android-text-input-formslisted

# Android Text Input & Forms (Compose) ## Overview Compose form patterns centre on three concerns: state (what the user has typed, what errors exist), keyboard (type, IME actions, navigation), and focus (moving between fields programmatically). Get these three right and every form — login, registration, checkout, settings — follows the same pattern. --- ## TextField vs OutlinedTextField Both accept the same parameters. Choose based on your design system: ```kotlin // Filled style — appropriate for forms inside a Surface TextField( value = state.email, onValueChange = { onAction(FormAction.EmailChanged(it)) }, label = { Text("Email") }, modifier = Modifier.fillMaxWidth() ) // Outlined style — stands out on a plain background OutlinedTextField( value = state.email, onValueChange = { onAction(FormAction.EmailChanged(it)) }, label = { Text("Email") }, modifier = Modifier.fillMaxWidth() ) ``` Prefer `OutlinedTextField` in forms — the outline makes the input boundary obvious without requiring a filled background. Use `TextField` only if your design system explicitly uses the filled variant. --- ## Form State Model Model form state as a single data class in the ViewModel's `UiState`. Each field gets a `value` and an `error`. Errors are typed as `UiText?` (null = no error) so they can be string resources or dynamic strings from the server. ```kotlin // Presentation model — lives in feature:presentation data class RegisterFormState( val