Right now i'm blocking on two things:

• Where should the tool go? It's currently in "Adjustments", but this feels like a weird place to put it. Maybe a new "effects" category should be made?
• I'm not too sure what the most intuitive behavior would be for this tool when using selections. Should it use the selection as the "object" to align? Use the selection as the bounding box for the alignment? And in the latter case, how do we deal with non-rectangular selections?

edit: actually, it's probably best to have two checkboxes, "Align inside selection only" and "Object from selection only".
This allows the user to do all possible combinations of ignoring selection, selecting a specific object and aligning it relative to the whole image, selecting a specific object and aligning it within the selection, aligning the whole image relative to the selection.
That last one does seem a little weird though, so maybe instead we could have a dropdown offering only the first 3 options.

Thanks for looking at this!

I think having either the option to align within the bounding box of the selection, or aligning the selection contents within the image, could be useful. Ignoring the selection seems like the user could just do that beforehand by deselecting?

With implementing this as an effect, I think you might run into challenges with modifying the whole image since the result of your effect will be masked by the selection afterwards (normally, effects are only applied to the selection's contents). So it might be easier to implement it more like the Auto Crop tool if you need a lot more flexibility, or we can figure out the right API for effects to indicate they need to modify the whole image.

Thanks for looking at this!

I think having either the option to align within the bounding box of the selection, or aligning the selection contents within the image, could be useful. Ignoring the selection seems like the user could just do that beforehand by deselecting?

With implementing this as an effect, I think you might run into challenges with modifying the whole image since the result of your effect will be masked by the selection afterwards (normally, effects are only applied to the selection's contents). So it might be easier to implement it more like the Auto Crop tool if you need a lot more flexibility, or we can figure out the right API for effects to indicate they need to modify the whole image.

Indeed, i ran into that exact problem of selection masking the effect a few hours ago 😅
I don't think a whole lot of flexibility is needed, an API allowing to just say we want to edit the whole image seems like it would suffice. And i do feel like "align object" fits better under the effects tab than the image tab.

On another note, when trying to implement the selection-related options, the only way i could find to access the selection was with the "rois" parameter, which seems to just be an array of rectangle, so i'm not too sure how to deal with things like a circular selection. Or does that array of rectangle already represent a circle?

Right now I don't think the document's actual selection is passed down through the effect's API (similarly, because the masking against the selection is done implicitly afterwards)
The rectangle list would be a single entry with the bounds of the selection if IsTileable is false, otherwise it'll be a list of smaller sub-regions to process in parallel

That's not too much of an issue for the "align within the selection" option (since we just use the bounds anyways), but it is an issue for the "align selection within the image" option.
That makes it 2 required change for that latter option, when the former should work right now without any API changes.

Maybe i should only implement "align within the selection" for now, and leave "align selection within the image" for a later PR?
Especially since the same effect can be achieved by just copying the selection to a new empty layer the using the align tool.

Yeah, that sounds like a good approach to take 👍

Should be all good, adding support for selection was surprisingly easy
I was thinking, with #953 just getting merged, it seems we're going to have a few object-based effects. Maybe we could create a new "object" effect category and put those there?

went ahead with it for now, we can always revert the commit if you would rather have it somewhere else

Added tests and took the comments into account
Should i also move the feather effect into the object category? Or is that too out-of-scope for the PR?

Added tests and took the comments into account Should i also move the feather effect into the object category? Or is that too out-of-scope for the PR?

Thanks! Updating the feather effect category is fine to add into this PR since it's a trivial change

Aligning object to selection (as bounding box) is still not implemented.

Aligning object to selection (as bounding box) is still not implemented.
2026-03-23.13-42-55.mp4

I believe what you're looking for is already implemented.
If you have an active selection, the algorithm will find the object in that selection, and then align it using the selection as bounding box.

In your video, the object is outside the selection, so it is ignored.
It's not really possible to move objects from outside the selection, since effects aren't allowed to edit the image outside of the current selection.

Aligning object to selection (as bounding box) is still not implemented.
2026-03-23.13-42-55.mp4

I believe what you're looking for is already implemented. If you have an active selection, the algorithm will find the object in that selection, and then align it using the selection as bounding box.

In your video, the object is outside the selection, so it is ignored. It's not really possible to move objects from outside the selection, since effects aren't allowed to edit the image outside of the current selection.

It should work even if the object is outside the selection too.