Improve editor toolbar for Control nodes

[YuriSizov]

Since #55630 is dead in waters for the time being, I've decided to extract the good parts from it, and specifically a better layout for anchor mode presets and container sizing options.

godot.windows.tools.64_2022-07-23_21-11-00.mp4

This also addresses concerns regarding changing anchor presets from the toolbar not changing grow direction and size flag options being behind that changes done in #55157.

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I've added a new control node, PopupButton, to serve as a base for MenuButton and an internal control that I've added for the toolbar. I needed to do this so I can share the switch on hover behavior, and use a different kind of popup at the same time. I figured, this was the best way. MenuButton should remain as is, functionality-wise.

Closes godotengine/godot-proposals#3559

[KoBeWi]

PopupButton crashes if there is no popup set.

Also, maybe the PopupButton change could be done in a separate PR? Then you could handle ColorPicker button too.
Although I guess it's not very useful by itself 🤔

[YuriSizov]

PopupButton crashes if there is no popup set.

At any specific moment? Or just having it in a scene?

Also, maybe the PopupButton change could be done in a separate PR? Then you could handle ColorPicker button too. Although I guess it's not very useful by itself 🤔

Indeed, it's unlikely to be very useful. To me it was a necessity to implement the activate-on-hover behavior without doing hacks and editor-specific code injection. I'm not 100% convinced this is the best solution, but I don't have other ideas. I could forgo the on-hover behavior entirely and we can revisit it if and when users complain. The introduction of the PopupButton as base type shouldn't be compat breaking even if we need to do this after 4.0.

[KoBeWi]

At any specific moment?

When it's pressed.

[KoBeWi]

What happened to "Anchors Only" option?

[YuriSizov]

What happened to "Anchors Only" option?

Ever since the original drawer's work nobody came forward and explained how it can be useful. I removed it because it was complicating the UI at this point, and now that presets also affect the grow direction, would we need more flags?..

[KoBeWi]

Well it's useful when you position a control, but forget to use anchors beforehand. It's rather rare, but I did use it a few times 🤔
(although the workaround is just copying the position value, so it's not much of a problem)

EDIT:
I just realized now but

To me it was a necessity to implement the activate-on-hover behavior without doing hacks and editor-specific code injection.

You mean switch on hover? It's only useful when two of the buttons are visible, which is rather uncommon when working with UI.

[YuriSizov]

You mean switch on hover? It's only useful when two of the buttons are visible, which is rather uncommon when working with UI.

The way switch on hover is currently implemented (and this PR doesn't change) is less than ideal. It's parent based, and so it breaks in our editor UI when we talk about toolbars. Each toolbar has its own parent hbox, so only the buttons inside of the same toolbar can be activated on hover. As a user I'd expect the entire toolbar to be able to be hover-selected like that.

So it's not just the two buttons in this toolbar, but also the buttons from other toolbars and the main toolbar that should play into this. But, as mentioned, I didn't change that here. Having a common parent class like that would allow for future improvements in this area.

But, at this point, I'm tired of dragging these toolbar improvements for almost a year already. Every time they end up entangled with something else that prevents it from moving. So I'll amend this PR today to remove anything related to the PopupButton (including having the switch-on-hover logic for these new buttons). And then maybe open a proposal for it to improve the switch on hover behavior. (Edit: Here it is, godotengine/godot-proposals#5197).

PS. Thanks for reviewing it thoroughly by the way <3

[YuriSizov]

Okay, removed any changes done to MenuButton and the concept of PopupButton. This resolves every related comment. I've addressed the rest of them.

For the picker popups I've created a new base class that pulled some of the shared code. But I didn't unite them entirely, because there is plenty of non-shared code in them too. But it should keep the code duplication to the minimum now.

[YuriSizov]

Would appreciate an approval from @KoBeWi as he's been with me and this change through every iteration 🙃

[YuriSizov]

Alright, seems very mutual :)