How to connect buttons with methods, which will be called on click - c++

Question

I started programming some custom gui application. But i need to know how to connect button with some method.
For example i have:
class Button
{
private:
string Text;
/*etc*/
public:
string GetLabel();
void SetLabel(string label);
void Connect(/*method name as param*/)
{
//TODO -this is that thing i need help here
/*this is method for connecting button with method, which will be
called on click, which im asking for help*/
}
};
class Window
{
private:
int sizeX,sizeY;
public:
void Put(Button * button,int _hpos,int _vpos);
void Show();
/*etc */
};
class MyWindow : public Window
{
public:
MyWindow()
{
InitializeComponents();
}
void Run()
{
this -> Put(btn1,10,10); //put button in window at position 10,10
this -> Show();
}
private:
Button * btn1;
void InitializeComponents()
{
btn1 = new Button();
btn1 -> Connect(on_btn1_click); //select which method will be called when user click this button, which I dont know how to do so pls help
}
void on_btn1_click() //this method is called when user click the button
{
//do something if user clicked btn1
}
};
int main()
{
MyWindow * win1 = new MyWindow();
win1 -> Run();
return 0;
}
So there is private method inside MyWindow class which will be called when user clicks the button (btn1). Method Connect() selects which method will be used for calling when user clicks the button.

Answer 1

You can check if the mouse is over a button/UI object, If it is than trigger a command/event.
const Button& GetObjectBelowMouse(int xMousePos, int yMousePos) // This would be equavalent to your Connect type
{
// all buttons would be your container of buttons / GUI objects.
for( const auto& button : allButtons)
{
// top,bottom,left,right would be the bounding rectangle that encapsulates the coordinates of the object
if( (xMousePos > button.left && xMousePos < button.right ) && (yMousePos > button.bottom && yMousePos < buttom.top))
{
return button;
}
}
// in this case we have a different constructor that creates a "empty" button that has no function
return Button(NO_OBJECT);
}
// the usage would be something like
int main()
{
/*
.. create button, set it's possition, etc
*/
// Option 1
if(GetObjectBelowMouse(mouse.x, mouse.y).type != NO_OBJECT)
{
// Do whatever you want, you know that the user has clicked a valid object
button.Foo();
}
// Option 2
GetObjectBelowMouse(mouse.x, mouse.y).Foo(); // You know that every button has a foo object, and that NO_OBJECT has a foo that does nothing, so you don't need to compare if it is NO_OBJECT or not.
}