1There are two libraries defined in this directory:
2First, com.android.media.remotedisplay.jar is a shared java library
3containing classes required by unbundled remote display providers.
4Second, com.android.media.remotedisplay.stubs.jar is a stub for the shared
5library which provides build-time APIs to the unbundled clients.
6
7At runtime, the shared library is added to the classloader of the app via the
8<uses-library> tag. And since Java always tries to load a class from the
9parent classloader, regardless of whether the stub library is linked to the
10app statically or dynamically, the real classes are loaded from the shared
11library.
12
13--- Rules of this library ---
14o The stub library is effectively a PUBLIC API for unbundled remote display providers
15  that may be distributed outside the system image. So it MUST BE API STABLE.
16  You can add but not remove. The rules are the same as for the
17  public platform SDK API.
18o This library can see and instantiate internal platform classes, but it must not
19  expose them in any public method (or by extending them via inheritance). This would
20  break clients of the library because they cannot see the internal platform classes.
21
22This library is distributed in the system image, and loaded as
23a shared library. So you can change the implementation, but not
24the interface. In this way it is like framework.jar.
25
26--- Why does this library exists? ---
27
28Unbundled remote display providers (such as Cast) cannot use internal
29platform classes.
30
31This library will eventually be replaced when the media route provider
32infrastructure that is currently defined in the support library is reintegrated
33with the framework in a new API.  That API isn't ready yet so this
34library is a compromise to make new capabilities available to the system
35without exposing the full surface area of the support library media
36route provider protocol.
37