November 1999
Intermediate to advanced
832 pages
19h 28m
English
Content preview from Practical Programming in Tcl & Tk, Third EditionBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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Animation with the update Command
Suppose you want to entertain your user while your application is busy. By default, the user interface hangs until your processing completes. Even if you change a label or entry widget in the middle of processing, the updates to that widget are deferred until an idle moment. The user does not see your feedback, and the window is not refreshed if it gets obscured and uncovered. The solution is to use the update command that forces Tk to go through its event loop and update the display.
The next example shows a Feedback procedure that displays status messages. A read-only entry widget displays the messages, and the update command ensures that the user sees each new message. An entry widget is used because it won't ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.