gricciardi00 / memorandum-android-app

Android application in java for MobDev course

Memorandum

Project for the Android part of the MobDev course, consists of an application for managing memos in java made with Android studio.

Key features and application examples

With the Memorandum app you can:

• Add memos with a title, description, place, date, and time.
  

• Set the memo to ''completed'' or return it to ''active'' state
  

• View active, complete, or expired memos.
  

• View all active reminders on the map.
  

• Receive a notification on your device when you approach an active memo (even if the app is closed).
  

A close look on it

The application is based on the model MVC: Model, View, Controller.

Model

The model is responsible for defining the application data.

The Memo and MemoList classes are the application model. MemoList allows you to derive a list of all active memos and also has other methods used by the various activities.

View

Views display the data contained in the model and 'capture' the user's interaction with the application

As for Views, all the activity of the application are based on the use of a ConstraintLayout, useful for developing a UI in an intuitive way (without the use of nested views groups).

The only fragment present has a linear vertical layout, given the simplicity of its content.

Controller

Controllers are the brain of the application: they provide the link between view and model, manage user inputs sent from the view, and send any updates to the model.

The application consists of 4 activities and a fragment, the communication between activities starting through the use of intent.

• The mainActivity is the main entry point of the application, consisting of a text label representing what type of memo you are viewing (active, completed or expired), 3 floatingActionButtons used to access the other 3 activities, and a RecyclerViewer used to display notes.
  

In addition to showing notes, MainActivity takes care of initialising the locationManager to obtain the user's location and initialising the geofences of active memos. Whenever the mainActivity "onPause" method is called (that is, when other activities are opened, or the app is left in the background), the "locationManager.removeUpdates()" method is called to stop using the user's location to avoid unnecessary battery consumption of the device.

• The addActivity takes care of adding the memos, once you have entered the title, a description, the place in the respective EditText and the date and the time in the appropriate widgets you can create the memo by pressing the appropriate button.
  

Once the key is pressed, a check is made to see if any fields are empty, check that the date entered by the user is valid (from the current day onwards) and finally check if the geocoding operation to derive latitude and longitude from the place entered has been successful.

The function that carries out all these checks is called 'saveInput' and is set as the onclick property of the FloatingActionButton in the activity_add XML file, in case of invalid or missing fields a ToastNotification is called to report it to the user.

• The detailActivity is called in the memoAdapter onclick event override. Shows title, expiration, location and description of the selected memo, also there is a button to change the status of the memo (active/completed), if the memo has expired (check done using the two methods of the Utils class) sets the TextColor of the TextView of the date to red.
  

• The mapActivity shows a map,created through the google map API, centred on the user's location.
  

The activity also creates an annotation on the map for each reminder of the ArrayList of active memos received by the mainActivity via Intent.

When the user clicks on an annotation its title is shown.

• The infoFragment is accessible from the MainActivity, by clicking on the menuButton of the question mark, it shows a TextView that shows a guide on how the app works. There is also another button in the menu to show expired memos.
  

RecyclerViewer

The RecyclerView class makes it easy to view and manage large data sets, it is a container for displaying large data sets that you can efficiently scroll through while maintaining a limited number of Views.

Memo displays are via the mainActivity recyclerViewer. The MemoAdapter class represents the recyclerView adaptor, it is used to provide the LayoutManager with information on how many items should be displayed and the actual View to be used.

In this project, all memos are present on a single Adaptor with a 'status' attribute that indicates what type of memo to show (active/completed/expired), depending on the button the user presses, one of the three states is set as the attribute by the MainActivity.

The control to decide which type of memo to display is performed in the override of the onBindViewHolder method, depending on the status the colour and style of the font to be set is also set, all memos are shown in order of date.
NB : An avaiable alternative to this type of approach is to use fragments with different memoadapters to represent the various types of memos.

Notifications & Geofencing

The classes that create geofences and manage the sending of notifications are: GeofenceHelper,Notification Helper, NotificationBroadcast receiver.

• GeofenceHelper includes all the methods useful for creating geofences (via Google API), used in the mainActivity. User authorisation is required to use geofences for: ACCESS_BACKGROUND_LOCATION. Each GeoFenceHelper has an associated memo that is used by the 'getPendingIntent' method to obtain the memo information and pass it to the GeoFencingClient who takes care of the geofence registration.

• NotificationBroadCastReceiver retrieves information passed to the GeoFencingClient and calls the ''sendHighPriorityNotification'' method of the NotificationHelper class to send a notification.

• NotificationHelper manages all NotificationManager operations, creates a notification receiving channel and sends notifications to that channel.