CODEWITHSUNDEEP
c++cocoamethodsobjective-c++
user1632861
user1632861

Reputation:

Objective-C++ / Cocoa attempt to create a window with button, not working?

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.

Upvotes: 3

Views: 1387

Answers (2)

iii
iii

Reputation: 1614

[[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.

Upvotes: 3

Jeremy W. Sherman
Jeremy W. Sherman

Reputation: 36143

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.

Upvotes: 3

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