feat: add minimal mode for lock surfaces only

crates/adapters/src/rendering/slint_integration/platform.rs

@@ -23,6 +23,14 @@ impl CustomSlintPlatform {
         })
     }
 
+    #[must_use]
+    pub fn new_empty() -> Rc<Self> {
+        Rc::new(Self {
+            pending_windows: RefCell::new(Vec::new()),
+            popup_creator: OnceCell::new(),
+        })
+    }
+
     pub fn add_window(&self, window: Rc<FemtoVGWindow>) {
         self.pending_windows.borrow_mut().push(window);
     }

crates/adapters/src/wayland/globals/context.rs

@@ -20,7 +20,7 @@ use crate::wayland::surfaces::app_state::AppState;
 pub struct GlobalContext {
     pub compositor: WlCompositor,
     pub outputs: Vec<WlOutput>,
-    pub layer_shell: ZwlrLayerShellV1,
+    pub layer_shell: Option<ZwlrLayerShellV1>,
     pub seat: WlSeat,
     pub xdg_wm_base: Option<XdgWmBase>,
     pub session_lock_manager: Option<ExtSessionLockManagerV1>,
@@ -38,14 +38,17 @@ impl GlobalContext {
             .map(|(global_list, _)| global_list)
             .map_err(|e| LayerShikaError::GlobalInitialization { source: e })?;
 
-        let (compositor, layer_shell, seat) = bind_globals!(
+        let (compositor, seat) = bind_globals!(
             &global_list,
             queue_handle,
             (WlCompositor, compositor, 3..=6),
-            (ZwlrLayerShellV1, layer_shell, 1..=5),
             (WlSeat, seat, 1..=9)
         )?;
 
+        let layer_shell = global_list
+            .bind::<ZwlrLayerShellV1, _, _>(queue_handle, 1..=5, ())
+            .ok();
+
         let output_names: Vec<u32> = global_list
             .contents()
             .clone_list()
@@ -115,6 +118,10 @@ impl GlobalContext {
             info!("Viewporter protocol not available");
         }
 
+        if layer_shell.is_none() {
+            info!("wlr-layer-shell protocol not available, layer surfaces disabled");
+        }
+
         let render_context_manager = RenderContextManager::new(&connection.display().id())?;
 
         Ok(Self {

crates/adapters/src/wayland/ops.rs

@@ -5,7 +5,7 @@ use crate::wayland::surfaces::app_state::AppState;
 use layer_shika_domain::value_objects::lock_config::LockConfig;
 use layer_shika_domain::value_objects::lock_state::LockState;
 use layer_shika_domain::value_objects::output_handle::OutputHandle;
-use slint_interpreter::ComponentInstance;
+use slint_interpreter::{ComponentInstance, CompilationResult};
 use slint_interpreter::Value;
 use smithay_client_toolkit::reexports::calloop::LoopHandle;
 use std::rc::Rc;
@@ -19,6 +19,8 @@ pub trait WaylandSystemOps {
 
     fn despawn_surface(&mut self, name: &str) -> Result<()>;
 
+    fn set_compilation_result(&mut self, compilation_result: Rc<CompilationResult>);
+
     fn activate_session_lock(&mut self, component_name: &str, config: LockConfig) -> Result<()>;
 
     fn deactivate_session_lock(&mut self) -> Result<()>;

crates/adapters/src/wayland/outputs/output_manager.rs

@@ -35,7 +35,7 @@ use super::OutputMapping;
 
