Compose Multi-Platform Main App Windows

A UI window can easily be created using the singleWindowApplication class.

At a minimum, you need to provide a title for the window.

By default, the window will be resizeable and will be of an arbitrary initial size.

The code for this is shown below:

                fun main() = singleWindowApplication(
                    title = "Basic Window"
                ) {
                    App()
                }

                @Composable
                fun App() {
                    // Window content
                }
            

Some things to note...

• The main() function sets up the Window
• The Window is then populated by the App() function
• The @Composable annotation indicates that this function is a UI 'building block'

The window can be refined by providing additional parameters, and through the use of Modifiers:

• The initial width / height of the window
• Centring the window on-screen
• Prevent the window from being resized

There are tutorial examples with various configurations here.

                fun main() = singleWindowApplication(
                    title = "Sized Window",
                    state = WindowState(
                        width = 250.dp,
                        height = 150.dp,
                        position = WindowPosition(Alignment.Center)
                    ),
                    resizable = false
                ) {
                    App()
                }

                @Composable
                fun App() {
                    // Window content
                }
            

The window icon can be any provided image (e.g. PNG, JPEG, etc.). It is set using the window's icon parameter.

The icon image should be placed into an 'images' folder within the resources folder within your project (see here).

                fun main() = singleWindowApplication(
                    title = "Window with Icon",
                    icon = BitmapPainter(useResource(
                        "images/logo.png",
                        ::loadImageBitmap
                    ))
                ) {
                    App()
                }

                @Composable
                fun App() {
                    // Window content
                }