Idlelib tkinter syntax highlighting reset/update/removal

Question

I am making an IDE that uses the idlelib percolator and colordelegator for syntax highlighting. In my special text widgets init function it runs:

import idlelib.colorizer as ic
import idlelib.percolator as ip
        self.cdg = ic.ColorDelegator()
        self.cdg.prog = re.compile(r"\b(?P<MYGROUP>tkinter)\b|" + ic.make_pat(), re.S)
        self.cdg.idprog = re.compile(r"\s+(\w+)", re.S)
        self.cdg.tagdefs["MYGROUP"] = {"foreground": tag_mygroup, "background": "#FFFFFF"}
        self.cdg.tagdefs["COMMENT"] = {"foreground": tag_comment, "background": "#FFFFFF"}
        self.cdg.tagdefs["KEYWORD"] = {"foreground": tag_keyword, "background": "#FFFFFF"}
        self.cdg.tagdefs["BUILTIN"] = {"foreground": tag_builtin, "background": "#FFFFFF"}
        self.cdg.tagdefs["STRING"] = {"foreground": tag_string, "background": "#FFFFFF"}
        self.cdg.tagdefs["DEFINITION"] = {"foreground": tag_definition, "background": "#FFFFFF"}
        self.cdg.tagdefs["CLASS"] = {"foreground": tag_class, "background": "#FFFFFF"}
        ip.Percolator(self.text).insertfilter(self.cdg)

This gives the text widget syntax highlighting as it is supposed to. I want to allow the user to change the color codes in the settings file and then reset/update or remove and then reapply the syntax highlighting with the new colors. The problem is that when I try to remove the highlighting with ip.Percolator(self.text).removefilter(self.cdg) it gives the error:

Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/tkinter/__init__.py", line 1892, in __call__
    return self.func(*args)
  File "/Users/joshyacky/Documents/PyApps/Working/JDE/JDE.py", line 129, in reset_syntax_colors
    main_text_box.reset_colors()
  File "/Users/joshyacky/Documents/PyApps/Working/JDE/custom_widgets.py", line 95, in reset_colors
    ip.Percolator(self.text).removefilter(self.cdg)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/idlelib/percolator.py", line 10, in __init__
    self.redir = WidgetRedirector(text)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/idlelib/redirector.py", line 44, in __init__
    tk.call("rename", w, self.orig)
_tkinter.TclError: can't rename to ".!ultra_text.!text_orig": command already exists

Any ideas on how to remove or update the syntax highlighting?

Answer 1

I suggest looking at how IDLE updates colors. When one clicks or selects [Ok] on the settings dialog, window.ResetColorizer is called on each editor window. That is defined in idlelib/editor.py at line 797. That in turn calls _rmcolorizer and _addcolorizer, defined on preceding lines. (The rest of the function is IDLE specific.) _rmcolorizer first calls the existing ColorDelegator().removecolors before per.removefilter. _addcolorizer thereafter creates a new ColorDelegator() before calling per.insertfilter. I don't know if all this is absolutely needed, but it works.

You are using nearly undocumented private code. It is not supported for 3rd party uses. However, I am open to suggestions, such as better doc for these modules, that would (also) aid their use for IDLE.