 pub struct OutputManagerContext {
     pub compositor: WlCompositor,
-    pub layer_shell: ZwlrLayerShellV1,
+    pub layer_shell: Option<ZwlrLayerShellV1>,
     pub fractional_scale_manager: Option<WpFractionalScaleManagerV1>,
     pub viewporter: Option<WpViewporter>,
     pub render_factory: Rc<RenderContextFactory>,
@@ -161,10 +161,16 @@ impl OutputManager {
         _output_id: &ObjectId,
         queue_handle: &QueueHandle<AppState>,
     ) -> Result<(SurfaceState, ObjectId)> {
+        let layer_shell = self.context.layer_shell.as_ref().ok_or_else(|| {
+            LayerShikaError::InvalidInput {
+                message: "wlr-layer-shell protocol not available - cannot create layer surfaces".into(),
+            }
+        })?;
+
         let setup_params = SurfaceSetupParams {
             compositor: &self.context.compositor,
             output,
-            layer_shell: &self.context.layer_shell,
+            layer_shell,
             fractional_scale_manager: self.context.fractional_scale_manager.as_ref(),
             viewporter: self.context.viewporter.as_ref(),
             queue_handle,

crates/adapters/src/wayland/shell_adapter.rs

@@ -37,7 +37,7 @@ use slint::{
     LogicalPosition, PhysicalSize, PlatformError, WindowPosition,
     platform::{WindowAdapter, femtovg_renderer::FemtoVGRenderer, set_platform, update_timers_and_animations},
 };
-use slint_interpreter::ComponentInstance;
+use slint_interpreter::{ComponentInstance, CompilationResult};
 use smithay_client_toolkit::reexports::calloop::{
     EventLoop, Interest, LoopHandle, Mode, PostAction, generic::Generic,
 };
@@ -97,9 +97,7 @@ impl WaylandShellSystem {
 
     pub fn new_multi(configs: &[ShellSurfaceConfig]) -> Result<Self> {
         if configs.is_empty() {
-            return Err(LayerShikaError::InvalidInput {
+            return Self::new_minimal();
-                message: "At least one surface config is required".into(),
-            });
         }
 
         info!(
@@ -120,6 +118,22 @@ impl WaylandShellSystem {
         })
     }
 
+    pub fn new_minimal() -> Result<Self> {
+        info!("Initializing WindowingSystem in minimal mode (no layer surfaces)");
+        let (connection, mut event_queue) = Self::init_wayland_connection()?;
+        let event_loop =
+            EventLoop::try_new().map_err(|e| EventLoopError::Creation { source: e })?;
+
+        let state = Self::init_state_minimal(&connection, &mut event_queue)?;
+
+        Ok(Self {
+            state,
+            connection,
+            event_queue,
+            event_loop,
+        })
+    }
+
     fn init_wayland_connection() -> Result<(Rc<Connection>, EventQueue<AppState>)> {
         let connection = Rc::new(Connection::connect_to_env()?);
         let event_queue = connection.new_event_queue();
@@ -145,6 +159,12 @@ impl WaylandShellSystem {
         pointer: &Rc<WlPointer>,
         layer_surface_config: &LayerSurfaceConfig,
     ) -> Result<Vec<OutputSetup>> {
+        let layer_shell = global_ctx.layer_shell.as_ref().ok_or_else(|| {
+            LayerShikaError::InvalidInput {
+                message: "wlr-layer-shell protocol not available - cannot create layer surfaces".into(),
+            }
+        })?;
+
         let mut setups = Vec::new();
 
         for (index, output) in global_ctx.outputs.iter().enumerate() {
@@ -163,7 +183,7 @@ impl WaylandShellSystem {
             let setup_params = SurfaceSetupParams {
                 compositor: &global_ctx.compositor,
                 output,
-                layer_shell: &global_ctx.layer_shell,
+                layer_shell,
                 fractional_scale_manager: global_ctx.fractional_scale_manager.as_ref(),
                 viewporter: global_ctx.viewporter.as_ref(),
                 queue_handle: &event_queue.handle(),
@@ -426,6 +446,38 @@ impl WaylandShellSystem {
         Ok(app_state)
     }
 
