wxruby users - Dec 2003 - widget hierarchy - program variables

Hi!

During developing my little program, I''ve noticed, that the objects
have
a hierarchy, but now I don''t know what to do, if a widget initiates an
event which has an effect to the parent, grandfather/brother/other
relatives.
Is there a tutorial for this aspect?

Gergo

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KONTRA Gergely wrote:
> Hi!
> 
> During developing my little program, I''ve noticed, that the
objects have
> a hierarchy, but now I don''t know what to do, if a widget
initiates an
> event which has an effect to the parent, grandfather/brother/other
> relatives.
It is difficult to answer that question without knowing specific details 
about what you are trying to do.

I just wrote a little program that might help, depending on your exact 
situation. It creates a subclass of TextCtrl, and filters input 
characters. If the character is legal, it delegates handling to the 
parent (TextCtrl itself, in this case). Otherwise, it consumes the event 
itself.

As far as I know, in wxRuby it is not a good idea to try to push 
specific events to specific widgets, as you might do in Win32 coding. 
Instead, it would be better to just call a ruby method to do the work. 
But that requires you to know which ruby object you want to control.

If you can ask a more specific question, perhaps with some sample code, 
I can try to give a better answer.

Kevin

-----
require ''wxruby''

class MyTextCtrl < Wx::TextCtrl
   def initialize(parent)
     super(parent, -1)

     evt_char do | e | on_char(e) end
   end

   def on_char(e)
     c = e.key_code
     if((?a .. ?z).member?(c) || (?A .. ?Z).member?(c))
       # legal, so pass this event to our parent
       e.skip
       puts("skip")
     else
       # illegal, so beep and consume this event
       Wx::bell
       puts("beep")
     end
   end
end

class MyFrame < Wx::Frame
   def initialize(title)
     super(nil, -1, title)
     text = MyTextCtrl.new(self)
     box = Wx::BoxSizer.new(Wx::VERTICAL)
     box.add(Wx::StaticText.new(self, -1,
                "This box only allows alpha input:"))
     box.add(text)
     set_sizer(box)
     text.set_focus
   end
end

class NothingApp < Wx::App
   def on_init
     frame = MyFrame.new("Event Filter Sample")
     frame.show
   end
end

a = NothingApp.new
a.main_loop()