A.2 The class TWindow and the function Paint

Having succeeded in creating our own window, we are well on the way to our final objective. An empty window, however, is of rather limited use! We must learn how to put into it text or graphics at will. The class TWindow possesses a virtual function Paint which provides the necessary facilities.

It suffices for the present to observe that the class TWindow may be partially declared to be:

   class TWindow : public TWindowsObject {   public:         TWindow (PTWindowsObject AParent, LPSTR ATitle,                                  PTModule AModule=NULL);         virtual ~TWindow ();         ........   protected:         virtual void Paint (HDC PaintDC,                                  PAINTSTRUCT &PaintInfo);   };

It contains a constructor with three parameters: the first a pointer to the parent window, if any; the second a title, or caption, for the window; and the third, a pointer to a TModule,...