Migrate UI bundles to required components

[alice-i-cecile]

Almost all of our bundle types have been migrated to required components after #14791. However, UI bundles have not been done yet.

#15550 will conflict with that, but since that PR needs more time to bake, we should press on with this work for the 0.15 release.

The strategy to do so is laid out here: https://hackmd.io/@bevy/required_components/%2FpuAA8c18TzeMhjclo36vEQ#Combined-Proposal-1-Conservative-Port-no-major-reworks-Selected

[ickshonpe]

Ah I'm stupid I was worried this was going to be terrible but I hadn't realised required components were transitive until now 😅

I think though that Style might be better a choice instead of Node for the primary component. I've been thinking of a few constructions where it might be useful to have unstyled Nodes. We might want to support alternative layout algorithms as well and it'd be easier if they could output Nodes and use the existing UI extraction setup.

[cart]

I think though that Style might be better a choice instead of Node for the primary component. I've been thinking of a few constructions where it might be useful to have unstyled Nodes. We might want to support alternative layout algorithms as well and it'd be easier if they could output Nodes and use the existing UI extraction setup.

I think most of Style's fields should be migrated to Node, the rest should be moved elsewhere, and Style should be removed. So in a way, I agree.

[alice-i-cecile]

I think most of Style's fields should be migrated to Node, the rest should be moved elsewhere, and Style should be removed. So in a way, I agree.

Do you want to do that now, or wait for 0.16? I firmly agree about the ultimate action though.

[ickshonpe]

Do you mean that Style and Node should be consolidated into one component containing both the layout constraints and the resolved layout values? Or is it more like Style being renamed to Node and the resolved layout values being moved somewhere else.

I'd prefer it if we had more granular UI components anyway.

[VitalyAnkh]

I also prefer more granular UI components, i.e., keeping Node and Style separated. I'm waiting for the community to reach a consensus before migrating the examples in the PR (there are about 300 instances that need to be migrated in the examples).

[cart]

Do you want to do that now, or wait for 0.16? I firmly agree about the ultimate action though.

I think we should do the conservative port as outlined in the hackmd and do more involved changes in a later release.

Do you mean that Style and Node should be consolidated into one component containing both the layout constraints and the resolved layout values? Or is it more like Style being renamed to Node and the resolved layout values being moved somewhere else.

I think Node should be the "driving" public facing interface containing all of the "styleable" properties inherent to a UI node. For computed values (such as calculated_size), we should move those to one or more separate components.

There should be no more generic Style component. You "style" fields on specific components, you don't set Style.