Upgrade compositor to v6 with output-aware surface preferences

compositor/src/handlers/compositor.rs

@@ -49,7 +49,16 @@ impl CompositorHandler for Ferese {
             .compositor_state
     }
 
+    fn new_surface(&mut self, surface: &WlSurface) {
+        self.update_surface_preferences(surface);
+    }
+
+    fn new_subsurface(&mut self, surface: &WlSurface, _parent: &WlSurface) {
+        self.update_surface_preferences(surface);
+    }
+
     fn commit(&mut self, surface: &WlSurface) {
+        self.update_surface_preferences(surface);
         self.capture_resize_before_commit(surface);
         if self.surface_affects_backdrop(surface) {
             self.backdrop_generation = self.backdrop_generation.wrapping_add(1);

compositor/src/handlers/layer_shell.rs

@@ -31,20 +31,19 @@ impl WlrLayerShellHandler for Ferese {
         }
 
         tracing::debug!(%namespace, output = %output.name(), "mapped layer surface");
-        super::set_surface_tree_scale(layer.wl_surface(), output.current_scale().fractional_scale());
+        super::set_surface_tree_output(layer.wl_surface(), &output);
         self.relayout();
         crate::backends::direct::render_all(self);
     }
 
     fn new_popup(&mut self, parent: LayerSurface, popup: PopupSurface) {
-        let scale = self.space.outputs().find_map(|output| {
+        let output = self.space.outputs().find(|output| {
             layer_map_for_output(output)
                 .layers()
                 .any(|layer| layer.wl_surface() == parent.wl_surface())
-                .then(|| output.current_scale().fractional_scale())
         });
-        if let Some(scale) = scale {
-            super::set_surface_tree_scale(popup.wl_surface(), scale);
+        if let Some(output) = output {
+            super::set_surface_tree_output(popup.wl_surface(), output);
         }
         self.unconstrain_popup(&popup);
         if let Err(error) = self.popups.track_popup(PopupKind::Xdg(popup)) {

compositor/src/handlers/mod.rs

@@ -79,18 +79,7 @@ impl OutputHandler for Ferese {}
 
 impl FractionalScaleHandler for Ferese {
     fn new_fractional_scale(&mut self, surface: WlSurface) {
-        let scale = self
-            .space
-            .outputs()
-            .next()
-            .map(|output| output.current_scale().fractional_scale())
-            .unwrap_or(1.0);
-
-        with_states(&surface, |states| {
-            with_fractional_scale(states, |surface_scale| {
-                surface_scale.set_preferred_scale(scale);
-            });
-        });
+        self.update_surface_preferences(&surface);
     }
 }
 
@@ -140,43 +129,69 @@ impl KeyboardShortcutsInhibitHandler for Ferese {
 }
 
 impl Ferese {
-    pub fn update_fractional_scale(&self, scale: f64) {
-        for window in self.space.elements() {
-            let Some(toplevel) = window.toplevel() else {
-                continue;
-            };
+    pub(crate) fn update_surface_preferences(&self, surface: &WlSurface) {
+        use smithay::desktop::{WindowSurfaceType, find_popup_root_surface};
+        use smithay::wayland::compositor::get_parent;
 
-            set_surface_tree_scale(toplevel.wl_surface(), scale);
+        let mut root = surface.clone();
+        while let Some(parent) = get_parent(&root) {
+            root = parent;
         }
-
-        // Layer surfaces are not Space elements. Use their own output's scale,
-        // rather than broadcasting one output's density to every bar.
-        for output in self.space.outputs() {
-            let scale = output.current_scale().fractional_scale();
-            let layers: Vec<_> = layer_map_for_output(output).layers().cloned().collect();
-            for layer in layers {
-                set_surface_tree_scale(layer.wl_surface(), scale);
-            }
+        if let Some(popup) = self.popups.find_popup(&root)
+            && let Ok(parent) = find_popup_root_surface(&popup)
+        {
+            root = parent;
         }
+        let window = self.window_ids.iter().find_map(|(window, id)| {
+            window
+                .toplevel()
+                .is_some_and(|toplevel| toplevel.wl_surface() == &root)
+                .then_some(*id)
+        });
+        let output = self.space.outputs().find(|output| {
+            window.is_some_and(|id| self.window_belongs_to_output(id, output))
+                || layer_map_for_output(output)
+                    .layer_for_surface(&root, WindowSurfaceType::ALL)
+                    .is_some()
+                || self
+                    .session_lock
+                    .surfaces
+                    .get(output)
+                    .is_some_and(|lock| lock.wl_surface() == &root)
+        });
+        // Hidden workspaces retain their last output preferences until presented again.
+        if window.is_some() && output.is_none() {
+            return;
+        }
+        let output = output
+            .or_else(|| self.focused_output())
+            .or_else(|| self.space.outputs().next());
+        with_states(surface, |states| set_surface_preferences(surface, states, output));
     }
 }
 
