How would I connect this signal to the slot - c++

Question

I would like to create a signal in my main class foo so that a static method in a different class could emit it.I just started of with QT so I am a bit confused. I currently have the following code
class Foo : public QMainWindow
{
Q_OBJECT
public:
Foo(QWidget *parent = 0, Qt::WFlags flags = 0);
~Foo();
signals:
void UpdateSignal(int val);
private slots:
void MySlot(int val);
};
Foo::Foo(QWidget *parent, Qt::WFlags flags): QMainWindow(parent, flags)
{
//How do I connect Bfoo::somemethod() here. I know its suppose to be like
connect(xx,SIGNAL(UpdateSignal(int)),this, SLOT(MySlot(int)));
ui.setupUi(this);
}
void Foo::MySlot(int val)
{
//Do something..
}
Now I have this class
Class Bfoo
{
static void somemethod()
{
emit UpdateSignal(12);
}
}
Any suggestions on how the static somemethod() could emit the UpdateSignal

Answer 1

When you emit signal it is necessary to know which object is emitting it. This is because signals are not implemented to be messages between different classes but messages between instances of (possibly different) classes.
Secondly, signals are protected methods. They are not accessible for external users. What you can do is define public method in Foo which will do the emission:
void Foo:EmitUpdateSignal(int x) {
emit UpdateSignal(x);
}
And then in your Bfoo::somemethod() you need to pass object which will emit signal:
void BFoo::somemethod(Foo &f) {
f.EmitUpdateSignal(12);
}
However, notice what you are doing. You emit signal which is connected to the slot in the same instance. This suggests design flaw but I cannot give any hints without more details about what are you going to achieve.