Hate to say it but a 'plugin system' for a gui application is a bad smell. Look at plugins for hyper -- people write a few and then quit. That's the good outcome.
A more likely outcome is to be like Eclipse which more or less works out of the box to develop Java, occasionally gets a group of plugins put together by a vendor that works, but it will fail if you install enough of them.
The trouble is that current gui frameworks do not support encapsulation in that there is a single thread used to draw everything. If component A takes 10 sec to draw, component B has to wait.
A more likely outcome is to be like Eclipse which more or less works out of the box to develop Java, occasionally gets a group of plugins put together by a vendor that works, but it will fail if you install enough of them.
The trouble is that current gui frameworks do not support encapsulation in that there is a single thread used to draw everything. If component A takes 10 sec to draw, component B has to wait.