Mailman 3 June 2005 - Tkinter-discuss

canvas.create_image
by Todd Lericos June 30, 2005

June 30, 2005

Hello all, I'm new to the list and to Python. It has been tough going, but alot of fun. Here is my problem. I am trying to display an image on canvas. I was searching to the list for similar problems. It does seem to be a common problem. I tried many of the suggested fixes. For example, heading off garbage collection of the image...etc. No dice. Can someone take a look at the code and let me know if they see any pitfalls I am stepping in. Thanks in advance for any help rendered. Todd P.S. Please not the program in not complete yet. Thus some variables passed to MakeGui go nowhere. I know this already. #!/usr/local/python/bin/python import os, sys, string import pickle, time from Tkinter import * import Image class MakeGui: def __init__(self, tooltitle, filedir, filetype, plotelem, filelist): self.row = 0 # Creating the Window and Row/Column stuff self.root = root = Tk() root.minsize(300,200) root.rowconfigure(0, weight=1) root.columnconfigure(0,weight=1) root.columnconfigure(1,weight=2) # Creating the Title Label Label(root, text=tooltitle, font='bold').grid(columnspan=2) self.row = self.row + 1 #Create the Canvas self.tfile = filedir + 'image.' + filetype print self.tfile self.Image = PhotoImage(file = self.tfile) self.canvas = Canvas(root, width=508, height=509) self.canvas.create_image(250, 250, image = self.Image) self.canvas.grid(columnspan=2) self.row = self.row + 1 tooltitle = 'Lightning Climatology Viewer' filedir = '/data/local/ltgdata/images/' filetype = 'gif' plotelem = ['500mb Map','Lightning Z','Lightning FWZ','Month Stats'] filelist =[("Type 1", "U01"), ("Type 2", "U02"), ("Type 3", "U03"), ("Type 4", "U04"), ("Type 5", "U05"), ("Type 6", "U06"), ("Type 7", "U07"), ("Type 8", "U08"), ("Type 9", "U09"), ("Type 10", "U10"), ("Type 11", "U11"), ("Type 12", "U12"), ("Type 13", "U13"), ] MakeGui(tooltitle, filedir, filetype, plotelem, filelist) mainloop()

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Help: _tkinter.createfilehandler not supported for threaded Tcl
by Michael Lange June 22, 2005

June 22, 2005

Hello list, the following error happened on a program I wrote that uses tkinter.createfilehandler() to catch the output of a shell command on someone else's box (for me it runs fine): Exception in Tkinter callback Traceback (most recent call last): File "/usr/lib/python2.4/lib-tk/Tkinter.py", line 1345, in __call__ return self.func(*args) File "/usr/local/bin/pyfloppy", line 293, in start self.format() File "/usr/local/bin/pyfloppy", line 303, in format self.mkfilehandler(self.pp, self.get_msg) File "/usr/local/bin/pyfloppy", line 379, in mkfilehandler tkinter.createfilehandler(fileobject, READABLE, function) RuntimeError: _tkinter.createfilehandler not supported for threaded Tcl When I googled for the traceback one of the results said: > If your Tcl installation is threaded, you should use > tkapp.createfilehandler instead. however (on my box) I cannot find tkapp anywhere (or should it be _tkinter.tkapp ?). Any help would be greatly appreciated. Thanks in advance Michael

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Zen of Learning Tkinter or any other type of technology out there for that matter
by Harlin Seritt June 17, 2005

