feat: support interactive window move and resize

compositor/src/grabs/mod.rs

@@ -0,0 +1,5 @@
+mod move_grab;
+mod resize_grab;
+
+pub use move_grab::MoveSurfaceGrab;
+pub use resize_grab::{ResizeEdge, ResizeSurfaceGrab, handle_resize_commit};

compositor/src/grabs/move_grab.rs

@@ -0,0 +1,147 @@
+use smithay::{
+    desktop::Window,
+    input::pointer::{
+        AxisFrame, ButtonEvent, GestureHoldBeginEvent, GestureHoldEndEvent, GesturePinchBeginEvent,
+        GesturePinchEndEvent, GesturePinchUpdateEvent, GestureSwipeBeginEvent,
+        GestureSwipeEndEvent, GestureSwipeUpdateEvent, GrabStartData, MotionEvent, PointerGrab,
+        PointerInnerHandle, RelativeMotionEvent,
+    },
+    reexports::wayland_server::protocol::wl_surface::WlSurface,
+    utils::{Logical, Point},
+};
+
+use crate::Ferese;
+
+pub struct MoveSurfaceGrab {
+    pub start_data: GrabStartData<Ferese>,
+    pub window: Window,
+    pub initial_location: Point<i32, Logical>,
+}
+
+impl PointerGrab<Ferese> for MoveSurfaceGrab {
+    fn motion(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        _focus: Option<(WlSurface, Point<f64, Logical>)>,
+        event: &MotionEvent,
+    ) {
+        handle.motion(data, None, event);
+        let location = self.initial_location.to_f64() + (event.location - self.start_data.location);
+        data.space
+            .map_element(self.window.clone(), location.to_i32_round(), true);
+    }
+
+    fn relative_motion(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        focus: Option<(WlSurface, Point<f64, Logical>)>,
+        event: &RelativeMotionEvent,
+    ) {
+        handle.relative_motion(data, focus, event);
+    }
+
+    fn button(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &ButtonEvent,
+    ) {
+        handle.button(data, event);
+        if handle.current_pressed().is_empty() {
+            handle.unset_grab(self, data, event.serial, event.time, true);
+        }
+    }
+
+    fn axis(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        frame: AxisFrame,
+    ) {
+        handle.axis(data, frame);
+    }
+
+    fn frame(&mut self, data: &mut Ferese, handle: &mut PointerInnerHandle<'_, Ferese>) {
+        handle.frame(data);
+    }
+
+    fn gesture_swipe_begin(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GestureSwipeBeginEvent,
+    ) {
+        handle.gesture_swipe_begin(data, event);
+    }
+
+    fn gesture_swipe_update(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GestureSwipeUpdateEvent,
+    ) {
+        handle.gesture_swipe_update(data, event);
+    }
+
+    fn gesture_swipe_end(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GestureSwipeEndEvent,
+    ) {
+        handle.gesture_swipe_end(data, event);
+    }
+
+    fn gesture_pinch_begin(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GesturePinchBeginEvent,
+    ) {
+        handle.gesture_pinch_begin(data, event);
+    }
+
+    fn gesture_pinch_update(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GesturePinchUpdateEvent,
+    ) {
+        handle.gesture_pinch_update(data, event);
+    }
+
+    fn gesture_pinch_end(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GesturePinchEndEvent,
+    ) {
+        handle.gesture_pinch_end(data, event);
+    }
+
+    fn gesture_hold_begin(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GestureHoldBeginEvent,
+    ) {
+        handle.gesture_hold_begin(data, event);
+    }
+
+    fn gesture_hold_end(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GestureHoldEndEvent,
+    ) {
+        handle.gesture_hold_end(data, event);
+    }
+
+    fn start_data(&self) -> &GrabStartData<Ferese> {
+        &self.start_data
+    }
+
+    fn unset(&mut self, _data: &mut Ferese) {}
+}

