Re: [wxperl-users] events and painting on a DC (need advice on creating a type tutor)

[Mattia B. <mb...@ds...>]

On Wed, 23 Apr 2003 05:39:19 -0700 (PDT) DH <cra...@ya...> wrote:

> With the help of the magical Canvas widget, I have created
> 
> perlTk Type Tutor - useful for learning a DVORAK keyboard layout
> http://perlmonks.com/index.pl?node_id=229960
> 
> Now I wanna write one in wx.
> 
> So milling about the wxperl docs like I always do, I realize I need
> to use a wxClientDC to setup my picture,
> and wxPaintDC to redraw as triggered by an OnPaint event.
  Yes. To be precise: if you are handling a paint event, you MUST create a
Wx::PaintDC (even if you don't use it!), if you aren't handling a paint
event, you just create a Wx::ClientDC and use it.

> So I would use ::wxPostEvent to post a wxPaintEvent to my
> wxFrame/wxPanel?
  No, you use Wx::Window->Refresh (because, in general, using
PostEvent/SendEvent to send "system" messages (move, resize, paint,
scroll...) is a bad idea (=unportable, might cause strange errors))

> Will I need to paint the entire picture (keyboard) every time
> a wxPaintEvent is triggered?
  You can use a clipping region, if you want (passing an invalidate rect to
->Refresh)

HTH
Mattia