make window zoom more flexible

[koekeishiya]

Allow a parent zoomed window to go directly into fullscreen and vice versa.

[FelixKratz]

An addition to this might be:

• Allow only one child at a time to zoom to parent node (https://github.com/FelixKratz/yabai/commit/7386dd22771e24ff01fb8494d0e14f010d021c98)
• Zoomed windows occlude windows below in the next-window-in-direction calculation (https://github.com/FelixKratz/yabai/commit/81cd0e5213b86280d118e3e80ddf29b269b7a0a5)

[koekeishiya]

Allow only one child at a time to zoom to parent node

This is how it used to work originally when I first implemented it, but for some reason I no longer remember I removed that restriction.. Will think about it for some time.

[koekeishiya]

So I use this functionality sometimes instead of using the window stack system, with both b and c having parent zoom active at the same time. Then I can toggle them using the normal directional commands, as they are "still in the bsp structure".

+---------+
|    |    |
|    |  b |
| a  |----|
|    |  c |
|    |    |
+---------+

Maybe that is an indicator to improve the stack system, heh.

[FelixKratz]

It always felt like a bug to me that directional operators (west, east, north, south) would focus a window that is not visible (occluded by the zoom of some other window). But I guess that without some kind of indicator (e.g. in SketchyBar or via the color of the border) for the state of a window it is easy to "loose" windows buried under some other zoomed windows.