Just quickly responding to your questions:
The source is available but not really supported – see the following, very stale, draft pull request: [cs_pinyin] CS-Pinyin keyboard initial public version by mcdurdin · Pull Request #64 · keymanapp/keyboards · GitHub
More background: a review of Keyman’s IMX support is much needed; we are currently very focused on implementing the LDML Keyboard spec, but once that lands we will be in a good place to do a solid redesign of a proper cross-platform, extensible IMX solution.
I am not sure if it will be based on the existing predictive text module, but it is likely to borrow some of the concepts.
Whatever solution we land on, it will need to support the existing IMX feature set:
- C API and bindings: so you can build with basically any compilable programming language
- UI extensibility: currently, imxlib does provide some focus and window management but that’s Windows-only, so we’d need this to work cross-platform
Also for consideration:
- database connectivity? (with external libraries)
- network connectivity? (with external or OS libraries)
But I want to emphasize that the IMX redesign is completely open at this point, so much too early to make any decisions based on it. Existing IMX would certainly need to be rewritten to work with it – but then would benefit from being cross-platform. (We’d try to keep the existing interfaces working on Windows, perhaps on Web, for legacy keyboards.)