Select all text of TextField in Jetpack Compose with mvvm pattern - android-jetpack-compose

Question

In the previous text field, when focused, there was a method in which all letters were selected. I found a way to make it remembered on the screen, but I wonder how to do it on the mvvm pattern.
#Composable
fun MainScreen(text: String, viewModel: HomeViewModel) {
val textState = remember { mutableStateOf(TextFieldValue()) }
val state = viewModel.mainState.text.collectAsState()
Column(
modifier = Modifier
.fillMaxWidth()
.fillMaxHeight(),
verticalArrangement = Arrangement.Center,
horizontalAlignment = Alignment.CenterHorizontally
) {
Text(
text = state.value,
color = Color.Blue,
fontSize = 40.sp
)
Button(
onClick = { viewModel.mainState.text.value = "New text" },
colors = ButtonDefaults.buttonColors(
backgroundColor = Color.Green
),
modifier = Modifier.padding(16.dp)
) {
Text(text)
}
TextField(
value = textState.value,
onValueChange = { textState.value = it },
label = { Text("Input text") }
)
}
}
The code above is from screen to remeber.
But I understand that remember is only declared within #Composable.
The view model does not declare #Composable, so I want to know how to do it in the mvvm pattern.
Below is my code.
LoginScreen
val text = viewModel.user_id.value
OutlinedTextField(
value = barcode,
onValueChange = {
viewModel.changeBarcode(it)
},
modifier = Modifier
.fillMaxWidth()
.padding(all = 4.dp)
.onFocusChanged { focusState ->
if (focusState.isFocused) {
//monitor value
}
},
label = { Text(text = "Barcode") },
singleLine = true,
keyboardOptions = KeyboardOptions(
keyboardType = KeyboardType.Number,
imeAction = ImeAction.Done
),
keyboardActions = KeyboardActions(
onDone = {
keyboardController?.hide()
viewModel.onTriggerEvent(MenuStateEvent.ScanEvent)
}
)
)
LoginViewModel
val user_id: MutableState<String> = mutableStateOf("")
How change it to mvvm pattern?

Answer 1

Maybe this will be the method you need.
in ViewModel：
val user_id = mutableStateOf(TextFieldValue(""))
in Compose：
TextField(
value = viewModel.user_id.value,
onValueChange = { viewModel.user_id.value = it },
label = { Text("Input text") }
)
Just change the mutableStateOf in ViewModel from "String" to "TextFieldValue(String)" to access it.