tree: support toggling floating with double clicks

jay-config/src/_private/client.rs

@@ -465,6 +465,14 @@ impl Client {
         *self.on_new_input_device.borrow_mut() = Some(Rc::new(f));
     }
 
+    pub fn set_double_click_interval(&self, usec: u64) {
+        self.send(&ClientMessage::SetDoubleClickIntervalUsec { usec });
+    }
+
+    pub fn set_double_click_distance(&self, dist: i32) {
+        self.send(&ClientMessage::SetDoubleClickDistance { dist });
+    }
+
     pub fn connector_set_position(&self, connector: Connector, x: i32, y: i32) {
         self.send(&ClientMessage::ConnectorSetPosition { connector, x, y });
     }

jay-config/src/_private/ipc.rs

@@ -346,6 +346,12 @@ pub enum ClientMessage<'a> {
         connector: Connector,
         transform: Transform,
     },
+    SetDoubleClickIntervalUsec {
+        usec: u64,
+    },
+    SetDoubleClickDistance {
+        dist: i32,
+    },
 }
 
 #[derive(Serialize, Deserialize, Debug)]

jay-config/src/input.rs

@@ -10,6 +10,7 @@ use {
         Axis, Direction, ModifiedKeySym, Workspace,
     },
     serde::{Deserialize, Serialize},
+    std::time::Duration,
 };
 
 /// An input device.
@@ -257,6 +258,8 @@ impl Seat {
     }
 
     /// Toggles whether the currently focused window is floating.
+    ///
+    /// You can do the same by double-clicking on the header.
     pub fn toggle_floating(self) {
         get!().toggle_floating(self);
     }
@@ -329,3 +332,28 @@ pub fn on_new_seat<F: Fn(Seat) + 'static>(f: F) {
 pub fn on_new_input_device<F: Fn(InputDevice) + 'static>(f: F) {
     get!().on_new_input_device(f)
 }
+
+/// Sets the maximum time between two clicks to be registered as a double click by the
+/// compositor.
+///
+/// This only affects interactions with the compositor UI and has no effect on
+/// applications.
+///
+/// The default is 400 ms.
+pub fn set_double_click_time(duration: Duration) {
+    let usec = duration.as_micros().min(u64::MAX as u128);
+    get!().set_double_click_interval(usec as u64)
+}
+
+/// Sets the maximum distance between two clicks to be registered as a double click by the
+/// compositor.
+///
+/// This only affects interactions with the compositor UI and has no effect on
+/// applications.
+///
+/// Setting a negative distance disables double clicks.
+///
+/// The default is 5.
+pub fn set_double_click_distance(distance: i32) {
+    get!().set_double_click_distance(distance)
+}

src/compositor.rs

@@ -205,6 +205,8 @@ fn start_compositor2(
         drm_feedback_ids: Default::default(),
         direct_scanout_enabled: Cell::new(true),
         output_transforms: Default::default(),
+        double_click_interval_usec: Cell::new(400 * 1000),
+        double_click_distance: Cell::new(5),
     });
     state.tracker.register(ClientId::from_raw(0));
     create_dummy_output(&state);

src/config/handler.rs

@@ -615,6 +615,14 @@ impl ConfigProxyHandler {
         self.state.default_workspace_capture.set(capture);
     }
 
+    fn handle_set_double_click_interval_usec(&self, usec: u64) {
+        self.state.double_click_interval_usec.set(usec);
+    }
+
+    fn handle_set_double_click_distance(&self, dist: i32) {
+        self.state.double_click_distance.set(dist);
+    }
+
     fn handle_get_seat_workspace(&self, seat: Seat) -> Result<(), CphError> {
         let seat = self.get_seat(seat)?;
         let output = seat.get_output();
@@ -1355,6 +1363,12 @@ impl ConfigProxyHandler {
             } => self
                 .handle_connector_set_transform(connector, transform)
                 .wrn("connector_set_transform")?,
+            ClientMessage::SetDoubleClickIntervalUsec { usec } => {
+                self.handle_set_double_click_interval_usec(usec)
+            }
+            ClientMessage::SetDoubleClickDistance { dist } => {
+                self.handle_set_double_click_distance(dist)
+            }
         }
         Ok(())
     }

src/ifs/wl_seat.rs

@@ -47,7 +47,7 @@ use {
         time::now_usec,
         tree::{
             generic_node_visitor, ContainerNode, ContainerSplit, Direction, FloatNode, FoundNode,
-            Node, OutputNode, WorkspaceNode,
+            Node, OutputNode, ToplevelNode, WorkspaceNode,
         },
         utils::{
             asyncevent::AsyncEvent,
@@ -623,6 +623,10 @@ impl WlSeatGlobal {
             Some(tl) => tl,
             _ => return,
         };
+        self.set_tl_floating(tl, floating);
+    }
+
+    pub fn set_tl_floating(self: &Rc<Self>, tl: Rc<dyn ToplevelNode>, floating: bool) {
         let data = tl.tl_data();
         if data.is_fullscreen.get() {
             return;
@@ -634,15 +638,13 @@ impl WlSeatGlobal {
             Some(p) => p,
             _ => return,
         };
-        if let Some(cn) = parent.node_into_containing_node() {
-            if !floating {
-                cn.cnode_remove_child2(tl.tl_as_node(), true);
-                self.state.map_tiled(tl);
-            } else if let Some(ws) = data.workspace.get() {
-                cn.cnode_remove_child2(tl.tl_as_node(), true);
-                let (width, height) = data.float_size(&ws);
-                self.state.map_floating(tl, width, height, &ws, None);
-            }
+        if !floating {
+            parent.cnode_remove_child2(tl.tl_as_node(), true);
+            self.state.map_tiled(tl);
+        } else if let Some(ws) = data.workspace.get() {
+            parent.cnode_remove_child2(tl.tl_as_node(), true);
+            let (width, height) = data.float_size(&ws);
+            self.state.map_floating(tl, width, height, &ws, None);
         }
     }
 

src/state.rs

@@ -154,6 +154,8 @@ pub struct State {
     pub drm_feedback_ids: DrmFeedbackIds,
     pub direct_scanout_enabled: Cell<bool>,
     pub output_transforms: RefCell<AHashMap<Rc<OutputId>, Transform>>,
+    pub double_click_interval_usec: Cell<u64>,
+    pub double_click_distance: Cell<i32>,
 }
 
