Question

As of ADT 14, resource fields cannot be used as switch
cases. Invoke this fix to get more information. whats the reason this is used for?

Answer 1

Take a look at the official blog post about this:

http://tools.android.com/recent/switchstatementconversion

http://tools.android.com/tips/non-constant-fields

Basically, resource constants in library projects are no longer “final”. From the ADT Site:

In other words, the constants are not final in a library project. The
reason for this is simple: When multiple library projects are
combined, the actual values of the fields (which must be unique) could
collide. Before ADT 14, all fields were final, so as a result, all
libraries had to have all their resources and associated Java code
recompiled along with the main project whenever they were used. This
was bad for performance, since it made builds very slow. It also
prevented distributing library projects that didn’t include the source
code, limiting the usage scope of library projects.