From: Hidetoshi NAGAI <nagai@...>
Date: 2004-12-04T12:36:14+09:00
Subject: Re: hide/show items on TkCanvas?

Hi, 

From: "R. Mark Volkmann" <mark@ociweb.com>
Subject: hide/show items on TkCanvas?
Date: Sat, 4 Dec 2004 11:11:28 +0900
Message-ID: <039d01c4d9a6$8e9e8b10$0200a8c0@MarkDesktop>
> If I have an item on a TkCanvas such as a Rectangle, is there a way to hide 
> it temporarily and then show it later?
> Hopefully I don't have to delete it and recreate it later. 

Probably, the simplest way is to move the item to out of 
the canvas's scrollregion. 
For exampke, when the scrollregion of the canvas is 
(min_x, min_y, max_x, max_y), you can hide the item by 
item.move(-(max_x - min_x), -(max_y - min_y)) and show 
it by item.move(max_x - min_x, max_y - min_y). 
Of course, if the part of the item exists on the out of 
the scrollregion, you never forget the out_of_range part 
when decide the moving delta. 
Then, bbox method (and canvas tags) may be useful.
-- 
Hidetoshi NAGAI (nagai@ai.kyutech.ac.jp)