signalMapper

Nirvana

I have been looking docs and other topics about singalMappers but I still couldn't make it work properly.

here is the function I want to call

void theme(QString a)
{

qDebug()<<a;

}

here is how I connected
for (int a=0;a<buttons.count();a++){
QPushButton *button = new QPushButton();

    QSignalMapper *signalMapper = new QSignalMapper();

    connect(signalMapper, SIGNAL(mapped(QString)), this, SIGNAL(theme(QString)));

    connect(button,  SIGNAL(clicked()), signalMapper,SLOT(map()));
    signalMapper->setMapping(button,button->text());

here is the header file

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
signals:
void theme(QString a);

private slots:
void on_pushButton_clicked();

void on_pushButton_10_clicked();

void on_temalar_button_clicked();

public:
Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

But when I click the button, I don't get any debug output. What is the thing that I'm doing wrongly?
Thanks

? Offline

Hi!
I think that

connect(signalMapper, SIGNAL(mapped(QString)), this, SIGNAL(theme(QString)));

should be

connect(signalMapper, SIGNAL(mapped(QString)), this, SLOT(theme(QString)));

Nirvana

@Wieland
I did but it is still not working.
I put theme from signals: to slots: in header file. And did what you said, now I'm having this:

/home/metin/QTProjects/build-settings-Desktop_Qt_5_5_1_GCC_64bit-Debug/moc_mainwindow.cpp:82: error: undefined reference to `MainWindow::theme(QString)'

? Offline

@Nirvana You probably need to clean your project and run qmake again.

SGaist

Hi and welcome to devnet,

MainWindow's theme is a signal so basically your initial connect line was correct from that perspective. However, your theme function is just a static function somewhere.

If you want it to be called, you should make theme a slot, and add the missing MainWindow:: between void and theme and keep the new version of the connect statement.