#  AnimationDemoGTKnoclass.py  (c) Kari Laitinen

#  2006-08-21  File created.
#  2009-02-25  Last modification.

#  A no-class version of the program.
#  Keyword 'global' demonstrated.

import pygtk
pygtk.require('2.0')
import gtk
from threading import Thread
from threading import Event
from time import sleep

#Initializing the gtk's thread engine
gtk.gdk.threads_init()

class AnimationThread ( Thread ) :

   def __init__( self, given_drawing_area ) :

      Thread.__init__( self ) 

      self.external_drawing_area  =  given_drawing_area

      self.thread_must_be_stopped  =  Event()

      print " thread init done "

   def stop_this_thread( self ) :

      self.thread_must_be_stopped.set()


   def run( self ) :

      while  not self.thread_must_be_stopped.isSet()  :

			# Acquiring the gtk global mutex
         gtk.gdk.threads_enter()

         self.external_drawing_area.queue_draw()

			# Releasing the gtk global mutex
         gtk.gdk.threads_leave()

         sleep( 1.000 )  # Delay of one second.

         print " xxx ",

      print " run method ends "


 

def drawing_area_exposed( area, event ) :

   print "drawing_area_exposed called"

   global ball_must_be_shown
   global drawing_area

   if  ball_must_be_shown  ==  True :

      graphics_context  =   \
         drawing_area.get_style().fg_gc[gtk.STATE_NORMAL]

      this_drawable  =  drawing_area.window

      #  Note that angles are expressed in 1/64ths of a degree.
      #  360 degrees is thus represented by value 360*64

      this_drawable.draw_arc( graphics_context, True,
                              200, 200, 100, 100,  0, 360*64 )

      ball_must_be_shown  =  False

   else :

      ball_must_be_shown  =  True

   return True


def exit_this_application( widget, data=None ) :

   global animation_thread ;

   animation_thread.stop_this_thread()
   gtk.main_quit()

   print  "exit called"


application_window = gtk.Window( gtk.WINDOW_TOPLEVEL )
application_window.set_title( "ANIMATION BY USING A THREAD" )
application_window.connect( "destroy", exit_this_application )

application_window.set_size_request( 600, 500 )
drawing_area = gtk.DrawingArea()

application_window.add( drawing_area )

drawing_area.connect( "expose-event", drawing_area_exposed )

drawing_area.show()
application_window.show()

ball_must_be_shown  =  True
animation_thread  =  AnimationThread( drawing_area )
animation_thread.start()

print " init done "


gtk.main()