[Idle-dev] Please help test astral char display in tkinter Text (especially *nix)

[Mark Lawrence]

On 03/11/2020 03:04, Terry Reedy wrote:
> tcl/tk supports unicode chars in the BMP (Basic Multilingual Plane, 
> utf-8 encoded with 1-3 bytes).  The presence of chars in other plains 
> ('astral', utf-8 encoded with 4 bytes, I believe) in a tkinter Text 
> widget messages up *editing*, but they can sometimes be displayed with 
> appropriate glyphs.
> 
> On my Windows 10 64-bit 2004 update, astral code points print as 
> unassigned [X], replaced [], or proper glyphs (see below).  On my 
> up-to-date macOS Mohave, as far as I know, no glyphs are actually 
> printed and some hang, freezing IDLE's Shell (and making extensive 
> testing difficult).  On Linux, behavior is mixed, including 'crashes', 
> with the use of multicolor rather than black/white fonts apparently an 
> issue.  https://bugs.python.org/issue42225.  I would like more 
> information about behavior on other systems, especially *nix.
> 
> The following runs to completion for me, without errors, in about 1 second.
> 
> tk = True
> if tk:

I'm not sure about the purpose of the tk variable here but hey ho.

>      from tkinter import Tk
>      from tkinter.scrolledtext import ScrolledText
>      root = Tk()
>      text = ScrolledText(root, width=80, height=40)
>      text.pack()
>      def print(txt):
>          text.insert('insert', txt+'\n')
> 
> errors = []
> for i in range(0x10000, 0x40000, 32):
>      chars = ''.join(chr(i+j) for j in range(32))
>      try:
>         print(f"{hex(i)} {chars}")
>      except Exception as e:
>          errors.append(f"{hex(i)} {e}")
> print("ERRORS:")
> for line in errors:
>      print(line)
> 

Did you mean your 'print' here or did you intend the builtin 'print'?  I 
assumed the latter so just renamed your 'print' to 'tkprint'.

> Perhaps half of the assigned chars in the first plane are printed 
> instead of being replaced with a narrow box. This includes emoticons as 
> foreground color outlines on background color.  Maybe all of the second 
> plane of extended CJK chars are printed.  The third plane is unassigned 
> and prints as unassigned boxes (with an X).
> 
> If you get errors, how many.  If you get a hang or crash, how far did 
> the program get?
> 

Ran to completion on ubuntu in negligible time using python3.7 and 3.8.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence