feat: support change region for wlr_layer

Author: SergioRibera

src/platform/wayland.rs

@@ -77,9 +77,16 @@ impl EventLoopBuilderExtWayland for EventLoopBuilder {
 /// Additional methods on [`Window`] that are specific to Wayland.
 ///
 /// [`Window`]: crate::window::Window
-pub trait WindowExtWayland {}
+pub trait WindowExtWayland {
+    fn set_region(&self, region: Option<(LogicalPosition<i32>, LogicalSize<i32>)>);
+}
 
-impl WindowExtWayland for dyn CoreWindow + '_ {}
+impl WindowExtWayland for dyn CoreWindow + '_ {
+    fn set_region(&self, region: Option<(LogicalPosition<i32>, LogicalSize<i32>)>) {
+        let window = self.as_any().downcast_ref::<crate::platform_impl::wayland::Window>().unwrap();
+        window.set_region(region);
+    }
+}
 
 /// Additional methods on [`WindowAttributes`] that are specific to Wayland.
 pub trait WindowAttributesExtWayland {

src/platform_impl/linux/wayland/window/mod.rs

@@ -3,6 +3,7 @@
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex};
 
+use dpi::LogicalPosition;
 use sctk::compositor::{CompositorState, Region, SurfaceData};
 use sctk::reexports::client::protocol::wl_display::WlDisplay;
 use sctk::reexports::client::protocol::wl_surface::WlSurface;
@@ -332,6 +333,22 @@ impl Window {
     pub fn set_layer(&self, layer: Layer) {
         self.window.set_layer(layer);
     }
+
+    #[inline]
+    pub fn set_region(&self, region: Option<(LogicalPosition<i32>, LogicalSize<i32>)>) {
+        match self.window {
+            WindowShell::WlrLayer { surface } => {
+                if let Some((pos, size)) = region {
+                    let region = Region::new(self.compositor.as_ref()).unwrap();
+                    region.add(pos.x, pos.y, size.width, size.height);
+                    surface.set_input_region(Some(region.wl_region()));
+                } else {
+                    surface.set_input_region(None);
+                }
+            },
+            WindowShell::Xdg { .. } => warn!("Region is ignored for XDG windows"),
+        }
+    }
 }
 
 impl Drop for Window {