June 17, 2005

Hi William, True, you can get some rather curt answers on some of these lists -- try not to take these sort of things too personally but rather take what you need from it and discard the rest. If you fight back, no doubt you'll get a flame going or --most likely-- you'll get ignored and almost certainly no one will help you again. So, in short, you can't control what others do -- in life or online. Now onto Tkinter... My advice to you as far as really getting into Tkinter and understanding how it all works is for you to take a look at Frederik Lundh's fine tutorial and reference here: http://www.pythonware.com/library/tkinter/introduction/. This was more than adequate to get me up and running about 2 years ago. Once you get an idea of the basic framework of how Tkinter works, you may begin to think like I do: How come other GUI toolkits (simple ones like Java Swing, .NET et al) are not organized and thought out in the same fashion? I'll give you an example of what I mean. Tkinter GUI construction is based on a few components that you'll see over and over: Widget classes themselves: Ex: Button, Label, Entry Widget options: Ex: bordersize, relief, text, etc. Widget methods: Ex: config(), after(), etc. Also there are other components to consider: Placing widgets: You'll find these three methods are all you'll need for layout... pack(): the most difficult perhaps but gives you the most flexibility ... certainly easier than using most of Java Swing layouts ;-) grid(): allows one to place widgets in a grid place(): if you insist on having total control of placement then use this. Note that it won't look near as good as pack() if your user tries to expand your app. Custom events (bind()): Most of the Tkinter widgets will have their own default events but by designing your own you'll find that you can have an almost infinite arrangement of events. Window protocols: These allow you to manipulate the windows almost like MFC or X/Motif (well, at least to me!) Tkinter constants: As 'constant' implies, there are many pre-designed constants that allow one to use very plain language to describe a widget's option or set variables that correspond to widget values. And there are quite a few others, but I'll let you discover them on your own ;-). You'll find that you don't have to have a lot of underlying GUI framework knowledge (for your particular platform) to pull off a great-looking GUI app in just a few minutes! After you're done with Mr. Lundh's fine tutorial, I suggest you go buy John Grayson's Python_and_Tkinter_Programming book from Manning publications (you can get it here: http://www.manning.com/books/grayson). It is almost 700 pages of pure Tkinter code. If I'm not mistaken, these days you can actually buy it in PDF format! Some of it is intermediate and advanced, so I advise you to look hard at the aforementioned tutorial and post your questions as well on comp.lang.python newsgroup before really diving in. You'll find that you'll get help from a lot of different Tkinter pros there -- even from the effbot himself (Frederik). An extra note... in the John Grayson book in the preface, John mentions that he is an avid martial arts disciple. In it one of his teachers mentions to him and other students that there are a few concepts that might not be taught directly. The master tells them a lot of times you'll have to STEAL these concepts from me. And so, you must do that occasionally. Google is your friend, as the saying goes. Google as much as possible. Read books. Ask many many questions in the right places while ignoring flames when appropriate but always learn from what tidbits you'll be given from these people. Technologists are only too happy to show how much they know even if they intend to mildly insult you. Steal their knowledge whenever possible. Sorry for all the zen but hopefully this helps you. Good luck, Harlin Seritt tkinter-discuss-request(a)python.org wrote: Send Tkinter-discuss mailing list submissions to tkinter-discuss(a)python.org To subscribe or unsubscribe via the World Wide Web, visit http://mail.python.org/mailman/listinfo/tkinter-discuss or, via email, send a message with subject or body 'help' to tkinter-discuss-request(a)python.org You can reach the person managing the list at tkinter-discuss-owner(a)python.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Tkinter-discuss digest..." Today's Topics: 1. Re: First Tkinter program (William O'Higgins) 2. Re: First Tkinter program (Jeff Epler) ---------------------------------------------------------------------- Message: 1 Date: Thu, 16 Jun 2005 09:45:29 -0400 From: William O'Higgins Subject: Re: [Tkinter-discuss] First Tkinter program To: tk Message-ID: <20050616134529.GA7948(a)sillyrabbi.dyndns.org> Content-Type: text/plain; charset="us-ascii" On Wed, Jun 15, 2005 at 01:35:38PM -0600, Stewart Midwinter wrote: >William, you sound like a candidate for one of the many introductions >to Tkinter that are available. You found this list, so that's a >start. Now you could try visiting the Tkinter wiki and take a look >at some of the resources available there. It's at >http://tkinter.unpy.net/wiki/ I have been to the wiki, but like all wikis, it is incomplete, the widgets I need more explanation of are not covered (listbox for example) and the recipes are overspecialized. The links to other resources are the same as those on python.org, which I have exhausted before contacting this list. >Unless what you are asking is for someone to write some widgets for >you, No, what I need is some explanatory help on what the structures inherent in Tkinter code *mean*. >there is no alternative to investing some time to learn the >basics of Tkinter. Otherwise you will flail around endlessly and in >the end spend more time than if you had devoted a minimal amount of >time to educating yourself. Thank you for flip assessment of the time I've spent, but you have no idea what I've done before contacting the list (which is partly my fault for not explaining my work to date). I would think that on a list with as little volume as this one you might be more polite. Now, perhaps someone else could contribute - here's what I need: Is there a reason that all the example programs I've seen start by defining a class for the actions, which has an __init__ function that refers to "self" all over the place, then creates an instance of a Tk() object, and then calls the class for the actions on (with?) the new Tk()instance? None of the examples seem to code in a straight line, and I'm having trouble following the progression of the "simple" examples. Can Tkinter programs been developed in a flat structure, without the class within class stuff that's hindering my understanding? Thanks. -- yours, William

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Re: [Tkinter-discuss] First Tkinter program
by William O'Higgins June 16, 2005

June 16, 2005

On Wed, Jun 15, 2005 at 01:35:38PM -0600, Stewart Midwinter wrote: >William, you sound like a candidate for one of the many introductions >to Tkinter that are available. You found this list, so that's a >start. Now you could try visiting the Tkinter wiki and take a look >at some of the resources available there. It's at >http://tkinter.unpy.net/wiki/ I have been to the wiki, but like all wikis, it is incomplete, the widgets I need more explanation of are not covered (listbox for example) and the recipes are overspecialized. The links to other resources are the same as those on python.org, which I have exhausted before contacting this list. >Unless what you are asking is for someone to write some widgets for >you, No, what I need is some explanatory help on what the structures inherent in Tkinter code *mean*. >there is no alternative to investing some time to learn the >basics of Tkinter. Otherwise you will flail around endlessly and in >the end spend more time than if you had devoted a minimal amount of >time to educating yourself. Thank you for flip assessment of the time I've spent, but you have no idea what I've done before contacting the list (which is partly my fault for not explaining my work to date). I would think that on a list with as little volume as this one you might be more polite. Now, perhaps someone else could contribute - here's what I need: Is there a reason that all the example programs I've seen start by defining a class for the actions, which has an __init__ function that refers to "self" all over the place, then creates an instance of a Tk() object, and then calls the class for the actions on (with?) the new Tk()instance? None of the examples seem to code in a straight line, and I'm having trouble following the progression of the "simple" examples. Can Tkinter programs been developed in a flat structure, without the class within class stuff that's hindering my understanding? Thanks. -- yours, William

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Fwd: First Tkinter program
by Stewart Midwinter June 15, 2005

June 15, 2005

William, you sound like a candidate for one of the many introductions to Tkinter that are available. You found this list, so that's a start. Now you could try visiting the Tkinter wiki and take a look at some of the resources available there. It's at http://tkinter.unpy.net/wiki/ Unless what you are asking is for someone to write some widgets for you, there is no alternative to investing some time to learn the basics of Tkinter. Otherwise you will flail around endlessly and in the end spend more time than if you had devoted a minimal amount of time to educating yourself. cheers S -- Stewart Midwinter stewart(a)midwinter.ca stewart.midwinter(a)gmail.com Skype: midtoad

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First Tkinter program
by William O'Higgins June 15, 2005

June 15, 2005

I am just starting out with Python, in hopes of getting my head around OO programming. I am running into trouble figuring out how to structure a GUI front-end for a simple program. Here's the general visual structure: Listbox populated by a list Some number of textentry and textarea pairs (five? or from a list?) Button one - says "Next" and it stores the contents of the textentry and textarea pairs (in a dictionary tied to the list entry seems natural), and then clears the interface to allow more entries Button two - "Done" - stores the contents of the textentry and textarea pairs and then closes the window. That's really it - very simple, but too much for me - I haven't even written a list box test that actually works - I do not understand OO well enough to make sense of examples (I don't really get what a constructor does, or understand the interactions of classes and instances of TKinter objects). The underlying functionality is easy - I can write it to use the command line or text files no problem - but the interface i giving me fits. Any pointers would be welcome. Thanks. -- yours, William

