[Qt-interest] Can't post a user event from compute thread to GUI thread

[Moinier, Pierre (UK)]

Hi!
 
I am trying to figure out how to send an event fom a thread to the main
visualisation thread using postEvent, installEventFilter and
eventFilter.
I am pasting parts of the test code I am using, which compiles, but
somehow, the event is probably not reaching the filter, beause I am not
geting any messages from eventFilter.
 
Could anyone tell me what I am doing wrong?
 
Regards,
 
    -Pierre.
 
-------------------------------------------------------------  Test Code
------------------------------------------------------------------
main.cpp:
 
#include <QApplication>
 
#include "ComputeThread.h"
#include <qpushbutton.h>
 
int main(int argc, char* argv[])
{
  QApplication app(argc, argv);
  ComputeThread thread;
  thread.start();
 
  QPushButton hello("Hello world!");
  hello.resize(100, 30);
 
  hello.show();
  return app.exec();
}

ComputeThread.cpp:
 
#include <iostream>
#include <QApplication>
#include <QEvent>
 

#include "ComputeThread.h"
#include "UpdateView.h"
 
void ComputeThread::run()
{
  for (int i=0;i<100;i++)
    {
      sleep(1);
      std::cout << "sending Event...." << UpdateView::UPDATE_EV1 <<
std::endl;
      QEvent *e = new QEvent(QEvent::User);
      QApplication::postEvent(&UpdateView::instance(), e);
      //  QCoreApplication::postEvent(&UpdateView::instance(), new
QEvent(static_cast<QEvent::Type>(UpdateView::UPDATE_EV1)));
    }
}

UpdateView.cpp:
 
#include <iostream>
#include <QEvent>
 
#include "UpdateView.h"
 

UpdateView::UpdateView()
{
  std::cout << "hello sailor" << std::endl;
  installEventFilter(this);
}
 
bool UpdateView::eventFilter(QObject *obj, QEvent *event)
{
  std::cout << "hello" << std::endl;
!!! I should get Hello on the sceen.....
  const Event ev = static_cast<Event>(event->type());
  switch(ev)
    {
    case UPDATE_EV1:
      std::cout << "Updating the scene..." << std::endl;
      break;
 
    default:
      return false;
    }
  return true;
}

UpdateView.h:
 
#ifndef UPDATEVIEW_H
#define UPDATEVIEW_H
 
#include <QEvent>
#include <QObject>
 
class UpdateView : public QObject
{
  Q_OBJECT
    public:
  UpdateView(); 
  static UpdateView& instance()
    {
      static UpdateView theinstance;
      return theinstance;
    }
 
  enum Event {UPDATE_EV1 = 1000 , UPDATE_EV2 = 1001};
 
  bool eventFilter(QObject *obj, QEvent *event);
 
};
 
#endif

 

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