Where can I find information about plugins and external programs? For example, how could I add a function to a context menu, or how could I grab a click signal and what what clicked ?
Specifically for 5.99 is there any documentation or examples somewhere to learn from ?
Current python interface is pretty limited in what kind of interactive things you can build. Essentially it allows you to read pcb state, modify and store it. Also some limited program state (like which items are currently selected).
You can’t extend menus or intercept clicks, at least not without some egregious hacks.
Documentation is here: https://docs.kicad.org/doxygen-python/namespacepcbnew.html
All of the above is about pcb editor (pcbnew) scripting. v5.99 is supposed to get support for schematic scripting soon but documentation for that is not yet available.
I haven’t yet moved to 5.99 so this may not help. But, I wanted to move my plugins into a panel or menu, too… Could not find a way to do it. I have too many homemade plugins (that I use) and that was making the window too wide. Thus, I wanted a Vertical plugin-bar.
So, I cheated and put them into a Vertical window that loads from a button-click in the Plugin-bar. Example below… I haven’t yet finished but this Idea could possibly work for 5.99 (if you look into making plugins…)