Control an application from another application

Question

I read this question and another question and I understand how to launch an application from another application (Let's call the other application LauncherApplication). However, my goal is not only to launch an application, but to use its functions, so I suppose the LauncherApplication should start an activity using an intent (explicit or implicit).

I should know the data and the actions the installed applications react on and I should add these information to an intent instance before starting it. I wish LauncherApplication allows the user (not the developer) to configure this intent, but how do I know in advance the parameters to put in an intent for the installed applications?

I should implement the "LauncherApplication* in order to allow the user to construct an intent via a graphical interface. Or I could make my application supports the addition of plugins: in this way, I could create a plugin for each installed application, where each plugin could be responsible to manage the configuration of the intent concerning the application associated with it.

UPDATE (added details). In particular, the LauncherApplication should be a service with a speech recognizer enabled, so the user may start an application uttering specific keywords: as well as launch an application, the user should be able to close it and use its functions.

For example, I could have installed an application ((Let's call it LibraryApp) to search for available books in a library; this application could have the following functions:

1. Search for a book (this function may return if the book is available, it has already been loaned or if it was booked by someone else).
2. Reserving a book (this function should return the completion of the reservation).

In this way, when I pronounce, for example, the words "start LibraryApp", then the LauncherApplication service should launch the LibraryApp application. Once the application is launched, the service should be able to send commands to it to use one of the available functions (search for a book, reserving a book).

How can I send commands to application that is already active, in order to control it?

Answer 1

how do I know in advance the parameters to put in an intent for the installed applications?

You talk to their developers. There are typically zero "parameters" on an Intent to launch the launcher activity (or activities) of an application, since home screens do not put such "parameters" on the Intent.