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tkinter and threading
by Greg Lee June 7, 2005

June 7, 2005

Are Tkinter callbacks run in separate threads? Do I need to use threading locks to protect data shared between callbacks that can run at the same time? I'm running Python 2.3 and Tkinter on Windows. I have two callbacks: cb_close and cb_run. cb_close cleans up, then uses Tkinter.Toplevel.destroy; it is bound to WM_DELETE_WINDOW via Tkinter.Toplevel.protocol. cb_run uses a COM component to perform a lengthy operation. The COM component calls back to the Python world often enough that I can keep my GUI responsive using Tkinter.Toplevel.update. Bad things happen if I allow cb_close to call destroy while cb_run is in progress: cb_run eventually asks the Tkinter world to post a completion dialog. To keep this from happening I use a state variable to tell cb_close that it should not call destroy if cb_run is in progress and to tell cb_run that it should not execute if a cb_close is in progress. I can definitely get cb_close to run at the same time as cb_run, which suggests that the Tkinter eventloop executes its callbacks in separate threads. All this lead me to use a lock to protect read/write of the state variable. Was this necessary? Is there something in the way that Tkinter handles callbacks that automatically protects shared data structures? -------------------------------------------- Greg Lee / Pharsight Corporation / Suite 200 800 W El Camino / Mountain View CA 94040 voice: 650-314-3860 / fax: 650-314-3810 This email message (including any attachments) is for the sole use of the intended recipient and may contain confidential and proprietary information. Any disclosure or distribution to third parties that is not specifically authorized by the sender is prohibited. If you are not the intended recipient, please contact the sender (greg(a)pharsight.com) by reply email and destroy all copies of the original message. Thank you.

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Re: [Tkinter-discuss] gui/thread issues
by Mark English June 7, 2005

June 7, 2005

> Date: Mon, 23 May 2005 14:25:04 -0400 > From: Perry Greenfield <perry(a)stsci.edu> > I think the problem is that, by and large, almost all uses of GUIs > are centered on their being standalone applications and thus > little thought is given to having a command line coexisting > with the GUI. > Our needs are pretty atypical in this regard. Count me in as another atypical user. I've had additional problems running through a plain Python interpreter if I don't use the main process thread as the main GUI thread on Windows XP. Typically the program will simply crash at some point. I'd like to be able to just import a module and call a function to run its GUI and still be able to continue at the command prompt. I suspect if I understood Tkinter better I could make this problem go away, which makes it all the more frustrating. When I have the time I'll try to create a simple test case and post it. Regards, Mark ----------------------------------------------------------------------- The information contained in this e-mail is confidential and solely for the intended addressee(s). Unauthorised reproduction, disclosure, modification, and/or distribution of this email may be unlawful. If you have received this email in error, please notify the sender immediately and delete it from your system. The views expressed in this message do not necessarily reflect those of LIFFE Holdings Plc or any of its subsidiary companies. -----------------------------------------------------------------------

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tk 8.3 and unicode
by Martin Franklin June 1, 2005

June 1, 2005

Hi all, Another possibly silly question..... My prodcution machines are stuck at python2.2 and tk 8.3 and *I* have a problem with the following code:- import codecs import Tkinter root=Tkinter.Tk() var = Tkinter.StringVar() e = Tkinter.Entry(root, textvariable=var) e.pack() var.set(u"\xa3 \xa3") #~ f = codecs.open("ce.tst", "w", "utf-8") #~ f.write(var.get()) #~ f.close() print repr(var.get()) root.mainloop() The GUI shows up and is correct, however when I un-comment the three save to file lines it fails with: UnicodeError: ASCII decoding error: ordinal not in range(128) Indeed when I look at the printed output from the code is shows:- '\xc2\xa3 \xc2\xa3' rather than what I put into that variable..... I assume this is a feature of tk 8.3 - i've tested on py2.3+tk8.4 and py2.4+tk8.5 and both those version *just work* is there any get around? Cheers Martin

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