Mailman 3 November 2013 - Tkinter-discuss

Control position of Tkinter common dialogs?
by python＠bdurham.com Dec. 9, 2016

Dec. 9, 2016

Python 2.7 under Windows: How can we control the position of Tkinter's common dialogs? Here's what we've discovered: * Certain common dialogs always open up relative to their parent window * Certain common dialogs always open up centered on the user's desktop * All common dialogs appear to ignore the optional parent= parameter Questions: * How can we force a dialog to open up relative to its parent window? * How can we force a dialog to open up centered on the user's desktop? Background: import tkColorChooser as colorchooser import tkFileDialog as filedialog import tkMessageBox as messagebox # always open up relative to parent windows fileOpen = filedialog.askopenfilename() fileOpens = filedialog.askopenfilenames() fileSaveAs = filedialog.asksaveasfilename() color = colorchooser.askcolor() # always open up centered on desktop folderOpen = filedialog.askdirectory() messagebox.askquestion() Malcolm

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tkinter: screenmmwidth
by Josef Gabriel Nov. 28, 2013

Nov. 28, 2013

I am not very familiar with the tkinter source code, please bear with me. I am using Windows7 Sp1 and python 2.7 on a laptop with no attached display. The screen specifications are 280 mm. The screen physically measures 275 mm. The screen EDID states 280 mm as well. winfo_screenmmwidth reports 361 mm. Where does tkinter extract the winfo_screenmmwidth information? I assume this is through the pywin32 api, but I don't know. I seem to have run into a dead end because I cannot view the _tkinter module. I assume the _tkinter module uses the pywin32 api, but I'm not sure where it's getting the information. I plan on using this data to calculate the pixels per centimeter (ppcm) for a gui I am writing. I have written a function to extract the extended display identification data (EDID) information from the windows registry. Is there anything wroing with this method? Thank you in advance.

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Using tkinter::ttk::treeview to implement data view
by Davnobezimeni Sasha Balagura Nov. 23, 2013

Nov. 23, 2013

Hello. I have to implement parcer on Python 3.3 for .txt file with special formating. There are a lot of data to display, modify, add. I decided to use tkinter::ttk:treeviev for this. And it really good one, very fast and good looking..but.. But I cant set borders between cells, like in Excel. Is it real at all for this widget? Or i've just overlooked something? Best regards, Alex

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Get value instead of PY_VAR
by Kevin Walzer Nov. 15, 2013

Nov. 15, 2013

I'm going around in circles trying to serialize some app configuration data in my Tkinter app via pickle, and I'd appreciate some help. I set various app configurations via checkboxes and StringVar(). Sometimes the value of one of the checkboxes is lost and when I try to print the value, I get PY_VAR#2 instead. Here's a relevant snippet setting the values: self.copytext= StringVar() self.copytext.set(self.defaults['copytext']) self.whoischeck = Tile.Checkbutton(self.whoisframe, variable=self.whois, text='Display Raw Whois Output') And here's the snippet that retrieves the value: self.defaults['copytext'] = self.copytext Using this call, printing the value of self.defaults['copytext'] results in PY_VAR#2, which doesn't actually retain the value of the var I'm setting (1 or 0). It also results in a error when I try to serialize the data, because pickle can't handle this type of data: Can't pickle 'tkapp' object: <tkapp object at 0x01FCB090> I can actually get the correct value if I change one call as follows: self.defaults['copytext'] = self.copytext.get() But then, trying to pickle this value, I get this error: 'str' object has no attribute 'get' What's the right way in Tkinter to get the value of a StringVar() from a checkbutton, and then serialize the value via pickle? Sometimes I can get this to work, but I don't understand the underlying dynamics of it; the intersection of Python objects and Tcl variables gives me headaches. I am especially unclear why I get PY_VAR rather than the value in some instances, but not others. Thanks, Kevin -- Kevin Walzer Code by Kevin/Mobile Code by Kevin http://www.codebykevin.com http://www.wtmobilesoftware.com

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Force Frame to resize after removing all widgets.
by Carlos Zuniga Nov. 13, 2013

Nov. 13, 2013

Hi, I have a problem with frames. If I remove a widget, it resizes to fit the remaining widgets, but if I remove all of them then the frame doesn't resize at all (in this case, the window is not resizable by the user). Here's a small example showing this: import Tkinter import ttk root = Tkinter.Tk() root.resizable(False, False) frame = ttk.Frame(root) frame.grid() #sep = ttk.Separator(frame) #sep.grid() labels = [] for i in range(5): l = ttk.Label(frame, text='label %d' % i) labels.append(l) add_all(labels) buttons = ttk.Frame(root) buttons.grid() def remove_all(labels): for i in labels: i.grid_forget() def add_all(labels): for i in labels: i.grid() b1 = ttk.Button(buttons, text='Remove All', command=lambda:remove_all(labels)) b2 = ttk.Button(buttons, text='Remove 4', command=lambda:remove_all(labels[:4])) b3 = ttk.Button(buttons, text='Add All', command=lambda:add_all(labels)) b1.grid() b2.grid() b3.grid() root.mainloop() I have a workaround by adding a Separator to the frame (uncommenting the #sep lines above), then it will always have one widget and resize every time. But I wonder if there a way to force it to resize instead? Thanks -- Carlos Z.

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New Book on Tkinter
by Bhaskar Chaudhary Nov. 11, 2013

Nov. 11, 2013

Dear Friends I am very pleased to announce the publication of my new book on Tkinter titled: "Tkinter GUI Application Development Hotshot" The book has been published by Packt Publishing and is aimed at readers who want to learn GUI programming with Tkinter. The book should complement the existing documentation on Tkinter as it discusses Tkinter by developing several real world projects like Notepad, Programmable Drum Machine, Chess, Audio Player, Drawing Application, Screen Saver, Weather forecaster and several other fun projects. More details and a sample chapter from the book can be found at: http://www.packtpub.com/tkinter-gui-application-development-hotshot/book Packt Publishing has also gracefully agreed to provide limited number of complementary copies for reviews by experienced Tkinter programmers. Please write back to me if you would like to review the book. thanks & regards Bhaskar Chaudhary

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Waking up the Tk event loop from a thread
by Guido van Rossum Nov. 7, 2013

Nov. 7, 2013

After many years I'm trying my hands at Tkinter again, and things have changed... :-) I'm using Python 2.7 here, but it doesn't look like 3.x changes the issue. Tcl/Tk version is 8.5, on Mac OS (10.8). I've got a situation where a background thread is doing I/O and wants to wake up the Tk event loop. It seems the established wisdom (e.g. http://code.activestate.com/recipes/82965-threads-tkinter-and-asynchronous-…) is to have the Tk event loop wake up every e.g. 100 msec and check a queue or other state shared with the thread. This works, but makes me worry that my app will be draining battery power even when no data from the bg thread is forthcoming. I've tried other things: - createfilehandler: This says it cannot work when Tcl/Tk is threaded and it will be removed in Python 3 anyway. - The bg thread can use after_idle() or after() to run a command on the Tk object; this works, but it doesn't seem to wake up the Tk main loop -- the command usually only runs when I cause a UI event to be generated (e.g. selecting the window). What other solutions could I try? I really don't like the "after(100, <repeat>)" solution. -- --Guido van Rossum (python.org/~guido)

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