By Jacob Lovie | GeoVis Project Assignment @RyersonGeo | SA8905 | Fall 2018
Introduction
With today’s technology becoming more and more mobile, and the ability to access everything you need on your mobile device, it is more important than even to ensure that GIS is evolving to meet these trends. My GeoVisualization project focused on designing an android application to allow users to explore Toronto’s green space and green initiatives, making layers such as parks and bike stations accessible in the palm of your hand. However, it is not just having access to this that is important. What’s important when working with these technologies is that a user can explore the map and retrieve the information seamlessly and efficiently.
Data and Hosting Feature Services
All the data for the project was retrieved from the city of Toronto’s open data portal. From there, all the data was uploaded to ArcGIS Online and set up as hosted feature services. A base map was also designed using ArcGIS for Developers and hosted. The application was able to target these hosted feature layer and use them in the map, making the size of the app small. The symbology and setup of the hosted feature layers was also done in ArcGIS online, so the app didn’t have to make any changes or set symbology when it wasn’t necessary.
Methods
The developer environment that I worked in to design my app was Android Studio, the baseline for designing any android apps. The programming language used in Android Studio is Java. Within Android Studio, the functionality of ArcGIS Runtime Software Developer Kit (SDK) for Android can be brought in, bringing in all the libraries and functions associated with ArcGIS Runtime SDK for Android. With this I was able to use ArcGIS functionality in android, designing maps, accessing hosted feature services, and perform geoprocessing.
Understanding how ArcGIS SDK for Android worked with in Android Studio was an important key in designing my app. When creating a map, I first had to create a Map object. An object is a variable that is of a certain datatype. If you were talking about having a text object as a variable that could be called, it would be of datatype string, and the word itself would be an object that is callable and referential. The Map object is what is displayed in an activity window (more on this later), which is what the user visualizes when using the app. The map can be set to view a certain area, which was Toronto in my app. A user can pan around the map like they would on any interactive map without having additional coding in Android Studio (it is natural to the Map datatype). The Map also has associated Layer objects that have their own set of parameters.
While designing my app, any time I would want something done in my design, such as creating a map object or adding a layer to a map object, I created a function that wold performs an action. This reduces repetition in the code when I attempted to do something complex multiple times. I designed 3 functions. The first was to create a Map, the second was to add a Layer that could be activated and deactivated in the Map through a switch that would be displayed in the main Activity Window. The final function added a layer that could be queried and would extract information from that layer.
When designing an android app, there are many fine details that are not necessarily considered when using an app on your phone. Simple things like having a window or text appear, opening a second window, or displaying information were things I very much appreciated after designing the app. Within my app, I wanted to display a second activity window to display information on neighbourhoods in Toronto when the user touched them. Within Android Studio this required creating a second activity window, and transferring the information obtained in the map to the second activity. This was done through my displayInformation function. I was then able to create a second activity and display this information using a custom list display to show the attribute data of a selected neighbourhood.
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Setting up the display in Android Studio is relatively simple. There is an interface that allows you to anchor different objects to parts of the screen. This allows the app to run smoothly across all devices, not based on the size and ratio of the device. The switches in my Main Activity window were anchored to the top left, and to each other. My Map is in the background, but appears as white in this activity window.
The Application
Once all the coding and testing was completed, running the app was simple. I was able to bundle my code and send it to my personal phone, a Galaxy S9. The functions called the hosted service layers and displayed them in the map (Wifi or internet connection was required). I was also able to click on neighbourhoods and it would open my second activity that displayed the attribute information of that neighbourhood. If you want a more in-depth look at my code, it is available at https://github.com/jclovie/GeoVis-Ryerson/.