shell: Add resize and move grabs

src/shell/grabs.rs

@@ -0,0 +1,435 @@
+// SPDX-License-Identifier: GPL-3.0-only
+
+use smithay::{
+    desktop::{Kind, Window},
+    reexports::{
+        wayland_protocols::xdg_shell::server::xdg_toplevel,
+        wayland_server::protocol::{wl_pointer::ButtonState, wl_surface},
+    },
+    utils::{Logical, Point, Rectangle, Size},
+    wayland::{
+        compositor::with_states,
+        seat::{AxisFrame, GrabStartData, PointerGrab, PointerInnerHandle},
+        shell::xdg::{SurfaceCachedState, ToplevelConfigure, XdgToplevelSurfaceRoleAttributes},
+        Serial,
+    },
+};
+use std::{cell::RefCell, sync::Mutex};
+
+#[derive(Debug, Default)]
+struct MoveData {
+    new_location: Point<i32, Logical>,
+}
+
+pub struct MoveSurfaceGrab {
+    start_data: GrabStartData,
+    window: Window,
+    initial_window_location: Point<i32, Logical>,
+}
+
+impl PointerGrab for MoveSurfaceGrab {
+    fn motion(
+        &mut self,
+        _handle: &mut PointerInnerHandle<'_>,
+        location: Point<f64, Logical>,
+        _focus: Option<(wl_surface::WlSurface, Point<i32, Logical>)>,
+        _serial: Serial,
+        _time: u32,
+    ) {
+        let delta = location - self.start_data.location;
+        let new_location = self.initial_window_location.to_f64() + delta;
+        self.window
+            .user_data()
+            .insert_if_missing(|| RefCell::<Option<MoveData>>::new(None));
+        let data = self
+            .window
+            .user_data()
+            .get::<RefCell<Option<MoveData>>>()
+            .unwrap();
+        *data.borrow_mut() = Some(MoveData {
+            new_location: new_location.to_i32_round(),
+        });
+    }
+
+    fn button(
+        &mut self,
+        handle: &mut PointerInnerHandle<'_>,
+        button: u32,
+        state: ButtonState,
+        serial: Serial,
+        time: u32,
+    ) {
+        handle.button(button, state, serial, time);
+        if handle.current_pressed().is_empty() {
+            // No more buttons are pressed, release the grab.
+            handle.unset_grab(serial, time);
+        }
+    }
+
+    fn axis(&mut self, handle: &mut PointerInnerHandle<'_>, details: AxisFrame) {
+        handle.axis(details)
+    }
+
+    fn start_data(&self) -> &GrabStartData {
+        &self.start_data
+    }
+}
+
+impl MoveSurfaceGrab {
+    pub fn new(
+        start_data: GrabStartData,
+        window: Window,
+        initial_window_location: Point<i32, Logical>,
+    ) -> MoveSurfaceGrab {
+        MoveSurfaceGrab {
+            start_data,
+            window,
+            initial_window_location,
+        }
+    }
+
+    pub fn apply_move_state(window: &Window) -> Option<Point<i32, Logical>> {
+        window
+            .user_data()
+            .get::<RefCell<Option<MoveData>>>()
+            .and_then(|opt| {
+                opt.borrow_mut()
+                    .take()
+                    .map(|move_data| move_data.new_location)
+            })
+    }
+}
+
+bitflags::bitflags! {
+    struct ResizeEdge: u32 {
+        const NONE = 0;
+        const TOP = 1;
+        const BOTTOM = 2;
+        const LEFT = 4;
+        const TOP_LEFT = 5;
+        const BOTTOM_LEFT = 6;
+        const RIGHT = 8;
+        const TOP_RIGHT = 9;
+        const BOTTOM_RIGHT = 10;
+    }
+}
+
+impl From<xdg_toplevel::ResizeEdge> for ResizeEdge {
+    #[inline]
+    fn from(x: xdg_toplevel::ResizeEdge) -> Self {
+        Self::from_bits(x.to_raw()).unwrap()
+    }
+}
+
+impl From<ResizeEdge> for xdg_toplevel::ResizeEdge {
+    #[inline]
+    fn from(x: ResizeEdge) -> Self {
+        Self::from_raw(x.bits()).unwrap()
+    }
+}
+
+/// Information about the resize operation.
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+struct ResizeData {
+    /// The edges the surface is being resized with.
+    edges: ResizeEdge,
+    /// The initial window location.
+    initial_window_location: Point<i32, Logical>,
+    /// The initial window size (geometry width and height).
+    initial_window_size: Size<i32, Logical>,
+}
+
+/// State of the resize operation.
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+enum ResizeState {
+    /// The surface is not being resized.
+    NotResizing,
+    /// The surface is currently being resized.
