Add test-only single-pixel-buffer support

src/handlers/mod.rs

@@ -62,8 +62,8 @@ use smithay::{
     delegate_input_method_manager, delegate_output, delegate_pointer_constraints,
     delegate_pointer_gestures, delegate_presentation, delegate_primary_selection,
     delegate_relative_pointer, delegate_seat, delegate_security_context, delegate_session_lock,
-    delegate_tablet_manager, delegate_text_input_manager, delegate_viewporter,
-    delegate_virtual_keyboard_manager, delegate_xdg_activation,
+    delegate_single_pixel_buffer, delegate_tablet_manager, delegate_text_input_manager,
+    delegate_viewporter, delegate_virtual_keyboard_manager, delegate_xdg_activation,
 };
 
 pub use crate::handlers::xdg_shell::KdeDecorationsModeState;
@@ -701,3 +701,5 @@ delegate_output_management!(State);
 
 impl MutterX11InteropHandler for State {}
 delegate_mutter_x11_interop!(State);
+
+delegate_single_pixel_buffer!(State);

src/niri.rs

@@ -92,6 +92,8 @@ use smithay::wayland::shell::wlr_layer::{self, Layer, WlrLayerShellState};
 use smithay::wayland::shell::xdg::decoration::XdgDecorationState;
 use smithay::wayland::shell::xdg::XdgShellState;
 use smithay::wayland::shm::ShmState;
+#[cfg(test)]
+use smithay::wayland::single_pixel_buffer::SinglePixelBufferState;
 use smithay::wayland::socket::ListeningSocketSource;
 use smithay::wayland::tablet_manager::TabletManagerState;
 use smithay::wayland::text_input::TextInputManagerState;
@@ -263,6 +265,15 @@ pub struct Niri {
     pub activation_state: XdgActivationState,
     pub mutter_x11_interop_state: MutterX11InteropManagerState,
 
+    // This will not work as is outside of tests, so it is gated with #[cfg(test)] for now. In
+    // particular, shaders will need to learn about the single pixel buffer. Also, it must be
+    // verified that a black single-pixel-buffer background lets the foreground surface to be
+    // unredirected.
+    //
+    // https://github.com/YaLTeR/niri/issues/619
+    #[cfg(test)]
+    pub single_pixel_buffer_state: SinglePixelBufferState,
+
     pub seat: Seat<State>,
     /// Scancodes of the keys to suppress.
     pub suppressed_keys: HashSet<Keycode>,
@@ -1818,6 +1829,9 @@ impl Niri {
         let mutter_x11_interop_state =
             MutterX11InteropManagerState::new::<State, _>(&display_handle, move |_| true);
 
+        #[cfg(test)]
+        let single_pixel_buffer_state = SinglePixelBufferState::new::<State>(&display_handle);
+
         let mut seat: Seat<State> = seat_state.new_wl_seat(&display_handle, backend.seat_name());
         seat.add_keyboard(
             config_.input.keyboard.xkb.to_xkb_config(),
@@ -1990,6 +2004,8 @@ impl Niri {
             gamma_control_manager_state,
             activation_state,
             mutter_x11_interop_state,
+            #[cfg(test)]
+            single_pixel_buffer_state,
 
             seat,
             keyboard_focus: KeyboardFocus::Layout { surface: None },