Add Window::set_blur

Allow clients to request blur behind their window, implemented on
Wayland for now.

src/platform_impl/linux/wayland/state.rs

@@ -31,6 +31,7 @@ use super::seat::{
     PointerConstraintsState, RelativePointerState, TextInputState, WinitPointerData,
     WinitPointerDataExt, WinitSeatState,
 };
+use super::types::kwin_blur::KWinBlurManager;
 use super::types::wp_fractional_scaling::FractionalScalingManager;
 use super::types::wp_viewporter::ViewporterState;
 use super::types::xdg_activation::XdgActivationState;
@@ -103,6 +104,9 @@ pub struct WinitState {
     /// Fractional scaling manager.
     pub fractional_scaling_manager: Option<FractionalScalingManager>,
 
+    /// KWin blur manager.
+    pub kwin_blur_manager: Option<KWinBlurManager>,
+
     /// Loop handle to re-register event sources, such as keyboard repeat.
     pub loop_handle: LoopHandle<'static, Self>,
 
@@ -161,6 +165,7 @@ impl WinitState {
             window_events_sink: Default::default(),
             viewporter_state,
             fractional_scaling_manager,
+            kwin_blur_manager: KWinBlurManager::new(globals, queue_handle).ok(),
 
             seats,
             text_input_state: TextInputState::new(globals, queue_handle).ok(),