Mailman 3 May 2012 - 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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Segfault in Image.PhotoImage on OS X
by Marc Culler Nov. 14, 2012

Nov. 14, 2012

This was reported here in February, but no debugging information was provided by the reporter: http://stackoverflow.com/questions/9142786/python-imagetk-photoimage-segfau… <view-source:http://stackoverflow.com/questions/9142786/python-imagetk-photo…> I can explain the nature of the problem, but I don't know how to fix it correctly. I am using the standard x86_64 Python 2.7.2 package from python.org and I have installed Active State Tcl/Tk 8.11. When I tried using easy_install to install PIL it would not load, claiming that _imaging.so did not exist. In fact, it existed but was only a thin i386 executable. So I compiled Imaging-1.1.7 with export CFLAGS='-arch i386 -arch x86_64' and export TCL_ROOT=/Library/Frameworks/Tcl.framework/Versions/8.5/Tcl I was then able to load the module. However, the following code produced a segfault: import Image import ImageTk import Tkinter W = Tkinter.Tk() Im = Image.open('test_image.jpg') x = ImageTk.PhotoImage(Im) The crash occurs in Tk_GetImageMasterData. More importantly, though, the crash was preceded by the following messages: objc[36554]: Class TKApplication is implemented in both /Library/Frameworks/Tk.framework/Versions/8.5/Tk and /System/Library/Frameworks/Tk.framework/Versions/8.5/Tk. One of the two will be used. Which one is undefined. objc[36554]: Class TKMenu is implemented in both /Library/Frameworks/Tk.framework/Versions/8.5/Tk and /System/Library/Frameworks/Tk.framework/Versions/8.5/Tk. One of the two will be used. Which one is undefined. objc[36554]: Class TKContentView is implemented in both /Library/Frameworks/Tk.framework/Versions/8.5/Tk and /System/Library/Frameworks/Tk.framework/Versions/8.5/Tk. One of the two will be used. Which one is undefined. objc[36554]: Class TKWindow is implemented in both /Library/Frameworks/Tk.framework/Versions/8.5/Tk and /System/Library/Frameworks/Tk.framework/Versions/8.5/Tk. One of the two will be used. Which one is undefined. Guessing that PIL was finding the System/Library/Frameworks/Tk.Framework instead of /Library/Frameworks/Tk.Framework, I tried hiding the system Tcl and Tk frameworks by renaming them. I was then able to create the PhotoImage and display it. I don't know where those messages come from, and I have never encountered them before. But I am guessing they are from OS X, since they are generated by an objective C program. Evidently _tkinter.so is able to specify which Tk.Framework to use. I don't know its mechanism for doing that. But, somehow, PIL is not doing it, and it ends up using the wrong one. A stack trace of the crash is below. - Marc 0x000000011517bccd in Tk_GetImageMasterData () (gdb) bt #0 0x000000011517bccd in Tk_GetImageMasterData () #1 0x0000000115183d9f in Tk_FindPhoto () #2 0x00000001014fbadc in PyImagingPhotoPut () #3 0x000000011502a05b in TclInvokeStringCommand () #4 0x000000010102142a in TclEvalObjvInternal () #5 0x000000010102261c in Tcl_EvalObjv () #6 0x000000010100646d in Tkapp_Call () #7 0x00000001000c102d in PyEval_EvalFrameEx () #8 0x00000001000c2d29 in PyEval_EvalCodeEx () #9 0x00000001000c0b6a in PyEval_EvalFrameEx () #10 0x00000001000c2d29 in PyEval_EvalCodeEx () #11 0x000000010003da80 in function_call () #12 0x000000010000c5e2 in PyObject_Call () #13 0x000000010001ebcb in instancemethod_call () #14 0x000000010000c5e2 in PyObject_Call () #15 0x00000001000ba5f7 in PyEval_CallObjectWithKeywords () #16 0x0000000100021e5e in PyInstance_New () #17 0x000000010000c5e2 in PyObject_Call () #18 0x00000001000be5f3 in PyEval_EvalFrameEx () #19 0x00000001000c2d29 in PyEval_EvalCodeEx () #20 0x00000001000c2e46 in PyEval_EvalCode () #21 0x00000001000e769c in PyRun_InteractiveOneFlags () #22 0x00000001000e78fe in PyRun_InteractiveLoopFlags () #23 0x00000001000e80e1 in PyRun_AnyFileExFlags () #24 0x00000001000fe77c in Py_Main () #25 0x0000000100000f14 in dyld_stub_strlen ()

