Trampoline child measurement/layout through the LayoutTree trait

[nicoburns]

Objective

The objective here it to make is easy to embed Taffy as part of a larger layout implementation rather than usage of Taffy requiring you to "buy in" to having all your layouting needs handled by Taffy.

This is the core change from #326
Fixes #28

Context

See #28 (comment)

Notes

Seems to be relatively perf-neutral.

[TimJentzsch]

Seems solid to me.

I think it would be great to add a simple example demonstrating how to use these new capabilities, if possible.
This would make it easier to detect limitations of the approach and also serve as a useful reference to library authors to integrate this.

[Weibye]

Seems solid to me.

I think it would be great to add a simple example demonstrating how to use these new capabilities, if possible. This would make it easier to detect limitations of the approach and also serve as a useful reference to library authors to integrate this.

Yes, it's strange that this doesn't affect any of our examples, which means our examples are lacking.

[nicoburns]

Seems solid to me.
I think it would be great to add a simple example demonstrating how to use these new capabilities, if possible. This would make it easier to detect limitations of the approach and also serve as a useful reference to library authors to integrate this.

Yes, it's strange that this doesn't affect any of our examples, which means our examples are lacking.

This API was never really properly designed/launched. It was introduced as part of a PR which was necesary for refactoring Flexbox to interop with CSS Grid. One of my main aims for Taffy 0.4 is to sort this out and make this API useful.