inheritance - Lazarus. How to invoke inherited method of dynamically created instance? -

i've searched , , didn't find situation. have variable of type tcustomcontrol:

var fcontrol:tcustomcontrol; 

then use rtti magic create instance of different classes-descendants of tcustomcontrol:

constructor tfgcontrol.create(theowner: tcomponent; control: string);         var classofcontrol:string; class_ref: tpersistentclass; begin   case control of 'formspec': classofcontrol:='tpanel';                      'label': classofcontrol:='tlabel';                     'button': classofcontrol:='tspeedbutton';   end;    class_ref:=getclass(classofcontrol);    fcontrol:=tcustomcontrol(class_ref.create);  

so, after have fcontrol point instance of desired class. , can assign methods of (given described needed) this:

  fcontrol class_ref        begin             parent:=parent;             if control='formspec'                begin                     width:=400;                     height:=300;                     color:=clgray;                end             else                 begin                      top:=20;                      left:=20;                      width:=50;                      height:=20;                      caption:=control+' - '+inttostr(parent.controlcount);                      font.color:=clwhite;                      color:=clred;                 end;              onmousedown:=@mousedown;             onmouseup:=@mouseup;             onmousemove:=@mousemove;             onclick:=@click;    

and works great.

but want dynamically created controls use different paint methods. want newly created instances use paint method of it's ancestors, e.g if class_ref.classname "tpanel" want fcontrol tpanel; , if class_ref.classname "tlabel" want fcontrol drawn common label.

the problem fcontrol declared tcustomcontrol , if write this:

            onpaint:=@paint; 

i can see (substitution) works. i'm supposed put inside new paint method invoke tpanel.paint if fcontrol tpanel; , tlabel.paint if fcontrol tlabel?

regards!

with fcontrol class_ref do

this not valid type-cast, nor needed. if want set property dynamically, can use rtti instead.

onpaint:=@paint;

that work actual tcustomcontrol-derived objects, use is operator check that:

if fcontrol tcustomcontrol   tcustomcontrol(fcontrol).onpaint:=@paint;