server: scale wl_touch events

Fixes #172

src/server/event.rs

@@ -711,29 +711,49 @@ impl Event for client::wl_keyboard::Event {
 
 impl Event for client::wl_touch::Event {
     fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
-        let touch = state.world.get::<&WlTouch>(target).unwrap();
+        match self {
+            Self::Down {
+                serial,
+                time,
+                surface,
+                id,
+                x,
+                y,
+            } => {
+                let mut cmd = CommandBuffer::new();
+                {
+                    let Some(mut s_query) = surface.data().copied().and_then(|key| {
+                        state
+                            .world
+                            .query_one::<(&WlSurface, &SurfaceScaleFactor)>(key)
+                            .ok()
+                    }) else {
+                        return;
+                    };
 
-        let s_surf;
-        simple_event_shunt! {
-            touch, self => [
-                Down {
-                    serial,
-                    time,
-                    |surface| {
-                        s_surf = surface.data().copied().and_then(|key| state.world.get::<&WlSurface>(key).ok());
-                        if let Some(s) = &s_surf { s } else { return; }
-                    },
-                    id,
-                    x,
-                    y
-                },
-                Up { serial, time, id },
-                Motion { time, id, x, y },
-                Frame,
-                Cancel,
-                Shape { id, major, minor },
-                Orientation { id, orientation }
-            ]
+                    let (s_surface, s_factor) = s_query.get().unwrap();
+                    cmd.insert(target, (*s_factor,));
+                    let touch = state.world.get::<&WlTouch>(target).unwrap();
+                    touch.down(serial, time, s_surface, id, x * s_factor.0, y * s_factor.0);
+                }
+                cmd.run_on(&mut state.world);
+            }
+            Self::Motion { time, id, x, y } => {
+                let (touch, scale) = state.world.query_one_mut::<(&WlTouch, &SurfaceScaleFactor)>(target).unwrap();
+                touch.motion(time, id, x * scale.0, y * scale.0);
+            }
+            _ => {
+                let touch = state.world.get::<&WlTouch>(target).unwrap();
+                simple_event_shunt! {
+                    touch, self => [
+                        Up { serial, time, id },
+                        Frame,
+                        Cancel,
+                        Shape { id, major, minor },
+                        Orientation { id, orientation }
+                    ]
+                }
+            }
         }
     }
 }

src/server/tests.rs

@@ -20,6 +20,7 @@ use wayland_client::{
         wl_shm::{Format, WlShm},
         wl_shm_pool::WlShmPool,
         wl_surface::WlSurface,
+        wl_touch::{self, WlTouch},
     },
     Connection, Proxy, WEnum,
 };
@@ -2246,6 +2247,49 @@ fn transient_for_toplevel() {
     );
 }
 
+#[test]
+fn touch_fractional_scale() {
+    let mut f = TestFixture::new_pre_connect(|testwl| {
+        testwl.enable_fractional_scale();
+    });
+    let comp = f.compositor();
+    let (_, output) = f.new_output(0, 0);
+    let touch = TestObject::<WlTouch>::from_request(&comp.seat.obj, wl_seat::Request::GetTouch {});
+    f.run();
+
+    let toplevel = unsafe { Window::new(1) };
+    let (_, id) = f.create_toplevel(&comp, toplevel);
+    f.testwl.move_surface_to_output(id, &output);
+
+    let data = f.testwl.get_surface_data(id).unwrap();
+    let server_surface = data.surface.clone();
+    let fractional = data.fractional.as_ref().cloned().unwrap();
+
+    let do_touch = |f: &mut TestFixture, x, y| {
+        f.testwl.touch().down(0, 0, &server_surface, 0, x, y);
+        f.testwl.dispatch();
+        f.run();
+        f.run();
+        let events = &mut touch.data.events.lock().unwrap();
+        assert_eq!(events.len(), 1);
+        let event = events.pop().unwrap();
+        let wl_touch::Event::Down { x, y, .. } = event else {
+            panic!("Got unexpected event: {event:?}");
+        };
+        (x, y)
+    };
+
+    let (x, y) = do_touch(&mut f, 20.0, 40.0);
+    assert_eq!(x, 20.0);
+    assert_eq!(y, 40.0);
+
+    fractional.preferred_scale(180); // 1.5 scale
+    f.run();
+    let (x, y) = do_touch(&mut f, 20.0, 40.0);
+    assert_eq!(x, 20.0 * 1.5);
+    assert_eq!(y, 40.0 * 1.5);
+}
+
 /// See Pointer::handle_event for an explanation.
 #[test]
 fn popup_pointer_motion_workaround() {}

testwl/src/lib.rs

@@ -72,6 +72,7 @@ use wayland_server::{
         wl_shm::WlShm,
         wl_shm_pool::WlShmPool,
         wl_surface::WlSurface,
+        wl_touch::{self, WlTouch},
     },
     Client, Dispatch, Display, DisplayHandle, GlobalDispatch, Resource, WEnum,
 };
@@ -225,6 +226,7 @@ struct State {
     seat: Option<WlSeat>,
     pointer: Option<WlPointer>,
     keyboard: Option<KeyboardState>,
+    touch: Option<WlTouch>,
     configure_serial: u32,
     selection: Option<WlDataSource>,
     data_device_man: Option<WlDataDeviceManager>,
@@ -248,6 +250,7 @@ impl Default for State {
             seat: None,
             pointer: None,
             keyboard: None,
+            touch: None,
             configure_serial: 0,
             selection: None,
             data_device_man: None,
@@ -752,6 +755,11 @@ impl Server {
             .create_global::<State, WpFractionalScaleManagerV1, _>(1, ());
         self.display.flush_clients().unwrap();
     }
+
+    #[track_caller]
+    pub fn touch(&mut self) -> &WlTouch {
+        self.state.touch.as_ref().expect("No touch object created")
+    }
 }
 
 #[derive(Clone, Eq, PartialEq, Debug)]
@@ -1067,6 +1075,9 @@ impl Dispatch<WlSeat, ()> for State {
                     current_focus: None,
                 });
             }
+            wl_seat::Request::GetTouch { id } => {
+                state.touch = Some(data_init.init(id, ()));
+            }
             wl_seat::Request::Release => {}
             other => todo!("unhandled request {other:?}"),
         }
@@ -1125,6 +1136,23 @@ impl Dispatch<WlKeyboard, ()> for State {
     }
 }
 
+impl Dispatch<WlTouch, ()> for State {
+    fn request(
+        _: &mut Self,
+        _: &Client,
+        _: &WlTouch,
+        request: <WlTouch as Resource>::Request,
+        _: &(),
+        _: &DisplayHandle,
+        _: &mut wayland_server::DataInit<'_, Self>,
+    ) {
+        match request {
+            wl_touch::Request::Release => {}
+            other => todo!("unhandled request {other:?}"),
+        }
+    }
+}
+
 impl Dispatch<XdgPopup, SurfaceId> for State {
     fn request(
         state: &mut Self,