fix: synchronize floating window geometry

compositor/src/grabs/move_grab.rs

@@ -16,6 +16,7 @@ pub struct MoveSurfaceGrab {
     pub start_data: GrabStartData<Ferese>,
     pub window: Window,
     pub initial_location: Point<i32, Logical>,
+    pub finished: bool,
 }
 
 impl PointerGrab<Ferese> for MoveSurfaceGrab {
@@ -28,8 +29,11 @@ impl PointerGrab<Ferese> for MoveSurfaceGrab {
     ) {
         handle.motion(data, None, event);
         let location = self.initial_location.to_f64() + (event.location - self.start_data.location);
-        data.space
+        let location = location.to_i32_round();
-            .map_element(self.window.clone(), location.to_i32_round(), true);
+        let size = self.window.geometry().size;
+
+        data.set_floating_window_geometry(&self.window, location, size);
+        data.space.map_element(self.window.clone(), location, true);
     }
 
     fn relative_motion(
@@ -50,6 +54,7 @@ impl PointerGrab<Ferese> for MoveSurfaceGrab {
     ) {
         handle.button(data, event);
         if handle.current_pressed().is_empty() {
+            self.finished = true;
             handle.unset_grab(self, data, event.serial, event.time, true);
         }
     }
@@ -143,5 +148,14 @@ impl PointerGrab<Ferese> for MoveSurfaceGrab {
         &self.start_data
     }
 
-    fn unset(&mut self, _data: &mut Ferese) {}
+    fn unset(&mut self, data: &mut Ferese) {
+        if self.finished {
+            return;
+        }
+
+        let size = self.window.geometry().size;
+        data.set_floating_window_geometry(&self.window, self.initial_location, size);
+        data.space
+            .map_element(self.window.clone(), self.initial_location, true);
+    }
 }

compositor/src/grabs/resize_grab.rs

@@ -71,6 +71,7 @@ pub struct ResizeSurfaceGrab {
     edges: ResizeEdge,
     initial_rect: Rectangle<i32, Logical>,
     last_size: Size<i32, Logical>,
+    finished: bool,
 }
 
 impl ResizeSurfaceGrab {
@@ -98,6 +99,7 @@ impl ResizeSurfaceGrab {
             edges,
             initial_rect,
             last_size: initial_rect.size,
+            finished: false,
         }
     }
 }
@@ -123,6 +125,8 @@ impl PointerGrab<Ferese> for ResizeSurfaceGrab {
         });
         self.last_size =
             constrained_size(self.initial_rect.size, delta, self.edges, minimum, maximum);
+        let rect = resized_rect(self.initial_rect, self.last_size, self.edges);
+        data.set_floating_window_geometry(&self.window, rect.loc, rect.size);
 
         surface.with_pending_state(|state| {
             state.states.set(xdg_toplevel::State::Resizing);
@@ -149,6 +153,7 @@ impl PointerGrab<Ferese> for ResizeSurfaceGrab {
     ) {
         handle.button(data, event);
         if handle.current_pressed().is_empty() {
+            self.finished = true;
             handle.unset_grab(self, data, event.serial, event.time, true);
             let surface = self
                 .window
@@ -250,7 +255,29 @@ impl PointerGrab<Ferese> for ResizeSurfaceGrab {
         &self.start_data
     }
 
-    fn unset(&mut self, _data: &mut Ferese) {}
+    fn unset(&mut self, data: &mut Ferese) {
+        if self.finished {
+            return;
+        }
+
+        let surface = self
+            .window
+            .toplevel()
+            .expect("managed window has a toplevel");
+        surface.with_pending_state(|state| {
+            state.states.unset(xdg_toplevel::State::Resizing);
+            state.size = Some(self.initial_rect.size);
+        });
+        surface.send_pending_configure();
+        ResizeState::with(surface.wl_surface(), |state| *state = ResizeState::Idle);
+        data.set_floating_window_geometry(
+            &self.window,
+            self.initial_rect.loc,
+            self.initial_rect.size,
+        );
+        data.space
+            .map_element(self.window.clone(), self.initial_rect.loc, true);
+    }
 }
 
 #[derive(Clone, Copy, Debug, Default)]
@@ -359,6 +386,23 @@ fn constrained_size(
         .into()
 }
 
