Jetpack compose for desktop: run application in background?

Question

i am new to the jetpack compose. I did a lot of research on that topic but i can't find anything useful. What i wanna achieve is that if I close my window, my application will stay in the background and can be opened again from the tray. I managed to create the tray, but when i close the application window it closes the whole application. How can i achieve that?

This application will be on Windows and MacOS only. I don't care about android right now

Verduzco

You should focus on one topic per question. See this answer as per shortcuts, and if it's not what're you looking for, you should create a separate question with more details, so it can be found by the title by anyone who is looking for the same problem. And edit this question by removing this second question. – Mauromaurois

As to the main question, I wasn't able to find enough API available atm, I suggest you asking in kotlin slack, #compose-desktop channel – Mauromaurois

@PhilipDukhov thank you for your answer. I edited the question and i will post it as a separate question. I need the shortcut to work even if the application is not in focus. – Verduzco

Answer 1

Edit: For version 0.4.0

I managed to figure it out. The main function should be an application, not the window

@OptIn(ExperimentalComposeUiApi::class)
fun main() = application { 
    
}

And if the application contains both the Window and the Tray, it will continue to run in the background and does not close after the window is closed.

@OptIn(ExperimentalComposeUiApi::class)
fun main() = application {

    Tray(
        icon = BufferedImage(24, 24, 1),
        menu = {
            Item(
                "Exit",
                onClick = { exitProcess(1) }
            )
        }
    )

    Window{
        Text("Hello World")
    }

}

Edit: For version 1.0.0-beta5

Now you have to specify the onCloseRequest on the window object, if you leave it blank it won't close the window. In the application, create a variable which will indicate whether the window is open or not. Create the tray as before. The tray icon now requires a Painter object instead of a BufferedImage. Than simply check if the window open state is true, show the window, otherwise do nothing.

@OptIn(ExperimentalComposeUiApi::class)
fun main() = application {
    val isOpen = remember { mutableStateOf(true)}
    Tray(
        icon = TrayIcon,
        menu = {
            Item(
                "Exit",
                onClick = { exitApplication() }
            )
        }
    )
    if(isOpen.value){
        Window(
            onCloseRequest = { isOpen.value = false }
        ) {
            MaterialTheme {
                Text("Hello World")
            }
        }
    }
}

object TrayIcon : Painter() {
    override val intrinsicSize = Size(256f, 256f)
    override fun DrawScope.onDraw() {
        drawOval(Color(0xFFFFA500))
    }
}

Verduzco