Built a simple dice roller application.

Refreshed knowledge on: Setting up Android studio Setting up devices on Emulator Basic app structure, detailed insight on every file in an android application. Layouts, Activities and Inflation. Gradle and Compatibility on Android.

Adding WorkManager to your project
Scheduling a simple task
Input and output parameters
Chaining work
Unique work
Displaying work status in the UI
Cancelling work
Work constraints

Using the Library "com.jakewharton.retrofit:retrofit2-kotlin-coroutines-adapter:" Retrofit is able to add a CoroutineCallAdapterFactory.

This enables retrofit to produce a Coroutine based Api. The CoroutineCallAdapterFactory allows the ability to replace the "Call" in the Service methods with Deferred from Coroutines.

Deferred is a type of non-blocking Cancellable job that can directly return a result.

Because Retrofit does everything on a background thread, we can use the UI thread andd dont need any other threads.

When using CoroutineScope/ Jobs in ViewModel, don't forget to cancel them in the OnClear Lifecycle.

Built a bindingAdapter that takes the url from an xml attribute associated with an imageview and use glide to load the image

Parcelling is a way of sharing objects between different processes by flattening objects into a stream of data called a Parcel.

• Used a Room Database to store retrieve and update my data.
• Created a sleepNights data class to define a database table and it's structure.
• Made a Data Access Object to define the API for our database, creating mappings between kotlin functions and SQLite queries.
• I made a room database singleton.
• ViewModelFactory for dependency injection.
• Added ViewModels to manage database operations and handle user clicks.
• Used Coroutines to make sure the database operations don't interfere with a smooth user experience.
• Implemented Observable state variables to keep UI operations, such as navigation in the fragment.

Because the git history of this project will become obscure, I'll mention here that the project started off completely Java and the task was to convert it to Kotlin. You can find a history of changes at the beginning of the master branch.

Added code to persist data upon application being stopped. Added Timber. Global Code Cleanup

Notes:

onCreate: Inflate the activity's UI, whether that's using findViewById or databinding. Initialize variables. Do any other initialization that only happens once during the activity lifetime.

onStart: Start any sensors, animations or other procedures that need to start when the activity is visible.

onResume: Start any sensors, animations or other procedures that need to start when the activity has focus (the activity the user is currently interacting with).

onPause: Stop any sensors, animations or other procedures that should not run when the activity doesn't have focus and is partially obscured. Keep execution fast. The next activity is not shown until this completes.

onStop: Stop any sensor, animations or other procedures that should not run when the activity is not on screen. You can use this to persist (permanently save) data, which you’ll be learning more about in Lesson 6 Stop logic that updates the UI. This should not be running when the activity is off-screen; it's a waste of resources. There are also restrictions as soon as the app goes into the background,

onDestroy: Tear down or release any resources that are related to the activity and are not automatically released for you. Forgetting to do this could cause a memory leak!