Autocomplete textview in Jetpack

In Jetpack Compose, there is no direct equivalent to the traditional AutoCompleteTextView. However, you can achieve the same functionality by combining a TextField with a dropdown menu (DropdownMenu) or similar composables to display suggestions as the user types.

Here’s how you can create an Autocomplete TextField:

Example: Autocomplete with a Dropdown Menu

import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.text.BasicTextField
import androidx.compose.material3.*
import androidx.compose.runtime.*
import androidx.compose.ui.Modifier
import androidx.compose.ui.text.input.TextFieldValue
import androidx.compose.ui.unit.dp

@Composable
fun AutoCompleteTextViewExample() {
    var text by remember { mutableStateOf(TextFieldValue("")) }
    val suggestions = listOf("Apple", "Banana", "Cherry", "Date", "Elderberry", "Fig", "Grape")
    var filteredSuggestions by remember { mutableStateOf(suggestions) }
    var expanded by remember { mutableStateOf(false) }

    Column(modifier = Modifier.padding(16.dp)) {
        // TextField with suggestion filtering
        TextField(
            value = text,
            onValueChange = { newValue ->
                text = TextFieldValue(newValue.text)
                filteredSuggestions = suggestions.filter { 
                    it.contains(newValue.text, ignoreCase = true) 
                }
                expanded = filteredSuggestions.isNotEmpty()
            },
            label = { Text("Enter a fruit") },
            modifier = Modifier.fillMaxWidth()
        )

        // Dropdown for suggestions
        DropdownMenu(
            expanded = expanded,
            onDismissRequest = { expanded = false },
            modifier = Modifier.fillMaxWidth()
        ) {
            filteredSuggestions.forEach { suggestion ->
                DropdownMenuItem(
                    text = { Text(suggestion) },
                    onClick = {
                        text = TextFieldValue(suggestion)
                        expanded = false
                    }
                )
            }
        }
    }
}

Explanation

1. TextField:

• Used for user input.
• The onValueChange lambda updates the text and filters suggestions dynamically.

1. DropdownMenu:

• Displays filtered suggestions.
• Triggered by the expanded state.

1. Dynamic Suggestions:

• The filteredSuggestions list updates based on the user’s input, showing matching options.

Key Features

• Dynamic Filtering: Suggestions are filtered based on the user’s input.
• Flexible Styling: You can customize the look of the dropdown and items.
• State Management:
• expanded controls whether the dropdown is visible.
• text manages the current input.

Advanced Example: Using ExposedDropdownMenuBox

You can also use ExposedDropdownMenuBox for a more Material Design-compliant implementation.

@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun AutoCompleteWithExposedDropdownMenu() {
    val suggestions = listOf("Red", "Green", "Blue", "Yellow", "Purple")
    var text by remember { mutableStateOf("") }
    var expanded by remember { mutableStateOf(false) }

    ExposedDropdownMenuBox(
        expanded = expanded,
        onExpandedChange = { expanded = !expanded }
    ) {
        TextField(
            value = text,
            onValueChange = { newValue ->
                text = newValue
                expanded = suggestions.any { it.contains(newValue, ignoreCase = true) }
            },
            label = { Text("Select a color") },
            trailingIcon = { ExposedDropdownMenuDefaults.TrailingIcon(expanded = expanded) },
            modifier = Modifier.menuAnchor()
        )

        ExposedDropdownMenu(
            expanded = expanded,
            onDismissRequest = { expanded = false }
        ) {
            suggestions.filter { it.contains(text, ignoreCase = true) }.forEach { suggestion ->
                DropdownMenuItem(
                    text = { Text(suggestion) },
                    onClick = {
                        text = suggestion
                        expanded = false
                    }
                )
            }
        }
    }
}

Benefits of Using Jetpack Compose

1. Declarative UI: Easy to build and customize autocomplete behavior.
2. Dynamic Updates: Filter suggestions dynamically in real-time.
3. Material Design: Use ExposedDropdownMenuBox for a polished, Material-styled dropdown.

This approach allows you to create a robust autocomplete feature fully integrated into the Jetpack Compose ecosystem.