overview: Add touchscreen gestures

src/input/mod.rs

@@ -35,6 +35,7 @@ use smithay::wayland::pointer_constraints::{with_pointer_constraint, PointerCons
 use smithay::wayland::selection::data_device::DnDGrab;
 use smithay::wayland::tablet_manager::{TabletDescriptor, TabletSeatTrait};
 use touch_move_grab::TouchMoveGrab;
+use touch_overview_grab::TouchOverviewGrab;
 
 use self::move_grab::MoveGrab;
 use self::resize_grab::ResizeGrab;
@@ -56,6 +57,7 @@ pub mod scroll_tracker;
 pub mod spatial_movement_grab;
 pub mod swipe_tracker;
 pub mod touch_move_grab;
+pub mod touch_overview_grab;
 pub mod touch_resize_grab;
 
 use backend_ext::{NiriInputBackend as InputBackend, NiriInputDevice as _};
@@ -3467,12 +3469,45 @@ impl State {
         let mod_key = self.backend.mod_key(&self.niri.config.borrow());
 
         if !handle.is_grabbed() {
-            if let Some((window, _)) = under.window {
+            let mods = self.niri.seat.get_keyboard().unwrap().modifier_state();
+            let mods = modifiers_from_state(mods);
+            let mod_down = mods.contains(mod_key.to_modifiers());
+
+            if self.niri.layout.is_overview_open() && !mod_down && under.layer.is_none() {
+                let (output, pos_within_output) = self.niri.output_under(touch_location).unwrap();
+                let output = output.clone();
+
+                let mut matched_narrow = true;
+                let mut ws = self.niri.workspace_under(false, touch_location);
+                if ws.is_none() {
+                    matched_narrow = false;
+                    ws = self.niri.workspace_under(true, touch_location);
+                }
+                let ws_id = ws.map(|(_, ws)| ws.id());
+
+                let mapped = self.niri.window_under(touch_location);
+                let window = mapped.map(|mapped| mapped.window.clone());
+
+                let start_data = TouchGrabStartData {
+                    focus: None,
+                    slot: evt.slot(),
+                    location: touch_location,
+                };
+                let start_timestamp = Duration::from_micros(evt.time());
+                let grab = TouchOverviewGrab::new(
+                    start_data,
+                    start_timestamp,
+                    output,
+                    pos_within_output,
+                    ws_id,
+                    matched_narrow,
+                    window,
+                );
+                handle.set_grab(self, grab, serial);
+            } else if let Some((window, _)) = under.window {
                 self.niri.layout.activate_window(&window);
 
                 // Check if we need to start an interactive move.
-                let mods = self.niri.seat.get_keyboard().unwrap().modifier_state();
-                let mod_down = modifiers_from_state(mods).contains(mod_key.to_modifiers());
                 if mod_down {
                     let (output, pos_within_output) =
                         self.niri.output_under(touch_location).unwrap();

