Hi, 

From: mhm26 / drexel.edu (matt)
Subject: Ruby Tk - dialog windows
Date: Tue, 15 Jun 2004 04:53:41 +0900
Message-ID: <13383d7a.0406141151.2adf579f / posting.google.com>
> Hi - I'm trying to make `modal' windows.  I'm confused about how to
> use TkDialog, though, is there any good documentation?  I need a
> window that will not let someone go to the `parent' window, can
> display stuff just like a TkToplevel or TkRoot...

Please read dialog1.rb and dialog2.rb included in the 'Ruby/Tk widget 
demos'. 
But if you want a more complex modal window, you should use 'grab'. 
The step is 

  (1) show the modal window (toplevel widget),
  (2) set grab to the modal window, 
  (3) wait TkVariable access on the window 
                and release grab from the window, 
      OR destroy the window (release grab automatically). 

(please read ruby/ext/tk/sample/tkcombobox.rb). 

------<dialog1.rb>---------------------------------
#
# a dialog box with a local grab (called by 'widget')
#
class TkDialog_Demo1 < TkDialog
  ###############
  private
  ###############
  def title
    "Dialog with local grab"
  end

  def message
    'This is a modal dialog box.  It uses Tk\'s "grab" command to create a "local grab" on the dialog box.  The grab prevents any pointer-related events from getting to any other windows in the application until you have answered the dialog by invoking one of the buttons below.  However, you can still interact with other applications.'
  end

  def bitmap
    'info'
  end

  def default_button
    0
  end

  def buttons
    # ["Dismiss", "", "Show Code"]
    ["OK", "Cancel", "Show Code"]
  end
end

ret =  TkDialog_Demo1.new('message_config'=>{'wraplength'=>'4i'}).value
case ret
when 0
  print "You pressed OK\n"
when 1
  print "You pressed Cancel\n"
when 2
  showCode 'dialog1'
end
---------------------------------------------------

------<tkcombobox.rb:part>-------------------------
  def _button_proc(dir = true)
    @btn.relief(:sunken)
    x = @frame.winfo_rootx
    y = @frame.winfo_rooty
    if dir
      @top.geometry("+#{x}+#{y + @frame.winfo_height}")
    else
      @btn.image(@@up_btn_bmp)
      @top.geometry("+#{x}+#{y - @top.winfo_reqheight}")
    end
    @top.deiconify
    @lst.focus

    if (idx = values.index(@ent.value))
      @lst.see(idx - 1)
      @lst.activate(idx)
      @lst.selection_set(idx)
    elsif @lst.size > 0
      @lst.see(0)
      @lst.activate(0)
      @lst.selection_set(0)
    end
    @top.grab

    begin
      @var.tkwait
      if (idx = @var.to_i) >= 0
	@ent.value = @lst.get(idx)
      end
      @top.withdraw
      @btn.relief(:raised)
      @btn.image(@@down_btn_bmp)
    rescue
    ensure
      begin
	@top.grab(:release)
	@ent.focus
      rescue
      end
    end
  end
  private :_button_proc
---------------------------------------------------
-- 
                                  Hidetoshi NAGAI (nagai / ai.kyutech.ac.jp)