G53MDP Coursework 2 – Running Tracker

Summary
In this exercise you are required to build an Android running tracking application, and
document its design and architecture in a report. This is an assessed exercise and will account
for 40% of your final module mark. This is an individual coursework, and your submission
must be entirely your own work – please pay particular attention to the section of this
document regarding plagiarism. This is a sizeable and open-ended coursework compared to
the previous assessed exercises. This document sets out general requirements that your
application should meet rather than specific instructions.

Your application and report should be submitted no later than:

• 3pm on Monday the 13th of January 2020

Submissions should be made electronically via Moodle. Standard penalties of 5% per working
day will be applied to late submissions.

Your coursework should be submitted as a .zip or .tar.gz file containing your report and
application, including all relevant source code, configuration and related files, and a compiled
.apk file – i.e. the contents of the directory containing your Android Studio project. Do not
submit RAR files.

Specification
The Quantified Self or life-logging movement has been around for a number of years, but
advances in mobile and wearable computing have increased the ability of people to collect
data about their physical activities. The most common of these track activity as it happens for
fitness, health or gamification purposes, for example displaying comparisons with previous
activities, keeping track of best time or longest distances etc.

Application
The goal of this coursework is to design and implement a mobile application that functions as
a basic Running Tracker, in that it should allow the user to track their movement when they
decide to walk, run or jog, principally by logging the change in physical location using GPS.

The application should allow the user to inspect this data in a useful manner. The user might
expect to want to be able to ask simple questions of the data such as “how far have I run so
far today?”, “how far have I run this month?” or “have I run faster than my best time today?”.

The application should allow the user to annotate their data. They might expect to be able to
tag a particular exercise activity as good, or bad, or note something about the weather
conditions, or they might want to associate a photograph with the exercise activity.



At the minimum, your application should support:

• Logging the movement of a user when they go running or walking
• Saving the movement data in an appropriate manner
• Allowing the user to inspect their data in an appropriate manner
• Allowing the user to annotate their data in a useful manner

How you approach building this application is up to you, however in principle appropriate use
of all four major Android application components is expected:

• Activity
• Service
• Content Provider
• Broadcast Receiver

For this reason, it is important to consider how the task can be broken down into multiple
atomic components, how they communicate with one another, and how their various
lifecycles should interact. There is no requirement that your components will be accessed by
components outside of the application, however it is good practice to consider how your
components might be made available to other processes for subsequent reuse.

Some hints and tips regarding getting started with location services / GPS monitoring are
provided below.

Your application must be written in Java or Kotlin and make use of the Android SDK. There
are no requirements to target a specific Android API version, however you can assume that
your application will be tested on an emulated device (1080 x 1920 420dpi) running Android
API version 29 (Android 10.0).

Your application should have appropriate comments and variable / class names, so that a
reader can easily understand how it works at the code level.

Adding further additional functionality to the application is encouraged, as are, for example,
different interpretations of what it means to log running – you could consider walking, or
other kinds of movement activity as might be measured by sensors on an Android device –
however as always your application should meet the above specification primarily. Indeed,
an appropriate interpretation of the app’s required functionality is an implicit part of this
assessment.

Report
You should provide a report alongside your application that documents its design and
technical architecture, in particular providing a rationale for the components that you have
implemented and their communication, and the behaviour of the application from the user’s
point of view.

The report should be at minimum 1000 words long, with a maximum length of 1500 words.

There is no set structure for the report, however you may wish to include a diagram showing
the components and their relationships, and a short explanation of each one, for example
how the task is broken down into discrete Activity components, how and when Services are
started, how data is abstracted from underlying storage etc.

Plagiarism
N.B. Use of third party assets (tutorials, images, example code, libraries etc.) MUST be
credited and referenced, and you MUST be able to demonstrate that they are available
under a license that allows their reuse.

Making significant use of tutorial code while referencing it is poor academic practice, and
will result in a lower mark that reflects the significance of your own original contribution.

Copying code from other students, from previous students, from any other source, or
soliciting code from online sources and submitting it as your own is plagiarism and will be
penalized as such. FAILING TO ATTRIBUTE a source will result in a mark of zero – and can
potentially result in failure of coursework, module or degree.

All submissions are checked using both plagiarism detection software and manually for
signs of cheating. If you have any doubts, then please ask.

