Hi,

I am trying to update a progressbar in a main widget from a job run from a qthread via a custom event.

The objective is to ensure the progress bar is updated as the "long job" is running. At the moment if I just run job from the main class the gui just freezes until the job is complete. I think threading it is the best of option for "real time" update of the qprogressbar. See my code below of a simple example of what I am trying to do. I do not think the thread is emitting the event correctly (i just get cout of thread and not event !!), I think the problem may be with the qobject receiver in the postevet, qApp.

Any suggestions or help would be great, its very frustating as I feel I am close to a solution.

main.cpp

Qt Code: 
  1. /*
  2. * external loop main.cpp 
  3. */
  4. #include "externalloop.h"
  5. #include <qapplication.h>
  6.  
  7. int main( int argc, char **argv )
  8. {
  9.     QApplication a( argc, argv );
  10.  
  11.     ExternalLoop externalloop;
  12.     externalloop.resize( 200, 100 );
  13.     externalloop.setCaption( "ExternalLoop" );
  14.     a.setMainWidget( &externalloop );
  15.     externalloop.show();
  16.  
  17.     return a.exec();
  18.  
  19. }
To copy to clipboard, switch view to plain text mode 

extarnalloop.h

Qt Code: 
  1. /*
  2. * externalloop.h
  3. */
  4. #ifndef GREY_BUTTON_H
  5. #define GREY_BUTTON_H
  6.  
  7. #include <qwidget.h>
  8. #include <qpushbutton.h>
  9. #include <qprogressbar.h>
  10. #include <qapplication.h>
  11. #include <qlayout.h>
  12. #include <qevent.h>
  13. #include <qthread.h>
  14. #include <iostream>
  15.  
  18.  
  19. class ExternalLoop : public QWidget
  20.  
  21. {
  22.     Q_OBJECT
  23.  
  24. public:
  25.     ExternalLoop( QWidget *parent = 0, const char *name = 0 );
  27.     QProgressBar *myProgress;
  28.     void customEvent(QCustomEvent * e);
  29.  
  30.  
  31. private:
  32.  
  33. public slots:
  34. 	void theLoop();
  35.  
  36. };
  37.  
  38. class myEvent : public QCustomEvent
  39. {
  40.  
  41. 	public:
  42.  
  43.     myEvent(int i): QCustomEvent( QEvent::User ),v(i){};
  44.     int done() const { return v; };
  45.  
  46. 	private:
  47.     int v;
  48.  
  49.  
  50. };
  51.  
  52. class MyThread : public QThread {
  53.  
  54.     public:
  55.  
  56.         virtual void run();
  57.  
  58. };
  59.  
  60. #endif
To copy to clipboard, switch view to plain text mode 

externalloop.cpp

Qt Code: 
  1. /*
  2. * externalloop.cpp
  3. */
  4. #include "externalloop.h"
  5.  
  6. using namespace std;
  7.  
  8. ExternalLoop::ExternalLoop( QWidget *parent, const char *name )
  9.     : QWidget( parent, name )
  10. {
  11.  
  12.  
  13.     QGridLayout *grid1 = new QGridLayout(this,2,1,10);
  14.  
  15.     pb1 = new QPushButton("Loop", this); 
  16.     grid1->addWidget( pb1, 0, 0 );
  17.     connect(pb1, SIGNAL( clicked() ), this, SLOT( theLoop() ) );
  18.  
  19.     myProgress = new QProgressBar(100, this);
  20.     grid1->addWidget( myProgress, 1, 0);    
  21.  
  22.     myProgress->setTotalSteps(10);
  23.  
  24.  
  25. }
  26. void ExternalLoop::theLoop()
  27. {
  28.  
  29. 	MyThread a;
  30. 	a.start();
  31.     a.wait();
  32.  
  33.  
  34. }
  35.  
  36. void ExternalLoop::customEvent(QCustomEvent * e)
  37. {
  38.  
  39. 	myEvent* lEvent = (myEvent*)e;
  40. 	int var = lEvent->done();
  41. 	myProgress->setProgress(var);
  42. 	qApp->processEvents();
  43. 	cout << "event " << var << endl;
  44.  
  45. }
  46.  
  47. void MyThread::run()
  48. {
  49.  
  50.         for( int count = 0; count < 11; count++ ) {
  51.             sleep( 1 );
  52.             cout << "thread " << count << endl;
  53.             myEvent* lEvent = new myEvent(count);
  54.             QApplication::postEvent( qApp, lEvent);
  55.  
  56.         }
  57. }
To copy to clipboard, switch view to plain text mode