src/input/touch_overview_grab.rs

@@ -0,0 +1,274 @@
+use std::time::Duration;
+
+use smithay::desktop::Window;
+use smithay::input::touch::{
+    DownEvent, GrabStartData as TouchGrabStartData, MotionEvent, OrientationEvent, ShapeEvent,
+    TouchGrab, TouchInnerHandle, UpEvent,
+};
+use smithay::input::SeatHandler;
+use smithay::output::Output;
+use smithay::utils::{IsAlive, Logical, Point, Serial};
+
+use crate::layout::workspace::{Workspace, WorkspaceId};
+use crate::niri::State;
+use crate::window::Mapped;
+
+// When the touch is stationary for this much time, it becomes an interactive move.
+const INTERACTIVE_MOVE_THRESHOLD: Duration = Duration::from_millis(500);
+
+pub struct TouchOverviewGrab {
+    start_data: TouchGrabStartData<State>,
+    start_timestamp: Duration,
+    last_location: Point<f64, Logical>,
+    output: Output,
+    start_pos_within_output: Point<f64, Logical>,
+    workspace_id: Option<WorkspaceId>,
+    workspace_matched_narrow: bool,
+    window: Option<Window>,
+    gesture: GestureState,
+}
+
+#[derive(Debug, Clone, Copy)]
+enum GestureState {
+    Recognizing,
+    ViewOffset,
+    WorkspaceSwitch,
+    InteractiveMove,
+}
+
+impl TouchOverviewGrab {
+    pub fn new(
+        start_data: TouchGrabStartData<State>,
+        start_timestamp: Duration,
+        output: Output,
+        start_pos_within_output: Point<f64, Logical>,
+        workspace_id: Option<WorkspaceId>,
+        workspace_matched_narrow: bool,
+        window: Option<Window>,
+    ) -> Self {
+        Self {
+            last_location: start_data.location,
+            start_timestamp,
+            start_data,
+            output,
+            start_pos_within_output,
+            workspace_id,
+            workspace_matched_narrow,
+            window,
+            gesture: GestureState::Recognizing,
+        }
+    }
+
+    fn on_ungrab(&mut self, state: &mut State) {
+        let layout = &mut state.niri.layout;
+        match self.gesture {
+            GestureState::Recognizing => {
+                // Tap to activate.
+                layout.focus_output(&self.output);
+
+                // Activate the workspace if necessary.
+                if self.window.is_some() || self.workspace_matched_narrow {
+                    // When activating a window, we want to activate the window's current
+                    // workspace. Otherwise, find the workspace that we tapped on.
+                    let ws_matches = |ws: &Workspace<Mapped>| {
+                        if let Some(window) = &self.window {
+                            ws.has_window(window)
+                        } else if let Some(ws_id) = self.workspace_id {
+                            ws.id() == ws_id
+                        } else {
+                            false
+                        }
+                    };
+
+                    let ws_idx = if let Some((Some(mon), ws_idx, _)) =
+                        layout.workspaces().find(|(_, _, ws)| ws_matches(ws))
+                    {
+                        // The workspace could've moved to a different output in the meantime.
+                        (*mon.output() == self.output).then_some(ws_idx)
+                    } else {
+                        None
+                    };
+
+                    if let Some(ws_idx) = ws_idx {
+                        layout.toggle_overview_to_workspace(ws_idx);
+                    }
+                }
+
+                if let Some(window) = self.window.as_ref() {
+                    layout.activate_window(window);
+                }
+            }
+            GestureState::ViewOffset => {
+                layout.view_offset_gesture_end(Some(false));
+            }
+            GestureState::WorkspaceSwitch => {
+                layout.workspace_switch_gesture_end(Some(false));
+            }
+            GestureState::InteractiveMove => {
+                layout.interactive_move_end(self.window.as_ref().unwrap());
+            }
+        };
+
+        state.niri.queue_redraw_all();
+    }
+}
+
+impl TouchGrab<State> for TouchOverviewGrab {
+    fn down(
+        &mut self,
+        data: &mut State,
+        handle: &mut TouchInnerHandle<'_, State>,
+        _focus: Option<(<State as SeatHandler>::TouchFocus, Point<f64, Logical>)>,
+        event: &DownEvent,
+        seq: Serial,
+    ) {
+        handle.down(data, None, event, seq);
+    }
+
+    fn up(
+        &mut self,
+        data: &mut State,
+        handle: &mut TouchInnerHandle<'_, State>,
+        event: &UpEvent,
+        seq: Serial,
+    ) {
+        handle.up(data, event, seq);
+
+        if event.slot != self.start_data.slot {
+            return;
+        }
+
