tkinter text width

[Eric Brunel]

On Wed, 27 Apr 2005 12:52:21 -0700, James Stroud <jstroud at mbi.ucla.edu> wrote:

[snip]
> How might I query the size of a fixed-width font in pixles? It appears that
> the width of the font in points does not correlate with its width in pixels
> based on some simple expriments I have done.

This is the case on all platforms, but far more sensible on Windows: Windows attempts to be "clever" and corrects the font size you give depending on your screen resolution so that a 12 point font is supposed to be actually 12/72 inches *on screen* (obviously ignoring the fact that this is almost never what you want, since all other dimensions are in screen points by default...). Other platforms than Windows are supposed to do this too, but (fortunately) it seems to fail and the computed factor is very close to 1 (I got something like 1.04 on Linux, whatever the screen resolution was).

To avoid this, you can try to use the winfo_* methods to get the screen resolution (I thought there was a more straightforward way, but the only way I see is to do someWidget.winfo_screenwidth() / someWidget.winfo_screenmmwidth(), with the usual adjustement to get inches instead of millimeters). You can then use this adjustement on all the dimensions you compute so that it will be consistent with the font sizes you get.

The other solution is to turn the adjustement off. You can do this at tk level with the command "tk scaling 1". Unfortunately, this command does not seem to be directly available at Tkinter level, so you'll have to do:
someWidget.tk.call('tk', 'scaling', 1)
After doing that, all your font sizes should be in screen points. But be aware that *all* your fonts will seem to shrink (the screen resolutions these days are usually closer to 92 dpi than to 72...). So you may have to do some adjustements on other parts of your application (the biggest problem I got was with menu items).

HTH
-- 
python -c "print ''.join([chr(154 - ord(c)) for c in 'U(17zX(%,5.zmz5(17;8(%,5.Z65\\'*9--56l7+-'])"