wow, that's excellent, thanks so much. I haven't got a clue how lambda functions work, but they seem pretty useful, so I'll try to figure them out.
----- Original Message ----- From: Kent Johnson <ken...@tds.net> Date: Thursday, January 15, 2009 10:24 pm Subject: Re: [Tutor] tkinter canvas > On Thu, Jan 15, 2009 at 12:41 AM, Mr Gerard Kelly > <s4027...@student.uq.edu.au> wrote: > > > I want to be able to bind these boxes to an event - so that I can > either> click on them, or hold the mouse cursor over them, and have > them change > > color. > > Here is a version of your program that binds the Enter and Leave > events to each box and changes the box color when the mouse is over > it: > > ######################### > > from Tkinter import * > > master = Tk() > > numboxes=6 > > width=40*(numboxes+2) > height=200 > w = Canvas(master, width=width, height=height) > w.pack() > > size=width/(numboxes+2) > > box=[0]*numboxes > > def enter(e, i): > e.widget.itemconfigure(box[i], fill='red') > > def leave(e, i): > e.widget.itemconfigure(box[i], fill='blue') > > for i in range(numboxes): > box[i]=w.create_rectangle((1+i)*40, 40, (2+i)*40, height-40, > fill="blue") w.tag_bind(box[i], '<Enter>', lambda e, i=i: > enter(e, i)) > w.tag_bind(box[i], '<Leave>', lambda e, i=i: leave(e, i)) > > mainloop() > > ####################### > > The 'i=i' in the lambda is needed due to the (surprising) way that > variables are bound to closures; without it, every event would be > bound to the same value of i. Some explanation here: > http://code.activestate.com/recipes/502271/ > > Kent > _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
