Model

Model

The App is implemented following the MVVM Pattern.

The Package Model contain all classes related to persistence, the local files and the remote (ftp) files.

FileStructure

The package FileStructure contains the classes RemoteFile and RemoteDirectory which are used throughout the app to represent files and directories on the server.

Repositories

Repositories in MVVM are classes which retrieve data from Servers, Databases etc. Here we differentiated between remote repositories and local repositories, where he remote repositories communicate with our server and the local repositories manage the local stored data such as the files in the OHDM directory or the SharedPreferences.

Repositories should be accessed through the ViewModel. They return LiveData objects which can be processed by the ViewModel and observed from the Views

Files

Local files will be stored in the "OHDM" directory on the phone or tablet, this will be created at the first start of the App. The FragmentHome will display the content of this directory in a recycler view.

RemoteFiles and RemoteDirectories (from the SFTP server) aren't completely persistent. They will be retrieved at each start of the App. But to minimize Server interactions they will be persisted by the Repositories during runtime.

Classes and Methods

MapFileSingleton

This singleton holds a reference to a local map File chosen my the user. This map will be displayed in the FragmentNavigation and can be changed by the user at any time in the FragmentHome.

Methods

Name	Returns	Parameters	Description	Notes
MapFileSingleton()				(Singleton) private constructor
getInstance()	MapFileSingleton, the instance		Will return the saved instance or a new instance in case it wasn't initialized before
getFile()	File, the saved file		returns the saved file
setFile(File)	void		setter for the referenced File

RemoteDirectory

A class to describes a remote directory (from the SFTP server)

Methods

Name	Returns	Parameters	Description	Notes
RemoteDirectory(String, String)		path = the path of the dir on the SFTP server, String creationDate		constructor
getFilename()	String, the name of the file		Getter for the filename
getCreationDate()	String, the creation date of the dir		Getter for the creation date
getPath()	String, the path of the dir on the SFTP Server		Getter for the path
setFilename()	void	String, the name of the file	Setter for the filename
setCreationDate()	void	String, the creation date	Setter for the creation date
setPath()	void	String, the path of the dir	Setter for the path

RemoteFile

A class to describes a remote file (from the SFTP Server).

Methods

Name	Returns	Parameters	Description	Notes
RemoteFile(String, String, Long, String)		the name of the file, its path, its size, and its date		constructor
getFilename()	String, the name of the file		Getter for the filename
getCreationDate()	String, the creation date		Getter for the creation date
getPath()	String, the path of the dir on the SFTP server		Getter for the path
getSize()	Long , the file size in KB		Getter for the size
setCreationDate(String)	void	String, the creation date	Setter for the creation date
setPath(String)	void	String, the path of the file	Setter for the path
setFileSize(long)	void	Long, the size of the file	Setter for fileSize
setFilename(String)	void	String, name of the file	Setter for the name

LocalMapsRepository

Singleton Used in FragmentHome / ViewModelHome. Reads files from the OHDM directory of the device and returns a LiveData<ArrayList<File>> Object which can be observed by the View. Note : Only files with .map ending will be returned

Methods

Name	Returns	Parameters	Description	Notes
readLocalMapFiles(File targetDir)	void	targetDir, a File usually with its path to the OHDM directory	Reads all .map files from the OHDM dir and adds them to the localMaps list	I passed the targetDir, to improve testability
deleteLocalMapFile(int)	void	position of the files in the localMaps ArrayList	Deletes the file from the ArrayList and from the local storage
getLocalFiles(File targetDir)	LiveData<ArrayList<File>>, the localMaps list inside a LiveData object	targetDir, a File usually with its path to the OHDM directory	Calls readLocalMapFiles() refreshes the LiveData object and returns it	I passed the targetDir to improve testability
chooseMapAt(File targetDir)	void	position of the file in the localMaps ArrayList	Set the file at "position" as the chosen file in the MapFileSingleton	This can be done better : delete the MapFileSingleton and make its functionality part of this class

UserPreferences

Singleton Initialized at App start by the MainActivity. I needed that to make data stored within the SharedPreferences available throughout the App without0 passing Contexts everywhere

For example: The ID is used in the HttpRequestRepository and it wouldn't be good practice to pass the context from the view

Methods

Name	Returns	Parameters	Description	Notes
init(SharedPreferences)	void	SharedPreferences from the App	Called at app start by MainActivity, gets the saved data from the SharedPreferences
getUserID()	String, the user ID		Getter for the user ID
isDarkmodeEnabled()	true, if enabled else false		Getter for the darkmode boolean
enableDarkmode(Boolean)	void	true, to enable false, to disable	Setter for the darkmode boolean, changes value in SharedPreferences too
setUserID(String)	void	String, the user ID	setter for the user ID,, changes value in SharedPrefs too

FtpRepository

Singleton

Manages Data from the STP server (or Sftp), returns LiveData Objects which can be observed by Views, Persists the Data during runtime. Uses the async FtpTasks to communicate with the server, used by the map download fragments / their view models.

Methods

Name	Returns	Parameters	Description	Notes
getDirectoryContents()	MutableLiveData<HashMap<String, ArrayList<RemoteFile>>> , A HashMap which contains the Name of the directories as Key and a ArrayList of Remote as their contents		Getter of the dirContents
getMostRecentMaps()	MutableLiveData<ArrayList<RemoteFile>>, List of all remoteFiles inside the most recent dir.		Getter for the most recently requested maps
getAllMaps()	MutableLiveData<ArrayList<RemoteFile>>, A list of all maps inside the root dir		Getter for the allMaps
getDirectories(Boolean)	MutableLiveData<ArrayList<RemoteDirectory>> ; a list of all Directories inside the root dir		Getter for the directories
retrieveRemoteFilesFrom(String, MutableLiveData)	void	Path of the directory	Gets all File's from path using FtpTaskFileListing and publishes them in the LiveData Object
retrieveRemoteDirectories()	void		Gets all Directories inside the root dir using FtpTaskDirListing and publishes them in the LiveData Object. Calls retireveDirContent()
retrieveDirContent(String)	void	Path of the directory
refresh()	void		Calls all retrieve Methods, used in the views SwipeToRefreshLayout, observing views will be notified about changes
downloadMap(RemoteFile)	void	the File to be downloaded	Downloads the file using FtpTaskFileDownload

HttpRequestsRepository

Singleton

Manages all Http requests and responses, persist the data during runtime.

**Note : At the moment just the FragmentRequestStatus / its ViewModel are using this Repository - the Main Activity and the FragmentRequestNewMap still making their Http request still from their ViewModel - this needs to be changed **

Methods

Name	Returns	Parameters	Description	Notes
getRequests()	A LiveData Object with the String of all requests		Getter for the LiveData Object
retrieveRequests()	void		retrieves all request which the user made from the Server using HttpTaskRequest

Variables

Class containing static final Variables such as the Server Ports and IP, Paths etc.