Add Auto width behavior to ItemList

[havi05]

I have rewritten the PR #39848 which implemented a Auto width functionality in the ItemList node, but never got rebased. It should be the same behavior like using the Auto height feature.

I had the problem that the last 2 letters of a word were not shown. That's why I added 6 pixels to the calculation in line 1481 (item_list.cpp) Please let me know if it is acceptable to hard-code this value.

Closes #31504

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This is my first PR at the GodotEngine. Please tell me if I have done any mistakes or if there is anything I can improve.

[AThousandShips]

Please ask if the original author has abandoned their work, otherwise there's no reason to take it over, please communicate with other developers

Regardless you need to cite them as a coauthor as you've copied their code, like so:

Co-authored-by: Craig Hupin <althar93@hotmail.com>

The empty line matters

[havi05]

Please ask if the original author has abandoned their work, otherwise there's no reason to take it over, please communicate with other developers

@AThousandShips Thank you for bringing this to my attention and asking Althar93 for me. I'll keep it in mind for next time.

[havi05]

Am I right that the auto_width documentation must be written below auto_height to solve the failling check?

[AThousandShips]

Yes it has to be alphabetical, use --doctool on the built binary to generate automatically

[havi05]

Since Althar93 has not responded to the question 5 months ago about continuing his work (#39848 (comment)) and his last commit in #39848 was 4 years ago, would it be possible to review these changes already, or would you prefer to wait?

[KoBeWi]

The feature is implemented correctly, but it has problems with fitting text. See the above comment.

[KoBeWi]

The text is no longer cut, but there is some excessive margin on the right.

godot.windows.editor.dev.x86_64_5SeNSEtuhg.mp4

[havi05]

I noticed I had theme_cache.panel_style->get_minimum_size().width two times in my calculation. I'm checking if thats the problem.

[havi05]

This depends on this pr #97439 for this issue #97438.

[havi05]

I applied the requested changes and fixed a bug that caused the right margin to be too wide when more than one column was used.

[KoBeWi]

The margin problem is fixed.
Though there is a problem where if you increase column count, the size doesn't update immediately:

godot.windows.editor.dev.x86_64_8g3HH9T339.mp4

[havi05]

I fixed the column update problem. I have noticed that after hiding the visibility of the scrollbar, the size is updated about one pixel too late. I could not figure out what is causing this problem.

2024-10-03.08-50-46.mp4

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Thank you for your quick replies and your patience testing my code so many times!

[akien-mga]

Thanks!