| # UserFileManager | |
| This class is used to generate file paths and SharedPreferences that is compatible for specific OS | |
| users in SystemUI. Due to constraints in SystemUI, we can only read/write files as the system user. | |
| Therefore, for secondary users, we want to store secondary user specific files into the system user | |
| directory. | |
| ## Usages | |
| Inject UserFileManager into your class. | |
| ### fun getFile(fileName: String, userId: Int): File | |
| Add a file name and user id. You can retrieve the current user id from UserTracker. This will | |
| return a java.io File object that contains the file path to write/read to. | |
| i.e. `fileManager.getFile("example.xml", userTracker.userId)` | |
| ### fun getSharedPreferences(fileName: String, mode: Int, userId: Int): SharedPreferences | |
| Add a file name, user id, and PreferencesMode. You can retrieve the current user id from | |
| UserTracker. This returns SharedPreferences object that is tied to the specific user. Note that if | |
| the SharedPreferences file does not exist, one will be created automatically. See | |
| [SharedPreferences documentation](https://developer.android.com/reference/android/content/Context#getSharedPreferences(java.lang.String,%20int)) | |
| for more details. | |
| i.e. `fileManager.getSharedPreferences("prefs.xml", userTracker.userId, 0)` | |
| ## Handling User Removal | |
| This class will listen for Intent.ACTION_USER_REMOVED and remove directories that no longer | |
| corresponding to active users. Additionally, upon start up, the class will run the same query for | |
| deletion to ensure that there is no stale data. | |