egui_winit: support winit with default features disabled (#1971)

* egui_winit: support winit with default features disabled

* Link to the PR in the changelog

crates/egui-winit/CHANGELOG.md

@@ -3,7 +3,8 @@ All notable changes to the `egui-winit` integration will be noted in this file.
 
 
 ## Unreleased
-
+* The default features of the `winit` crate are not enabled if the default features of `egui-winit` are disabled too ([#1971](https://github.com/emilk/egui/pull/1971))
+* Added new feature `wayland` which enables Wayland support ([#1971](https://github.com/emilk/egui/pull/1971))
 
 ## 0.19.0 - 2022-08-20
 * MSRV (Minimum Supported Rust Version) is now `1.61.0` ([#1846](https://github.com/emilk/egui/pull/1846)).

crates/egui-winit/Cargo.toml

@@ -18,7 +18,7 @@ all-features = true
 
 
 [features]
-default = ["clipboard", "links"]
+default = ["clipboard", "links", "wayland", "winit/default"]
 
 ## [`bytemuck`](https://docs.rs/bytemuck) enables you to cast [`egui::epaint::Vertex`], [`egui::Vec2`] etc to `&[u8]`.
 bytemuck = ["egui/bytemuck"]
@@ -39,6 +39,8 @@ screen_reader = ["tts"]
 ## Allow serialization of [`WindowSettings`] using [`serde`](https://docs.rs/serde).
 serde = ["egui/serde", "dep:serde"]
 
+## Enables Wayland support.
+wayland = ["winit/wayland"]
 
 [dependencies]
 egui = { version = "0.19.0", path = "../egui", default-features = false, features = [
@@ -46,7 +48,7 @@ egui = { version = "0.19.0", path = "../egui", default-features = false, feature
 ] }
 instant = { version = "0.1", features = ["wasm-bindgen"] } # We use instant so we can (maybe) compile for web
 tracing = { version = "0.1", default-features = false, features = ["std"] }
-winit = "0.27.2"
+winit = { version = "0.27.2", default-features = false }
 
 #! ### Optional dependencies
 

crates/egui-winit/src/lib.rs

@@ -21,6 +21,8 @@ mod window_settings;
 pub use window_settings::WindowSettings;
 
 use winit::event_loop::EventLoopWindowTarget;
+
+#[cfg(feature = "wayland")]
 #[cfg(any(
     target_os = "linux",
     target_os = "dragonfly",
@@ -777,6 +779,7 @@ fn translate_cursor(cursor_icon: egui::CursorIcon) -> Option<winit::window::Curs
 
 /// Returns a Wayland display handle if the target is running Wayland
 fn wayland_display<T>(_event_loop: &EventLoopWindowTarget<T>) -> Option<*mut c_void> {
+    #[cfg(feature = "wayland")]
     #[cfg(any(
         target_os = "linux",
         target_os = "dragonfly",

sh/check.sh

@@ -37,7 +37,8 @@ cargo doc --document-private-items --no-deps --all-features
 (cd crates/egui_extras && cargo check --no-default-features)
 (cd crates/egui_glium && cargo check --no-default-features)
 (cd crates/egui_glow && cargo check --no-default-features)
-(cd crates/egui-winit && cargo check --no-default-features)
+(cd crates/egui-winit && cargo check --no-default-features --features "wayland")
+(cd crates/egui-winit && cargo check --no-default-features --features "winit/x11")
 (cd crates/emath && cargo check --no-default-features)
 (cd crates/epaint && cargo check --no-default-features --release)
 (cd crates/epaint && cargo check --no-default-features)