3

I'm supposed to create a c++ class with c++ methods, that are made of objective-c and use cocoa, but now I've ran into a problem, and simply can't figure it out, cause I'm pretty new at objective-c. Also the point is that I should be able to create windows and buttons from c++. So when ever I build and run this program, it starts up but then instantly turns into a "not responding" state. Anyways, here's what I got:

Window.h

#ifndef WINDOW_H #define WINDOW_H class Window { public: Window(); void createButton(); }; #endif

Window.mm

#include "Window.h" #include "Button.h" Window::Window(){ NSWindow *window = [[NSWindow alloc] initWithContentRect: NSMakeRect(100, 100, 200, 200) styleMask: NSTitledWindowMask | NSMiniaturizableWindowMask backing: NSBackingStoreBuffered defer: NO]; [window setTitle: @"Test window"]; } void Window::createButton(){ Button *button; [[this contentView] addSubView: button]; // word this gives warning: no '-addSubView:' method found // this is probably causing the problem I have }

Button.h

class Button{ Button(); }; // There will be more methods here eventually

Button.mm

#include "Button.h" Button::Button(){ NSButton *button = [[NSButton alloc] initWithFrame: NSMakeRect(14, 100, 120, 40)]; [button setTitle: @"Hello world"]; [button setAction: @selector(invisible)]; [button setBezelStyle: NSRoundedBezelStyle]; [button setButtonType: NSMomentaryLightButton]; [button setBezelStyle: NSTexturedSquareBezelStyle]; }

Main.cpp

#include "Window.h" #include "Button.h" int main(int argc, char *argv[]){ Window x; x.createButton(); }

So, does anyone have any idea why ain't it working, like I mentioned, I'm pretty new at Cocoa and Objective-C, still learning :P And yeah, I've tried to fix it.

Improve this question
3
  • 1
    If you're still learning, why start with Obj-C++, which lets you combine all the complexity of C++ with your lack of familiarity with Obj-C? Why not just start with straight Obj-C? Commented Jun 15, 2011 at 17:22
  • I can control C++ perfectly, so "complexity of C++" ain't a problem, I just have to learn how to merge C++ with Objective-C. And why to start with Obj-C++? Cause that's what I need to do for this program to work, I have my reasons :"> Also, I already did this same program in Objective-C and it worked perfectly, so the problem I have is merging C++ with Objective-C Commented Jun 15, 2011 at 17:38
  • You need to understand how Cocoa works in isolation before you have any hope of combining it with C++. Commented Jun 27, 2011 at 16:15

2 Answers 2

Reset to default
3

[[this contentView] addSubView: button];

As you suspect, that is causing your problem. "This" is not referring to the window; it refers to the class itself. (Remember, your class is not a subclass of an NSWindow)

One option is to declare your NSWindow in the header so it can be used globally. So make your header:

#ifndef WINDOW_H #define WINDOW_H class Window { public: Window(); void createButton(); NSWindow *window; }; #endif

And then change the aforementioned line to:

[[window contentView] addSubview: button]; (Also notice to fix the capitalization on 'addSubview')

It's a similar problem with your button constructor. You are creating an NSButton, but that button is never seen or heard from again.

Improve this answer
Sign up to request clarification or add additional context in comments.

1 Comment

Seems like declaring NSWindow window in public (or private) will just give me an error: "ISO C++ forbids declaration of 'NSWINDOW' with no type" and "expected ';' before '' token", both given at the line where I declare window.
3

Your main function is not running the run loop, so the drawing and event handling systems will be non-responsive.

You never show the window you created.

I don't see where you save away the Cocoa objects so that your C++ API can manipulate them. For example, your Window constructor does not save the created window to a member variable, so you will have no way to manipulate that window after its creation.

Improve this answer

Comments