compositor/src/grabs/resize_grab.rs

@@ -0,0 +1,401 @@
+use std::cell::RefCell;
+
+use smithay::{
+    desktop::{Space, Window},
+    input::pointer::{
+        AxisFrame, ButtonEvent, GestureHoldBeginEvent, GestureHoldEndEvent, GesturePinchBeginEvent,
+        GesturePinchEndEvent, GesturePinchUpdateEvent, GestureSwipeBeginEvent,
+        GestureSwipeEndEvent, GestureSwipeUpdateEvent, GrabStartData, MotionEvent, PointerGrab,
+        PointerInnerHandle, RelativeMotionEvent,
+    },
+    reexports::{
+        wayland_protocols::xdg::shell::server::xdg_toplevel,
+        wayland_server::protocol::wl_surface::WlSurface,
+    },
+    utils::{Logical, Point, Rectangle, Size},
+    wayland::{compositor::with_states, shell::xdg::SurfaceCachedState},
+};
+
+use crate::Ferese;
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub struct ResizeEdge(xdg_toplevel::ResizeEdge);
+
+impl From<xdg_toplevel::ResizeEdge> for ResizeEdge {
+    fn from(edge: xdg_toplevel::ResizeEdge) -> Self {
+        Self(edge)
+    }
+}
+
+impl ResizeEdge {
+    fn left(self) -> bool {
+        matches!(
+            self.0,
+            xdg_toplevel::ResizeEdge::Left
+                | xdg_toplevel::ResizeEdge::TopLeft
+                | xdg_toplevel::ResizeEdge::BottomLeft
+        )
+    }
+
+    fn right(self) -> bool {
+        matches!(
+            self.0,
+            xdg_toplevel::ResizeEdge::Right
+                | xdg_toplevel::ResizeEdge::TopRight
+                | xdg_toplevel::ResizeEdge::BottomRight
+        )
+    }
+
+    fn top(self) -> bool {
+        matches!(
+            self.0,
+            xdg_toplevel::ResizeEdge::Top
+                | xdg_toplevel::ResizeEdge::TopLeft
+                | xdg_toplevel::ResizeEdge::TopRight
+        )
+    }
+
+    fn bottom(self) -> bool {
+        matches!(
+            self.0,
+            xdg_toplevel::ResizeEdge::Bottom
+                | xdg_toplevel::ResizeEdge::BottomLeft
+                | xdg_toplevel::ResizeEdge::BottomRight
+        )
+    }
+}
+
+pub struct ResizeSurfaceGrab {
+    start_data: GrabStartData<Ferese>,
+    window: Window,
+    edges: ResizeEdge,
+    initial_rect: Rectangle<i32, Logical>,
+    last_size: Size<i32, Logical>,
+}
+
+impl ResizeSurfaceGrab {
+    pub fn new(
+        start_data: GrabStartData<Ferese>,
+        window: Window,
+        edges: ResizeEdge,
+        initial_rect: Rectangle<i32, Logical>,
+    ) -> Self {
+        ResizeState::with(
+            window
+                .toplevel()
+                .expect("managed window has a toplevel")
+                .wl_surface(),
+            |state| {
+                *state = ResizeState::Resizing {
+                    edges,
+                    initial_rect,
+                }
+            },
+        );
+        Self {
+            start_data,
+            window,
+            edges,
+            initial_rect,
+            last_size: initial_rect.size,
+        }
+    }
+}
+
+impl PointerGrab<Ferese> for ResizeSurfaceGrab {
+    fn motion(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        _focus: Option<(WlSurface, Point<f64, Logical>)>,
+        event: &MotionEvent,
+    ) {
+        handle.motion(data, None, event);
+        let delta = event.location - self.start_data.location;
+        let surface = self
+            .window
+            .toplevel()
+            .expect("managed window has a toplevel");
+        let (minimum, maximum) = with_states(surface.wl_surface(), |states| {
+            let mut cached = states.cached_state.get::<SurfaceCachedState>();
+            let state = cached.current();
+            (state.min_size, state.max_size)
+        });
+        self.last_size =
+            constrained_size(self.initial_rect.size, delta, self.edges, minimum, maximum);
+
+        surface.with_pending_state(|state| {
+            state.states.set(xdg_toplevel::State::Resizing);
+            state.size = Some(self.last_size);
+        });
+        surface.send_pending_configure();
+    }
+
+    fn relative_motion(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        focus: Option<(WlSurface, Point<f64, Logical>)>,
+        event: &RelativeMotionEvent,
+    ) {
+        handle.relative_motion(data, focus, event);
+    }
+
+    fn button(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &ButtonEvent,
+    ) {
+        handle.button(data, event);
+        if handle.current_pressed().is_empty() {
+            handle.unset_grab(self, data, event.serial, event.time, true);
+            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.last_size);
+            });
+            surface.send_pending_configure();
+            ResizeState::with(surface.wl_surface(), |state| {
+                *state = ResizeState::WaitingForFinalCommit {
+                    edges: self.edges,
+                    initial_rect: self.initial_rect,
+                };
+            });
+        }
+    }
+
+    fn axis(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        frame: AxisFrame,
+    ) {
+        handle.axis(data, frame);
+    }
+
+    fn frame(&mut self, data: &mut Ferese, handle: &mut PointerInnerHandle<'_, Ferese>) {
+        handle.frame(data);
+    }
+
+    fn gesture_swipe_begin(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GestureSwipeBeginEvent,
+    ) {
+        handle.gesture_swipe_begin(data, event);
+    }
+    fn gesture_swipe_update(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GestureSwipeUpdateEvent,
