use qt table with buttons - c++

Question

I have a table with some data. However since not all the information fits into the table, the user should have the option to get further information on the line by pressing a button in this line. I currently add the buttons in the following way:
int lastRow = table->rowCount();
table->insertRow(lastRow);
QWidget* pWidget = new QWidget();
pWidget->setFixedWidth(30);
LdtButton* btn_help = new LdtButton();
btn_help->addInactiveIcon(QPixmap(":/icons/help_inactive.png"));
btn_help->addHoverIcon(QPixmap(":/icons/help_hovered.png"));
QHBoxLayout* pLayout = new QHBoxLayout(pWidget);
pLayout->addWidget(btn_help);
pLayout->setAlignment(Qt::AlignCenter);
pLayout->setContentsMargins(0, 0, 0, 0);
pWidget->setLayout(pLayout);
table->setCellWidget(lastRow, 1, pWidget);
However I do not really have a idea how to connect these buttons, so I get the row the button was in when it gets pressed, so I can output the appropriate informations. (not every row has a button)

Answer 1

Use the signal QPushButton::clicked and a lambda to call the right method (use the capture to pass the row).
QTableWidget* table = new QTableWidget(0, 2);
QStringList values = {"foo", "bar", "spam"};
for (QString const& value : values)
{
int lastRow = table->rowCount();
table->insertRow(lastRow);
table->setItem(lastRow, 0, new QTableWidgetItem(value));
QWidget* pWidget = new QWidget();
QPushButton* btn_help = new QPushButton("help");
QHBoxLayout* pLayout = new QHBoxLayout(pWidget);
pLayout->addWidget(btn_help);
pLayout->setAlignment(Qt::AlignCenter);
pLayout->setContentsMargins(0, 0, 0, 0);
pWidget->setLayout(pLayout);
table->setCellWidget(lastRow, 1, pWidget);
// Call your method in the lambda
QObject::connect(btn_help, &QPushButton::clicked, [lastRow]() {qDebug() << "Show help for " << lastRow; });
}
table->show();
It will display:
Show help for 0
Show help for 1
Show help for 2