This is just an experiment for testing purposes.
Until fairly recently, joining screen areas required that the edges of those areas line up exactly (as seen in the left of the following image). But that requirement has been relaxed somewhat over the last year and we can now join areas that are bit misaligned (as shown in the second and third image below):
This patch is part of experiments in relaxing that alignment requirement much further. In fact it largely tosses out the test for near-alignment and instead uses different types of tests to see if the join is possible. It can let you do some very disparate joins between the areas, like those shown below:
For just the default layout, the new joins you can do are highlighted below with yellow:
What is required for joining?
- the two areas must share part of one edge, but only for a small distance (about double the height of a header)
- the areas have to be able to join without removing any other area
- the areas have to be able to be joined simply, without needing to split any participant first.
- the areas have to have edges that are oriented to allow them to be joined and aligned.
This seems like a long list, but the practical result is that if two areas can be joined somehow then they will be joined. You will only get the "stopsign" while attempting a join when it really isn't possible to do so without some drastic action like bisecting or subsuming some other area.
