support resizing, start on layer shell support

src/handlers/wlr_layer_shell.rs

@@ -0,0 +1,30 @@
+use smithay::{
+    desktop::{layer_map_for_output, LayerSurface},
+    output::Output,
+    wayland::shell::wlr_layer::WlrLayerShellHandler,
+};
+use wayland_server::protocol::wl_output::WlOutput;
+
+use crate::State;
+
+impl WlrLayerShellHandler for State {
+    fn shell_state(&mut self) -> &mut smithay::wayland::shell::wlr_layer::WlrLayerShellState {
+        &mut self.wlr_layer_shell_state
+    }
+
+    fn new_layer_surface(
+        &mut self,
+        surface: smithay::wayland::shell::wlr_layer::LayerSurface,
+        output: Option<WlOutput>,
+        layer: smithay::wayland::shell::wlr_layer::Layer,
+        namespace: String,
+    ) {
+        let output = output
+            .as_ref()
+            .and_then(Output::from_resource)
+            .unwrap_or_else(|| self.space.outputs().next().unwrap().clone());
+        let mut map = layer_map_for_output(&output);
+        map.map_layer(&LayerSurface::new(surface, namespace))
+            .unwrap();
+    }
+}