Is there any documentation around Compose Desktop's handling of multiple physical screens? Context:...

# compose-desktop

[rob42]

Is there any documentation around Compose Desktop's handling of multiple physical screens?

Context: I am aligning windows relative to each other, but it's unclear how this will work in Compose, because WindowState only contains coordinates with no "display" that they are relative to.

[Alex Styl]

Not that I know off. if i were you I would look at how this can be done using Swing. Use those APIs and then 'translate' that to Compose if needed

[Alexander Maryanovsky]

You can get the underlying AWT window and use that.

[rob42]

Window.graphicsConfiguration.device has the right information, it's just not observable since it's not part of Compose 😞

It also seems like even if you have the GraphicsDevice from that, Swing offers no way to move a window between screens, other than Window.setLocationRelativeTo(Component), which isn't really ideal.

It'd be great if WindowState (or WindowPosition) had a display field on it

[Alexander Maryanovsky]

You have the same tools as we do in that regard.

[ephemient]

Wayland doesn't allow clients to place their own windows, so such an approach would be limited on some platforms at least

[rob42]

Oh very interesting. Even undecorated windows? How do things like menus/popovers that extend outside the window bounds work in that case?

[Alexander Maryanovsky]

By specifying the parent/owner window, I imagine.

[rob42]

Context: I've built fairly robust support for these features for compose on Windows -- essentially NSPopover/Flyout that aren't constrained to the window itself

[rob42]

Ah, definitely looks like I'll need to investigate Wayland at some point. Currently using DialogWindow as the base, which I believe does set the owner properly.

[rob42]

And as a sidenote, life would be way easier if there were more window lifecycle hooks available when instantiating windows.

A good example is that ComposeWindow is implicitly final, but Swing requires subclassing and method overrides to customise certain advanced behaviours (e.g. changing paint behaviour)

[Alex Styl]

what is wayland?

[rob42]

A system for drawing/managing windows used by some Linux distributions.