QVBoxLayout;
    left->addLayout(leftTop);
    left->addStretch();
    left->addLayout(leftDown);
 
    QVBoxLayout *right = new QVBoxLayout;
    right->addWidget(this->calendar);
 
    QHBoxLayout *main = new QHBoxLayout;
    main->addLayout(left);
    main->addLayout(right);
 
    this->setLayout(main);
    this->setWindowTitle(QObject::tr("Date"));
 
    QString FilePath = "E:\\linux-penguin-computing.jpg";
    this->setWindowIcon(QIcon(FilePath));
    this->setFixedSize(sizeHint().width(), sizeHint().height());
}
 
void DateDialog::EnableOKButton(const QString &text)
{
 this->OkButton->setEnabled(!text.isEmpty());
 OkButton->setEnabled(true);
}
 
void DateDialog::GetDateToLine()
{
 this->line->setText(calendar->selectedDate().toString("dd/MM/yyyy dddd"));
}
 
void DateDialog::ShowMessageBox(const QString &text)
{
 QMessageBox msg;
 msg.setText(text);
 msg.setWindowTitle(QObject::tr("Information before closing"));
 msg.setIcon(QMessageBox::Warning);
 msg.exec();
 this->close();
}
 
void DateDialog::BeforeShowMsg()
{
    if(!line->text().isEmpty())
    {
     emit SendText(line->text());
    }
}

#include "datedialog.h"
#include <QHBoxLayout>
#include <QCalendarWidget>
#include <QLineEdit>
#include <QPushButton>
#include <QIcon>
#include <QString>
#include <QMessageBox>

DateDialog::DateDialog(QWidget *parent):QDialog(parent)
{
    Initialization();
}

void DateDialog::Initialization()
{
    calendar = new QCalendarWidget();
    line = new QLineEdit();
    line->setFocus();
    OkButton = new QPushButton(QObject::tr("Press me!"));
    OkButton->setDefault(true);
    OkButton->setEnabled(false);
    connect(this->calendar, SIGNAL(selectionChanged()),
            this, SLOT(GetDateToLine()));
    connect(this->line, SIGNAL(textChanged(const QString &)),
            this, SLOT(EnableOKButton(const QString &)));
    connect(this->OkButton, SIGNAL(clicked()),
            this, SLOT(BeforeShowMsg()));
   connect(this, SIGNAL(SendText(cosnt QString &)),
            this, SLOT(ShowMessageBox(const QString &)));
    PlacingElements();
}

void DateDialog::PlacingElements()
{
    QHBoxLayout *leftTop = new QHBoxLayout;
    leftTop->addWidget(this->line);
    QHBoxLayout *leftDown = new QHBoxLayout;
    leftDown->addWidget(OkButton);

    QVBoxLayout *left = new QVBoxLayout;
    left->addLayout(leftTop);
    left->addStretch();
    left->addLayout(leftDown);

    QVBoxLayout *right = new QVBoxLayout;
    right->addWidget(this->calendar);

    QHBoxLayout *main = new QHBoxLayout;
    main->addLayout(left);
    main->addLayout(right);

    this->setLayout(main);
    this->setWindowTitle(QObject::tr("Date"));

    QString FilePath = "E:\\linux-penguin-computing.jpg";
    this->setWindowIcon(QIcon(FilePath));
    this->setFixedSize(sizeHint().width(), sizeHint().height());
}

void DateDialog::EnableOKButton(const QString &text)
{
 this->OkButton->setEnabled(!text.isEmpty());
 OkButton->setEnabled(true);
}

void DateDialog::GetDateToLine()
{
 this->line->setText(calendar->selectedDate().toString("dd/MM/yyyy dddd"));
}

void DateDialog::ShowMessageBox(const QString &text)
{
 QMessageBox msg;
 msg.setText(text);
 msg.setWindowTitle(QObject::tr("Information before closing"));
 msg.setIcon(QMessageBox::Warning);
 msg.exec();
 this->close();
}

void DateDialog::BeforeShowMsg()
{
    if(!line->text().isEmpty())
    {
     emit SendText(line->text());
    }
}

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main.cpp:

#include <QtGui/QApplication>
#include "datedialog.h"
 
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
 
    DateDialog date;
    date.exec();
 
    return app.exec();
}

#include <QtGui/QApplication>
#include "datedialog.h"

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

    DateDialog date;
    date.exec();

    return app.exec();
}

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The first question that I have is: why?
And the second one is: How it can be rectified?

Thank you beforehand for answers.

[stampede]

You have a typo - "cosnt" in line 29.

[DmitryNik]

Thank you so much! I didn't notice that typo at all.

[Gokulnathvc]

You have to use QObject::connect method.

[FelixB]

You have to use QObject::connect method.

he *does* use this method... or where do you think does the "connect" in his code come from? the mistake is a simple typo.