[solved]Qt 4.8 signalMapper doesn't work

[dheerendra]

yes, I have taken few things from your code and modified slightly. See the following code. Just try with simple one first and see how it works.

@QPushButton *button = new QPushButton("Pthinks");
signalMapper->setMapping(button, 1);
button.show();
QObject::connect(button, SIGNAL(clicked()), signalMapper, SLOT(map()));

QObject::connect(signalMapper, SIGNAL(mapped(int)), this, SLOT(mySlot(int)));

void class::mySlot(int position)
{
QMessageBox msgBox;
msgBox.setText(QString("Button #: %1").arg(position));
msgBox.exec();
}@

[Edoll]

I have already tried with another method with a single slot not using signalMapper. And it works fine. What I did is to use mySlot_test function

@
void class::mySlot_test()
{
QMessageBox msgBox;
msgBox.setText(QString("Button clicked");
msgBox.exec();
}

QObject::connect(button[i], SIGNAL(clicked()), this, SLOT(mySlot_test()));
@

When I clicked every single button, this function is called and works fine.

[dheerendra]

Looks like you are missing something. Here is the complete code. Just try this. Make program like the following. It will work.

@===main.cpp=====
#include "widget.h"
#include <QApplication>

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
Widget w;
w.show();

return a.exec();

}

====widget.h=====
#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QMessageBox>
class Widget : public QWidget
{
Q_OBJECT

public:
Widget(QWidget *parent = 0);
~Widget();
public slots:
void myslot(int);
};
===widget.cpp====

#include "widget.h"
#include <QPushButton>
#include <QSignalMapper>
Widget::Widget(QWidget *parent)
: QWidget(parent)
{
QSignalMapper *signalMapper = new QSignalMapper;
QPushButton *button = new QPushButton("Pthinks");
signalMapper->setMapping(button, 1);
button->show();
connect(button, SIGNAL(clicked()), signalMapper, SLOT(map()));
connect(signalMapper, SIGNAL(mapped(int)), this, SLOT(myslot(int)));

}

void Widget::myslot(int position)
{
QMessageBox msgBox;
msgBox.setText(QString("Button #: %1").arg(position));
msgBox.exec();;
}

Widget::~Widget()
{

}
@

[Edoll]

I have been trying to figure out this problem for more than a day... Thank you for providing simple code. But my program is a bit huge and mixed (more than 16,000 lines). I am using Visual Studio 2010 with osg library. And I am using Qt for GUI.

@
QsignalMapper *signalMapper = new QSignalMapper;
QPushButton *buttonTest = new QPushButton("Test");
signalMapper->setMapping(buttonTest, 1);
gridLayout>addWidget(buttonTest, 0, 0, 1, 1);

QObject::connect(buttonTest, SIGNAL(clicked()), signalMapper, SLOT(QSignalMapper::map()));
signalMapper->setMapping(buttonTest, 1);

// Check if signalMapper works ->* this doesn't work
QObject::connect(signalMapper, SIGNAL(QSignalMapper::mapped(int)), this, SLOT(mySlot(int)));
*
// Check if button clicked -> this works fine
QObject::connect(buttonTest, SIGNAL(clicked()), this, SLOT(mySlot_Test()));

void Widget::mySlot(int position)
{
QMessageBox msgBox;
msgBox.setText(QString("Button #%1").arg(position));
msgBox.exec();
}

void Widget::mySlot_Test()
{
QMessageBox msgBox;
msgBox.setText(QString("Button Clicked"));
msgBox.exec();
}
@

mySlot method is not called through signalMapper but mySlot_Test which can confirm if the button is clicked works. The button is showing without any problems. The message of "Button Clicked" pops up, but "Button #1" message windows never comes up. If mySlot_Test function goes can receive signal. There is nothing wrong with the other part of my code, such as deceleration of header file etc...

[SGaist]

Hi,

@QObject::connect(signalMapper, SIGNAL(QSignalMapper::mapped(int)), this, SLOT(mySlot(int)));@

is wrong, it should be

@QObject::connect(signalMapper, SIGNAL(mapped(int)), this, SLOT(mySlot(int)));@

[Edoll]

Why those are different? How about these?
@
QObject::connect(buttonTest, SIGNAL(clicked()), signalMapper, SLOT(QSignalMapper::map()));

QObject::connect(buttonTest, SIGNAL(clicked()), signalMapper, SLOT(map()))
@

[SGaist]

For connections to work with the old syntax, connect expects only the signal/slot signatures, no class name, no variable name etc.

[Edoll]

LoL... That did a trick... I do really appreciate your help!

Originally, I was avoiding calling osgEarth::map() for the connector. I had same methods (map() and mapped()). This is something I need to be aware of when I implement these SIGNAL-SLOT.

Thanks again! Problem Solved.

[SGaist]

You're welcome !

Since you have your mapper running, please update the thread title prepending [solved] so other forum users may know a solution has been found :)

[Edoll]

Thank you again. I have just updated title.