+    ) {
+        handle.gesture_swipe_update(data, event);
+    }
+    fn gesture_swipe_end(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GestureSwipeEndEvent,
+    ) {
+        handle.gesture_swipe_end(data, event);
+    }
+    fn gesture_pinch_begin(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GesturePinchBeginEvent,
+    ) {
+        handle.gesture_pinch_begin(data, event);
+    }
+    fn gesture_pinch_update(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GesturePinchUpdateEvent,
+    ) {
+        handle.gesture_pinch_update(data, event);
+    }
+    fn gesture_pinch_end(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GesturePinchEndEvent,
+    ) {
+        handle.gesture_pinch_end(data, event);
+    }
+    fn gesture_hold_begin(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GestureHoldBeginEvent,
+    ) {
+        handle.gesture_hold_begin(data, event);
+    }
+    fn gesture_hold_end(
+        &mut self,
+        data: &mut Ferese,
+        handle: &mut PointerInnerHandle<'_, Ferese>,
+        event: &GestureHoldEndEvent,
+    ) {
+        handle.gesture_hold_end(data, event);
+    }
+
+    fn start_data(&self) -> &GrabStartData<Ferese> {
+        &self.start_data
+    }
+
+    fn unset(&mut self, _data: &mut Ferese) {}
+}
+
+#[derive(Clone, Copy, Debug, Default)]
+enum ResizeState {
+    #[default]
+    Idle,
+    Resizing {
+        edges: ResizeEdge,
+        initial_rect: Rectangle<i32, Logical>,
+    },
+    WaitingForFinalCommit {
+        edges: ResizeEdge,
+        initial_rect: Rectangle<i32, Logical>,
+    },
+}
+
+impl ResizeState {
+    fn with<T>(surface: &WlSurface, callback: impl FnOnce(&mut Self) -> T) -> T {
+        with_states(surface, |states| {
+            states.data_map.insert_if_missing(RefCell::<Self>::default);
+            callback(
+                &mut states
+                    .data_map
+                    .get::<RefCell<Self>>()
+                    .expect("resize state was inserted")
+                    .borrow_mut(),
+            )
+        })
+    }
+
+    fn commit(&mut self) -> Option<(ResizeEdge, Rectangle<i32, Logical>)> {
+        match *self {
+            Self::Idle => None,
+            Self::Resizing {
+                edges,
+                initial_rect,
+            } => Some((edges, initial_rect)),
+            Self::WaitingForFinalCommit {
+                edges,
+                initial_rect,
+            } => {
+                *self = Self::Idle;
+                Some((edges, initial_rect))
+            }
+        }
+    }
+}
+
+pub fn handle_resize_commit(space: &mut Space<Window>, surface: &WlSurface) {
+    let Some(window) = space
+        .elements()
+        .find(|window| {
+            window
+                .toplevel()
+                .is_some_and(|toplevel| toplevel.wl_surface() == surface)
+        })
+        .cloned()
+    else {
+        return;
+    };
+    let Some(mut location) = space.element_location(&window) else {
+        return;
+    };
+    let geometry = window.geometry();
+    let Some((edges, initial_rect)) = ResizeState::with(surface, ResizeState::commit) else {
+        return;
+    };
+
+    if edges.left() {
+        location.x = initial_rect.loc.x + initial_rect.size.w - geometry.size.w;
+    }
+    if edges.top() {
+        location.y = initial_rect.loc.y + initial_rect.size.h - geometry.size.h;
+    }
+    if edges.left() || edges.top() {
+        space.map_element(window, location, false);
+    }
+}
+
+fn constrained_size(
+    initial: Size<i32, Logical>,
+    delta: Point<f64, Logical>,
+    edges: ResizeEdge,
+    minimum: Size<i32, Logical>,
+    maximum: Size<i32, Logical>,
+) -> Size<i32, Logical> {
+    let mut width = initial.w;
+    let mut height = initial.h;
+    if edges.left() {
+        width -= delta.x as i32;
+    } else if edges.right() {
+        width += delta.x as i32;
+    }
+    if edges.top() {
+        height -= delta.y as i32;
+    } else if edges.bottom() {
+        height += delta.y as i32;
+    }
+
+    let maximum_width = if maximum.w == 0 { i32::MAX } else { maximum.w };
+    let maximum_height = if maximum.h == 0 { i32::MAX } else { maximum.h };
+    (
+        width.clamp(minimum.w.max(1), maximum_width),
+        height.clamp(minimum.h.max(1), maximum_height),
+    )
+        .into()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn left_and_top_edges_invert_pointer_delta() {
+        let size = constrained_size(
+            (800, 600).into(),
+            (100.0, 50.0).into(),
+            ResizeEdge(xdg_toplevel::ResizeEdge::TopLeft),
+            (1, 1).into(),
+            (0, 0).into(),
+        );
+        assert_eq!(size, (700, 550).into());
+    }
+
+    #[test]
+    fn right_and_bottom_edges_follow_pointer_delta() {
+        let size = constrained_size(
+            (800, 600).into(),
+            (100.0, 50.0).into(),
+            ResizeEdge(xdg_toplevel::ResizeEdge::BottomRight),
+            (1, 1).into(),
+            (0, 0).into(),
+        );
+        assert_eq!(size, (900, 650).into());
+    }
+
+    #[test]
+    fn client_constraints_clamp_interactive_size() {
+        let size = constrained_size(
+            (800, 600).into(),
+            (1_000.0, 1_000.0).into(),
+            ResizeEdge(xdg_toplevel::ResizeEdge::BottomRight),
+            (640, 480).into(),
+            (1_024, 768).into(),
+        );
+        assert_eq!(size, (1_024, 768).into());
+    }
+}