Assessment Criteria
Marks
Available
Application Functionality
The application meets the Activity Tracker specification, including novelty
and appropriateness
40
Application Structure and Implementation
Implementation and appropriate use of Android components 30
Programming style
The application is easy to understand, with comments explaining each
part of the code, correct formatting, and meaningful variable names
10
Report
Description of the design and architecture 20
Total 100

Each element of your coursework will be assessed against the standard criteria:

https://workspace.nottingham.ac.uk/display/CompSci/Marking+Criteria

The following areas will be taken into account for each part of the assessment:

• Demonstrating knowledge of the area

• Quality of the concept, including appropriateness and novelty

• Quality of the technological design, including appropriate use of software design
concepts, and appropriate good coding practice (abstraction, commenting, naming)

• Quality of the realization, including how well it works and elaborations over and above
the basic requirements

• Including all of the above aspects, clarity of structure, quality of argument / evidence,
and insight / novelty

Hints and tips
Using Location / GPS tracking
There are different mechanisms for obtaining the location of the device, including GPS, Wi-Fi
or cell-tower signal triangulation, and different mechanisms for how this data can be accessed
by the device.

Increasingly Android is attempting to push this functionality into Google Play services (giving
Google more control over parts of the Android stack), and this provides a unified approach
that fuses multiple location systems into one to provide an abstraction over multiple pieces
of hardware and to reduce battery usage. This requires making use of an emulator with the
Google APIs installed – generally this will be a different emulator system image.

https://developer.android.com/training/location/receive-location-updates

There is, however, a simpler approach that is perfectly adequate for this coursework, and that
is to use the LocationManager system service to provide GPS (global positioning system)
updates that reveal the user’s location.

https://developer.android.com/reference/android/location/package-summary.html

Accessing location requires permission from the user:




import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;

The LocationManager is a system service, and so needs to be retrieved from the service
manager via getSystemService. Then it can be passed an instance of a LocationListener that
will receive updates from the GPS provider. The two other parameters specify the minimum
frequency of updates (i.e. we can say that we want at most 1 update every 5 seconds), and
distance between updates (i.e. we can say that we only want to be told when the device has
moved at least 5 metres). The fastest update frequency for GPS is around 1 second, and
accuracy varies from a few metres upwards depending on environmental conditions.



LocationManager locationManager =
(LocationManager)getSystemService(Context.LOCATION_SERVICE);
MyLocationListener locationListener = new MyLocationListener();

try {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
5, // minimum time interval between updates
5, // minimum distance between updates, in metres
locationListener);
} catch(SecurityException e) {
Log.d("g53mdp", e.toString());
}

The MyLocationListener class receives these location events by implementing the
LocationListener interface as follows:

public class MyLocationListener implements LocationListener {
@Override
public void onLocationChanged(Location location) {
Log.d("g53mdp", location.getLatitude() + " " + location.getLongitude());
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// information about the signal, i.e. number of satellites
Log.d("g53mdp", "onStatusChanged: " + provider + " " + status);
}

@Override
public void onProviderEnabled(String provider) {
// the user enabled (for example) the GPS
Log.d("g53mdp", "onProviderEnabled: " + provider);

}

@Override
public void onProviderDisabled(String provider) {
// the user disabled (for example) the GPS
Log.d("g53mdp", "onProviderDisabled: " + provider);

}
}

onProviderEnabled and onProviderDisabled methods are called when the user enables or
disables the GPS, and onStatusChanged gives information about the status of the GPS signal:

https://developer.android.com/reference/android/location/LocationListener.html

The important method call is onLocationChanged, which reports the current location as it is
measured, and provides a Location object that can be inspected to obtain WGS 84 latitude,
longitude, altitude (elevation), reported accuracy of the signal etc.

https://developer.android.com/reference/android/location/Location.html

Note that geodesy and global positioning are incredibly complicated subjects in their own
right - the Earth is in no way perfectly spherical, and we like to think of linear distances on a
locally flat surface as opposed to degrees around the world – however the Location class hides
most of this from us. In particular the distanceTo method will calculate the distance between
two points given as latitude and longitude:

float distance = myLocation.distanceTo(someOtherLocation);

Emulating GPS
It is possible to complete this coursework entirely using the emulator – there is no advantage
to or necessity of having a physical Android phone. There is also no expectation that you
handle the everyday practical details of GPS – losing signal, inaccurate signals etc. You can
assume that it will be tested on an emulated device with “perfect” GPS.



The emulator provides a mock GPS device that feeds NMEA (latitude and longitude position
updates) to the phone where they will be handled by the LocationManager as if they were
real updates, via the extended controls menu. This can be found by clicking “…” on the
emulator side bar.

Furthermore, the emulator can replay a series of GPS events from a GPX file (a standard log
format for many GPS devices and applications). It is also possible to export from Google Maps
to GPX.

Three example GPX files have been uploaded to Moodle for use as “real” latitude and
longitude positions that can be played out.