Getting QMetaMethod of slot member function to connect "later"

yakumoklesk

Hi. I have a class that I want to use as a container to hold the receiver and the slot method of a class. So that later the first class instance will pass as a parameter to a function that will make the final connect, using whatever sender and signal to the stored receiver and slot. I am not sure how could I store the address of a member method (a slot) from a class to a QMetaMethod object to later use the overload connect method.

At the moment I am managing to do so by making the class to be a templated class, but then the signature gets a little weird to pass the parameters, and I would simplify it as the connect method from QObject.

Thanks a lot!

Regards,

David.

SGaist

Hi and welcome to devnet,

Can you show some pseudo code to explain what you would like to achieve ?

yakumoklesk

I want to refactor from THIS:


class ManageUserWorkflow : public QObject
{
    Q_OBJECT;
	enum WorkflowStep {
		WS_STEP_1,
		WS_STEP_2,
		WS_STEP_3
	}
	enum Action {
		A_OK,
		A_CANCEL,
		A_RETRY
	}
public:
    ManageUserWorkflow(){};
public slot:
    void ActionHandler(){ // do Handle code }
	FooterController* createFooter(const QList<Action>& actions)
	{
		FooterController* fc = new FooterController();
		for( int i = 0; i < actionList.size(); ++i)
		{
			Button* b = new Button(actions.at(i));
			connect(button, &Button::clicked, this, &ManageUserWorkflow::ActionHandler);
			fc->addButton(b);
		}
	}
    DialogController* createDialog(WorkflowStep step) {
		
		QList<Action> actions;
        switch( step ) {
            case WS_STEP_1:
			{
				dialog = new DialogController("A");
				actions << A_OK;
				break;
			}
            case WS_STEP_2:
			{
				dialog = new DialogController("B");
				actions << A_OK;
				actions << A_CANCEL;
				break;
			}
            case WS_STEP_2:
			{
				dialog = new DialogController("C");
				actions << A_RETRY;
				actions << A_CANCEL;
				break;
			}
        }
		
		FooterController footer = new FooterController(actions);
		dialog->setFooter( footer );
    }
}

to THIS:

class WorkflowDialogCreator : public QObject
{
    Q_OBJECT;
public:
    WorkflowDialogCreator(){};

	FooterController* createFooter(const QList<Action>& actions, const QList<QPair<QObject*, QMetaMethod*>> actionHandlers)
	{
		FooterController* fc = new FooterController();
		for( int i = 0; i < actionList.size(); ++i)
		{
			Button* b = new Button(actions.at(i));
			connect(button, &Button::clicked, actionHandlers.at(i).first, actionHandlers.at(i).first.second);
			fc->addButton(b);
		}
	}
}

class ManageUserWorkflow : public QObject
    Q_OBJECT;
	enum WorkflowStep {
		WS_STEP_1,
		WS_STEP_2,
		WS_STEP_3
	}
	enum Action {
		A_OK,
		A_CANCEL,
		A_RETRY
	}
public:
    ManageUserWorkflow(WorkflowDialogCreator* dc) :
	dc_(dc){};
public slot:
    void ActionHandler(){ // do Handle code }
	FooterController* createFooter(const QList<Action>& actions)
	{
		FooterController* fc = new FooterController();
		for( int i = 0; i < actionList.size(); ++i)
		{
			Button* b = new Button(actions.at(i));
			connect(button, &Button::clicked, this, &ManageUserWorkflow::ActionHandler);
			fc->addButton(b);
		}
	}
    DialogController* createDialog(WorkflowStep step) {
		
		QList<Action> actions;
		QList<QPair<QObject*, QMetaMethod*>> actionHandlers
        switch( step ) {
            case WS_STEP_1:
			{
				dialog = new DialogController("A");
				actions << A_OK;
				actionHandlers << QPair(this, &ManageUserWorkflow::ActionHandler);
				break;
			}
            case WS_STEP_2:
			{
				dialog = new DialogController("B");
				actions << A_OK;
				actions << A_CANCEL;
				actionHandlers << QPair(this, &ManageUserWorkflow::ActionHandler);
				actionHandlers << QPair(this, &ManageUserWorkflow::ActionHandler);
				break;
			}
            case WS_STEP_2:
			{
				dialog = new DialogController("C");
				actions << A_RETRY;
				actions << A_CANCEL;
				actionHandlers << QPair(this, &ManageUserWorkflow::ActionHandler);
				actionHandlers << QPair(this, &ManageUserWorkflow::ActionHandler);
				break;
			}
        }
		
		FooterController footer = dc_.createFooter(actions, actionHandlers);
		dialog->setFooter( footer );
    }
	
	WorkflowDialogCreator* dc_;
}

Please forget constant correctness and other things. I made it fast in purpose. Also take into account this is a simplification of what the real code is.

yakumoklesk

The most similar solution of what I think I need found it here:
https://stackoverflow.com/questions/31836199/how-to-store-qt-signal-slot-names-to-a-data-structure