Question

I have a global object “X” and a class “A”.
I need a function F in A which have the ability to modify the content of X.

For some reason, X cannot be a data member of A (but A can contain some member Y as reference of X), and also, F cannot have any parameter, so I cannot pass X as an parameter into F. (Here A is an dialog and F is a slot without any parameter, such as accept() )

How can I modify X within F if I cannot pass X into it? Is there any way to let A know that “X” is the object it need to modify?? I try to add something such as SetItem to specify X in A, but failed.

Answer 1

If you don’t want F to reference X globally, then you could ‘set’ it on the object before calling the “worker” method. E.g.

class A
{
public:
   A() : member_x(NULL) { }
   void SetX(X* an_x) { member_x = an_x; }
   void F(); { member_x->Manipulate(); }

private:
   X* member_x;
};

X global_x;
A global_a;

void DoStuff()
{
   global_a.SetX(&global_x);
   global_a.F();
}