Give some love to LUA preferences

[masterpiga]

Lua preferences UI improvements

Addresses #20692 — the flat, unsorted list of Lua preferences is replaced with a structured UI.

Co-authored with Claude.

As requested by @wpferguson.

Screen.Recording.2026-03-28.at.07.31.42.mp4

UI changes

• Global scripts (script_manager, _scripts_install) keep their preferences at the top level, ungrouped
• Per-script preferences are grouped behind a combobox selector; scripts are sorted alphabetically by display name
• A section label below the combobox updates to reflect the selected script, visually grouping its preferences

New Lua API

Scripts can register a human-readable display name used in the combobox:

darktable.preferences.register_script_name("OpenInExplorer", _("open in explorer"))

Falls back to the internal script name if no display name is registered.

Bug fixes

• Fixed ref leak in destroy_tab_lua: the extra g_object_ref before gtk_container_remove was unnecessary (the widget is already kept alive by pref_element via g_object_ref_sink) and was never balanced
• Fixed GtkSizeGroup leak on early return when no per-script preferences exist

Code cleanup

• Use dt_ui_label_new instead of gtk_label_new per GUI guidelines (ensures proper text ellipsization)
• Collapsed five identical string-read cases in read_pref into a single fallthrough
• Collapsed four identical string-write cases in write_pref into a single fallthrough
• Merged the identical response_callback_dir and response_callback_file into response_callback_filechooser

[TurboGit]

I like it but I'll let @wpferguson have the final word on this.

Thanks @masterpiga and Claude.

[wpferguson]

@masterpiga I like it. You can take out _scripts_installer. It's going away for 5.6, since the scripts will be bundled in the release. tools/scripts_installer will replace it and only get run when the user wants to install the latest version of the scripts.

I'm trying to decide about darktable.preferences.register_script_name. My thoughts/questions are

• Can we do an optional second argument to dt.preferences.register(MODULE, script_data.metadata.name, ...?
• Or maybe we could just change the arguments to dt.references.register(script_data.metadata.name, ... though I'd have to check how spaces in preferences are handled. Maybe not a good idea.
• Or we stick with what you suggested 😄

I'll play with it a little bit.

Thanks @masterpiga and Claude

[wpferguson]

After a little testing....

Boy, it's so much nicer...

I tried option 2 above, script_data.metadata.name and it works. However, that is translatable and I'm not sure how well Lua with handle the translated string, so I think it's probably best to go with the additional function. That way we don't have compatibility issues.

It's good for me. Thanks again @masterpiga

EDIT: @TurboGit 👍 👍

[masterpiga]

Glad that you like it, @wpferguson and @TurboGit :)

@wpferguson so in the end I am not sure if you asked for any changes other than the handling of _script_install. And also there, I am not sure what you mean with "remove". Should I not include it in _global_scripts? In that case it will get its own entry in the combobox. Or should it just be ignored? Or will you take care of it in a follow up?

[wpferguson]

so in the end I am not sure if you asked for any changes other than the handling of _script_install

Correct

Should I not include it in _global_scripts?

Yes, it's going to go away in a few weeks (or less, I hope). If you don't include it in the _global_scripts, it will hang around as a separate entry in the combobox and then just disappear when it's removed.

[masterpiga]

Thanks for clarifying, @wpferguson. Done.