C++ Qt setting up signal and slots for QMenu

Question

I am trying to make a make a program that allows a user to right click a cell in a gridView and choose from a menu of actions.

I have the menu display, but am having trouble getting the signal and slot to work without getting errors. I am working in Qt 5.5 C++11, not very advanced with Qt or C++ yet so any help would be greatly appreciated

using namespace std;
QStandardItemModel* model;
QStandardItem *value;

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    model = new QStandardItemModel(9,9,this);

    ui->tableView->setModel(model);
    ui->tableView->setShowGrid(true);
    ui->tableView->setWordWrap(true);
    //to allow menu
    ui->tableView->setContextMenuPolicy(Qt::CustomContextMenu);

for(int row = 0; row < 9; row++){
            ui->tableView->setRowHeight(row, 75);
            for(int col = 0; col < 9; col++){
                ui->tableView->setColumnWidth(col, 75);
                QFont f("Consolas");

                f.setPointSize(10);
                value = new QStandardItem(QString("1 2 3\n4 5 6\n7 8 9"));


                if ((row < 3 && col < 3) || (row > 5 && col < 3)
                        || (row < 3 && col > 5) || (row > 5 && col > 5)
                        || ((row > 2 && row < 6) && (col > 2 && col < 6))){
                    QBrush b(QColor("Moccasin"));
                    value->setBackground(b);
                }

                value->setFont(f);
                value->setTextAlignment(Qt::AlignCenter);
                model->setItem(row,col,value);
            }
        }

        //connects model so functions run when a cell's text is changed
        connect(model, SIGNAL(itemChanged(QStandardItem*)), this, SLOT(on_cell_changed(QStandardItem*)));
        //this sets up the menu
        connect(ui->tableView, SIGNAL(customContextMenuRequested(QPoint)), this, SLOT(menuRequest(QPoint)));

    }

this is the main window part of the program. It is (going to be) a sudoku solver, so the model represents the 9x9 grid and the for loop is populating the grid with choices for input (but that's not the thing I'm having trouble with). I need help with the menu part below (the above was just for context):

void  MainWindow::menuRequest(QPoint pos)
{
    QModelIndex index = ui->tableView->indexAt(pos);
    std::cout << "MainWindow::menuRequest - at" << " QModelIndex row = " <<
                 index.row() << ", column = " << index.column() << std::endl;
    QMenu   menu(this);

    QMenu setValues("Initialize Grid", this);
    QAction *setValue1;
    QAction *setValue2;
    QAction *setValue3;
    QAction *setValue4;
    QAction *setValue5;
    QAction *setValue6;
    QAction *setValue7;
    QAction *setValue8;
    QAction *setValue9;
    setValue1 = setValues.addAction("Set value to 1");
    setValue2 = setValues.addAction("Set value to 2");
    setValue3 = setValues.addAction("Set value to 3");
    setValue4 = setValues.addAction("Set value to 4");
    setValue5 = setValues.addAction("Set value to 5");
    setValue6 = setValues.addAction("Set value to 6");
    setValue7 = setValues.addAction("Set value to 7");
    setValue8 = setValues.addAction("Set value to 8");
    setValue9 = setValues.addAction("Set value to 9");

    connect(menu, SIGNAL(triggered(QAction*)), this, SLOT(on_menu_clicked(QAction*)));

    menu.addMenu(&setValues);
    QAction *action = menu.exec(
                ui->tableView->viewport()->mapToGlobal(pos));

}

void MainWindow::on_menu_clicked(QAction*){
    cout << "test menu click worked";
}

The connect statement in the MenuRequest function is throwing an error:

connect(menu, SIGNAL(triggered(QAction*)), this, SLOT(on_menu_clicked(QAction*)));

C2664: 'QMetaObject::Connection QObject::connect(const QObject *, const char *, const char *, Qt::ConnectionType)const' : cannot convert argument 1 from 'QMenu' to 'const QObject *'

When it is supposed to go to the on_menu_click function it throws the above error

I know that means that menu isn't of the QObject type but I'm not sure how to fix this. Any help would be greatly appreciated

U missing address pointer... connect(&menu, SIGNAL(triggered(QAction*)), this, SLOT(on_menu_clicked(QAction*))); — Devopia

MillerTime MillerTime · Accepted Answer · 2015-11-04T09:45:48

As stated in the comment your first argument in the connect() function needs to be a pointer. The documentation States the following:

connect(const QObject * sender, const char * signal, const QObject * receiver, const char * method, Qt::ConnectionType type = Qt::AutoConnection)

http://doc.qt.io/qt-5/qobject.html#connect

C++ Qt setting up signal and slots for QMenu

1 Answers