How to add a parameter to a slot

[Potch]

Hello,

This is the first time I use Qt and I need an advice to perform the following task.
With this loop, I display a combobox on each column of the first row of my QTableWidget.

for (int col=0 ; col <= colonnes ; ++col)
        {
        	QComboBox *moncombo = new QComboBox;
        	moncombo->addItems(PL_variables);
        	TableW->setCellWidget(0, col, moncombo);	
        	connect(moncombo, SIGNAL(activated(int)),this, SLOT(associate(int)));
        }

for (int col=0 ; col <= colonnes ; ++col)
        {
        	QComboBox *moncombo = new QComboBox;
        	moncombo->addItems(PL_variables);
        	TableW->setCellWidget(0, col, moncombo);	
        	connect(moncombo, SIGNAL(activated(int)),this, SLOT(associate(int)));
        }

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With connect(moncombo, SIGNAL(activated(int)),this, SLOT(associate(int))); I can transmet the index of the combo to the slot.

My problem is that I also have to transmet the number of the column on which the signal had been sent.
I guess I should to use the horizontalHeader function or something like that, but I don't really know how to do this.

Thanks

[marcel]

You could use QSignalMapper for this.

[Potch]

Thanks for your quick answer Marcel. I didn"t know this class yet, I read the documentation right now...

[wysota]

It would probably be wiser to use a custom delegate instead of cell widgets. It'll get awfully slow if you have more than 10 of them.

[Potch]

Thank you for your advise Wysota. I'm currently learning Qt and custom delegates is the next chapter for me Normaly, they are only 8 of them, so it's not to slow to execute.

I could finaly manage to retrieve the number of column as follow :

for (int col=0 ; col <= colonnes ; ++col)
        {
            QComboBox *moncombo = new QComboBox;
            moncombo->addItems(PL_variables);
            moncombo->setObjectName(QString::number(col));   // the name of my combo is the number of my column
            TableW->setCellWidget(0, col, moncombo);    
            connect(moncombo, SIGNAL(activated(int)),this, SLOT(associate(int)));
        }

for (int col=0 ; col <= colonnes ; ++col)
        {
            QComboBox *moncombo = new QComboBox;
            moncombo->addItems(PL_variables);
            moncombo->setObjectName(QString::number(col));   // the name of my combo is the number of my column
            TableW->setCellWidget(0, col, moncombo);    
            connect(moncombo, SIGNAL(activated(int)),this, SLOT(associate(int)));
        }

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The slot

void MainWindow::associate(int index)
{...
int c = sender()->objectName().toInt();      
...}

void MainWindow::associate(int index)
{...
int c = sender()->objectName().toInt();      
...}

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Regarding to the documentation, it's not a very correct way to do this... That's why I try to implement another solution using QSignalMapper.

Thanks for your advices...