compositor/src/handlers/compositor.rs

@@ -44,7 +44,7 @@ impl CompositorHandler for Ferese {
                 window.on_commit();
             }
         }
-        xdg_shell::handle_commit(&mut self.popups, &self.space, surface);
+        xdg_shell::handle_commit(&mut self.popups, &mut self.space, surface);
     }
 }
 

compositor/src/handlers/xdg_shell.rs

@@ -2,9 +2,16 @@ use smithay::{
     desktop::{
         PopupKind, PopupManager, Space, Window, find_popup_root_surface, get_popup_toplevel_coords,
     },
+    input::{
+        Seat,
+        pointer::{Focus, GrabStartData},
+    },
     reexports::wayland_protocols::xdg::decoration::zv1::server::zxdg_toplevel_decoration_v1::Mode,
-    reexports::wayland_server::protocol::{wl_seat, wl_surface::WlSurface},
-    utils::Serial,
+    reexports::wayland_server::{
+        Resource,
+        protocol::{wl_seat, wl_surface::WlSurface},
+    },
+    utils::{Rectangle, Serial},
     wayland::{
         compositor::with_states,
         shell::xdg::decoration::XdgDecorationHandler,
@@ -15,7 +22,10 @@ use smithay::{
     },
 };
 
-use crate::Ferese;
+use crate::{
+    Ferese,
+    grabs::{MoveSurfaceGrab, ResizeEdge, ResizeSurfaceGrab, handle_resize_commit},
+};
 
 impl XdgShellHandler for Ferese {
     fn xdg_shell_state(&mut self) -> &mut XdgShellState {
@@ -48,20 +58,103 @@ impl XdgShellHandler for Ferese {
         surface.send_repositioned(token);
     }
 
