[Jetpack Compose] DatePickerとTimePickerの表示

@OptIn(ExperimentalMaterial3Api::class)
@Preview(showBackground = false)
@Composable
private fun SampleDateAndTimePickerView() {
    Scaffold(
        topBar = {
            TopAppBar(title = { Text("Date & Time Picker Example") })
        }
    ) { paddingValues ->
        Column(
            modifier = Modifier
                .padding(paddingValues)
                .fillMaxSize()
                .padding(16.dp),
            horizontalAlignment = Alignment.CenterHorizontally,
            verticalArrangement = Arrangement.Center
        ) {
            DateTimePickerScreen()
        }
    }
}

@OptIn(ExperimentalMaterial3Api::class)
@Composable
private fun DateTimePickerScreen() {
    val calendar = Calendar.getInstance()
    val year = calendar.get(Calendar.YEAR)
    val month = calendar.get(Calendar.MONTH)
    val day = calendar.get(Calendar.DAY_OF_MONTH)
    var selectedDate by remember { mutableStateOf("$day/${month + 1}/$year") }

    val hour = calendar.get(Calendar.HOUR_OF_DAY)
    val minute = calendar.get(Calendar.MINUTE)
    var selectedTime by remember { mutableStateOf(String.format("%02d:%02d", hour, minute)) }

    var isShowDatePickerDialog by remember { mutableStateOf(false) }
    var isShowTimePickerDialog by remember { mutableStateOf(false) }

    Text(
        text = "Selected Date: $selectedDate",
        style = MaterialTheme.typography.headlineMedium
    )
    Button(
        modifier = Modifier.fillMaxWidth(),
        onClick = {
            isShowDatePickerDialog = true
        }
    ) {
        Text("Pick Date")
    }
    Spacer(modifier = Modifier.height(24.dp))
    Text(
        text = "Selected Time: $selectedTime",
        style = MaterialTheme.typography.headlineMedium,
        modifier = Modifier.padding(bottom = 8.dp)
    )

    Button(
        modifier = Modifier.fillMaxWidth(),
        onClick = {
            isShowTimePickerDialog = true
        }
    ) {
        Text("Pick Time")
    }

    if (isShowDatePickerDialog) {
        val context = LocalContext.current
        android.app.DatePickerDialog(
            context,
            { _, selectedYear, selectedMonth, selectedDay ->
                selectedDate =
                    "$selectedDay/${selectedMonth + 1}/$selectedYear"
                isShowDatePickerDialog = false
            },
            year,
            month,
            day
        ).show()
    }

    if (isShowTimePickerDialog) {
        val context = LocalContext.current
        TimePickerDialog(
            context,
            { _, selectedHour, selectedMinute ->
                // Update the selected time state when a time is picked
                selectedTime = String.format("%02d:%02d", selectedHour, selectedMinute)
                isShowTimePickerDialog = false
            },
            hour,
            minute,
            true 
        ).show()
    }
}