+    Resizing(ResizeData),
+    /// The resize has finished, and the surface needs to ack the final configure.
+    WaitingForFinalAck(ResizeData, Serial),
+    /// The resize has finished, and the surface needs to commit its final state.
+    WaitingForCommit(ResizeData),
+}
+
+impl Default for ResizeState {
+    fn default() -> Self {
+        ResizeState::NotResizing
+    }
+}
+
+pub struct ResizeSurfaceGrab {
+    start_data: GrabStartData,
+    window: Window,
+    edges: ResizeEdge,
+    initial_window_size: Size<i32, Logical>,
+    last_window_size: Size<i32, Logical>,
+}
+
+impl PointerGrab for ResizeSurfaceGrab {
+    fn motion(
+        &mut self,
+        handle: &mut PointerInnerHandle<'_>,
+        location: Point<f64, Logical>,
+        _focus: Option<(wl_surface::WlSurface, Point<i32, Logical>)>,
+        serial: Serial,
+        time: u32,
+    ) {
+        // It is impossible to get `min_size` and `max_size` of dead toplevel, so we return early.
+        if !self.window.toplevel().alive() | self.window.toplevel().get_surface().is_none() {
+            handle.unset_grab(serial, time);
+            return;
+        }
+
+        let (mut dx, mut dy) = (location - self.start_data.location).into();
+
+        let mut new_window_width = self.initial_window_size.w;
+        let mut new_window_height = self.initial_window_size.h;
+
+        let left_right = ResizeEdge::LEFT | ResizeEdge::RIGHT;
+        let top_bottom = ResizeEdge::TOP | ResizeEdge::BOTTOM;
+
+        if self.edges.intersects(left_right) {
+            if self.edges.intersects(ResizeEdge::LEFT) {
+                dx = -dx;
+            }
+
+            new_window_width = (self.initial_window_size.w as f64 + dx) as i32;
+        }
+
+        if self.edges.intersects(top_bottom) {
+            if self.edges.intersects(ResizeEdge::TOP) {
+                dy = -dy;
+            }
+
+            new_window_height = (self.initial_window_size.h as f64 + dy) as i32;
+        }
+
+        let (min_size, max_size) =
+            with_states(self.window.toplevel().get_surface().unwrap(), |states| {
+                let data = states.cached_state.current::<SurfaceCachedState>();
+                (data.min_size, data.max_size)
+            })
+            .unwrap();
+
+        let min_width = min_size.w.max(1);
+        let min_height = min_size.h.max(1);
+        let max_width = if max_size.w == 0 {
+            i32::max_value()
+        } else {
+            max_size.w
+        };
+        let max_height = if max_size.h == 0 {
+            i32::max_value()
+        } else {
+            max_size.h
+        };
+
+        new_window_width = new_window_width.max(min_width).min(max_width);
+        new_window_height = new_window_height.max(min_height).min(max_height);
+
+        self.last_window_size = (new_window_width, new_window_height).into();
+
+        match &self.window.toplevel() {
+            Kind::Xdg(xdg) => {
+                let ret = xdg.with_pending_state(|state| {
+                    state.states.set(xdg_toplevel::State::Resizing);
+                    state.size = Some(self.last_window_size);
+                });
+                if ret.is_ok() {
+                    xdg.send_configure();
+                }
+            }
+        }
+    }
+
+    fn button(
+        &mut self,
+        handle: &mut PointerInnerHandle<'_>,
+        button: u32,
+        state: ButtonState,
+        serial: Serial,
+        time: u32,
+    ) {
+        handle.button(button, state, serial, time);
+        if handle.current_pressed().is_empty() {
+            // No more buttons are pressed, release the grab.
+            handle.unset_grab(serial, time);
+
+            // If toplevel is dead, we can't resize it, so we return early.