+    fn init_state_minimal(
+        connection: &Connection,
+        event_queue: &mut EventQueue<AppState>,
+    ) -> Result<AppState> {
+        let global_ctx = Rc::new(GlobalContext::initialize(
+            connection,
+            &event_queue.handle(),
+        )?);
+
+        let pointer = Rc::new(global_ctx.seat.get_pointer(&event_queue.handle(), ()));
+        let keyboard = Rc::new(global_ctx.seat.get_keyboard(&event_queue.handle(), ()));
+        let shared_serial = Rc::new(SharedPointerSerial::new());
+
+        let mut app_state = AppState::new(
+            ManagedWlPointer::new(Rc::clone(&pointer), Rc::new(connection.clone())),
+            ManagedWlKeyboard::new(Rc::clone(&keyboard), Rc::new(connection.clone())),
+            Rc::clone(&shared_serial),
+        );
+
+        app_state.set_queue_handle(event_queue.handle());
+        app_state.set_global_context(Rc::clone(&global_ctx));
+
+        let platform = CustomSlintPlatform::new_empty();
+        set_platform(Box::new(PlatformWrapper(Rc::clone(&platform))))
+            .map_err(|e| LayerShikaError::PlatformSetup { source: e })?;
+        app_state.set_slint_platform(Rc::clone(&platform));
+
+        info!("Minimal state initialized successfully (no layer surfaces, empty Slint platform for session locks)");
+
+        Ok(app_state)
+    }
+
     fn create_output_setups_multi(
         configs: &[ShellSurfaceConfig],
         global_ctx: &GlobalContext,
@@ -433,6 +485,12 @@ impl WaylandShellSystem {
         event_queue: &mut EventQueue<AppState>,
         pointer: &Rc<WlPointer>,
     ) -> Result<Vec<OutputSetup>> {
+        let layer_shell = global_ctx.layer_shell.as_ref().ok_or_else(|| {
+            LayerShikaError::InvalidInput {
+                message: "wlr-layer-shell protocol not available - cannot create layer surfaces".into(),
+            }
+        })?;
+
         let mut setups = Vec::new();
 
         for (output_index, output) in global_ctx.outputs.iter().enumerate() {
@@ -458,7 +516,7 @@ impl WaylandShellSystem {
                 let setup_params = SurfaceSetupParams {
                     compositor: &global_ctx.compositor,
                     output,
-                    layer_shell: &global_ctx.layer_shell,
+                    layer_shell,
                     fractional_scale_manager: global_ctx.fractional_scale_manager.as_ref(),
                     viewporter: global_ctx.viewporter.as_ref(),
                     queue_handle: &event_queue.handle(),
@@ -805,6 +863,10 @@ impl WaylandSystemOps for WaylandShellSystem {
         WaylandShellSystem::despawn_surface(self, name)
     }
 
+    fn set_compilation_result(&mut self, compilation_result: Rc<CompilationResult>) {
+        self.state.set_compilation_result(compilation_result);
+    }
+
     fn activate_session_lock(&mut self, component_name: &str, config: LockConfig) -> Result<()> {
         self.state.activate_session_lock(component_name, config)
     }

crates/adapters/src/wayland/surfaces/app_state.rs

@@ -54,6 +54,7 @@ pub struct AppState {
     global_context: Option<Rc<GlobalContext>>,
     known_outputs: Vec<WlOutput>,
     slint_platform: Option<Rc<CustomSlintPlatform>>,
+    compilation_result: Option<Rc<CompilationResult>>,
     output_registry: OutputRegistry,
     output_mapping: OutputMapping,
     surfaces: HashMap<ShellSurfaceKey, PerOutputSurface>,
@@ -83,6 +84,7 @@ impl AppState {
             global_context: None,
             known_outputs: Vec::new(),
             slint_platform: None,
+            compilation_result: None,
             output_registry: OutputRegistry::new(),
             output_mapping: OutputMapping::new(),
             surfaces: HashMap::new(),
@@ -112,6 +114,10 @@ impl AppState {
         self.slint_platform = Some(platform);
     }
 