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Deadlock on graceful exit
by Matteo Landi June 2, 2012

June 2, 2012

Hi list, recently I started to work on an application [1] which makes use of the Tkinter module to handle interaction with the user. Simply put, the app is a text widget displaying a file filtered by given criteria, with a handy feature that the window is raised each time a new line is added to the widget. The application mainly consists of three threads: the first one, the file processor, reads the file, filters the lines of interest, and pushes them into a shared queue (henceforth `lines_queue`); the second one, the gui_updater, pops elements from `lines_queue`, and schedule GUI updates using the `after_idle` method of the Tkinter module; finally the last one, the worker spawner, receives commands by the gui (by means of a shared queue, `filters_queue`), and drives the application, terminating or spawning new threads. For example, let's see what happens when you start the application, fill the filter entry and press Enter button: 1 the associated even handler is scheduled (we should be inside the Tkinter mainloop thread), and the filter is pushed into `filters_queue`; 2 the worker spawner receives the new filter, terminate a possibly running working thread, and once done, create a new file processor; 3 the file processor actually processes the file and fills the `lines_queue` with the lines matching given filter; 4 the gui updater schedules GUI updates as soon as items are pushed into `lines_queue` 5 Tkinter mainloop thread updates the gui when idle What happens when the main window is closed? Here is how I implemented the graceful shutdown of the app: 1 a quit event is scheduled and a _special_ message is pushed into both `filter_queue` and `lines_queue` 2 the gui updater threads receives the _special_ message, and terminates 3 the worker spawner receives the message, terminates the working thread and interrupts her execution. 4 Tk.quit() is called after the quit event handler, and we finally quit the mainloop Honestly speaking, I see no issues with the algorithm presented above; however, if I close the window in the middle of updates of the text widget, the applications hangs indefinitely. On the other hand, everything works as expected if I close the app when the file processor, for example, is waiting for new content to filter. I put some logging messages to analyze the deadlock (?!), and noticed that both the worker spawner and the file processor are terminated correctly. The only thread still active for some strange reasons, is the gui updater. Do you see anything wrong with the description presented above? Please say so, because I can't figure it out! Regards, Matteo -- http://www.matteolandi.net

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ttk.Scrollbar in Notebook widget freezes
by David Beck May 30, 2012

May 30, 2012

Hello, I am working on an iMac running OS 10.7, TK 8.5.11. I built a simple app containing a Notebook widget, and with Listboxes and linked tkk.Scrollbars on each of three tabs. All of the Scrollbars work the first time I manipulate them, but once the Scrollbar on third tab (the last one created by the script) is manipulated, the others become unresponsive to mouse clicks (though the Scrollbars continue to move when the Listboxes are scrolled using the mouse/trackpad. I first found this issue working with Python 3.2.3 (using IDLE), but the same thing happens with Python 3.3. The problem was recreated by someone on the Python Bug Report list using the same system configuration. I asked someone to try this on a PC (Windows 7, Python 3.2.3, Tkinter 8.5), but the problem wasn't recreated. David Beck

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Tkinter Windows don't appear under MacOSX Lion
by Michael O'Donnell May 23, 2012

