☂️ Refactor Plugins and FFI pages

[mit-mit]

Page URL

https://docs.flutter.dev/development/packages-and-plugins/developing-packages#plugin-ffi

Describe the problem

The plugins and and FFI docs could use a bit of cleanup.

Relevant pages are:

• https://docs.flutter.dev/development/packages-and-plugins/developing-packages#plugin-ffi
• https://docs.flutter.dev/development/platform-integration/c-interop
• https://github.com/flutter/flutter/wiki/Binding-to-native-code-via-FFI

Issues include:

1. The 'Developing packages and plugins' page is getting very, very long
2. There is duplication related to FFI across these three pages

---

Should include:

• [ ] │#1913
• [ ] │#2507
• [ ] │#7776
• [x] │#8442
• [ ] │#5359
• [ ] │#6715
• [ ] │#7123
• [ ] │#7164
• [ ] │#7379
• [ ] │#8843

[timsneath]

Also see video https://www.youtube.com/watch?v=05Wn2oM_nWw, referenced in https://github.com/flutter/website/issues/6511

[parlough]

We used to have a singular page at /development/platform-integration/c-interop and people keep finding the dead link. Now we don't have any singular entry point for Flutter FFI that's not tied to a specific platform.

Sounds like we should introduce an FFI for Flutter overview page, which can reduce some of the location and be the new destination for that link.

[atsansone]

From #9072

@mit-mit

Our documentation for how to create plugins (i.e. packages with platform specific code) have grown over time as we added more and more technical capabilities. They are now spread out over two main pages:

• Developing packages & plugins
• Writing custom platform-specific code

Each of these are in different places in the left menu, are each very long, and quite complicated.

I think it may be worthwhile to break this up into some smaller, more targeted pages, each handling just a single topic. For example:

1. method channels
2. Dart direct interop (FFI/JNIgen/etc.)
3. pigeon
4. package basics
5. plugins (i.e. packages with platform specific code)
6. federated plugin packages