Since I think WindowManagerService might be the most often used code in android, I decide to start from WindowManagerService, although it seems to be a little more complicated.
But right away, I have an issue, the definition of WindowManagerService.
public class WindowManagerService extends IWindowManager.Stub
What's IWindowManager.Stub? I google it, and www.androidjavadoc.com says android.view.IWindowManager.Stub. Then I reach frameworks\base\core\java\android\view\IWindowManager.aidl.
But in aidl, there's only an interface definition, so where's the implementation?
http://blog.csdn.net/stonecao/article/details/6425019 tells me that there should be some .java file for the implementation. And http://blog.csdn.net/innost/article/details/6172893 shows the usage of aidl tool.
Then I search the built source, and find out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/src/core/java/android/view/IWindowManager.java, which I think is the implementation of IWindowManager.