#include <Application.h>
#include <Window.h>
#include <Button.h>

class Button : public BButton
{
    public:
        Button(char *name, char *label, BMessage *message) : BButton(BRect(0,0,300,300), name, label, message, B_FOLLOW_ALL)
        {
        }

        void MessageReceived(BMessage *msg)
        {
            switch(msg->what)
            {
                case 'STLB':
                    char *label;
                    if(msg->FindString((const char *)"label", (const char **)&label) == B_OK )
                        SetLabel(label);
                    break;
            }
        }
};

class Win : public BWindow
{
    private:
        Button *b;

    public:
        Win() : BWindow(BRect(100,100,400,400),"App", B_TITLED_WINDOW, 0)
        {
            b = new Button((char *)"button",(char *)"Press me!", new BMessage('MSGB'));
            AddChild(b);
        }

        void ChangeLabel()
        {
            BMessage *mess = new BMessage('STLB');
            mess->AddString("label","Hello world!");
                b->MessageReceived(mess);
                delete mess;
        }

        void MessageReceived(BMessage *msg)
        {
            switch (msg->what)
            {
                case 'MSGB':
                    ChangeLabel();
                    break;
                default:
                    be_app->PostMessage(msg);
                    break;
            }
        }

        bool QuitRequested()
        {
            be_app->PostMessage(B_QUIT_REQUESTED);
            return true;
        }
};

class App : public BApplication
{
    private:
        Win *w;

    public:
        App() : BApplication("application/x-vnd.App")
        {
            w = new Win();
            w->Show();
        }

        ~App()
        {
            delete w;
        }
};

int main()
{
    App *a = new App();

    a->Run();
    delete a;

    return 0;
}