Country Selector

Country selector allows you to get quick information about a country.

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Project Overview

The purpose of this project is to demonstrate the current quality level of the code I write and the UI/UX that I design, which will help the companies who are considering hiring me to have a cleaner perspective of my skill level.
You can find brief technical information about the project here.

Model-View-ViewModel

This project uses the recommended design pattern by Google, MVVM, which helps to have a nice, maintainable structure that is easy to unit test since the modules are independent.

Also, it helps a lot to have a lifecycle aware inheritable ViewModel class that is working perfectly with also lifecycle aware LiveData class.

Dependency Injection

This project also uses the dependency injection since it drastically helps with unit testing, maintaining loosely coupled code and having reusable modules.

As a framework, Dagger 2 was preferred since it has no effect on performance, reduces boilerplate code (even though not in this particular case (: ) and also recommended and supported by Google.

Testing

A significant amount of the cases in this project whether it is a module or a UI is covered by unit, integration and UI tests. The following libraries was preferred due to their quality and popularity:

• Junit 4
• Mockito
• MockWebServer
• Hamcrest
• Espresso
• UIAutomator

Custom Themes & Styles

In the designing of the UI, custom themes were created and view attributes like color, dimensions, strings are not hardcoded which allows additional themes to be created easily.

Views have their own styles which reduces the need copy to and paste the attributes and provides consistency when creating similar views.

Designing

• While designing the layouts, most of the time ConstraintLayout was preferred for the best performance.

• I avoided stacking the layouts as much as possible to achieve the best optimization.

• Layouts are compatible with both portrait and landscape mode.

• Avoided displaying too much options or information in one view for the best user experience.

• Used ViewStub for ErrorCard to optimize rendering of the layout since it has stacked layouts and it does not need to be inflated immediately.

The Globe Icon is edited, given gradient and drop shadow by me. Android error icon is designed by me getting inspired by another design.

Documentation Of The Code

The project is well-documented by using javadoc and is ready to be exported as HTML.

Design Insight

Integration Of Countries To The Project

When I was planning to integrate a list of countries and their flags with the application, I decided I should demonstrate how I would approach a changeable large piece of data (since it wasn't actually a large piece of data, I preferred to have a fast scroller with an alphabetical letter indicator in favor of the pagination) .

Therefore, even though it would be easier and more applicable to copy-paste a static list of country names and codes from an open-source Java project, I chose to add a JSON file containing the list of the countries and querying them once on each launch. Since I stored them in a List within a singleton class, JSONCountriesRepository, countries are already in memory. Hence, it does not require to be queried each time it is needed. And I added the images of every flag by using a batch drawable importer plugin.

I thought that this list could be used in multiple places. Therefore I thought that if it would be a DialogFragment it would not only be more easy to access by the users but also would be much more easy to implement on the other screens. So I proceeded with that idea and used the observer pattern in the DialogFragment to have flexibility on implementation since every screen might want to take a different action when a country is clicked.

Retrieving The Country Details

I used Retrofit to send GET requests since it is reliable, easy and compatible with GSON out of the box.

I handled the exceptional cases like slow network connection, no internet connection, not found responses, etc. and added a modern informative UI to convey the error.

I also wrote singleton ScheduledExecutorService and Retrofit service classes by considering the scalability, reusability, and performance.

Dagger 2

I did not creat any subcomponent like MainActivity component because there is not a dependency in the application that should not be accessed by the another lifecycle (no login or auth system) and there is also not a chain of dependencies that are only being used to satistfy one class.

Further Development

• Custom FastScrolller With SectionIndexer The library that I used for FastScrolling with SectionIndexer for RecyclerView does not work very well. Writing a custom one and using an AbsListView would have been better.

• DayNight Theme I really like the new DayNight feature/theme, it could have been impemented into the application but I did not implement it yet because time was running out and I want to keep the dark theme as default unless the user choses to do otherwise which means not only I would have to create a light theme but also create a SharedPreferences repository, instrumentation test, and a settings screen. And this is not a production application, so I did not find it efficient to do so.