If you’ve not read the article on Smartspacer itself, I recommend you read that first. This article will focus on how Smartspacer works, and will be quite technical.
tl;dr give me the source code? It’s here
As was discussed in the previous article, Smartspacer is able to replace the “Smartspace” service on Android, while also keeping the connection to the original intact to not lose any functionality. The reason this option is even available is the Android Compatibility Test Suite — the test system for the OS itself. In order to test Smartspace, Google added an override option to the service, which can be accessed with an ADB shell command. Running the command “cmd smartspace” details this option: