iOS UI

Source Code

Now to iOS. Here we use Swift UI to program our UI and like in Android a timer updates the state of the game every half a second.

struct BoardView: View {

    @Binding var board: Board

    var body: some View {

        VStack(spacing: 2) {
            ForEach(0..<Int(self.board.rows)) { rowIdx in
                HStack(spacing: 2) {
                    ForEach(0..<Int(self.board.columns)) { columnIdx in
                        self.createCell(rowIdx: rowIdx, columnIdx: columnIdx)
                    }
                }
            }
        }
    }

    private func createCell(rowIdx: Int, columnIdx: Int) -> some View {
        let cell = self.board.cellAt(column: Int32(columnIdx), row: Int32(rowIdx))
        if (cell.alive) {
            return Rectangle()
            .fill(Color.gray)
            .frame(width: 10, height: 10)
        }
        return Rectangle()
        .fill(Color.white)
        .frame(width: 10, height: 10)
    }

}

struct ContentView: View {

    @ObservedObject var boardStore = BoardStore()
    let timer = Timer.publish(every: 0.5, on: .main, in: .common).autoconnect()

    var body: some View {

        BoardView(board: $boardStore.board).onReceive(self.timer) { time in
            self.boardStore.calculateNextGeneration()
        }
    }
}

Swift UI redraws the UI automatically based on the state of the application, so we need to make sure the game state is reflecting in the application state correctly.

class BoardStore: ObservableObject {

    let columns: Int32 = 30
    let rows: Int32 = 50

    let objectWillChange = ObservableObjectPublisher()

    var board: Board

    init() {
        self.board = Board.init(columns: columns, rows: rows)
        let cells = BoardKt.cells(
            """
            ***_*
            *____
            ___**
            _**_*
            *_*_*
            """)
        let cellsCentered = BoardKt.translatedTo(
            cells, column: columns / 2 - 2, row: rows / 2 - 2 )
        board.setCells(cellDefinitions: cellsCentered)

    }

    func calculateNextGeneration() {
        self.board.calculateNextGeneration()
        self.objectWillChange.send()
    }

}

iOS UI