-    fn move_request(&mut self, _: ToplevelSurface, _: wl_seat::WlSeat, _: Serial) {}
+    fn move_request(&mut self, surface: ToplevelSurface, seat: wl_seat::WlSeat, serial: Serial) {
+        let Some(seat) = Seat::from_resource(&seat) else {
+            return;
+        };
+        let Some(start_data) = check_grab(&seat, surface.wl_surface(), serial) else {
+            return;
+        };
+        let Some(pointer) = seat.get_pointer() else {
+            return;
+        };
+        let Some(window) = self
+            .space
+            .elements()
+            .find(|window| {
+                window
+                    .toplevel()
+                    .is_some_and(|toplevel| toplevel.wl_surface() == surface.wl_surface())
+            })
+            .cloned()
+        else {
+            return;
+        };
+        let Some(initial_location) = self.space.element_location(&window) else {
+            return;
+        };
+        pointer.set_grab(
+            self,
+            MoveSurfaceGrab {
+                start_data,
+                window,
+                initial_location,
+            },
+            serial,
+            Focus::Clear,
+        );
+    }
 
     fn resize_request(
         &mut self,
-        _: ToplevelSurface,
-        _: wl_seat::WlSeat,
-        _: Serial,
-        _: smithay::reexports::wayland_protocols::xdg::shell::server::xdg_toplevel::ResizeEdge,
+        surface: ToplevelSurface,
+        seat: wl_seat::WlSeat,
+        serial: Serial,
+        edges: smithay::reexports::wayland_protocols::xdg::shell::server::xdg_toplevel::ResizeEdge,
     ) {
+        let Some(seat) = Seat::from_resource(&seat) else {
+            return;
+        };
+        let Some(start_data) = check_grab(&seat, surface.wl_surface(), serial) else {
+            return;
+        };
+        let Some(pointer) = seat.get_pointer() else {
+            return;
+        };
+        let Some(window) = self
+            .space
+            .elements()
+            .find(|window| {
+                window
+                    .toplevel()
+                    .is_some_and(|toplevel| toplevel.wl_surface() == surface.wl_surface())
+            })
+            .cloned()
+        else {
+            return;
+        };
+        let Some(location) = self.space.element_location(&window) else {
+            return;
+        };
+        let rect = Rectangle::new(location, window.geometry().size);
+        pointer.set_grab(
+            self,
+            ResizeSurfaceGrab::new(start_data, window, ResizeEdge::from(edges), rect),
+            serial,
+            Focus::Clear,
+        );
     }
 
     fn grab(&mut self, _: PopupSurface, _: wl_seat::WlSeat, _: Serial) {}
 }
 
+fn check_grab(
+    seat: &Seat<Ferese>,
+    surface: &WlSurface,
+    serial: Serial,
+) -> Option<GrabStartData<Ferese>> {
+    let pointer = seat.get_pointer()?;
+    if !pointer.has_grab(serial) {
+        return None;
+    }
+    let start_data = pointer.grab_start_data()?;
+    let (focus, _) = start_data.focus.as_ref()?;
+    focus
+        .id()
+        .same_client_as(&surface.id())
+        .then_some(start_data)
+}
+
 impl XdgDecorationHandler for Ferese {
     fn new_decoration(&mut self, toplevel: ToplevelSurface) {
         set_decoration_mode(&toplevel, Mode::ClientSide);
@@ -87,7 +180,8 @@ fn set_decoration_mode(toplevel: &ToplevelSurface, mode: Mode) {
     toplevel.send_pending_configure();
 }
 
-pub fn handle_commit(popups: &mut PopupManager, space: &Space<Window>, surface: &WlSurface) {
+pub fn handle_commit(popups: &mut PopupManager, space: &mut Space<Window>, surface: &WlSurface) {
+    handle_resize_commit(space, surface);
     if let Some(window) = space
         .elements()
         .find(|window| {

compositor/src/main.rs

@@ -1,5 +1,6 @@
 #![allow(irrefutable_let_patterns)]
 
+mod grabs;
 mod handlers;
 mod input;
 mod state;