From: james@...
Date: 2002-03-27T03:46:02+09:00
Subject: Error calling Tk in a loop

I'm trying to write some code that pops up a Tk window when for certain
events.

The first call to display works, but the next one gives this error:
C:/Ruby/lib/ruby/1.6/tk.rb:986:in `_invoke': can't invoke "label" command:
application has been destroyed (RuntimeError)

The Ruby version is ruby 1.6.6 (2001-12-26) [i586-mswin32]
This is on a Win2K box. I haven't installed any other Tcl/Tk but what came
with the Ruby installation.
I get the same error on my Linux box using Ruby 1.6.7.

Any ides on what causes this, and how to avoid it?



Here's example code:
#-----------------------------------------------
require 'tk'

class AlertBox
  def initialize( caption, box_text )
    root = TkRoot.new { title caption }
    TkLabel.new(root) {
      text  box_text
      pack  { padx 25 ; pady 25; side 'left' }
    }
    Tk.mainloop
  end
end

if __FILE__ == $0
  1.upto(3){ |x|
    AlertBox.new( "Alert #{x}", "This is #{x}")
    # First call works, next call fails.

    sleep(5)
  }
end

#-----------------------------------------------


Thanks,



James