 // impl Drop for State {

src/tree/container.rs

@@ -18,6 +18,7 @@ use {
         },
         utils::{
             clonecell::CloneCell,
+            double_click_state::DoubleClickState,
             errorfmt::ErrorFmt,
             linkedlist::{LinkedList, LinkedNode, NodeRef},
             numcell::NumCell,
@@ -146,6 +147,7 @@ struct SeatState {
     x: i32,
     y: i32,
     op: Option<SeatOp>,
+    double_click_state: DoubleClickState,
 }
 
 impl ContainerChild {
@@ -521,6 +523,7 @@ impl ContainerNode {
             x,
             y,
             op: None,
+            double_click_state: Default::default(),
         });
         let mut changed = false;
         changed |= mem::replace(&mut seat_state.x, x) != x;
@@ -1176,7 +1179,7 @@ impl Node for ContainerNode {
     fn node_on_button(
         self: Rc<Self>,
         seat: &Rc<WlSeatGlobal>,
-        _time_usec: u64,
+        time_usec: u64,
         button: u32,
         state: KeyState,
         _serial: u32,
@@ -1232,6 +1235,15 @@ impl Node for ContainerNode {
                 }
                 return;
             };
+            if seat_data
+                .double_click_state
+                .click(&self.state, time_usec, seat_data.x, seat_data.y)
+                && kind == SeatOpKind::Move
+            {
+                drop(seat_datas);
+                seat.set_tl_floating(child.node.clone(), true);
+                return;
+            }
             seat_data.op = Some(SeatOp { child, kind })
         } else if state == KeyState::Released {
             let op = seat_data.op.take().unwrap();

src/tree/float.rs

@@ -14,8 +14,8 @@ use {
             StackedNode, ToplevelNode, WorkspaceNode,
         },
         utils::{
-            clonecell::CloneCell, copyhashmap::CopyHashMap, errorfmt::ErrorFmt,
-            linkedlist::LinkedNode,
+            clonecell::CloneCell, copyhashmap::CopyHashMap, double_click_state::DoubleClickState,
+            errorfmt::ErrorFmt, linkedlist::LinkedNode,
         },
     },
     ahash::AHashMap,
@@ -57,6 +57,7 @@ struct SeatState {
     op_active: bool,
     dist_hor: i32,
     dist_ver: i32,
+    double_click_state: DoubleClickState,
 }
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
@@ -228,6 +229,7 @@ impl FloatNode {
             op_active: false,
             dist_hor: 0,
             dist_ver: 0,
+            double_click_state: Default::default(),
         });
         seat_state.x = x;
         seat_state.y = y;
@@ -462,7 +464,7 @@ impl Node for FloatNode {
     fn node_on_button(
         self: Rc<Self>,
         seat: &Rc<WlSeatGlobal>,
-        _time_usec: u64,
+        time_usec: u64,
         button: u32,
         state: KeyState,
         _serial: u32,
@@ -479,6 +481,17 @@ impl Node for FloatNode {
             if state != KeyState::Pressed {
                 return;
             }
+            if seat_data
+                .double_click_state
+                .click(&self.state, time_usec, seat_data.x, seat_data.y)
+                && seat_data.op_type == OpType::Move
+            {
+                if let Some(tl) = self.child.get() {
+                    drop(seat_datas);
+                    seat.set_tl_floating(tl, false);
+                    return;
+                }
+            }
             seat_data.op_active = true;
             let pos = self.position.get();
             match seat_data.op_type {

src/utils.rs

@@ -10,6 +10,7 @@ pub mod cell_ext;
 pub mod clonecell;
 pub mod copyhashmap;
 pub mod debug_fn;
+pub mod double_click_state;
 pub mod errorfmt;
 pub mod fdcloser;
 pub mod hex;

src/utils/double_click_state.rs

@@ -0,0 +1,35 @@
+use crate::state::State;
+
+#[derive(Default)]
+pub struct DoubleClickState {
+    last_click: Option<(u64, i32, i32)>,
+}
+
+impl DoubleClickState {
+    pub fn click(&mut self, state: &State, time_usec: u64, x: i32, y: i32) -> bool {
+        let res = self.click_(state, time_usec, x, y);
+        if !res {
+            self.last_click = Some((time_usec, x, y));
+        }
+        res
+    }
+
+    fn click_(&mut self, state: &State, time_usec: u64, x: i32, y: i32) -> bool {
+        let Some((last_usec, last_x, last_y)) = self.last_click.take() else {
+            return false;
+        };
+        if time_usec.wrapping_sub(last_usec) > state.double_click_interval_usec.get() {
+            return false;
+        }
+        let max_dist = state.double_click_distance.get();
+        if max_dist < 0 {
+            return false;
+        }
+        let dist_x = last_x - x;
+        let dist_y = last_y - y;
+        if dist_x * dist_x + dist_y * dist_y > max_dist * max_dist {
+            return false;
+        }
+        true
+    }
+}