The project is divided in three packages Controller ,DBHelper, Presenter
The presenter is responsible for all the User Interface and the connection with the Xml code. It contains four java file ListView , MainActivity, Sale, Search each responsible for a corresponding XML activity.
The Controller is responsible for the program's logic filters the input and output of the current program.
The DBHelper is responsible for the communication of the program with the data Base. The DBHelper also creates the database if it's the first time the program has been created The database use was an SqLite database that creates a file inside the device and runs locally Note that when the application closes the data do not get deleted