CODEWITHSUNDEEP
qtqpushbutton
ansanders
ansanders

Reputation: 17

Incompatible Sender/ Receiver arguments

I want to write a Signalmapper. It should connect a button to a function. This function should get the clicked Qpushbutton itself.

   void StrategicWidget::addTransporterImages(int i,unsigned int  numberTransporters)
      {
      Planet* p = PLANETS_VEC[i];
      QString qBasePath = QString::fromStdString(basePath);
       for(int j=0; j<numberTransporters; j++)
      {
         QPushButton* button = new QPushButton("", this);
         button->setGeometry(QRect(QPoint(p->getXCoord() + 30 + 15*j, p->getYCoord()+ 30 + 15*j), QSize(53, 53)));
         QString css = "background-image: url(" + qBasePath + "/Transporter.png)";
         button->setStyleSheet(css);  // sets button background image

      /*
       *SignalMapper zum festlegen welcher transporter der zu bewegende Transporter ist.
       *
       */
      QSignalMapper* transporterMapper = new QSignalMapper (button);
      // connecting button signal with signal mapper
       connect (button, SIGNAL(clicked()), transporterMapper, SLOT(map())) ;

      // giving parameter to the buttons
      transporterMapper->setMapping (button, button); 
      // map the signalMapper mapped signal to the transporterIconClicked-Slot of this widget
      connect (transporterMapper, SIGNAL(mapped(int)), this, SLOT(transporterIconClicked(QPushButton*)));

      }
    }

Why do I get this error message at runtime?

QObject::connect: Incompatible sender/receiver arguments QSignalMapper::mapped(int) --> asteroids::StrategicWidget::transporterIconClicked(QPushButton*)

I know that some other posts include this problem too, but the solutions didn't work for me.

Upvotes: 0

Views: 2760

Answers (1)

Kuba hasn&#39;t forgotten Monica
Kuba hasn&#39;t forgotten Monica

Reputation: 98425

Well, you're connecting a signal with an int argument to a slot taking a QPushButton*. What did you expect? It can't work.

What you need to do instead is to connect the mapped(QWidget*) signal to a slot taking QWidget*, and then ensure that you indeed get a button:

void addTransporterImages(int i, unsigned int numberTransporters) {
  ...
  connect (transporterMapper, SIGNAL(mapped(QWidget*)), 
    SLOT(transporterIconClicked(QWidget*)));
  ...
}

Q_SLOT void transporterIconClicked(QWidget * widget) {
  auto button = qobject_cast<QPushButton*>(widget);
  if (!button) return;
  ....
}

Upvotes: 0

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