Signals and Slots - c++

Question

I have written some code, where if I log in as a customer it should hide column customer (value of that column is 1). I need to pass parameter to the signals. I have used my customerLogin is isSa. How to pass these parameters to signals and slots?
Main.cpp:
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
initialize();
SafeOTPWindow w;
Login login;
login.connect(&login, SIGNAL(loggedIn()), &w, SLOT(show()) );
login.connect(&login, SIGNAL(loginCancelled() ), &w, SLOT(close()) );
login.show();
a.exec();
}
Login.h:
#ifndef LOGIN_H
#define LOGIN_H
#include <QDialog>
namespace Ui {
class Login;
}
class Login : public QDialog
{
Q_OBJECT
public:
explicit Login(QWidget *parent = 0);
~Login();
bool isSa;
signals:
void loggedIn();
void loginCancelled();
private slots:
void on_buttonBox_accepted();
void on_buttonBox_rejected();
private:
Ui::Login *ui;
};
#endif // LOGIN_H
And here is my another file where I need to hide the column (Customer), OtpWindow.cpp:
void SafeOTPWindow::initLogTable()
{
QList<OtpLog> logs;
int ret = otpRepo.fetchOtpLogs(logs);
if( ret != errorCodes::SUCCESS )
{
QMessageBox msgBox(QMessageBox::Critical, QString("SafeOTP"),
QString("OTPLogs could not be fetched"),QMessageBox::Ok, this);
msgBox.exec();
QLOG_ERROR() << "fetchLogs error " << ret;
return;
}
QStandardItemModel *model = new QStandardItemModel(0,5,this); //5 columns
model->setHorizontalHeaderItem(0, new QStandardItem(QString("Date")));
model->setHorizontalHeaderItem(1, new QStandardItem(QString("Customer")));
model->setHorizontalHeaderItem(2, new QStandardItem(QString("Server")));
model->setHorizontalHeaderItem(3, new QStandardItem(QString("Authorized by")));
model->setHorizontalHeaderItem(4, new QStandardItem(QString("Description")));
for(QList<OtpLog>::Iterator lIt = logs.begin(); lIt != logs.end(); lIt++)
{
OtpLog& log = *lIt;
QList<QStandardItem*> row;
row.push_back(new QStandardItem(log.when.toString("dd MMM yyyy, hh:mm")));
row.push_back(new QStandardItem(QString(log.customer)));
row.push_back(new QStandardItem(QString(log.server)));
row.push_back(new QStandardItem(QString(log.author)));
row.push_back(new QStandardItem(QString(log.reason)));
model->appendRow(row);
}
// set the data model
ui->tblLog->setModel(model);
//Set the column to hide
ui->tblLog->setColumnHidden(1,true);
// set the column widths
int tw = ui->tblLog->width() - 5;
int w = tw / 6;
for(int i=0; i<4;i++)
{
ui->tblLog->setColumnWidth(i,w);
tw -= w;
}
ui->tblLog->setColumnWidth(4,tw);
}

Answer 1

For the slot/signal example, you need to connect two objects having the same parameters. so let me modify a bit your example:
Let's say you have:
signals:
void loginStatusChanged(bool isLoggedIn);
In your Login method you will have something like:
bool status = checkLogin();
emit loginStatusChanged(status);
And then you should have a dedicated slot in SafeOTPWindow doing something like that:
void SafeOTPWindow::UpdateTableAfterLogin(bool isLoggedIn)
{
ui->tblLog->setColumnHidden(1,isLoggedIn);
}
and you connect as usual:
connect(&login, SIGNAL(loginStatusChanged()), &w, SLOT(UpdateTableAfterLogin(bool)) );