Try the morcinek code generator. Its really simple to use.
This are the steps to install the plugin:
After install process you may want to configurate a package to get the classes built by the generator, on the IDE -> Window -> Preferences on Bookmark Android Code Generator you can change that parameter.
The plugin does need a better interface for custom activities, still you could get the code, its really simple to make the changes you need, at least the inline listeners.
This solution doesnt work to modify classes you already have, that would be a really good improvement... i'll give it a try in a couple days with more time.