Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder1.news.weretis.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed4a.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.015 X-Spam-Evidence: '*H*': 0.97; '*S*': 0.00; '21,': 0.07; 'correct.': 0.07; '22,': 0.09; 'callback': 0.09; 'chunk': 0.09; 'e.g.,': 0.09; 'terminates': 0.09; 'cc:addr:python-list': 0.11; 'gui': 0.12; 'closed,': 0.16; 'expects': 0.16; 'somewhere.': 0.16; 'uncommon': 0.16; 'thanks,': 0.17; 'wrote:': 0.18; 'feb': 0.22; 'cc:addr:python.org': 0.22; 'cc:2**0': 0.24; 'header:In-Reply- To:1': 0.27; 'chris': 0.29; 'am,': 0.29; "i'm": 0.30; 'program,': 0.31; 'code': 0.31; 'breaking': 0.31; 'information?': 0.31; 'but': 0.35; 'received:google.com': 0.35; 'returning': 0.36; 'done': 0.36; 'charset:us-ascii': 0.36; 'message-id:@gmail.com': 0.38; 'window': 0.38; 'handle': 0.38; 'little': 0.38; 'how': 0.40; 'most': 0.60; 'simple': 0.61; "you're": 0.61; 'making': 0.63; 'header:Message-Id:1': 0.63; 'to:addr:gmail.com': 0.65; 'close': 0.67; 'subject:Design': 0.78; '2015': 0.84; 'everything.': 0.84; 'subject:thought': 0.84 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=content-type:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=fCBBiEPLKJbS+AjVWfZtmMkKHREdAoYF3JKg8J3RMjU=; b=MlfMi4ghIN9nVHw3DbrRWsKsIYzyndhJYqn1zVAfl94IoaZgmVLdJgNOTb/kfQ6Ddd /7I+0/0aw/SVyzZ/kxiYy28lii1IztSp2pJRqTmjuOZo+OccUJPs69ykHJ83g+E8Hvcz Y+iizv7oQYh+G/B55Bn3QkAE2S4bL4oClslc8DkTPrE8C8qzIyTGcGQN0PKMJEplYadX TQSKsyowaIN4wgoNxFVlhr1uydGxpfUzFlgLgnK1ikVXn0n3PEejaR/fgGMOkRg2Rgfw 614AUddOz7QAf3R6qZ3CbZ1isGfhPpxrjBUkzZIWsHJWSYnpjXah01peAu9MWh6C1QHw 2LkQ== X-Received: by 10.52.181.33 with SMTP id dt1mr6240948vdc.42.1424606839590; Sun, 22 Feb 2015 04:07:19 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 6.6 \(1510\)) Subject: Re: Design thought for callbacks From: Cem Karan In-Reply-To: Date: Sun, 22 Feb 2015 07:07:17 -0500 Content-Transfer-Encoding: quoted-printable References: <33677AE8-B2FA-49F9-9304-C8D93784255D@gmail.com> <39813568-6DB8-4341-A130-C256CFF352EE@gmail.com> To: Chris Angelico X-Mailer: Apple Mail (2.1510) Cc: "comp.lang.python" X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 25 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1424606842 news.xs4all.nl 2884 [2001:888:2000:d::a6]:52107 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:86100 On Feb 21, 2015, at 10:55 AM, Chris Angelico wrote: > On Sun, Feb 22, 2015 at 2:45 AM, Cem Karan wrote: >> OK, so if I'm reading your code correctly, you're breaking the cycle = in your object graph by making the GUI the owner of the callback, = correct? No other chunk of code has a reference to the callback, = correct? >=20 > Correct. The GUI engine ultimately owns everything. Of course, this is > a very simple case (imagine a little notification popup; you don't > care about it, you don't need to know when it's been closed, the only > event on it is "hit Close to destroy the window"), and most usage > would have other complications, but it's not uncommon for me to build > a GUI program that leaves everything owned by the GUI engine. > Everything is done through callbacks. Destroy a window, clean up its > callbacks. The main window will have an "on-deletion" callback that > terminates the program, perhaps. It's pretty straight-forward. How do you handle returning information? E.g., the user types in a = number and expects that to update the internal state of your code = somewhere. Thanks, Cem Karan=