This method notes in Ruby the ownership of the timer, from both sides, and sets up an event hook if needed for the window’s destruction.

Source Code

# File wx/classes/timer.rb, line 30
def setup_owner_destruction_hook(new_owner)
  this_timer = self

  # Class-wide list of global (unowned) timers
  @@__unowned_timers__ ||= []

  # remove from list of previous owner
  if defined?(@__owner__) and @__owner__
    @__owner__.instance_eval { @__owned_timers__.delete(this_timer) }
  end

  # If becoming global unowned timer, add to list of those timers
  if not new_owner
    @__owner__ = nil
    @@__unowned_timers__ << self      
    return
  end

  # Otherwise, if previously unowned, remove from global owned
  @@__unowned_timers__.delete(self)
  @__owner__ = new_owner

  # Then add to list of new owner, setting destructor hook if required    
  new_owner.instance_eval do
    if not defined?(@__owned_timers__)
      @__owned_timers__ = []
      unless self.kind_of?(Wx::App) # Don't set up hook on App
        evt_window_destroy do | evt |
          # If it's the owning window being destroyed...
          if evt.get_event_object == self
            @__owned_timers__.each { | timer | timer.stop }
          end
          evt.skip
        end
      end
    end
    @__owned_timers__ << this_timer
  end
end