TicTacToe

Game with noughts and corsses that has different ways to win:

4 in row horizontal
4 in row vertical
2x2 box
Main diagonal
Reverse diagonal

Libraries used

Koin for dependency injection.
Junit 5 & Mockito for testing.
ViewModel, dataBinding and LiveData.

Project architecture

The different modules have different responsibilities:

app -> Has the main logic of the app.
core -> Contain all the logic that could potentially use all over the app. Here I have implemented the base classes and all the extensions.
components -> Contain all the custom views that would be used all over the app.

Presentation layer architecture

The presentation layer is now based on three different files:

ViewModel, Fragment and State

Where the ViewModel would do all the logic and the states would be managed in the Fragment. For example:

The viewModel (Does an API call) -> the viewModel receives data from the API -> the viewModel updates the state -> The state is observed in the Fragment -> when the state is updated, then in the Fragment we are able to make the pertinent updates.

DataBinding

In this project I have used two different ways to bind data to the custom view GameBoard.

Using 2 way dataBinding

For this, I have created a BindingAdapter and an InverseBindingAdapter for the attribute playerTurn, where it is going to emit data to the view when user touch any cell of the board and there is no winner combination or draw.

@JvmStatic
@InverseBindingAdapter(attribute = "playerTurn", event = "playerTurnAttrChanged")
fun getPlayerTurn(view: GameBoard): Int {
    return view.viewModel.player
}
@SuppressLint("ClickableViewAccessibility")
@JvmStatic
@BindingAdapter(value = ["playerTurnAttrChanged"])
fun setListener(view: GameBoard, listener: InverseBindingListener?) {
    listener?.let {
        view.setOnTouchListener { _, motionEvent ->
            listener.onChange()
            view.onTouchEvent(motionEvent)
        }
    }
}

Access to variables of the view using View binding

In the GameBoard custom view, I have created two different variables called isWinnerMovement and isDraw that has a custom get function that is triggered when any of them are consulted.

viewModel.checkGameStatus(
    binding.gbGame.isWinnerMovement,
    binding.gbGame.isDraw,
    playerTurn
)

Testing

For this project, I have created unit tests for the two viewModels that I have created in this project, TTTViewModel and GameBoardViewModel. For these uni tests I have used JUnit 5 and I have also created a custom annotation to be able to test LiveData objects (InstantExecutorExtension).

Gradle files structure

BASE.GRADLE contain all the common logic for all the different modules (app, core and components).
DEPENDENCIES.GRADLE contain a list of LinkedHashMaps with all the dependencies and all the correspondent versions.
The rest of the gradle files only contain the specific setup that each module require.

smoralb / TicTacToe