wxruby users - Aug 2009 - Drag & drop problems with ListCtrl

Hi!

I''m having some trouble using a ListCtrl as a drag & drop source. I
select a row and then try to drag it, but nothing happens. The
evt_list_begin_drag doesn''t seem to trigger.

I''ve found no good examples of it anywhere, except an old sample that
seems to have been a part of wxruby 0.6.0 that I found here:
http://www.koders.com/ruby/fid431E286522E3E0DEE10CFA48B571A48A0B1BE9EE.aspx?s=kevin+smith+dragdrop#L1
I know it''s old, but after (briefly) comparing it to the current
documentation I can''t see why the code shouldn''t work... Or at
least
trigger the evt_list_begin_drag. I hope I am mistaken, and that
someone can point out some easy fix... I need to drag rows in a
ListCtrl and either drop on the same ListCtrl or a TreeCtrl, but as
the evt_list_begin_drag doesn''t seem to trigger, I''m sort of
stuck.
Neither the drag & drop samples that ship with the wxruby gem nor any
mailing list discussion I''ve found seem to cover what I''m
after.

I''ve run the code basically unmodified (just changing the requires to
''rubygems'' and ''wx'' instead of
''wxruby'', and removing '':'' characters
on the case-when so it works in Ruby 1.9) on OS X 10.5.7 both with
ruby 1.8.6 (p287) and the wxruby 1.9.9 gem, and with ruby 1.9.1 (p129)
and the wxruby-ruby19 2.0.0 gem, and neither work. The latter is my
preferred target.

Any help getting this to work would be *greatly* appreciated! A code
sample that works (atleast on someone elses machine) with a ListCtrl
as a drag & drop source and target would be superb, so I could try the
same sample, and if it doesn''t work try to figure out why.
I''ve pasted
the sample I tried at the end of the mail, modified as noted above for
convenience if anyone has the time to try it out.

Best regards and thanks in advance,
Mathias

Code sample follows:

# dragdrop.rb sample by Kevin Smith

#require ''wxruby''
require ''rubygems''
require ''wx''

class DragListBox < Wx::ListCtrl
    def initialize(parent)
        super(parent, -1, Wx::DEFAULT_POSITION, Wx::DEFAULT_SIZE,
                Wx::LC_REPORT | Wx::LC_SINGLE_SEL)

        insert_column(0, ''Fruits'')

        evt_list_begin_drag(get_id) do | e | on_drag(e) end
    end

    def append(text)
        row = get_item_count
        insert_item(row, text)
        set_item_text(row, text)
    end

	def get_selected_row
		return get_next_item(-1, Wx::LIST_NEXT_ALL, Wx::LIST_STATE_SELECTED)
	end
	
    def on_drag(event)
        selected_row = get_selected_row
        if(selected_row < 0)
            puts("nothing to drag")
            return
        end
        data = Wx::TextDataObject.new(get_item_text(selected_row))
        dragSource = Wx::DropSource.new(self);
        dragSource.set_data(data);
        result = dragSource.do_drag_drop(Wx::DRAG_ALLOW_MOVE)
        case result
            when Wx::DRAG_NONE
                puts("Drop was rejected")
            when Wx::DRAG_CANCEL
                puts("Drag canceled by user")
            when Wx::DRAG_COPY
                puts("Copied")
            when Wx::DRAG_MOVE
                puts("Moved")
                delete_item(selected_row)
            else
                puts("ERROR or Unknown result!")
        end
    end
end

class MyDropTarget < Wx::TextDropTarget
    def initialize(owner)
        super()
        @owner = owner
        @owner.set_drop_target(self)
    end

    def on_drop_text(x, y, text)
        puts("Accepting drop of #{text} at #{x}, #{y}")
        @owner.handle_drop(text)
        return true
    end
end

class DropListBox < Wx::ListBox
    def initialize(parent)
        super(parent, -1)

        target = MyDropTarget.new(self)
    end

    def handle_drop(text)
        append(text)
    end
end

class MyFrame < Wx::Frame
  def initialize(title)
    super(nil, -1, title)
    list1 = DragListBox.new(self)
    list1.append(''Apple'')
    list1.append(''Banana'')
    list1.append(''Cranberry'')
    list2 = DropListBox.new(self)

    lists = Wx::BoxSizer.new(Wx::HORIZONTAL)
    lists.add(list1, 1, Wx::EXPAND)
    lists.add(list2, 1, Wx::EXPAND)

    instructions = Wx::StaticText.new(self, -1,
        "You can drag items from the left list to the right\n" +
        "(or to any window in your system that accepts text drops.\n"
+
        "If you hold down shift while releasing, the item \n" +
        "will be MOVED instead of COPIED\n")

    main_sizer = Wx::BoxSizer.new(Wx::VERTICAL)
    main_sizer.add(instructions, 0, Wx::EXPAND)
    main_sizer.add(lists, 1, Wx::EXPAND)
    set_sizer(main_sizer)

  end
end

class DragDropApp < Wx::App
  def on_init
    frame = MyFrame.new("wxRuby Drag and Drop App")
	frame.show
  end
end

a = DragDropApp.new
a.main_loop()