+            if !self.window.toplevel().alive() | self.window.toplevel().get_surface().is_none() {
+                return;
+            }
+
+            #[allow(irrefutable_let_patterns)]
+            if let Kind::Xdg(xdg) = &self.window.toplevel() {
+                let ret = xdg.with_pending_state(|state| {
+                    state.states.unset(xdg_toplevel::State::Resizing);
+                    state.size = Some(self.last_window_size);
+                });
+                if ret.is_ok() {
+                    xdg.send_configure();
+                }
+            }
+
+            let mut resize_state = self
+                .window
+                .user_data()
+                .get::<RefCell<ResizeState>>()
+                .unwrap()
+                .borrow_mut();
+            if let ResizeState::Resizing(resize_data) = *resize_state {
+                *resize_state = ResizeState::WaitingForFinalAck(resize_data, serial);
+            } else {
+                panic!("invalid resize state: {:?}", resize_state);
+            }
+        }
+    }
+
+    fn axis(&mut self, handle: &mut PointerInnerHandle<'_>, details: AxisFrame) {
+        handle.axis(details)
+    }
+
+    fn start_data(&self) -> &GrabStartData {
+        &self.start_data
+    }
+}
+
+impl ResizeSurfaceGrab {
+    pub fn new(
+        start_data: GrabStartData,
+        window: Window,
+        edges: xdg_toplevel::ResizeEdge,
+        initial_window_geometry: Rectangle<i32, Logical>,
+    ) -> ResizeSurfaceGrab {
+        let (initial_window_location, initial_window_size) =
+            (initial_window_geometry.loc, initial_window_geometry.size);
+        let resize_state = ResizeState::Resizing(ResizeData {
+            edges: edges.into(),
+            initial_window_location,
+            initial_window_size,
+        });
+
+        window
+            .user_data()
+            .insert_if_missing(|| RefCell::new(ResizeState::default()));
+        *window
+            .user_data()
+            .get::<RefCell<ResizeState>>()
+            .unwrap()
+            .borrow_mut() = resize_state;
+
+        ResizeSurfaceGrab {
+            start_data,
+            window,
+            edges: edges.into(),
+            initial_window_size,
+            last_window_size: initial_window_size,
+        }
+    }
+
+    pub fn ack_configure(window: &Window, configure: ToplevelConfigure) {
+        let surface = if let Some(surface) = window.toplevel().get_surface() {
+            surface
+        } else {
+            return;
+        };
+
+        let waiting_for_serial =
+            if let Some(data) = window.user_data().get::<RefCell<ResizeState>>() {
+                if let ResizeState::WaitingForFinalAck(_, serial) = *data.borrow() {
+                    Some(serial)
+                } else {
+                    None
+                }
+            } else {
+                None
+            };
+
+        if let Some(serial) = waiting_for_serial {
+            // When the resize grab is released the surface
+            // resize state will be set to WaitingForFinalAck
+            // and the client will receive a configure request
+            // without the resize state to inform the client
+            // resizing has finished. Here we will wait for
+            // the client to acknowledge the end of the
+            // resizing. To check if the surface was resizing
+            // before sending the configure we need to use
+            // the current state as the received acknowledge
+            // will no longer have the resize state set
+            let is_resizing = with_states(&surface, |states| {
+                states
+                    .data_map
+                    .get::<Mutex<XdgToplevelSurfaceRoleAttributes>>()
+                    .unwrap()
+                    .lock()
+                    .unwrap()
+                    .current
+                    .states
+                    .contains(xdg_toplevel::State::Resizing)
+            })
+            .unwrap();
+
+            if configure.serial >= serial && is_resizing {
+                let mut resize_state = window
+                    .user_data()
+                    .get::<RefCell<ResizeState>>()
+                    .unwrap()
+                    .borrow_mut();
+                if let ResizeState::WaitingForFinalAck(resize_data, _) = *resize_state {
+                    *resize_state = ResizeState::WaitingForCommit(resize_data);
+                } else {
+                    unreachable!()
+                }
+            }
+        }
+    }
+
+    pub fn apply_resize_state(
+        window: &Window,
+        geometry: Rectangle<i32, Logical>,
+    ) -> Option<Point<i32, Logical>> {
+        let mut new_location = None;
+
+        if let Some(resize_state) = window.user_data().get::<RefCell<ResizeState>>() {
+            let mut resize_state = resize_state.borrow_mut();
+
+            // If the window is being resized by top or left, its location must be adjusted
+            // accordingly.
+            match *resize_state {
+                ResizeState::Resizing(resize_data)
+                | ResizeState::WaitingForFinalAck(resize_data, _)
+                | ResizeState::WaitingForCommit(resize_data) => {
+                    let ResizeData {
+                        edges,
+                        initial_window_location,
+                        initial_window_size,
+                    } = resize_data;
+
+                    if edges.intersects(ResizeEdge::TOP_LEFT) {
+                        let mut location = geometry.loc;
+
+                        if edges.intersects(ResizeEdge::LEFT) {
+                            location.x = initial_window_location.x
+                                + (initial_window_size.w - geometry.size.w);
+                        }
+                        if edges.intersects(ResizeEdge::TOP) {
+                            location.y = initial_window_location.y
+                                + (initial_window_size.h - geometry.size.h);
+                        }
+
+                        new_location = Some(location);
+                    }
+                }
+                ResizeState::NotResizing => (),
+            }
+
+            // Finish resizing.
+            if let ResizeState::WaitingForCommit(_) = *resize_state {
+                *resize_state = ResizeState::NotResizing;
+            }
+        }
+
+        new_location
+    }
+}