Initial revision

Demo/tkinter/guido/electrons.py

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+#!/ufs/guido/bin/sgi/tkpython
+# Simulate "electrons" migrating across the screen.  
+# An optional bitmap file in can be in the background.
+#
+# Usage: electrons [n [bitmapfile]]
+#
+# n is the number of electrons to animate; default is 4, maximum 15.
+#
+# The bitmap file can be any X11 bitmap file (look in
+# /usr/include/X11/bitmaps for samples); it is displayed as the
+# background of the animation.  Default is no bitmap.
+
+# This uses Steen Lumholt's Tk interface
+from Tkinter import *
+
+
+
+# The graphical interface
+class Electrons:
+
+	# Create our objects
+	def __init__(self, n, bitmap = None):
+		self.n = n
+		self.tk = tk = Tk()
+		self.canvas = c = Canvas(tk)
+		c.pack()
+		width, height = tk.getint(c['width']), tk.getint(c['height'])
+
+		# Add background bitmap
+		if bitmap:
+			self.bitmap = c.create_bitmap(width/2, height/2,
+						      {'bitmap': bitmap,
+						       'foreground': 'blue'})
+
+		self.pieces = {}
+		x1, y1, x2, y2 = 10,70,14,74
+		for i in range(n,0,-1):
+			p = c.create_oval(x1, y1, x2, y2,
+					       {'fill': 'red'})
+			self.pieces[i] = p
+			y1, y2 = y1 +2, y2 + 2
+		self.tk.update()
+
+	def random_move(self,n):
+		for i in range(1,n+1):
+			p = self.pieces[i]
+			c = self.canvas
+			import rand
+			x = rand.choice(range(-2,4))
+			y = rand.choice(range(-3,4))
+			c.move(p, x, y)
+		self.tk.update()
+	# Run -- never returns
+	def run(self):
+		while 1:
+			self.random_move(self.n)
+		self.tk.mainloop() # Hang around...
+
+# Main program
+def main():
+	import sys, string
+
+	# First argument is number of pegs, default 4
+	if sys.argv[1:]:
+		n = string.atoi(sys.argv[1])
+	else:
+		n = 30
+
+	# Second argument is bitmap file, default none
+	if sys.argv[2:]:
+		bitmap = sys.argv[2]
+		# Reverse meaning of leading '@' compared to Tk
+		if bitmap[0] == '@': bitmap = bitmap[1:]
+		else: bitmap = '@' + bitmap
+	else:
+		bitmap = None
+
+	# Create the graphical objects...
+	h = Electrons(n, bitmap)
+
+	# ...and run!
+	h.run()
+
+
+# Call main when run as script
+if __name__ == '__main__':
+	main()
+
+