WearOS Dice App

It is been so long for me to try to make a wearOS app. Last time I check, the building experience is too slow. And Android development is preference is also a pain.

This time I tried to make a simple dice app. Using ViewModel. There are some packages needed to be added in the build.gradle file. The editor still not remind you, but you can ask Gemini to find the packages.

// Dice.kt
class Dice {
    fun roll(): Int {
        return (1..6).random()
    }
}

// DiceViewModel.kt
class DiceViewModel: ViewModel() {
    private val dice = Dice()
    private val _currentRoll = MutableStateFlow(1)
    val currentRoll: StateFlow<Int> = _currentRoll

    fun rollDice() {
        viewModelScope.launch {
            val result = dice.roll()
            _currentRoll.value = result
        }
    }
}

// MainActivity.kt

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        installSplashScreen()

        super.onCreate(savedInstanceState)

        setTheme(android.R.style.Theme_DeviceDefault)

        setContent {
            WearApp()
        }
    }
}

@Composable
fun WearApp(diceViewModel: DiceViewModel = DiceViewModel()) {
    DiceTheme {
        val currentRoll by diceViewModel.currentRoll.collectAsState()

        Scaffold(
            timeText = { TimeText() },
            vignette = { Vignette(vignettePosition = VignettePosition.TopAndBottom) },
        ) {
            Column(
                modifier = Modifier
                    .fillMaxSize()
                    .padding(16.dp),
                verticalArrangement = Arrangement.Center,
                horizontalAlignment = Alignment.CenterHorizontally
            ) {
                Text(
                    text = currentRoll.toString(),
                    fontSize = 80.sp,
                    fontWeight = FontWeight.Bold,
                    modifier = Modifier.padding(bottom = 24.dp)
                )

                Button(
                    onClick = {diceViewModel.rollDice()},
                    modifier = Modifier.size(24.dp)
                ) {
                    Icon(
                        imageVector = Icons.Default.Casino,
                        contentDescription = "Roll Dice",
                        modifier = Modifier.size(24.dp)
                    )
                    Spacer(modifier = Modifier.width(8.dp))
                }
            }
        }
    }
}

@Preview(device = WearDevices.SMALL_ROUND, showSystemUi = true)
@Composable
fun DefaultPreview() {
    WearApp()
}

Send the app to the watch is still a pain. Now I am using wearos toolbox to install the apk.