Problem with Kotlin compose for desktop Window - kotlin

Question

I'm trying to make a chess engine desktop app with an ui component to it.
The game() method that I mention is a simple while loop that allows me to ask for moves in algebraic notation and make the moves if they are valid ones.
I have the following main and my problem is that if I uncomment and run the game() method inside the classe it wont start the App window, and if I instead try to uncomment the same method but from outside the Window it still wont start the desktop App.
On the other hand if i run it has it is, it will start the UI window.
fun main() = application {
resetBoard()
printBoardSmall()
Window(onCloseRequest = ::exitApplication, icon = painterResource("black_knight.png"), title = "Chess") {
ui()
//game()
}
//game()
}
#Composable
fun ui() {
var squarePair = false
Row {
Column {
for (n in 8 downTo 1) {
Row {
Text(
"" + n,
textAlign = TextAlign.Center,
modifier = Modifier.width(SIZE_TILE),
fontSize = FONT_SIZE_BOARD,
fontWeight = FontWeight.Bold
)
squarePair = boardLines(n, squarePair)
}
}
Row {
Text(" ", textAlign = TextAlign.Center, modifier = Modifier.width(SIZE_TILE))
for (n in 0..7) {
Text(
"" + ('A' + n),
textAlign = TextAlign.Center,
modifier = Modifier.width(SIZE_TILE),
fontSize = FONT_SIZE_BOARD,
fontWeight = FontWeight.Bold
)
}
}
}
Column {
Text(" Play", textAlign = TextAlign.Center, fontSize = 30.sp)
var move = ""
//var move by remember { mutableStateOf("") }
TextField(
value = move,
onValueChange = { move = it },
label = { Text("Move") },
maxLines = 1,
textStyle = TextStyle(color = Color.Black, fontWeight = FontWeight.Bold),
modifier = Modifier.padding(20.dp)
)
print(move)
}
}
}
#Composable
fun board(n: Int, i: Int){
var team = ""
if(utils.isWhite(BOARD[n-1][i-1])) team = TEAM[0]
if(utils.isBlack(BOARD[n-1][i-1])) team = TEAM[1]
for(k in LOWER_CASE_LETTERS.indices) {
if (BOARD[n-1][i-1] == LOWER_CASE_LETTERS[k] || BOARD[n-1][i-1] == UPPER_CASE_LETTERS[k]) {
Image(painter = painterResource(team + "_" + PIECES[k] + ".png"), contentDescription = PIECES[k])
}
}
}
Im new to compose and I can't figure out whats the problem, expecially since im trying to run the method outside the Window

Answer 1

I'm no expert, but I'll try my best to help.
It doesn't work, when you call it in the Window, 'cause that's what it uses to init it's layout. So the Window won't show, 'till the game() stops.
I don't know, why it doesn't work, when you put it after the Window. Looking at fun main() = application { ... } I suspect, that initiating the application is similar to initiating the Window, so it also won't start, untill the game() is over.
You should try putting game() in a seperate thread. Something like this should work:
fun() main = application {
resetBoard()
printBoardSmall()
Window( ... ){
ui()
}
Thread {
game()
}.start()
}
P.S. I'm also very new to compose. And kinda new to programming. And really, really sorry for all the gross oversimplifications I made.
P.P.S. You could add a TextField to your app and use Button's onClick parameter to call a move checking function. Wouldn't need to play with Threads and coroutines then. And you could also use Buttons for the board squares, cause you can assign them a background and an image. If you would need help with any of that - HMU.