Editor lags when selecting color for StyleBox

[floppyhammer]

Godot version

v3.4.beta5.official [dd0ee48]

System information

Windows 11, GLES3

Issue description

Editor lags when selecting color for StyleBox.

Steps to reproduce

Open the reproduction project, click theme.tres in the FileSystem tab, change bg_color of a StyleBoxFlat.

Minimal reproduction project

StyleBoxColorTest.zip

[YuriSizov]

Note that this doesn't happen in the latest 3.x version anymore because the StyleBox resource will now open in a new inspector instead of showing in a sub-inspector (regardless of how the editor is configured). This is ultimately a performance problem of the inspector with huge objects, which is made bigger by the fact that we have a theme editor now that also syncs up with the resource.

This is still a problem in master though.

[floppyhammer]

No such an issue in 3.3. And it's not only lagging but also mouse input interruption which effectively makes the color selection process uncontrollable.

[YuriSizov]

Yes, this is not so obvious in 3.3 and prior because basically nothing happens in the old theme editor. But the chokepoint is in the inspector nonetheless. You also don't see this in 3.4 with smaller theme resources.