After some other tests, I think I've found which is the issue and how to solve it.
Here a simplified snippet of my code, where there is a class Button used by a class Parent.
When button is clicked, it could cause a panel change, or raise a message, or do some other actions (not detailed beause not relevant to the question).
What I found is in slot onClicked of class Button: entering the first if, the program emits the signal request_GoToPrev, which cause the class Panel to delete current panel (and its childs, even compirsed the Button!) and raise a new one.
But after emitting the signal and do all actions required, the program "comes back" to the point when it has emitted the signal and continue the instruction execution: when it reaches the second if it creashes because this is no more consistent.
That's what it seems to be after my tests. Putting a return call just after the signal emission in the first if problem is solved.
// HEADER: Button.h class Button : public QPushButton { Q_OBJECT public: Button( QWidget *parent = 0 ); ~Button(); signals: void request_GoToPrev(); //!< Go to previous panel void request_GoToNext( QString ); //!< Go to next panel void signal_Error( int ); //!< Error code private slots: void onClicked(); private: typ_Button_tags *widgetTags; //!< Pointer to the tags structure that defines the \ref Button widget typ_Shared *privateCtx; //!< Reference to runtime application structure }; // C: Button.cpp Button::Button( QWidget *parent ) : QPushButton(parent) { // Do some settings, like: font, stylesheet, focus, size.. } Button::~Button() { } void Button::onClicked() { // Callback to be called when button clicked if( !this->widgetTags->callbackClick.isEmpty() ) { emit this->request_GoToPrev(); /* !!! ATTENTION !!! * * Here the instruction return HAS to be written, otherwise the application crashes. * In fact, when running, the signal 'request_GoToPrev' is sent, but the flow of the * process should exit the call of this slot. * Doing that, 'this' is no more consistent after having emitted the signal, so the * application face a segmentation fault. */ return; } // Message box if( !this->widgetTags->msgText.isEmpty() ) { // Do some other actions on 'this'... } } // HEADER: Panel.h class Panel : public QMainWindow { Q_OBJECT public: Panel( QWidget *parent = 0 ); private slots: void on_GoToNext(int index); void on_GoToPrevious(); void on_Error(int errId); private: Button *Btn; }; // C: Panel.h Panel::Panel( QWidget *parent ) : QMainWindow(parent) { // Do some settings: font, stylesheet, focus, size... this->Btn = new Button( this ); connect( this->Btn, SIGNAL(request_GoToPrev()), this, SLOT(on_GoToPrevious()), Qt::UniqueConnection ); // Do some actions to layout the button inside the panel } void Panel::on_GoToPrevious() { // Do some check... delete this->Btn; // Do some actions... }
