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rust-windowing / winit

Window handling library in pure Rust
https://docs.rs/winit/
Apache License 2.0
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Xlib must die #3198

Open notgull opened 1 year ago

notgull commented 1 year ago

Xlib is the legacy strategy for interacting with the X server. It has since been replaced by libxcb, which is lighter and has fewer soundless holes. x11rb wraps around libxcb and reimplements the protocol parsing logic in safe Rust, further reducing the number of places where unsound logic can occur.

List of places in winit where Xlib still lurks:

Discussion questions:

kchibisov commented 1 year ago

Cursor handling code

isn't cursor being drawn on the server? Or we must submit a Xcursor theme to the server? How does it all work? I thought you just send names, it's not wayland with its client side cursors in the end of the day.

I want to be able to replace x11-dl with tiny-xlib, is this possible?

doesn't matter, but we don't need x11-dl that hard.

Do we want to add a feature to remove Xlib entirely and just use XCB?

yes

Is this also available for Wayland?

no.

notgull commented 1 year ago

Is this also available for Wayland?

no.

Can you elaborate on this? I know that wayland-rs has a pure-Rust implementation available.

kchibisov commented 1 year ago

Can you elaborate on this? I know that wayland-rs has a pure-Rust implementation available.

any API wants a wl_proxy from libwayland, so unless you write a EGL/Vulkan platform to use whatever wayland-rs provides, this won't change.

bjorn3 commented 1 year ago

I believe Haiku has Xlib compatibility through the xlibe library, but not XCB compatibility. So without a native implementation of Haiku's GUI api, dropping Xlib support would mean dropping Haiku support.

kchibisov commented 1 year ago

dropping Xlib support would mean dropping Haiku support.

if they are interested they can send patches like redox did to even have their native platform working.

ids1024 commented 1 year ago

Haiku apparently has some kind of Wayland support too. Which is better for running applications currently?

Native Haiku support in winit would be good.

ids1024 commented 1 year ago

Going further, do we want to add a feature to remove these two external libraries from our X backend altogether and just use x11rb's pure-Rust backend?

Doesn't this run into https://github.com/rust-windowing/raw-window-handle/issues/120?

psychon commented 10 months ago

Cursor handling code (could use https://github.com/esposm03/xcursor-rs instead)

x11rb's cursor feature could be used as well. I do not know Xlib's API, but this was modeled after what libxcb-cursor does. And from your link, xcursor-rs seems to at least try to do something similar (but it uses e.g. XDG env vars for finding stuff which libxcb-cursor and x11rb do not and I doubt a lot that libX11 uses anything like that).

isn't cursor being drawn on the server? Or we must submit a Xcursor theme to the server? How does it all work? I thought you just send names, it's not wayland with its client side cursors in the end of the day.

This is X11. Of course everything is horrible. ;-)

Like windows, pixmaps, fonts, cursors are objects. Once created, one can tell the server to use the cursor when the mouse is inside "your" window. For creating a cursor, there are many options, but besides the legacy ones, you basically update an image (or a list of images and a delay between them) to the X11 server. Everything else happens client side and is convention.