Undefined reference to resizeEvent(QResizeEvent*)

Tom asso

My application includes a class “Parabola” which is a subclass of QOpenGLWindow, which is a subclass of QObject. The Parabola class includes the Q_OBJECT macro:

#ifndef PARABOLAWINDOW_H
#define PARABOLAWINDOW_H

#include <QOpenGLWindow>
#include <QOpenGLFunctions>
#include <QOpenGLBuffer>
#include <QOpenGLVertexArrayObject>
#include <QMatrix4x4>

class QOpenGLShaderProgram;

class ParabolaWindow : public QOpenGLWindow,
               protected QOpenGLFunctions
{
  Q_OBJECT

The project compiles, but the linker gives this result:

g++ -Wl,-O1 -Wl,-rpath,/home/oreilly/Qt/5.14.2/gcc_64/lib -o parabola main.o ParabolaWindow.o qrc_qml.o moc_ParabolaWindow.o   /home/oreilly/Qt/5.14.2/gcc_64/lib/libQt5Quick.so /home/oreilly/Qt/5.14.2/gcc_64/lib/libQt5Gui.so /home/oreilly/Qt/5.14.2/gcc_64/lib/libQt5QmlModels.so /home/oreilly/Qt/5.14.2/gcc_64/lib/libQt5Qml.so /home/oreilly/Qt/5.14.2/gcc_64/lib/libQt5Network.so /home/oreilly/Qt/5.14.2/gcc_64/lib/libQt5Core.so -lGL -lpthread   

moc_ParabolaWindow.o:(.data.rel.ro._ZTV14ParabolaWindow[_ZTV14ParabolaWindow]+0xa0): undefined reference to `ParabolaWindow::resizeEvent(QResizeEvent*)'
collect2: error: ld returned 1 exit status
Makefile:282: recipe for target 'parabola' failed
make: *** [parabola] Error 1

Parent class QOpenGLWindow defines method resizeEvent(QResizeEvent*), which is defined in libQt5Gui.so, and I am linking with that library. I have other projects that subclass QOpenGLWindow, yet they do not have this error when I link. What is causing this error?

Thanks!

Christian Ehrlicher

@Tom-asso said in Undefined reference to resizeEvent(QResizeEvent*):

resizeEvent

You defined resizeEvent() in your class but did not implement it.

SGaist

Hi,

Beside @Christian-Ehrlicher good point, you seem to have made it a slot which is wrong. This method will automatically be called but it is not a slot.

Tom asso

@Christian-Ehrlicher and @SGaist - thanks very much for help, and you are both right of course. Super-useful to have your additional eyes on my code!