TextFieldState

BasicTextFieldStateCompleteSample

fun BasicTextFieldStateCompleteSample() {
    class SearchViewModel(val searchFieldState: TextFieldState = TextFieldState()) {
        private val queryValidationRegex = """\w+""".toRegex()
        // Use derived state to avoid recomposing every time the text changes, and only recompose
        // when the input becomes valid or invalid.
        val isQueryValid by derivedStateOf {
            // This lambda will be re-executed every time inputState.text changes.
            searchFieldState.text.matches(queryValidationRegex)
        }
        var searchResults: List<String> by mutableStateOf(emptyList())
            private set
        /** Called while the view model is active, e.g. from a LaunchedEffect. */
        suspend fun run() {
            snapshotFlow { searchFieldState.text }
                .collectLatest { queryText ->
                    // Start a new search every time the user types something valid. If the previous
                    // search is still being processed when the text is changed, it will be
                    // cancelled
                    // and this code will run again with the latest query text.
                    if (isQueryValid) {
                        searchResults = performSearch(query = queryText)
                    }
                }
        }
        fun clearQuery() {
            searchFieldState.setTextAndPlaceCursorAtEnd("")
        }
        private suspend fun performSearch(query: CharSequence): List<String> {
            TODO()
        }
    }
    @Composable
    fun SearchScreen(viewModel: SearchViewModel) {
        Column {
            Row {
                BasicTextField(viewModel.searchFieldState)
                IconButton(onClick = { viewModel.clearQuery() }) {
                    Icon(Icons.Default.Clear, contentDescription = "clear search query")
                }
            }
            if (!viewModel.isQueryValid) {
                Text("Invalid query", style = TextStyle(color = Color.Red))
            }
            LazyColumn { items(viewModel.searchResults) { TODO() } }
        }
    }
}