Added ability to unfold editor sections when dragging and dropping.

[EricEzaM]

Also added editor setting to control the delay used before unfold occurs.

Closes #37524

Edit: oh, and I also cleaned up the gui_input() function a bit. Everything it was doing is encapsulated in unfold() and fold(), so we might as well use those functions since they are there. Now the code is much easier to follow. It's basically just should_unfold ? unfold() : fold()

[fire]

Does this code also give the ability to expand all the folds for a specific property? Was trying to get that to work.

[EricEzaM]

Does this code also give the ability to expand all the folds for a specific property? Was trying to get that to work.

All the folds for a specific property? Not sure what you mean by that, could you clarify if possible?

[fire]

So I have a property albedo_texture, but it's hidden inside of a "Albedo" group. So I want to show the albedo texture from code, but it's nested and the group nearest to it is not related because albedo_texture is a top level property (like without "/").

[Edited]

I think that is a different issue unrelated, looking at your code.

[EricEzaM]

Ah yeah I think I understand what you mean. Like if you had:

• Section 1
  • Section 2
    • Property

You want to be able to unfold Section 1 and 2 by querying to say "unfold all sections for 'property'".

This PR hasn't got anything to do with that functionality, no.

[fire]

Is it possible to set a highlight on the section? Currently there's no visual feedback.

[Edited] It's more complicated. Not sure if it's worth setting the highlight on drop and then when you move away set a timer to unset the highlight. However, it's worth trying to show activity.

[EricEzaM]

@fire It might actually be worth implementing a highlight whenever a user hovers over a section, no matter if they are dragging or not. I think that would be another PR tho.

[fire]

= nullptr.

[EricEzaM]

Sorry, I don't understand. memnew(Timer) is used in the constructor. Why does it need = nullptr? That is not used anywhere else in the codebase where a Timer* is defined.

[fire]

godot/modules/mono/csharp_script.h

Line 364 in b2096ba

ManagedCallableMiddleman *managed_callable_middleman = memnew(ManagedCallableMiddleman);

Here's an example of:

Timer *dropping_unfold_timer = memnew(Timer);

[EricEzaM]

Yeah so that's in the header, I'm saying the timer is initialised in the constructor:

https://github.com/godotengine/godot/pull/41138/files#diff-554c9c97362d5a6f63b7244253542ffeR1312

I'm just wondering why this needs to explicitly specify = nullptr when I can't seem to find that happening anywhere else in the codebase. For example:

godot/scene/gui/spin_box.h

Line 44 in d3b5c09

Timer *range_click_timer;

It is then initialised in the constructor:

godot/scene/gui/spin_box.cpp

Lines 272 to 274 in d3b5c09

	range_click_timer = memnew(Timer);
	range_click_timer->connect("timeout", callable_mp(this, &SpinBox::_range_click_timeout));
	add_child(range_click_timer);

[fire]

I don't remember exactly, but every so often Akien runs a script that moves the construction stuff to initialization.

[EricEzaM]

Ah ok, no worries. I was just wondering if there was some convention as I couldn't see other cases of this being used.

[stijn-h]

I have an old PR (#39650) that implements unfolding with highlighting. Without highlighting it's hard to know that you can even unfold. Also, if you look at the code you can see it is not that much work, so I think you should add it to your PR.

[EricEzaM]

Updated. You can only expand sections if the sections contains properties which accept the drag data. Section is also highlighted as such:

[EricEzaM]

Sorry... forgot to rebase before pushing so some unnecessary reviewers were added. Apologies. They can be removed if a mod sees this and can do so.

[fire]

Looks great. [Tested on my backport to 3.2.]

[akien-mga]

Thanks!