May 23, 2012

Dear all, I use py2app to package my python 2.7.2 program into a distributable. My previously working application seems not to work under MacOSX Lion, windows (the root window, and Toplevel windows) until I use apple-tab to cycle in and then back to the application. I have seen numerous other complaints of this. , e.g., http://stackoverflow.com/questions/9083687/python-tkinter-gui-always-loads-… http://stackoverflow.com/questions/8691655/python-put-window-on-top-tkinter… http://www.velocityreviews.com/forums/t593134-tkinter-osx-and-lift.html However, these address the main window not appearing on duble clicking the application. What concerns me more is that it seems to apply also to Toplevel windows created within an application. I really don't want to search through the 1000s of lines of my code to find all places where some sort of toplevel (or subclass thereof) is created, insert some hack code which forces the window to appear, given this is a problem that only affects my program on Macs, and then only in Lion. Rather, I would rather understand what is going on, and whether there is perhaps a general fix. Firstly, I note that this only affects me on Mac, and only on Lion. Also, it does not affect my code when run under idle, or when I run my script directly using python. It only happens with a py2app application. For instance, I use the following code in a file called 'test.py': from Tkinter import * tk = Tk() fr=Frame(tk, height=400, width=400) fr.pack() #tk.grab_set() def openWin(): t=Toplevel(tk) Button(t, text="Close", command=lambda w=t: w.destroy()).pack() for i in range(4): for j in range(4): Button(fr, text="Open", command=openWin).grid(row=i, column=j) tk.iconify() tk.update() tk.deiconify() tk.lift() tk.mainloop() Then I use py2app to make an application, e.g., from setuptools import setup import sys sys.argv=[sys.argv[0]] sys.argv.append("py2app") setup( app=['test.py'], data_files=[], options={'py2app': {'argv_emulation': True, 'resources': []}}, setup_requires=['py2app'], ) This makes an application, test.app, which, when double clicked, brings up the application menubar, but no window. If I apple-tab and then apple-tab again (to return to this app), the window appears. Clicking on buttons does NOT open the Toplevel window which should appear (but the window will apear if I cycle in and out of the app). Also if I click multiple buttons, each of the toplevel windows is listed in the list of windows associated with the app (visible by clicking on the app's icon in the doc). Now, after much experimentation, I find if I put a grab_set() in the code (uncommenting line 3 in the test.py), then at least the toplevels appear as expected. Does anyone have any idea why this is so? Why is this line only needed on Lion? Does this happen the same on your macs? I would like to know, as my code may change the grab_set somewhere in the code and stop things working (hard to tell in the spagetti of my program). (using ActivePython 2.7.2.5 (ActiveState Software Inc.) based on Python 2.7.2 (default, Jun 24 2011, 12:20:15) Tk 8.5 Mick -- Not sent from my iPhone

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How to prevent a selection when double-clicking?
by Juha Salo May 20, 2012

May 20, 2012

Hi! Is there a way to get rid of the selection (blue area in the window) after double-clicking on a Text widget? I use Vista and Python 3.2.3. I have the following example: import tkinter as tk root = tk.Tk() def dbclick(e): print('db click') #Can I add some code here to automatically prevent the selection from appearing? txt = tk.Text() txt.insert('insert', 'fooo') txt['state'] = 'disabled' txt.bind('<Double-Button-1>', dbclick) txt.pack() root.mainloop()

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Python 3.3.0a3 on Macs
by Michael O'Donnell May 12, 2012

May 12, 2012

Dear all, Just tried the latest release of Python 3.3.0a3 (v3.3.0a3:0b53b70a40a0, May 1 2012, 11:10:44) on my MacOSX Lion. It seems use of tkinter NoteBook breaks: from tkinter import * import tkinter.ttk root = Tk() nb=tkinter.ttk.Notebook(root) nb.pack(expand=True, fill=BOTH) nb.add(Canvas(nb, bg="red"), text="Pane 1") nb.add(Canvas(nb, bg="blue"), text="Pane 2") root.mainloop() Traceback (most recent call last): File "/Users/micko/Google Drive/ALL_FILES/TO DO/CorpusTool30b1/NotebookTest.py", line 5, in <module> nb=tkinter.ttk.Notebook(root) File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/tkinter/ttk.py", line 857, in __init__ Widget.__init__(self, master, "ttk::notebook", kw) File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/tkinter/ttk.py", line 559, in __init__ _load_tile(master) File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/tkinter/ttk.py", line 47, in _load_tile master.tk.eval('package require tile') # TclError may be raised here _tkinter.TclError: can't find package tile Now, I though Tile had been folded into Tkinter. Or do I need to download and install it separately still? (I thought it would be nice if all core Tkinter widgets worked 'out of the box', so i suspect this is a bug) Mick -- Not sent from my iPhone

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Unbinding Individual Events
by Lion Kimbro May 11, 2012

