So the tl;dr on this is that we’ve made some changes to how the tree works that aren’t quite complete. It’s coming, but probably not in the next release.
This is essentially the issue with source order vs. display order vs. z-indexing that we’ve discussed here:
Based on the feedback and in-canvas order re-arranging features we introduced in 4145, Kevin and I decided to make the tree work more similarly to existing tools. In other words, moving elements inside of a parent in the tree changes the z-indexing, but not the display order.
- More familiar behavior coming from existing tools
- CSS layout is rapidly moving towards source order independence: it’s optional in Flexbox, inherent in CSS grid and absolute positioning. These are the layout models for the future of the web and the models we’re hewing to in Subform. Constraint-solver layout systems like Apple’s AutoLayout and Android’s ConstraintLayout are also source order independent
- It solves the design problems highlighted in the aforementioned topics
We took out the old behavior (dragging between elements in the tree) as a part of the 4145 enhancements. We intend to reintroduce that behavior in an upcoming release solely as a means to control z-indexing.