Crash on connect

Hi all,

I have a crash on connect in constructor

Code:

---

BuilderAppInstanceUI::BuilderAppInstanceUI(const Workflow &wf)
	:ObserverAdapter(wf)
{
 	connect(Datasets, SIGNAL(currentItemChanged(QListWidgetItem*,QListWidgetItem*)), Variables, SLOT(datasetChanged(QListWidgetItem*,QListWidgetItem*))); 
}

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with

Code:

---

Datasets

---

and

Code:

---

Variables

---

two members of

Code:

---

BuilderAppInstanceUI

---

:

Code:

---

class BuilderAppInstanceUI : public QWidget
                               , public ObserverAdapter 
{
    Q_OBJECT
 
public:
    BuilderAppInstanceUI(const Workflow &workflow);
    ~BuilderAppInstanceUI();
 
 	void retranslateUi(QWidget *Form);
	void setupUi(QWidget *Form);
 
	QStackedWidget *stackedWidget;
 
 
	BuilderAppListWidget *Datasets;
	QTreeWidget *Variables;
 
	private slots:
		void datasetChanged(QListWidgetItem* current, QListWidgetItem* previous);
 
};

---

Code:

---

BuilderAppListWidget

---

inherits from

Code:

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QListWidget

---

and as such can emit this signal

Code:

---

SIGNAL(currentItemChanged(QListWidgetItem*,QListWidgetItem*))

---

Code:

---

class BuilderAppListWidget : public QListWidget
{
    Q_OBJECT
 
public:
	BuilderAppListWidget (QWidget* qwdgt = nullptr);
	~BuilderAppListWidget (){};
 
	void dragEnterEvent( QDragEnterEvent * event ) ;
	void dragMoveEvent( QDragMoveEvent * event ) ;
	void dropEvent( QDropEvent * event );
	void keyReleaseEvent( QKeyEvent * event ) final ;
 
private:
	BuilderAppInstanceUI* m_instance ;
 
};

---

Should I declare explicitly

Code:

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currentItemChanged

---

in body for

Code:

---

BuilderAppListWidget

---

class ? If not, where does problem come from ?

Regards

datasetChanged is a slot of BuilderAppInstanceUI (not Variables), the connect should look like

Code:

---

connect(Datasets, SIGNAL(currentItemChanged(QListWidgetItem*,QListWidgetItem*)), this, SLOT(datasetChanged(QListWidgetItem*,QListWidgetItem*)));

---

Quote:

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datasetChanged is a slot of BuilderAppInstanceUI (not Variables), the connect should look like

---

This wouldn't cause a crash, Qt would simply complain that the slot didn't exist.

However, if the code posted for the BuilderAppInstanceUI constructor is the whole thing, then the "Datasets" and "Variables" members have not been initialized prior to the connect() so they point to random locations in memory, not to actual instances of the widgets they represent. This would most certainly cause the crash as Qt attempts to resolve the meta-objects in the connect() method's execution.