May 11, 2012

Unbinding individual events from widgets has been a long standing tkinter bug. I've been working on a workaround for tkhelp.py, but never really liked the solutions I came up with. Most involved multiplexing from a single event receiver. Here is a brief demonstration: import tkinter global_tk = tkinter.Tk() def tcl(tcl_code): """Execute tcl code string directly & return the result.""" return global_tk.tk.eval(tcl_code) tl = tkinter.Toplevel(name="top", width=400, height=200) tl.title("testing") That's the setup frame... Now: >>> tl.bind('<Motion>', lambda evt:print(evt)) '37533768<lambda>' Moving the mouse over the toplevel, you can see the events roll in. Now we can look at the events in tcl: >>> tcl('bind .top') '<Motion>' >>> tcl('bind .top <Motion>') 'if {"[37533768<lambda> %# %b %f %h %k %s %t %w %x %y %A %E %K %N %W %T %X %Y %D]" == "break"} break\n' The important thing to recognize is that the whole string ('if {"[375...]" == "break"} break\n') is the binding -- NOT the individual function item '37533768<lambda>'. Now if you add another binding -- >>> tl.bind("<Motion>", lambda evt:print("whoopie!"), add="+") '37531848<lambda>' You can roll the mouse over, and you'll see TWO event bindings. Now let's look at it in detail: >>> tcl('bind .top <Motion>') 'if {"[37533768<lambda> %# %b %f %h %k %s %t %w %x %y %A %E %K %N %W %T %X %Y %D]" == "break"} break\n\nif {"[37531848<l ambda> %# %b %f %h %k %s %t %w %x %y %A %E %K %N %W %T %X %Y %D]" == "break"} break\n' Okay, now let's say we want to remove the first method? We can rebind, cutting it out. First, we isolate the second entry, which we want: >>> scripts = tcl('bind .top <Motion>') >>> scripts.split("\n") ['if {"[37533768<lambda> %# %b %f %h %k %s %t %w %x %y %A %E %K %N %W %T %X %Y %D]" == "break"} break', '', 'if {"[37531 848<lambda> %# %b %f %h %k %s %t %w %x %y %A %E %K %N %W %T %X %Y %D]" == "break"} break', ''] >>> s=scripts.split("\n")[-2] And then bind it: >>> tcl('bind .top <Motion> {%s}' % s) '' You'll see the "whoopie!" printing, but the first event printer will be gone! So my thought to systematize this is: A. Make a function (fn-A) for making a Python list out all binding strings on a widget-sequence pair. B. Make a function (fn-B) that constructs the binding string for a given function binding. C. Patch(/replace) widget.unbind so that it retrieves all binding strings (via fn-A), and then removes the string that matches fn-B(funcid), and then rebind the widget via the new list I think that should work. My main concern is that, if _tkinter does any reference counting on function uses, then there is a memory hole. Thoughts?

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PanedWindow proportional resizing of panes
by Vasilis Vlachoudis May 10, 2012

May 10, 2012

Hi all, in my application I am using the recipe of http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52266 to create a multilistbox. I have modified it to use the panedwindow in order to allow the resize of the rows, like in the code below. My problem(s) (all related to the resizing of the panes) 1. is how to make the resizing of the window to resize proportionally the panes (Now only the last row "Four" expands/reduce its size) 2. when the user manually resize one pane (e.g. drag between two|three, only the panes two and three are resized while I would prefer more a behavior like all other window toolkits that only "two" will be resized, "three" will remain the same and the last one "Four" will be reduced or expanded. 3. How to save/recall the size of the panes. The paneconfig(child,"width") returns a tuple with ('width','','','') from Tkinter import * tk = Tk() paned = PanedWindow(tk, orient=HORIZONTAL, showhandle=0, handlepad=0, handlesize=0, sashwidth=2, opaqueresize=1) paned.pack(side=LEFT, expand=YES, fill=BOTH) for l,w in [("One",5),("Two",10),("Three",15), ("Four",30)]: frame = Frame(paned, border=0) paned.add(frame,minsize=16) lbl = Label(frame, text=l, borderwidth=1, relief=RAISED) lbl.pack(fill=X) lst = Listbox(frame, width=w, background="White") lst.pack(expand=YES, fill=BOTH) for i in range(100): lst.insert(END,"#%d"%(i)) tk.mainloop() Vasilis

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Which virtual event have I received ?
by hamiljf May 9, 2012

May 9, 2012

I want to be able to process more than one event type in an event handler (I know that there may be other ways of doing this, and I might well use them) Now 'real' events are distinguished by event.type having a numeric value listed all over the place, for example in http://infohost.nmt.edu/tcc/help/pubs/tkinter/events.html new mexico tech dox , and I think virtualevents are #35 (not in the list). But how can I tell which of two virtual events an event object represents: the virtual event name doesn't seem to be anywhere around. If there really isn't any way, it would always be possible to write additional handler methods as an alternative. -- View this message in context: http://python.6.n6.nabble.com/Which-virtual-event-have-I-received-tp4962788… Sent from the Python - tkinter-discuss mailing list archive at Nabble.com.

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