feat: add nested Phase 0 compositor

compositor/src/handlers/compositor.rs

@@ -0,0 +1,59 @@
+use smithay::{
+    backend::renderer::utils::on_commit_buffer_handler,
+    reexports::wayland_server::{
+        Client,
+        protocol::{wl_buffer, wl_surface::WlSurface},
+    },
+    wayland::{
+        buffer::BufferHandler,
+        compositor::{
+            CompositorClientState, CompositorHandler, CompositorState, get_parent,
+            is_sync_subsurface,
+        },
+        shm::{ShmHandler, ShmState},
+    },
+};
+
+use super::xdg_shell;
+use crate::{Ferese, state::ClientState};
+
+impl CompositorHandler for Ferese {
+    fn compositor_state(&mut self) -> &mut CompositorState {
+        &mut self.compositor_state
+    }
+
+    fn client_compositor_state<'a>(&self, client: &'a Client) -> &'a CompositorClientState {
+        &client
+            .get_data::<ClientState>()
+            .expect("all clients have Ferese client state")
+            .compositor_state
+    }
+
+    fn commit(&mut self, surface: &WlSurface) {
+        on_commit_buffer_handler::<Self>(surface);
+        if !is_sync_subsurface(surface) {
+            let mut root = surface.clone();
+            while let Some(parent) = get_parent(&root) {
+                root = parent;
+            }
+            if let Some(window) = self.space.elements().find(|window| {
+                window
+                    .toplevel()
+                    .is_some_and(|toplevel| toplevel.wl_surface() == &root)
+            }) {
+                window.on_commit();
+            }
+        }
+        xdg_shell::handle_commit(&mut self.popups, &self.space, surface);
+    }
+}
+
+impl BufferHandler for Ferese {
+    fn buffer_destroyed(&mut self, _buffer: &wl_buffer::WlBuffer) {}
+}
+
+impl ShmHandler for Ferese {
+    fn shm_state(&self) -> &ShmState {
+        &self.shm_state
+    }
+}