Question

I’ve developed a working framework for windows at school, which has all the classes and methods needed for a window to work. Here’s an example of part of few classes, I’m not gonna paste all the code here tho.

Widget.h (base class)

class Widget {
    public:
        Widget(...);
        ...
        virtual std::string getLabel() const;
        virtual void setLabel(const std::string label);
        ...
    private:
        std::string m_label;
        Widget* m_parent;
        Measure m_position; // struct: int x, int y
        Measure m_size;
};

Button.h

class Button : public Widget {
    public:
        Button(...);
        ...
        virtual void setTarget(Widget* target);
        ...
    private:
        Widget* m_target;
};

LineEdit.h

class LineEdit : public Widget {
    public:
        LineEdit(...);
        ...
        virtual void setMaximumLenght(int lenght);
        ...
    private:
        int m_maximumLength;
};

And so on… These are all just header files, and I have implemented methods etc. inside the corresponding .cpp file.

My homework for this period is to implement them for Mac’s OS-X in Objective-C and Cocoa, so the headers work in both OS-X and Windows. I can do rest myself, but I would like to know how to use these header files in the OS-X, and therefore just rewrite the implementations into a .m file, instead of .cpp. Any ideas? I’m new to this stuff.

Answer 1

You can combine .cpp files and .m files in the same project, which means that if your implementation doesn’t have any Windows-specific code you can add it to the project and compile it. There is also the concept of Objective-C++. With it, you can write code in .mm files using both C++ and Objective-C and make calls between them.

On the other hand, if you really need to implement everything in Objective-C, you’ll need to rewrite the headers to define Objective-C classes (not C++ ones) as well as rewriting the implementation.