Q: Multiple top-level windows?

[jgarvin]

I'm not sure if the APIs needed to do this exist for the web backend, but for native is multiple top-level window support a goal? It's something that non-game apps would probably use, since without it multi-monitor use of the same app is pretty inconvenient (you need one big native window to stretch over all your screens). Even for games might be nice for egui to be able to 'pop out' to be in a separate window from the game instead of always being an overlay.

[mitchmindtree]

I'm considering starting to use egui alongside nannou for some of our audiovisual installation work. These often involve multi-screen or multi-projector setups with content split across each, separating the control window from the visualisation window, etc.

Even if there's no real "multi-window" support in egui, I'd be satisfied knowing that I could have a unique Ui per window without messing up any global state or anything like that. Does that sound feasible with egui in its current state?

Great work on the lib btw! I just came across the web demo and was blown away by the list of features :)

[parasyte]

AFAIK, supporting multiple windows is mostly the responsibility of the platform implementation. For most users this is egui_glium, but it's also true of alternatives like egui_winit_platform.

egui_glium takes over handling of the windowing subsystem and the main event loop, so it is going to need some work to handle multiple windows.

egui_winit_platform puts all those responsibilities into the caller's hands, so it's up to the user to define how they want their windows created and managed. It should be trivial to have as many Platform instances as you like with a single event loop using this architecture. Each platform gives you its own CtxRef when you are ready to render the UI. You just have to be careful in your event loop to update the platform using events from the correct window reference.

[emilk]

@parasyte is right - adding multi-window support to egui_glium is maybe possible, but I don't know. If you have an integration with multiple windows already, then having one egui::Context per window is the way to go, and should not produce any problems.

[parasyte]

See also #1044

[emilk]

eframe now support multiple viewports/windows.

The egui_glium backend has been moved out to a separate repo (https://github.com/fayalalebrun/egui_glium).