TextEdit set_line_gutter_icon does not show an icon in projects

[aaronfranke]

Tested versions

Latest master as of writing, 4.3-dev 99addd6

System information

macOS 14.2.1, Apple M1 Pro

Issue description

In TextEdit, set_line_gutter_icon does not show an icon when used in projects. However, the similar set_line_gutter_text function does show text, so this is evidence that my gutters are set up correctly.

However, the strange part is that set_line_gutter_icon is working when called from the editor for use with the script editor's gutter icons, but it does not work when called from user script in a project.

Steps to reproduce

Download and run the minimal reproduction project, which contains this code:

func _ready() -> void:
	add_gutter(0)
	set_gutter_width(0, get_line_height())
	set_line_gutter_icon(1, 0, preload("res://icon.svg"))
	set_line_gutter_text(2, 0, "hi")

This script adds a gutter, sets an icon for line index 1 (line 2), and sets text for line index 2 (line 3).

Expected behavior: The icon is displayed in the gutter, on the second line, to the left of the letter b.

Observed behavior: No icon is displayed in the gutter.

Minimal reproduction project (MRP)

TextEditIconBroken.zip

[aaronfranke]

Also, a related bug, it seems that gutter custom draw callbacks are not being run at all:

func _ready() -> void:
	add_gutter(0)
	set_gutter_custom_draw(0, draw_gutter)
	set_gutter_width(0, get_line_height())


func draw_gutter(line: int, gutter: int, area: Rect2) -> void:
	print("draw_gutter")

Expected behavior: It prints draw_gutter sometimes.

Observed behavior: Nothing is ever printed.

[AeioMuch]

Also, a related bug, it seems that gutter custom draw callbacks are not being run at all:

func _ready() -> void:
	add_gutter(0)
	set_gutter_custom_draw(0, draw_gutter)
	set_gutter_width(0, get_line_height())


func draw_gutter(line: int, gutter: int, area: Rect2) -> void:
	print("draw_gutter")

Expected behavior: It prints draw_gutter sometimes.

Observed behavior: Nothing is ever printed.

It works if you add this line set_gutter_type(0, TextEdit.GUTTER_TYPE_CUSTOM)
Same for the icon you need to do set_gutter_type(0, TextEdit.GUTTER_TYPE_ICON)

I imagine that the custom is for when you want to handle both strings and icons at the same time ?

[aaronfranke]

Thank you @AeioMuch that was it. I opened PR #88875 to document this.