I also found a post about doing this on Android (https://dev.to/pchmielowski/automate-taking-screenshots-of-android-app-with-jetpack-compose-2950), however I don't think this can be ported to desktop right away

Use it to wrap your content, then call

render()

+

encodeToData().bytes

+

File.writeBytes()

Got a screenshot of my app rendered like that. Basically replaced my

Window

with

ImageComposeScene

and was able to render and store to file the way you suggested. I'm still curious whether it's possible or planned to use the testing API similar to the way its possible with Android. I found Maven artifact

org.jetbrains.compose.ui:ui-test-junit4:1.1.1

and was able to change most imports on the Android example in the blog post above so that they resolve. What does not seem to be available is

captureToImage()

, I'm assuming it's going to be added eventually:

onRoot()
        .captureToImage()
        .asAndroidBitmap()
        .save(file)

Why I'm interested in this: the testing API also has support for simulating clicks on UI elements, so I guess it will help making series of screenshots from various parts of the UI without needing to manipulate state internally, but can be manipulated by simulated mouse and key events.

And kind of out of curiousity, I'm wondering if there's still an equivalent of the Swing approach, i.e.

BufferedImage image = new BufferedImage(
      component.getWidth(),
      component.getHeight(),
      BufferedImage.TYPE_INT_RGB
      );
    // call the Component's paint method, using
    // the Graphics object of the image.
    component.paint( image.getGraphics() );

I find it kind of fascinating that you can just call the component's

paint()

on the graphics obtained from a buffered image. Kind of cool and wondering if there's potentially a way to trick compose into rendering into an offscreen buffer, too. That would allow to capture screenshots of an app in production (say with some magic keyboard shortcut) without using external screenshot tools.