[news.eclipse.platform.rcp] Calling method from different plugins

[Martin Jedlička <jedlicka@xxxxxxx>]

1) How can I call from one plugin (ViewPart) method of the another, i.e. 
How to get to method of same class which are in different plugins? e.g. 
I have plugin ViewPart with button and click on the button method from 
another plugin will be called.

2) How can I create plugin which I will use in another plugin like 
library (jar file)?

Thanks.

M.