https://github.com/johnpapa/angular-styleguide
and using this:
Google's implementation of Material Design in Angular. Excellent examples of complex, accessible and well-documented components implemented on top of Angular 1.
AFAIK none of them are opensource.
I'm a huge fan of the Ionic framework, but it's sourcecode is a mess and even the good parts are usually complex implementations of things you would definitely not be doing (such as keeping view state live, overriding default elements etc...)
In regards to managing view states, then yes it's very common,but you don't usually write those yourself, you use things like Ionic (or ui-router).