-pub(crate) fn set_surface_tree_scale(surface: &WlSurface, scale: f64) {
+fn set_surface_preferences(
+    surface: &WlSurface,
+    states: &smithay::wayland::compositor::SurfaceData,
+    output: Option<&smithay::output::Output>,
+) {
+    let scale = output.map_or(1.0, |output| output.current_scale().fractional_scale());
+    let transform = output.map_or(smithay::utils::Transform::Normal, |output| output.current_transform());
+    smithay::wayland::compositor::send_surface_state(surface, states, scale.ceil() as i32, transform);
+    with_fractional_scale(states, |surface_scale| surface_scale.set_preferred_scale(scale));
+}
+
+pub(crate) fn set_surface_tree_output(surface: &WlSurface, output: &smithay::output::Output) {
     let update_tree = |root: &WlSurface| {
         with_surface_tree_downward(
             root,
             (),
             |_, _, &()| TraversalAction::DoChildren(()),
-            |_, states, &()| {
-                with_fractional_scale(states, |surface_scale| {
-                    surface_scale.set_preferred_scale(scale);
-                });
-            },
+            |surface, states, &()| set_surface_preferences(surface, states, Some(output)),
             |_, _, &()| true,
         );
     };
     update_tree(surface);
-    // XDG popups are separate surface trees, not wl_subsurfaces.
     for (popup, _) in PopupManager::popups_for_surface(surface) {
         update_tree(popup.wl_surface());
     }

compositor/src/session_lock.rs

@@ -202,6 +202,7 @@ impl Ferese {
 
     pub(crate) fn configure_lock_surfaces(&mut self) {
         for (output, surface) in &self.session_lock.surfaces {
+            crate::handlers::set_surface_tree_output(surface.wl_surface(), output);
             if let Some(geometry) = self.space.output_geometry(output) {
                 surface.with_pending_state(|state| {
                     state.size = Some((geometry.size.w as u32, geometry.size.h as u32).into())
@@ -316,6 +317,7 @@ impl SessionLockHandler for Ferese {
         {
             surface
                 .with_pending_state(|state| state.size = Some((geometry.size.w as u32, geometry.size.h as u32).into()));
+            crate::handlers::set_surface_tree_output(surface.wl_surface(), &output);
             self.session_lock.surfaces.insert(output, surface);
             self.focus_lock_surface();
         }

compositor/src/state.rs

@@ -473,7 +473,7 @@ impl Ferese {
         crate::shell_control::init_global(&display_handle);
 
         let alpha_modifier_state = AlphaModifierState::new::<Self>(&display_handle);
-        let compositor_state = CompositorState::new::<Self>(&display_handle);
+        let compositor_state = CompositorState::new_v6::<Self>(&display_handle);
         let cursor_shape_state = CursorShapeManagerState::new::<Self>(&display_handle);
         let xdg_shell_state = XdgShellState::new::<Self>(&display_handle);
         let decoration_state = XdgDecorationState::new::<Self>(&display_handle);

compositor/src/state/layout.rs

@@ -81,9 +81,8 @@ impl Ferese {
                 continue;
             };
             let fullscreen_bounds = self.full_output_bounds_for(&output).unwrap_or(bounds);
-            let scale = output.current_scale().fractional_scale();
             for layer in layer_map_for_output(&output).layers() {
-                crate::handlers::set_surface_tree_scale(layer.wl_surface(), scale);
+                crate::handlers::set_surface_tree_output(layer.wl_surface(), &output);
             }
             let Some(workspace) = self.workspaces.workspace(workspace_id) else {
                 continue;
@@ -140,7 +139,7 @@ impl Ferese {
                     continue;
                 }
                 if let Some(toplevel) = window.toplevel() {
-                    crate::handlers::set_surface_tree_scale(toplevel.wl_surface(), scale);
+                    crate::handlers::set_surface_tree_output(toplevel.wl_surface(), &output);
                 }
 
                 let is_maximized = self.maximized_windows.contains(id) && workspace_fullscreen != Some(*id);

compositor/src/winit.rs

@@ -70,7 +70,6 @@ pub fn init(event_loop: &mut EventLoop<Ferese>, state: &mut Ferese) -> Result<()
     let clock = Clock::<Monotonic>::new();
     let mut sequence = 0_u64;
     let mut missed_deadlines = 0_u64;
-    let mut output_scale = initial_scale;
     let mut render_metrics = RenderMetrics::from_environment(output.name());
 
     // Do not request a redraw recursively: a no-damage redraw has no EGL
@@ -112,11 +111,6 @@ pub fn init(event_loop: &mut EventLoop<Ferese>, state: &mut Ferese) -> Result<()
                         None,
                     );
 
-                    if scale != output_scale {
-                        output_scale = scale;
-                        state.update_fractional_scale(scale);
-                    }
-
                     state.relayout();
                     if let Err(error) = state.display_handle.flush_clients() {
                         tracing::debug!(%error, "failed to flush output-resize configure");