'''
Based on
https://stackoverflow.com/questions/17915440/python-tkinter-save-canvas-as-image-using-pil
Simple scribble program
'''

try:
  # Python 3
  import tkinter
except ImportError:
  # Python 2
  import Tkinter
  tkinter = Tkinter

def ImageGenerator(parent):
  global b1
  b1 = "up"
  drawing_area=tkinter.Canvas(parent,width=250,height=200)
  drawing_area.pack()
  drawing_area.bind("<Motion>", motion)
  drawing_area.bind("<ButtonPress-1>", b1down)
  drawing_area.bind("<ButtonRelease-1>", b1up)

def b1down(event):
  global b1
  b1 = "down"

def b1up(event):
  global b1
  b1 = "up"

def motion(event):
  global b1, xold, yold

  if b1 == "down":
    event.widget.create_line(xold,yold,event.x,event.y,width=3,fill='blue')

  xold = event.x
  yold = event.y

if __name__ == "__main__":
    root=tkinter.Tk()
    root.wm_title("Image Demo")
    root.config(bg='white')
    ImageGenerator(root)
    root.mainloop()