#!/usr/bin/env python
# Basic animation template by Chuck Liang.  Updated 9/09

import pygtk
import gtk
import gobject
import time
import threading
from random import randint

width,height = 900,700
delaytime = 70   # 100ms delay between animation frames

window = gtk.Window(gtk.WINDOW_TOPLEVEL)
window.set_title("Simplified Drawing Example")
window.connect("destroy", lambda w: gtk.main_quit())
area = gtk.DrawingArea()
area.set_size_request(width,height)
window.resize(width,height)
window.add(area)

window.show_all()
window.move(0,0)

gc0 = area.window.new_gc()
cmap = gc0.get_colormap()

# common colors
green = cmap.alloc_color(red=0,green=65535,blue=0)
blue = cmap.alloc_color(red=0,green=0,blue=65535)
red = cmap.alloc_color(red=65535,green=0,blue=0)
white = cmap.alloc_color("white")
black = cmap.alloc_color("black")
gray = cmap.alloc_color("gray")
yellow = cmap.alloc_color("yellow")
purple = cmap.alloc_color("purple")

gc0.set_foreground(green)
gc0.set_background(blue)
gc0.line_width = 1

# double buffering setup
dbuf = gtk.gdk.Pixmap(area.window,width,height,-1)
gc1 = dbuf.new_gc()
gc1.set_colormap(cmap)

### Thread control
syn = threading.Event()   # throttles mainloop
syn2 = threading.Event()  # throttles user thread
syn.clear()
syn2.clear()
stopall = False           # for cleanup

# Thread permits a while loop inside mydraw
class MyThread ( threading.Thread ):
   def __init__(self,brush,gc):
       self.win = brush
       self.dgc = gc
       threading.Thread.__init__(self)
   def run ( self ):
       global mydraw
       mydraw(self.win,self.dgc)   


def area_expose_cb(area, event):
    global mainloop, eehandler;
    my = MyThread(dbuf,gc1)
    my.start()             # start student thread, which calls mydraw
    area.handler_block(eehandler)  # prevent restart when window moved.    
    mainloop(area.window)  # sxxtart main animation refresh cycle
    return True

# get ready for expose event
eehandler = area.connect("expose_event", area_expose_cb)


# animation refresh control loop:
def mainloop(brush):
    if not stopall:
        syn.wait()  # wait for permission to refresh screen
        syn.clear() # reset for next round
        brush.draw_drawable(gc0,dbuf,0,0,0,0,width,height) # refresh
        syn2.set()   # informs user thread to goto next iteration
        eid = gobject.timeout_add(delaytime, mainloop, brush) # reschedule
        return False
# end mainloop

def updateDisplay():
    syn.set()         # release mainloop to refresh screen
    syn2.wait()       # synch with mainloop before looping again
    syn2.clear()      # reset for next round
# end updateDisplay

def cleanup():
    global stopall
    stopall = True
    syn.set()
    syn2.set()
# end cleanup


##########################################################################

def drawcircle(brush,gc,x,y,radius,fill):
    brush.draw_arc(gc,fill,x-radius,y-radius,2*radius,2*radius,0,360*64)
def drawcircle(brush,x,y,radius,fill):
    brush.draw_arc(gc1,fill,x-radius,y-radius,2*radius,2*radius,0,360*64)

# distance:
def dist(x1,y1,x2,y2):
   dx = x1-x2
   dy = y1-y2
   return (dx*dx + dy*dy)**0.5

# make sure coordinates stay within width, height:
def inbounds(x,y):
    if (x<15): x = width-15
    if (x>(width-15)): x = 15
    if (y<15): y = height-15
    if (y>height-15): y = 15
    return (x,y)     # return the tuple x,y
# end inbounds

# main animation procedure MUST be called mydraw

#################### YOUR CODE GOES HERE ######################
def mydraw(brush,gc):
    x = 80  # center coordinates
    y = 200
    scale = 100  # size

    while x<=width:
       gc.set_foreground(white)   # sets drawing color
       brush.draw_rectangle(gc,True,0,0,width,height)  # clear background
       gc.set_foreground(blue)
       brush.draw_line(gc,x,y-scale,x-scale,y)  # upper left
       brush.draw_line(gc,x-scale,y,x,y+scale)  # lower left
       brush.draw_line(gc,x,y+scale,x+scale,y)  # lower right
       brush.draw_line(gc,x+scale,y,x,y-scale)  # upper right

       x = x+10
       scale = scale-10
       updateDisplay()  # show animation frame (call at end of while loop)
    #end animation loop
    cleanup()   # should be called after end of all animation
# end mydraw

##########################################################################
# The following line must be the last line in the program
gtk.main()