DropDownCheckboxMenuState.kt

// Copyright 2023 Google LLC.
// SPDX-License-Identifier: Apache-2.0

/**
 * State holder for DropDownCheckBoxMenu
 */
class DropDownCheckboxMenuState(
    var items: List<String>,
) {
    // Internal set of selected items managed by wrapper
    internal var _selectedItems by mutableStateOf(emptySet<Int>())

    // External read-only set of selected items in the menu
    public val selectedItems: Set<Int>
        get() = _selectedItems
}

@Composable
fun DropDownCheckboxMenu(
    state: DropDownCheckboxMenuState,
    onItemToggled: (Boolean, Int) -> Unit,
    modifier: Modifier = Modifier
) {
    val currentOnItemToggled by rememberUpdatedState(newValue = onItemToggled)
    AndroidView(
        factory = {
            // Create DropDownCheckboxMenuView here
            val view = DropDownCheckboxMenuView(it)
            view.setOnItemToggled { selected, index ->
                if (selected) {
                    state._selectedItems += index
                } else {
                    state._selectedItems -= index
                }
                currentOnItemToggled(selected, index)
            }
            view
        },
        // ...
    )
}