QSignalMapper

here is what i have, just doing some test to get familiar with QT Creator. This compiles but when I click one of the buttons the clicked signal does not trigger. Any Ideas?

Code:

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#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QtGui/QMainWindow>
#include <QtGui>
#include <QGridLayout>
#include <QSignalMapper>
 
namespace Ui {
    class MainWindow;
}
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
 
signals:
     void clicked(const QString &text);
 
protected:
    void changeEvent(QEvent *e);
 
private:
    Ui::MainWindow *ui;
    QPushButton *theButton;
    QGridLayout *theLayout;
    QSignalMapper *theMapper;
};
 
#endif // MAINWINDOW_H

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Code:

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#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
 
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
 
    theMapper = new QSignalMapper(this);
    QGridLayout *theLayout = new QGridLayout();
 
    int count = 0;
    for (int t = 0; t < 10 ; t++)
    {
        count++;
        QString buttonName;
        buttonName.setNum(count);
        buttonName.prepend("Sequence");
        QPushButton *theButton = new QPushButton(buttonName);
        theLayout->addWidget(theButton,count,1,1,1);
        connect(theButton, SIGNAL(clicked()), theMapper, SLOT(map()));
        theMapper->setMapping(theButton,buttonName);
    }
 
    centralWidget()->setLayout(theLayout);
    connect(theMapper,SIGNAL(mapped(const QString &)),this,SIGNAL(clicked(const QString &)));
 
}
 
void clicked(const QString &text)
{
 
    qDebug() << text;
}
 
MainWindow::~MainWindow()
{
    delete ui;
}
 
void MainWindow::changeEvent(QEvent *e)
{
    QMainWindow::changeEvent(e);
    switch (e->type()) {
    case QEvent::LanguageChange:
        ui->retranslateUi(this);
        break;
    default:
        break;
    }
}

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Make your "clicked" a slot, not a signal.

Thanks you so much, the QT documentation(QSignalMapper) I used, stated to use signal... changed to slot everything works now. Much appreciated

Quote:

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Originally Posted by axisdj

Thanks you so much, the QT documentation(QSignalMapper) I used, stated to use signal...

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No, it didn't, read again.

I must be missing something, I am a complete newbie, but here is the sample code from the QSignalMapper

Code:

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class ButtonWidget : public QWidget
 {
     Q_OBJECT
 
 public:
     ButtonWidget(QStringList texts, QWidget *parent = 0);
 
 signals:
     void clicked(const QString &text);   ///Uses Signals???
 
 private:
     QSignalMapper *signalMapper;
 };
The only function that we need to implement is the constructor:
 
 ButtonWidget::ButtonWidget(QStringList texts, QWidget *parent)
     : QWidget(parent)
 {
     signalMapper = new QSignalMapper(this);
 
     QGridLayout *gridLayout = new QGridLayout;
     for (int i = 0; i < texts.size(); ++i) {
         QPushButton *button = new QPushButton(texts[i]);
         connect(button, SIGNAL(clicked()), signalMapper, SLOT(map()));
         signalMapper->setMapping(button, texts[i]);
         gridLayout->addWidget(button, i / 3, i % 3);
     }
 
     connect(signalMapper, SIGNAL(mapped(const QString &)),
             this, SIGNAL(clicked(const QString &)));  ////Notice it says SIGNAL????
 
     setLayout(gridLayout);
 }

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This is a completely different situation. Notice that in the docs the "clicked" method is not implemented. It is a signal which is then connected to some other slot (which is not part of the example). Since you implemented "clicked" this can't be a signal (and the compiler should refuse to build such a program). It would be ok to use a signal if you moved the body of "clicked" to another method (slot), most probably in a different object.

Thanks again for taking the time to explain, i really appreciate it.:)