Tk Source Code

With Tcl8.7a6 / Tk9.0b1 the following script shows how the text widget breaks graphemes obtained using combining diacritical marks into two distinct chars. This doesn't happen with labels or entries, both tk or ttk ones. Tested on linux 32 bits.

package require Tk
set txt a\u0300e\u0301i\u0302o\u0303u\u0304
pack [label .tkl] [ttk::label .ttkl] [entry .tke] [ttk::entry .ttke] \
     [text .t -width 20 -height 3]
.tkl  configure -text $txt
.ttkl configure -text $txt
.tke  insert 0 $txt
.ttke insert 0 $txt
.t    insert end $txt

I suspect that this ticket is related to:

#define TK_LAYOUT_WITH_BASE_CHUNKS     1
#define TK_DRAW_IN_CONTEXT             1

Also, see the following note in the TkpDrawCharsInContext() implementation on Windows and UNIX (both X11 and xft):

 *      Note: TK_DRAW_IN_CONTEXT being currently defined only on macOS, this
 *            function is unused (and possibly unfinished). See [7655f65ae7].

If this is the cause, it explains why this issue only shows on Windows and UNIX, and not on MacOS.

With xft I agree with what you wrote.

Without xft however, all widgets are broken.

On Linux, I see exactly the same as the attached image shows. So on X11 it's not solved. For label and entry everything is fine, but not for the text widget. Work to be done.

> I cannot reproduce the problem on Windows.

Me neither! That means, probably, one of the fixes in [53fdb87e49] fixed this one at the same time. Good news.

I'll retest on Linux

I cannot reproduce the problem on Windows.

Now that [53fdb87e49] is fixed, this ticket is the next challenge. Since on MacOS everything works, this means that the MacOS and the generic code is fine. So, the coolpit must be in the win32 (tkWinFont.c) and the X11 code (tkUnixFont.c).

We could split this ticket into 2, one for win32 and one for X11. I could use some help. Christian Werner, maybe? Anyone?

I see the same on Windows and Linux. On MacOS it works fine. Still some work to do to make full Unicode support 100% right on all platforms

Tk 8.7 still has more problems, I'm aware of. Some code from Tk 9.0 still needs to be backported to 8.7.