Tk Source Code

[tk print $text] on windows has limited support (if any) for i18n text.

The code builds an array of character widths but only for the range 0-255 (I presume of the active code page) and then fails when trying to lookup for characters not in this range. Running the attached demo script (paired with the plain text data file "utf8demo.txt") produces

can't read "charwidths(‾)": no such element in array can't read "charwidths(‾)": no such element in array while executing "incr totwidth $charwidths([string index $string $i])" (procedure "_print_page_nextline" line 16) invoked from within "_print_page_nextline $linestring printcharwid printargs $curhgt $font" (procedure "::tk::print::_print_data" line 38) invoked from within "::tk::print::_print_data {UTF-8 encoded sample plain-text file ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾..." ("after" script)

Moreover, the built lookup array resides in the global namespace and not in the ::tk::print namespace, being subject to a potential name clash.

Other issue is that the default font used for text widgets is a proportional font, making it unsuitable for things like printing code. This is also an inconsistency with *nix, and I pressume also MacOS, where the cups printing system uses a monospaced font for Tk text printing (and plaintext files).

The branch tk-print-fixes has a fix for these issues. In the case of the character width lookup array is a workaround: use [array default set] to provide a fallback width.

There's no output attached as they result in a big file and is easy to reproduce.

The attached data file "utf8demo.txt" comes from the cups source code here

Merged to core-9-0-branch (and trunk) now

Thanks, that's definitely a valuable improvement!

I didn't review the code patch, but I have tried your script (it works for me).