Fix utf8 cursor col #397
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Fix utf8 cursor col #397
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When using Harbour with UTF-8 codepage (UTF8EX), the `col()`
function returns incorrect column positions for text containing
wide characters (e.g., CJK characters like 中文, Japanese
characters like 日, Korean characters, etc.).
This fixes cursor mis-alignment in UTF-8 terminals when output contains CJK, Emoji or other multi-column characters.
Key points:
New HB_GTI_WIDECHARWIDTH switch, disabled by default, zero run-time overhead.
Width logic is activated only after hb_gtInfo(HB_GTI_WIDECHARWIDTH, .T.).
Implementation based on public-domain mk_wcwidth; supports narrow(1), wide(2) and zero-width(0) characters.
No binary bloat, no breaking changes—existing applications compile and run unchanged.
Example:
hb_cdpSelect("UTF8EX")
hb_gtInfo(HB_GTI_WIDECHARWIDTH, .T.) && enable wide-char calculation
The cursor now advances by actual display columns, so subsequent prompts are correctly aligned.
Contributor
|
I'm not able to look at it extensievly right now, but pulling in |
alcz
reviewed
Jan 5, 2026
src/rtl/cdpapi.c
Outdated
| #include "hbapi.h" | ||
| #include "hbapierr.h" | ||
| #include "hbapicdp.h" | ||
| #include "hbgtcore.h" |
Contributor
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Calling GT core api from here doesn't look like a good idea, respecting the setting should be done somehow still in terminal code.
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The fix add the `hb_cdpUTF8CharWidth` function in `cdpapi.c` to check
the GT driver's `fWideCharWidth` flag. When enabled, it uses the `mk_wcwidth`
function from the public domain implementation for accurate Unicode TR11
width calculation. When disabled, it returns the default width of 1 for
backward compatibility.
- Add HB_GTI_WIDECHARWIDTH switch, disabled by default for zero overhead
- Only activate width calculation when user calls
hb_gtInfo(HB_GTI_WIDECHARWIDTH,.T.)
- Based on public-domain mk_wcwidth; supports narrow(1)/wide(2)/zero(0)
- 100% backward compatible, no binary bloat
- Fixes cursor mis-alignment in UTF-8 terminals with CJK/Emoji
Usage:
hb_cdpSelect("UTF8EX")
hb_gtInfo(HB_GTI_WIDECHARWIDTH,.T.) && enable
woodhead2019
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Author
|
Thank you for your patient review and guidance—I’ve revised the code accordingly. I last used Clipper over thirty years ago and then left the IT industry. With the help of AI, I’m now trying to fix UTF-8 character-display issues in CJK terminals, and I hope the solution meets Harbour’s standards. |
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Fixes cursor mis-alignment in UTF-8 terminals with CJK/Emoji
gt: optional Unicode wide-char width calculation (HB_GTI_WIDECHARWIDTH)
hb_gtInfo(HB_GTI_WIDECHARWIDTH,.T.)
Usage:
hb_cdpSelect("UTF8EX")
hb_gtInfo(HB_GTI_WIDECHARWIDTH,.T.) && enable