[lazarus] some questions about design

[Stefan Hille]

Hi,

hope you've all recovered now from your millenium parties;-)

Ok, here some things I've noticed during the last days of development:

- There's a problem with all classes derived from TGraphicControl.
  (currently these are TPaintBox and TBevel).
  The problem is, that there are a lot of places where these are casted to
  TWinControl, although TGraphicControl is derived from TControl.

  any suggestions how to solve this?
  
- TCheckBox is quite OK now, but if you assign OnClick and try to find out
  if the object is checked/unchecked you'll get the wrong state. Seems as
  if GTK is calling the handler before it actually changes the state.

- I'm not sure about it but it seems to me as if some controls (e.g.
  TCustomForm) don't recognize if their visual representation changes.
  For example if you resize a form the width/height properties won't get
  updated.
  Could anybody please check this.

- To keep the properties of TTrackBar / TCheckBox up to date I introduced
  some messages (LM_GETCHECKBOX...) which will sync the state of the
  lazarus object with that one of the GTK library. I think that we'll need
  more of these messages in the future and I'd like to create one special
  message for this. In the gtk interface we could then make a new procedure
  which makes a "case fCompStyle of". Thus we could avoid a lot of
  different messages.
  Any comments?

bye,

  Stefan

-- 
---------------------------------------------------------
Stefan Hille          email: stoppok at osibisa.ms.sub.org 
48155 Muenster	      voice: 0251/664695