+    pub fn set_compilation_result(&mut self, compilation_result: Rc<CompilationResult>) {
+        self.compilation_result = Some(compilation_result);
+    }
+
     pub fn set_queue_handle(&mut self, queue_handle: wayland_client::QueueHandle<AppState>) {
         self.queue_handle = Some(queue_handle);
     }
@@ -255,8 +261,12 @@ impl AppState {
         component_name: &str,
     ) -> Result<(ComponentDefinition, Option<Rc<CompilationResult>>)> {
         let compilation_result = self
-            .primary_output()
+            .compilation_result
+            .clone()
+            .or_else(|| {
+                self.primary_output()
                     .and_then(SurfaceState::compilation_result)
+            })
             .ok_or_else(|| LayerShikaError::InvalidInput {
                 message: "No compilation result available for session lock".to_string(),
             })?;

crates/composition/src/shell.rs

@@ -77,15 +77,11 @@ impl ShellBuilder {
     }
 
     /// Builds the shell from the configured surfaces
+    ///
+    /// If no surfaces are configured, creates a minimal shell without layer surfaces.
+    /// This is useful for lock-only applications that don't need persistent UI surfaces.
     pub fn build(self) -> Result<Shell> {
-        let surfaces = if self.surfaces.is_empty() {
+        let surfaces = self.surfaces;
-            vec![SurfaceDefinition {
-                component: DEFAULT_COMPONENT_NAME.to_string(),
-                config: SurfaceConfig::default(),
-            }]
-        } else {
-            self.surfaces
-        };
 
         let compilation_result = match self.compilation {
             CompilationSource::File { path, compiler } => {
@@ -399,27 +395,24 @@ impl Shell {
     ) -> Result<Self> {
         log::info!("Creating Shell with {} windows", definitions.len());
 
-        if definitions.is_empty() {
-            return Err(Error::Domain(DomainError::Configuration {
-                message: "At least one window definition is required".to_string(),
-            }));
-        }
-
         for def in &definitions {
             def.config.validate().map_err(Error::Domain)?;
         }
 
-        let is_single_window = definitions.len() == 1;
+        match definitions.len() {
-
+            0 => {
-        if is_single_window {
+                log::info!("Creating minimal shell without layer surfaces");
+                Self::new_minimal(compilation_result)
+            }
+            1 => {
                 let definition = definitions.into_iter().next().ok_or_else(|| {
                     Error::Domain(DomainError::Configuration {
                         message: "Expected at least one window definition".to_string(),
                     })
                 })?;
                 Self::new_single_window(compilation_result, definition)
-        } else {
+            }
-            Self::new_multi_window(compilation_result, &definitions)
+            _ => Self::new_multi_window(compilation_result, &definitions),
         }
     }
 
@@ -545,6 +538,34 @@ impl Shell {
         Ok(shell)
     }
 
+    fn new_minimal(compilation_result: Rc<CompilationResult>) -> Result<Self> {
+        let inner = layer_shika_adapters::WaylandShellSystem::new_minimal()?;
+        let inner_rc: Rc<RefCell<dyn WaylandSystemOps>> = Rc::new(RefCell::new(inner));
+
+        inner_rc
+            .borrow_mut()
+            .set_compilation_result(Rc::clone(&compilation_result));
+
+        let (sender, receiver) = channel::channel();
+
+        let registry = SurfaceRegistry::new();
+
+        let shell = Self {
+            inner: Rc::clone(&inner_rc),
+            registry,
+            compilation_result,
+            command_sender: sender,
+            output_connected_handlers: Rc::new(RefCell::new(Vec::new())),
+            output_disconnected_handlers: Rc::new(RefCell::new(Vec::new())),
+        };
+
+        shell.setup_command_handler(receiver)?;
+
+        log::info!("Shell created (minimal mode - no layer surfaces)");
+
+        Ok(shell)
+    }
+
     fn setup_command_handler(&self, receiver: channel::Channel<ShellCommand>) -> Result<()> {
         let loop_handle = self.inner.borrow().event_loop_handle();
         let control = self.control();