| msg61042 - (view) |
Author: Wojciech Mula (wmula) |
Date: 2006-11-25 16:27 |
| Tkinter: canvas itemconfigure bug Consider following code: -- tkbug.py --- from Tkinter import * root = Tk() canvas = Canvas(root) text = "sample text with spaces" id = canvas.create_text(0, 0, text=text) text2 = canvas.itemconfigure(id)['text'][-1] print text print text2 --- eof --- This toy prints: sample text with spaces ('sample', 'text', 'with', 'spaces') The returned value is not a string -- Tk returns the same string as passed on creating item, but Tkinter split it. To fix this problem, internal method '_configure' have to be changed a bit: *** Tkinter.py.old 2006-11-20 16:48:27.000000000 +0100 --- Tkinter.py 2006-11-20 17:00:13.000000000 +0100 *************** *** 1122,1129 **** cnf = _cnfmerge(cnf) if cnf is None: cnf = {} ! for x in self.tk.split( self.tk.call(_flatten((self._w, cmd)))): cnf[x[0][1:]] = (x[0][1:],) + x[1:] return cnf if type(cnf) is StringType: --- 1122,1134 ---- cnf = _cnfmerge(cnf) if cnf is None: cnf = {} ! for x in self.tk.splitlist( self.tk.call(_flatten((self._w, cmd)))): + if type(x) is StringType: + if x.startswith('-text '): + x = self.tk.splitlist(x) + else: + x = self.tk.split(x) cnf[x[0][1:]] = (x[0][1:],) + x[1:] return cnf if type(cnf) is StringType: Maybe better/faster way is to provide Canvas method, that return a 'text' property for text items: --- def get_text(self, text_id): try: r = self.tk.call(self._w, 'itemconfigure', text_id, '-text') return self.tk.splitlist(r)[-1] except TclError: return '' --- |
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| msg61043 - (view) |
Author: Matthias Kievernagel (mkiever) * |
Date: 2007-01-19 18:35 |
| There is a simple workaround: use itemcget. The error applies to other options as well: dash, activedash, disableddash, tags, arrowshape, font These options also may contain a space in their value. I collected this information from 'man n Canvas' from Tk 8.4.6 I hope I didn't miss any. BTW the itemconfigure document string is broken. Greetings, Matthias Kievernagel |
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| msg64848 - (view) |
Author: Matthias Kievernagel (mkiever) * |
Date: 2008-04-02 11:11 |
| I no longer know what I meant with "document string is broken". It is not very clear, but not broken. It does not specify clearly the return value in the case of 'without arguments'. The problem is still present in trunk. Problem is as far as I understand it: Some return values from tcl are strings that may contain spaces (or are even certain to contain spaces). They are nonetheless translated to a Python tuple by Tcl_SplitList in _tkinter.c. There is no difference in syntax between tcl lists and tcl strings (with spaces). You have to have contextual knowledge to do the right thing. This knowledge cannot be attached to itemconfigure alone (for reconstitution of strings) because then information about whitespace is already lost. For return values known to be strings _tkinter/TkApp_SplitList must not be used. So I think it's a more general bug related to tcl string return values. Other Tkinter bugs may have the same explanation. Don't know how to resolve this without a lot of work. Matthias. |
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| msg73270 - (view) |
Author: Guilherme Polo (gpolo) *  |
Date: 2008-09-15 17:07 |
| The problem is actually on Tkinter side, not really tcl/tk fault here. Tkinter should be formatting that text option as "{text here}" when the value contains one or more spaces (it is actually fine to use this tcl formatting when there are no spaces either). To try this yourself, just change text to: text = "{sample text with spaces}" I can't look at Tkinter source right now to propose a correct solution, but will do later (today hopefully). |
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| msg73288 - (view) |
Author: Guilherme Polo (gpolo) * |
Date: 2008-09-16 01:37 |
| Uhm, now I see.. Tkinter already formats it correctly, and you shouldn't be using itemconfigure for this task. If you try it directly in tk, like this: canvas .c .c create text 0 0 -text {a b} .c itemconfigure 1 -text You would get something like this: -text {} {} {} {a b} While .c itemcget 1 -text Will return the same as Python: "a b" Now what remains is to see how useful is to use itemconfigure for this, and if it is worth making canvas.itemconfigure(id)['text'][-1] return "a b" instead of ("a", "b"). Changing Misc._configure is too risky given there are no tests for Tkinter (and I find it weird sometimes, someone will still have to explain me why Tkinter plays with cnf and kw all the time), the other option involves leaving these special needings in Text and is something I dislike because other widgets could use these new things that would be added. Yet another option would be to start writing unit tests for Tkinter and much of these bugs would end up being caught and hopefully fixed properly. |
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| msg197770 - (view) |
Author: Serhiy Storchaka (serhiy.storchaka) * |
Date: 2013-09-15 13:02 |
| The patch for fixes this issue. |
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| msg222404 - (view) |
Author: Francis MB (francismb) * |
Date: 2014-07-06 13:30 |
| Hi, just a question: the status of this issue is pending but it seems to be already resolved/duplicated. Means that this issue can be closed? Thansk in advance! |
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