+fn resized_rect(
+    initial: Rectangle<i32, Logical>,
+    size: Size<i32, Logical>,
+    edges: ResizeEdge,
+) -> Rectangle<i32, Logical> {
+    let mut location = initial.loc;
+
+    if edges.left() {
+        location.x += initial.size.w - size.w;
+    }
+    if edges.top() {
+        location.y += initial.size.h - size.h;
+    }
+
+    Rectangle::new(location, size)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -398,4 +442,17 @@ mod tests {
         );
         assert_eq!(size, (1_024, 768).into());
     }
+
+    #[test]
+    fn resized_rect_keeps_the_opposite_edge_fixed() {
+        let initial = Rectangle::new((100, 80).into(), (800, 600).into());
+        let resized = resized_rect(
+            initial,
+            (700, 550).into(),
+            ResizeEdge(xdg_toplevel::ResizeEdge::TopLeft),
+        );
+
+        assert_eq!(resized.loc, (200, 130).into());
+        assert_eq!(resized.size, (700, 550).into());
+    }
 }

compositor/src/handlers/xdg_shell.rs

@@ -100,12 +100,16 @@ impl XdgShellHandler for Ferese {
         let Some(initial_location) = self.space.element_location(&window) else {
             return;
         };
+        if !self.is_floating_window(&window) {
+            return;
+        }
         pointer.set_grab(
             self,
             MoveSurfaceGrab {
                 start_data,
                 window,
                 initial_location,
+                finished: false,
             },
             serial,
             Focus::Clear,
@@ -143,6 +147,9 @@ impl XdgShellHandler for Ferese {
         let Some(location) = self.space.element_location(&window) else {
             return;
         };
+        if !self.is_floating_window(&window) {
+            return;
+        }
         let rect = Rectangle::new(location, window.geometry().size);
         pointer.set_grab(
             self,

compositor/src/state.rs

@@ -21,7 +21,7 @@ use smithay::{
             protocol::wl_surface::WlSurface,
         },
     },
-    utils::{Logical, Point},
+    utils::{Logical, Point, Size},
     wayland::{
         compositor::{CompositorClientState, CompositorState},
         fractional_scale::FractionalScaleManagerState,
@@ -440,6 +440,34 @@ impl Ferese {
         }
     }
 
+    pub fn is_floating_window(&self, window: &Window) -> bool {
+        self.window_ids
+            .get(window)
+            .and_then(|id| self.workspaces.placement(*id))
+            .is_some_and(|placement| matches!(placement, WindowPlacement::Floating { .. }))
+    }
+
+    pub fn set_floating_window_geometry(
+        &mut self,
+        window: &Window,
+        location: Point<i32, Logical>,
+        size: Size<i32, Logical>,
+    ) {
+        let Some(id) = self.window_ids.get(window).copied() else {
+            return;
+        };
+        let rect = Rect::new(
+            location.x as f64,
+            location.y as f64,
+            size.w.max(1) as f64,
+            size.h.max(1) as f64,
+        );
+
+        if let Err(error) = self.workspaces.set_floating_rect(id, rect) {
+            tracing::error!(%error, ?id, "failed to update floating window geometry");
+        }
+    }
+
     pub fn switch_workspace(&mut self, index: u32) {
         let focus = match self.workspaces.switch_to_numeric(index) {
             Ok(focus) => focus,

crates/ferese-core/src/workspace.rs

@@ -127,6 +127,28 @@ impl WorkspaceSet {
         self.placements.get(&window).copied()
     }
 
+    pub fn set_floating_rect(
+        &mut self,
+        window: WindowId,
+        rect: Rect,
+    ) -> Result<(), WorkspaceError> {
+        let placement = self
+            .placements
+            .get_mut(&window)
+            .ok_or(LayoutError::UnknownWindow(window))?;
+
+        if !matches!(placement, WindowPlacement::Floating { .. }) {
+            return Err(WorkspaceError::InvalidState("window is not floating"));
+        }
+
+        *placement = WindowPlacement::Floating {
+            rect: normalized_floating_rect(rect),
+        };
+
+        debug_assert!(self.validate().is_ok());
+        Ok(())
+    }
+
     pub fn focus_window(&mut self, window: WindowId) -> Result<(), WorkspaceError> {
         if self.workspace_for_window(window) != Some(self.active) {
             return Err(WorkspaceError::InvalidState(
@@ -621,6 +643,38 @@ mod tests {
         assert!(workspaces.validate().is_ok());
     }
 
+    #[test]
+    fn floating_geometry_updates_are_authoritative_and_validated() {
+        let mut workspaces = WorkspaceSet::default();
+        workspaces
+            .insert_window(WindowId(1), Axis::Horizontal, 0.5)
+            .unwrap();
+        assert_eq!(
+            workspaces.set_floating_rect(WindowId(1), Rect::default()),
+            Err(WorkspaceError::InvalidState("window is not floating"))
+        );
+
+        workspaces
+            .toggle_floating(
+                WindowId(1),
+                Rect::new(10.0, 20.0, 640.0, 480.0),
+                Axis::Horizontal,
+                0.5,
+            )
+            .unwrap();
+        workspaces
+            .set_floating_rect(WindowId(1), Rect::new(30.0, 40.0, f64::NAN, -2.0))
+            .unwrap();
+
+        assert_eq!(
+            workspaces.placement(WindowId(1)),
+            Some(WindowPlacement::Floating {
+                rect: Rect::new(30.0, 40.0, 1.0, 1.0)
+            })
+        );
+        assert!(workspaces.validate().is_ok());
+    }
+
     #[test]
     fn fullscreen_preserves_underlying_placement() {
         let mut workspaces = WorkspaceSet::default();