#!/usr/local/bin/python
##
#   Brian's Theme
#   -------------
#   This version copyright (c) 1996-1998 by Lachlan Patrick.
#   Written using GraphApp.
# 
#   This is a complex example not for beginners. It makes use of
#   the timer functions, colour, windows and keyboard call-backs.
#   It also uses a lot of global variables, which is not really
#   the "Python way", but I've left this the same as in the
#   C language version, for comparison.
##

from graphapp import *

import os
import sys
import string
import time
import random

##
#   Global variables.
##
width = 400
height = 240
banner_height = 40
banner = "0-9 to change the step size, Q to stop, R,G,B,C,M,Y,K for colours."

win = None

step_size = 3
step_location = 0

origin = pt(0,0)

colour = Blue

##
#   Functions.
##

def rand(max):
	return int(random.random() * max)

def change_location():
	global origin, width, height, step_location

	origin.x = rand(width)
	origin.y = rand(height)
	step_location = 0

def handle_mouse(w, buttons, xy):
	global origin, step_location, win

	origin = xy
	step_location = 0
	redraw(win)

def handle_keydown(w, key):
	global step_size, colour

	if (key in string.digits):
		step_size = ord(key) - ord('0')
	elif ((key == 'q') or (key == 'Q') or (key == ESC)):
		exitapp()
	else:
		key = string.lower(key)
		if   (key == 'r'):	colour = Red
		elif (key == 'g'):	colour = Green
		elif (key == 'b'):	colour = Blue
		elif (key == 'c'):	colour = Cyan
		elif (key == 'm'):	colour = Magenta
		elif (key == 'y'):	colour = Yellow
		elif (key == 'k'):	colour = Black

def draw_window(w, r):
	global banner_height, height, banner

	if (banner_height > 0):
		r.y = height
		r.height = banner_height
		setcolour(Black)
		drawtext(r, Center + VCenter, banner)

def resize_window(w, r):
	global banner_height, width, height

	banner_height = 2*getheight(SystemFont)+8

	if (r.height < 4*banner_height):   # too small for banner
		banner_height = 0

	height = r.height - banner_height
	width = r.width

	change_location()

## create and display the window
def init_window():
	global win, banner_height, width, height

	banner_height = getheight(SystemFont)*2+8

	win = newwindow("Brian's Theme",
			rect(0,0,width,height+banner_height),
			StandardWindow | Centered )
	setmouseup(win, handle_mouse)
	setkeydown(win, handle_keydown)
	setredraw(win, draw_window)
	setresize(win, resize_window)
	show(win)

def draw_and_step(data):
	global win, colour, origin, step_location, step_size, width, height

	drawto(win)
	setcolour(colour)

	if (step_location <= height):
		drawline(origin, pt(0, height-step_location))
		drawline(origin, pt(width, step_location))
	if (step_location <= width):
		drawline(origin, pt(step_location, 0))
		drawline(origin, pt(width-step_location, height))

	step_location = step_location + step_size

	if ((step_location > width+100) and (step_location > height+100)):
		change_location()
		redraw(win)

def main():
	initapp(0,0)
	init_window()
	settimerfn(draw_and_step, None)
	settimer(80)
	mainloop()

main()