Composable Window API breaking changes in 0.5.0-bu...

# compose-desktop

[Igor Demin]

Composable Window API breaking changes in 0.5.0-build226:
1. Window(onCloseRequest=) is required parameter now
2. WindowState.isMaximized, WindowState.isFullscreen are merged to WindowState.placement { Floating, Maximized, Fullscreen }
3. WindowPosition is sealed class { PlatformDefault, Aligned, Absolute }, initialAlignment removed from Window/Dialog

[Igor Demin]

Window(onCloseRequest=) is required parameter now

We have only one case where omitting that parameter is useful - a single-window application. In the other cases if we omit this parameter - we will have state desynchronization:

var isSecondWindowOpen = ...
if (isSecondWindowOpen) {
 // when we close the window, we change internal isOpen state, but don't change   isSecondWindowOpen state. And because we don't change isSecondWindowOpen, we can't reopen the window
  Window {

  }
}

For the single-window case we created a special function exitApplication, that closes all windows/trays and cancels `LaunchedEffect`'s inside application block. An alternative to exitApplication - is to use your own state:

fun main() = application {
  var isApplicationOpen by remember { mutableStateOf(true) }
  if (isApplicationOpen) {
     Window(onCloseRequest = { isApplicationOpen = false }) { ... }
     Tray(...)
     LaunchedEffect(Unit) { ... }
  }
}