User Input -> AmigaOS Signal -> SignalResponder -> Object Method -> Application Response

// From SignalResponder.cxx:75-85 - actual event handling
void SignalResponder::WaitSignal()
{
   // wait for the set of signals from all responder objects
   ULONG receivedSig = Wait(waitSignalSet);

   // spread the received signal to all SignalResponders.
   sigRespChain.apply((void*)receivedSig);
   _dprintf("SignalResponder::WaitSignal returned.\n");
}

// From IntuiObject.cxx:60-70 - actual memory management
IntuiObject::IntuiObject(IntuiObject* owner,const AttrList& attrs)
   : attrList(attrs)
{
   // ... object initialization
   if (owner==OWNER_ROOT)
   {
      if (IntuiRoot::APPIntuiRoot)
         IntuiRoot::APPIntuiRoot->addTail(this);
   }
   else
   {
      if (ptr_cast(IntuiObject,owner))
         owner->addTail(this);
   }
}

// From source analysis - C++ integration
class IntuiObject : public MinNodeC, private APPObject, public MinListC
{
   public:
      virtual ~IntuiObject(); // Automatic cleanup
      // ... rest of class
};

// Custom class creation
class MyWindow : public GWindow
{
   public:
      MyWindow(OWNER,AttrList& attrs) : GWindow(owner,attrs)
      {
         modifyIDCMP(CLASS_NEWSIZE|CLASS_CLOSEWINDOW|CLASS_ACTIVEWINDOW);
      }
      // ... custom methods
};

// Inheritance through C++
class MyGadget : public GadgetCV
{
   public:
      MyGadget(IntuiObject* owner, AttrList& attrs) 
         : GadgetCV(owner, attrs) { }
      // ... custom gadget behavior
};

// Event handling through virtual methods
void MyWindow::On_CLOSEWINDOW(const IntuiMessageC* msg)
{
   putText("CLOSEWINDOW.");
   delete this;   // Self-destruction allowed
}

// MFC's document-view pattern
class CMyDocument : public CDocument
{
    DECLARE_DYNCREATE(CMyDocument)
public:
    virtual BOOL OnNewDocument();
    virtual void Serialize(CArchive& ar);
};

class CMyView : public CView
{
    DECLARE_DYNCREATE(CMyView)
public:
    virtual void OnDraw(CDC* pDC);
    virtual BOOL PreCreateWindow(CREATESTRUCT& cs);
};

// APlusPlus's basic object system
class IntuiObject : public MinNodeC, private APPObject, public MinListC
{
   public:
      virtual ~IntuiObject();
      virtual ULONG setAttributes(AttrList&);
      virtual ULONG getAttribute(Tag tagValue,ULONG& tagData);
};

// ReAction's GadTools-based approach
struct Window *window = OpenWindowTags(&newWindow, 
    WA_Title, "My Window",
    WA_Width, 400,
    WA_Height, 300,
    TAG_DONE);

// APlusPlus's C++-based approach
class MyWindow : public GWindow
{
   public:
      MyWindow(OWNER,AttrList& attrs) : GWindow(owner,attrs)
      {
         modifyIDCMP(CLASS_NEWSIZE|CLASS_CLOSEWINDOW|CLASS_ACTIVEWINDOW);
      }
      // ... event handling methods
};