Tkinter.Canvas.create_line.coords

[Arnd Baecker]

Hi,

I have a question concerning modifying a line created
within a Canvas:

It boils down to that (for `plot`  being a Canvas)
    self.plot.coords(self.line,10,0,10,10,80,100,100,200)
works, whereas
    liste=[10,0,10,10,80,100,100,200]
    self.plot.coords(self.line,liste)
raises the error:
    self.tk.splitlist(
    TclError: bad screen distance "[10,"
((Maybe the example below more clearly demonstrates what I mean here.))

Actually, help(Tkinter.Canvas.coords) gives
  coords(self, *args) unbound Tkinter.Canvas method
      Return a list of coordinates for the item given in ARGS.
which seems to me a bit different from the description on page 14
given in the "Tkinter reference: A GUI for Python"
(John Shipman, New Mexico Tech Computer Center), which says
that you can do the above as well, i.e. passing a new set of
coordinates. Alternative reference for this:
http://www.pythonware.com/library/tkinter/introduction/canvas-line.htm


Is there a different method I should use to change the coordinates?
  ((More background: For a <B1-Motion> event for the above line
    I want to change its points according to the mouse position,
    so deleting and recreating the object does not work
    for a continuous change.
    Also I need around 100-300 points in my application.))


Any help is appreciated!

Arnd



##### sample programm:


"""
Click on the "Action" button to reveal the problem
"""

from Tkinter import *


class Test(Frame):
    def __init__(self, master=None):
	Frame.__init__(self, master)
	Pack.config(self)
	self.createWidgets()

    def action_(self):
        print "action"
        self.plot.coords(self.line,10,0,10,10,80,100,100,200)

    def action(self):
        print "action2, This one fails:"
        liste=[10,0,10,10,80,100,100,200]
        self.plot.coords(self.line,liste)

    def createWidgets(self):
	self.QUIT = Button(self, text='QUIT', foreground='red',
			   command=self.quit)

	self.Action = Button(self, text='Action', foreground='red',
			   command=self.action)
        self.plot=Canvas(self, width="5i", height="5i")
        liste=[0,0,10,10,80,150,200,200]
        self.line=self.plot.create_line(liste)

	self.plot.pack(side=TOP)
	self.QUIT.pack(side=LEFT, fill=BOTH)
	self.Action.pack(side=LEFT, fill=BOTH)

test = Test()
test.mainloop()