Plugin/Host interfacing: Communicating UI sizes

[LibrarySeph]

If hosts could ask plugins about their UI size limitations, it would make it possible to inline them.

For instance:
Bitwig - "Hello plugin, can your UI be shorter than 250px tall and less wide than 800px?"
Plugin - "Yes I can"
Bitwig - "Okay, give me a UI within those size limitations and I'll do whatever I want with it"
Bitwig then adds the UI inline to its device chain, similar to how it adds its own native devices.

These sizes would not have to be standardized, if the plugin couldn't fit it would just get a window. Further, hosts could create many different tiling or organization techniques.

Another property that might be cool is "full vs reduced" forms. So:
Host - "Is this UI a full or reduced version?"
Plugin - "It is a reduced version"
Host - "Okay, then I'll make sure to include a button for opening the full window"

Reduces versions would be especially useful for plugins that have a lot of depth, but revolve around a single visual item. Examples might include spectrums and oscilloscopes.

The one big drawback is that -- at least last time I checked -- responsive/scalable UIs aren't very easy to make.

Anecdotally, the biggest reason I quit using Logic and no longer use plug-ins unless I absolutely must is because opening little windows for every different thing is super clunky.

[LibrarySeph]

I knew this wasn't a new idea. Found another post of it: #206