wxruby development - Oct 2007 - CheckListBox : delete method bug !

Hi,

I''ve practically finished a patch for removing the limitation of
CheckListBox
(http://rubyforge.org/pipermail/wxruby-development/2007-October/000973.html)
but I just discovered a new bug related with this control !!

I need to redefine the delete method to take into account the deletion
of the associated data. The problem is that if I just redefine this
method and simply call super, the control doesn''t work anymore !

Here is a sample code that shows the problem (for wxRuby 1.9.1 with
some copy/paste of wxRuby 1.9.2 for convenience). I''m running on
Windows 2000.

require "wx"

######################################
# Copy/Paste of wxRuby 1.9.2 additions
class Wx::App
  def self.run(&block)
    app_klass = Class.new(self)
    app_klass.class_eval do
      define_method(:on_init, &block)
    end
    the_app = app_klass.new
    the_app.main_loop
  end
end

class Wx::CommandEvent
  alias :get_index :get_int
end
# End of Copy/Paste of wxRuby 1.9.2 additions
#############################################

class Wx::CheckListBox
  # if the following method is defined, some items cannot be checked !
  def delete n
    super
  end
end

Wx::App.run do
  helloframe = Wx::Frame.new(nil, :title => "CheckListBox Sample")
do |frame|
    lb = Wx::CheckListBox.new(frame) do |c|
      # use of append within the initializer
      0.upto(3) { |i| c.append "item#{i+1}" }
    end

    evt_listbox lb.wx_id do |event|
      lb.delete event.index
    end

  end
  helloframe.show
end

---------------

If I run the application, and if I select the "item2", this item is
deleted as expected.
But afterwards, "item4" cannot be checked.

If I just remove/comment the delete method within the Wx::CheckListBox
class, everything is OK and I can check/uncheck all items as expected
after the deletion.

I don''t know if it is a wxRuby or a wxWidgets problem, but given all
issues I discovered with CheckListBox, I had the impression that this
control is a second class citizen.

Cheers.

Chauk-Mean.

Chauk-Mean P wrote:
> I''ve practically finished a patch for removing the limitation of
> CheckListBox 
Thanks for following this up.
> I need to redefine the delete method to take into account the deletion
> of the associated data. The problem is that if I just redefine this
> method and simply call super, the control doesn''t work anymore !
The problem here is that you should not be calling super, but rather the 
old definition of ''delete'' in CheckListBox. If you call super
you''re
calling ControlWithItems#delete, which probably misses some specific 
code in wxCLB to deal with deleting. The following code works for me 
(and will also avoid warnings):

class Wx::CheckListBox
  alias :__wx_delete :delete
  define_method(:delete) do | n |
    __wx_delete(n)
  end
end

cheers
alex

Alex Fenton wrote:
> class Wx::CheckListBox
>   alias :__wx_delete :delete
>   define_method(:delete) do | n |
>     __wx_delete(n)
>   end
> end
PS - or an alternative, commonly used in the ruby part of core wxRuby - 
eg bitmap.rb

class Wx::CheckListBox
  __wx_delete = self.instance_method(:delete)
  define_method(:delete) do | n |
    __wx_delete.bind(self).call(n)
  end
end

The advantage of this is that it avoids cluttering the method table with 
additional aliased methods.

cheers
alex

Alex,

2007/10/23, Alex Fenton <alex at pressure.to>:
> The problem here is that you should not be calling super, but rather the
> old definition of ''delete'' in CheckListBox. If you call
super you''re
> calling ControlWithItems#delete, which probably misses some specific
> code in wxCLB to deal with deleting. The following code works for me
> (and will also avoid warnings):
You''re right. This works. I''m glad that this was not a
CheckListBox issue :-).

I''m gonna attach the patch files with the other message.

Cheers.

Chauk-Mean.