If you're having trouble or run into any bugs with the code, post a comment here! I will try to get back to you within a few days.
It's pretty nice and useful. Especially if I wanna check quickly if there's any graphical error. I just wished the viewport on the right was as flexible as the one for the Image Attributes Tool (where you could zoom/dezoom/move around the sprite). As of now it's displaying the sprite twice, which can waste quite a bit of space (especially if you're trying to see the whole body). Maybe only keep one view (where you can zoom/dezoom) would be nicer.
Also personal preference but I'd rather when I click on a group, it replaces everything with the current group, than adding it to the current stack (maybe if you right click it, it could have this additional functionality?). Because I have a lot of attribute so I end up hiding/showing everytime I want to see a different group.
Mhh also I guess it has the issue where you can have conflicting attributes in the viewport.
For example if you have
layeredimage alice:
group outfit:
attribute outfit_secretary
attribute outfit_punk
group accessories:
attribute outfit_secretary:
"glasses"
Then in your editor, we could select outfit_punk from the outfit group, but we could also select outfit_secretary from the accessories group. So both outfit_punk and outfit_secretary are on the tag.
If you tried that ingame it would throw an error, the two attributes are mutually exclusive (and rightfully so).
But that seems like an annoying bug to resolve lol, it's really because somehow, add "alice outfit_secretary outfit_punk" in a screen is valid, but "show alice outfit_secretary outfit_punk" is not valid in a label? I'm not sure I get it either.
It's not really a big deal for me, but I might as well write it down.