setOnKeyListener for AlertDialog in jetpack compose

Question

We can have a listener for dialog in Android :

dialog.setOnKeyListener(new Dialog.OnKeyListener() {

  @Override
  public boolean onKey(DialogInterface arg0, int keyCode,KeyEvent event)
  {
     if (keyCode == KeyEvent.KEYCODE_BACK) {
           /* The user pressed back button - do whatever here.
           Normally you dismiss the dialog like dialog.dismiss(); */

         }
        return true;
        }
    });

How we can do that for AlertDialog in jetpack compose?

@Composable
    private fun DisplayAlertDialog() {
        val openDialog = remember { mutableStateOf(true) }
        if (openDialog.value) {
            AlertDialog(
                onDismissRequest = {  },
                title = {
                    Text(
                        text = stringResource(id = R.string.settings),
                        fontSize = 18.sp
                    )
                },
                confirmButton = {
                    TextButton(
                        onClick = {
                            openDialog.value = false
                        }
                    ) {
                        Text(stringResource(id = R.string.yes))
                    }
                },
                dismissButton = {
                    TextButton(
                        onClick = {
                            openDialog.value = false
                        }
                    ) {
                        Text(stringResource(id = R.string.no))
                    }
                },
                backgroundColor = Color.White,
                contentColor = Color.Black
            )
        }
    }

Answer 1

Check out details of Modifier.onKeyEvent usage in this answer .

In this case requestFocus has to be called from inside AlertDialog to make sure it already appeared.

In my example I use a text field to show that the modifier is not interrupted.

var displayed by remember { mutableStateOf(true) }
if (displayed) {
    val requester = remember { FocusRequester() }
    AlertDialog(
        onDismissRequest = {
            println("dismissOnClickOutside")
            displayed = false
        },
        buttons = {
            var text by remember { mutableStateOf("") }
            TextField(value = text, onValueChange = {text = it})
            LaunchedEffect(Unit) {
                requester.requestFocus()
            }
        },
        properties = DialogProperties(
            dismissOnBackPress = false,
        ),
        modifier = Modifier
            .focusRequester(requester)
            .focusable()
            .onKeyEvent {
                if (it.nativeKeyEvent.keyCode != KeyEvent.KEYCODE_BACK) {
                    return@onKeyEvent false
                }
                println("dismissOnBackPress")
                displayed = false
                false
            }
    )
}