+        handle.unset_grab(self, data);
+    }
+
+    fn motion(
+        &mut self,
+        data: &mut State,
+        handle: &mut TouchInnerHandle<'_, State>,
+        _focus: Option<(<State as SeatHandler>::TouchFocus, Point<f64, Logical>)>,
+        event: &MotionEvent,
+        seq: Serial,
+    ) {
+        handle.motion(data, None, event, seq);
+
+        if event.slot != self.start_data.slot {
+            return;
+        }
+
+        let timestamp = Duration::from_millis(u64::from(event.time));
+        let layout = &mut data.niri.layout;
+
+        // Check if we should become interactive move.
+        if matches!(self.gesture, GestureState::Recognizing) {
+            if let Some(window) = self.window.as_ref().filter(|win| win.alive()) {
+                let passed = timestamp.saturating_sub(self.start_timestamp);
+                if INTERACTIVE_MOVE_THRESHOLD <= passed
+                    && layout.interactive_move_begin(
+                        window.clone(),
+                        &self.output,
+                        self.start_pos_within_output,
+                    )
+                {
+                    self.gesture = GestureState::InteractiveMove;
+                }
+            }
+        }
+
+        // Check if we should become a spatial scroll.
+        if matches!(self.gesture, GestureState::Recognizing) {
+            let c = event.location - self.start_data.location;
+
+            // Check if the gesture moved far enough to decide. Threshold copied from libadwaita.
+            if c.x * c.x + c.y * c.y >= 16. * 16. {
+                if let Some(ws_id) = self.workspace_id.filter(|_| c.x.abs() > c.y.abs()) {
+                    if let Some((ws_idx, ws)) = layout.find_workspace_by_id(ws_id) {
+                        if ws.current_output() == Some(&self.output) {
+                            layout.view_offset_gesture_begin(&self.output, Some(ws_idx), false);
+                            self.gesture = GestureState::ViewOffset;
+                        }
+                    }
+                }
+
+                if matches!(self.gesture, GestureState::Recognizing) {
+                    layout.workspace_switch_gesture_begin(&self.output, false);
+                    self.gesture = GestureState::WorkspaceSwitch;
+                }
+            }
+        }
+
+        // Do nothing if still recognizing.
+        if matches!(self.gesture, GestureState::Recognizing) {
+            return;
+        }
+
+        let delta = event.location - self.last_location;
+        self.last_location = event.location;
+
+        let ongoing = match self.gesture {
+            GestureState::Recognizing => unreachable!(),
+            GestureState::ViewOffset => layout
+                .view_offset_gesture_update(-delta.x, timestamp, false)
+                .is_some(),
+            GestureState::WorkspaceSwitch => layout
+                .workspace_switch_gesture_update(-delta.y, timestamp, false)
+                .is_some(),
+            GestureState::InteractiveMove => {
+                let window = self.window.as_ref().unwrap();
+                if let Some((output, pos_within_output)) = data.niri.output_under(event.location) {
+                    let output = output.clone();
+                    data.niri.layout.interactive_move_update(
+                        window,
+                        delta,
+                        output,
+                        pos_within_output,
+                    )
+                } else {
+                    false
+                }
+            }
+        };
+
+        if ongoing {
+            data.niri.queue_redraw_all();
+        } else {
+            handle.unset_grab(self, data);
+        }
+    }
+
+    fn frame(&mut self, data: &mut State, handle: &mut TouchInnerHandle<'_, State>, seq: Serial) {
+        handle.frame(data, seq);
+    }
+
+    fn cancel(&mut self, data: &mut State, handle: &mut TouchInnerHandle<'_, State>, seq: Serial) {
+        handle.cancel(data, seq);
+        handle.unset_grab(self, data);
+    }
+
+    fn shape(
+        &mut self,
+        data: &mut State,
+        handle: &mut TouchInnerHandle<'_, State>,
+        event: &ShapeEvent,
+        seq: Serial,
+    ) {
+        handle.shape(data, event, seq);
+    }
+
+    fn orientation(
+        &mut self,
+        data: &mut State,
+        handle: &mut TouchInnerHandle<'_, State>,
+        event: &OrientationEvent,
+        seq: Serial,
+    ) {
+        handle.orientation(data, event, seq);
+    }
+
+    fn start_data(&self) -> &TouchGrabStartData<State> {
+        &self.start_data
+    }
+
+    fn unset(&mut self, data: &mut State) {
+        self.on_ungrab(data);
+    }
+}