Qt signals slots again

Hi,
A really newbie question.

Code:

---

QPushButton* buttonRun = new QPushButton(QString("Run"));
 
QGridLayout* layout_ = new QGridLayout;
layout_->addWidget(buttonRun,1,0);	
widget->setLayout(layout_);
 
connect(buttonRun,SIGNAL(clicked()),this,SLOT(runAlgorithm()));

---

connect() returns true, but the slot is never called. I'm pretty sure the signal is emitted, because

Code:

---

connect(buttonRun,SIGNAL(clicked()),qApp,SLOT(aboutQt()));

---

works. I also think that the slot is defined properly, because if I do something like:

Code:

---

QObject::connect(this,SIGNAL(runThisBastard()),this,SLOT(runAlgorithm()));
emit runThisBastard();

---

the slot is called properly.

Just in case here's my definition of the class:

Code:

---

class A: public QObject, public IHasPropertiesPage
{
	Q_OBJECT
public:
 ....
public slots:
	void runAlgorithm ();
...
};

---

Any help would be greatly appreciated.

Based on what you wrote I can't see an error. So could you please make a minimal, compilable example reproducing your problem.

Here you go. The full solution (VS 2010) is attached, I paste the code here for convenience. Thanks for help!

Code:

---

//A.h
#ifndef _A_H_
#define _A_H_
 
#include <qobject>
#include <qlayout.h>
#include <qpushbutton.h>
#include <qlineedit.h>
#include <QtGlobal>
#include <qapplication.h>
 
#include "IHasPropertiesPage.h"
 
class A: public QObject, public IHasPropertiesPage
{
	Q_OBJECT
public:
	A() {};
	void showProperties(QWidget* widget);
signals:
	void runThisBastard();
public slots:
	void run();
private:
	QLineEdit* edit_;
};
 
#endif

---

Code:

---

//A.cpp
#include "A.h"
 
void  A::showProperties(QWidget* widget)
{
	edit_ = new QLineEdit(QString::number(0.1)); 
	QPushButton* buttonRun = new QPushButton(QString("Run"));
 
 
	//connect(this,SIGNAL(runThisBastard()),this,SLOT(run()));
	//emit runThisBastard();
	QGridLayout* layout_ = new QGridLayout;
	layout_->addWidget(edit_,0,0);
	layout_->addWidget(buttonRun,1,0);	
	widget->setLayout(layout_);
	//connect(buttonRun,SIGNAL(clicked()),qApp,SLOT(aboutQt()));
	connect(buttonRun,SIGNAL(clicked()),this,SLOT(run()));
}
 
void A::run()
{
	int i = 0; //just do something, I set a breakpoint here
}

---

Code:

---

//tempqt.cpp
#include "tempqt.h"
#include "A.h"
tempQt::tempQt(QWidget *parent, Qt::WFlags flags)
	: QMainWindow(parent, flags)
{
	ui.setupUi(this);
 
	A a;
	a.showProperties(ui.centralWidget);
}
 
tempQt::~tempQt()
{}

---

Code:

---

//tempqt.h
#ifndef TEMPQT_H
#define TEMPQT_H
 
#include <QtGui/QMainWindow>
#include "ui_tempqt.h"
 
class tempQt : public QMainWindow
{
	Q_OBJECT
public:
	tempQt(QWidget *parent = 0, Qt::WFlags flags = 0);
	~tempQt();
private:
	Ui::tempQtClass ui;
};
 
#endif // TEMPQT_H

---

Code:

---

//IHasPropertiesPage.h
#ifndef _IHASPROPERTIESPAGE_H_
#define _IHASPROPERTIESPAGE_H_
 
#include <qwidget.h>
 
class IHasPropertiesPage
{
public:
	virtual void showProperties(QWidget* widget) = 0;
};
 
#endif

---

Attachment 7150

Well A::run() could not be reached, since it is long go... It is deleted after the c-tor (Basic C++ :eek:)! So make A a private member or create it on the heap.

Wow, this is stupid of me. Thanks!