将 Objective-C 方法传递给 C++ 方法

Question

I created void type method in Objective-C to pass it to C++ method shown below:

C++ method to which Objectiv-C method will be passed:

glfwSetWindowSizeCallback(m_Window, windowResize);

Here is Objective-C method:

- (void) windowResize:(GLFWwindow *)window :(int)width :(int)height {glViewport(0, 0, width, height);}

I know it can be solved by adding C++ file to the project and linking it to .m file with C++ method, but i would like to implement it in Cocoa syntax

Answer 1

ObjC methods can be passed arround as selector s like

SEL method = @selector(windowResize:width:height:);
glfwSetWindowSizeCallback(m_Window, method);

Then applied inside glfwSetWindowSizeCallback. Alternately you could wrap the ObjC call in ac function and pass the function pointer.

A more complete example might be:

void func(NSApplication * target, SEL method) {
    if ([target respondsToSelector: method] ) {
       [target performSelector:method];
    }
}

elsewhere:

- (void)applicationWillTerminate:(NSNotification *)aNotification {
    SEL method = @selector(unhideAllApplications:);
    func([NSApplication sharedApplication] , method);
  }