chore: remove platform FingerId

The same as for `WindowId`.

src/event.rs

@@ -634,12 +634,23 @@ impl DeviceId {
 /// Whenever a touch event is received it contains a `FingerId` which uniquely identifies the finger
 /// used for the current interaction.
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct FingerId(pub(crate) platform_impl::FingerId);
+pub struct FingerId(pub(crate) usize);
 
 impl FingerId {
-    #[cfg(test)]
-    pub(crate) const fn dummy() -> Self {
-        FingerId(platform_impl::FingerId::dummy())
+    /// Convert the [`FingerId`] into the underlying integer.
+    ///
+    /// This is useful if you need to pass the ID across an FFI boundary, or store it in an atomic.
+    #[allow(dead_code)]
+    pub(crate) const fn into_raw(self) -> usize {
+        self.0
+    }
+
+    /// Construct a [`FingerId`] from the underlying integer.
+    ///
+    /// This should only be called with integers returned from [`FingerId::into_raw`].
+    #[allow(dead_code)]
+    pub(crate) const fn from_raw(id: usize) -> Self {
+        Self(id)
     }
 }
 
@@ -1154,7 +1165,7 @@ mod tests {
         ($closure:expr) => {{
             #[allow(unused_mut)]
             let mut x = $closure;
-            let fid = event::FingerId::dummy();
+            let fid = event::FingerId::from_raw(0);
 
             #[allow(deprecated)]
             {
@@ -1291,7 +1302,7 @@ mod tests {
         });
         let _ = event::StartCause::Init.clone();
 
-        let fid = crate::event::FingerId::dummy().clone();
+        let fid = crate::event::FingerId::from_raw(0).clone();
         HashSet::new().insert(fid);
         let mut set = [fid, fid, fid];
         set.sort_unstable();

src/platform/mod.rs

@@ -21,6 +21,7 @@ pub mod windows;
 #[cfg(any(x11_platform, docsrs))]
 pub mod x11;
 
+#[allow(unused_imports)]
 #[cfg(any(
     windows_platform,
     macos_platform,

src/platform_impl/android/mod.rs

@@ -15,7 +15,7 @@ use crate::application::ApplicationHandler;
 use crate::cursor::Cursor;
 use crate::dpi::{PhysicalPosition, PhysicalSize, Position, Size};
 use crate::error::{EventLoopError, NotSupportedError, RequestError};
-use crate::event::{self, DeviceId, Force, StartCause, SurfaceSizeWriter};
+use crate::event::{self, DeviceId, FingerId, Force, StartCause, SurfaceSizeWriter};
 use crate::event_loop::{
     ActiveEventLoop as RootActiveEventLoop, ControlFlow, DeviceEvents,
     EventLoopProxy as RootEventLoopProxy, OwnedDisplayHandle as RootOwnedDisplayHandle,
@@ -107,7 +107,7 @@ pub struct EventLoop {
     running: bool,
     pending_redraw: bool,
     cause: StartCause,
-    primary_pointer: FingerId,
+    primary_pointer: Option<FingerId>,
     ignore_volume_keys: bool,
     combining_accent: Option<char>,
 }
@@ -141,7 +141,7 @@ impl EventLoop {
 
         Ok(Self {
             android_app: android_app.clone(),
-            primary_pointer: FingerId::dummy(),
+            primary_pointer: None,
             window_target: ActiveEventLoop {
                 app: android_app.clone(),
                 control_flow: Cell::new(ControlFlow::default()),
@@ -342,14 +342,14 @@ impl EventLoop {
                         "Input event {device_id:?}, {action:?}, loc={position:?}, \
                          pointer={pointer:?}, tool_type={tool_type:?}"
                     );
-                    let finger_id = event::FingerId(FingerId(pointer.pointer_id()));
+                    let finger_id = FingerId::from_raw(pointer.pointer_id() as usize);
                     let force = Some(Force::Normalized(pointer.pressure() as f64));
 
                     match action {
                         MotionAction::Down | MotionAction::PointerDown => {
                             let primary = action == MotionAction::Down;
                             if primary {
-                                self.primary_pointer = finger_id.0;
+                                self.primary_pointer = Some(finger_id);
                             }
                             let event = event::WindowEvent::PointerEntered {
                                 device_id,
@@ -382,7 +382,7 @@ impl EventLoop {
                             app.window_event(&self.window_target, GLOBAL_WINDOW, event);
                         },
                         MotionAction::Move => {
-                            let primary = self.primary_pointer == finger_id.0;
+                            let primary = self.primary_pointer == Some(finger_id);
                             let event = event::WindowEvent::PointerMoved {
                                 device_id,
                                 primary,
@@ -401,10 +401,10 @@ impl EventLoop {
                         MotionAction::Up | MotionAction::PointerUp | MotionAction::Cancel => {
                             let primary = action == MotionAction::Up
                                 || (action == MotionAction::Cancel
-                                    && self.primary_pointer == finger_id.0);
+                                    && self.primary_pointer == Some(finger_id));
 
                             if primary {
-                                self.primary_pointer = FingerId::dummy();
+                                self.primary_pointer = None;
                             }
 
                             if let MotionAction::Up | MotionAction::PointerUp = action {
@@ -745,15 +745,6 @@ impl OwnedDisplayHandle {
     }
 }
 
-#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
-pub struct FingerId(i32);
-
-impl FingerId {
-    pub const fn dummy() -> Self {
-        FingerId(0)
-    }
-}
-
 #[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
 pub struct PlatformSpecificWindowAttributes;
 

src/platform_impl/apple/appkit/mod.rs

@@ -26,13 +26,3 @@ pub(crate) use self::window_delegate::PlatformSpecificWindowAttributes;
 pub(crate) use crate::cursor::OnlyCursorImageSource as PlatformCustomCursorSource;
 pub(crate) use crate::icon::NoIcon as PlatformIcon;
 pub(crate) use crate::platform_impl::Fullscreen;
-
-#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct FingerId;
-
-impl FingerId {
-    #[cfg(test)]
-    pub const fn dummy() -> Self {
-        FingerId
-    }
-}

src/platform_impl/apple/mod.rs

@@ -7,7 +7,9 @@ mod notification_center;
 #[cfg(not(target_os = "macos"))]
 mod uikit;
 
+#[allow(unused_imports)]
 #[cfg(target_os = "macos")]
 pub use self::appkit::*;
+#[allow(unused_imports)]
 #[cfg(not(target_os = "macos"))]
 pub use self::uikit::*;

src/platform_impl/apple/uikit/mod.rs

@@ -21,16 +21,6 @@ pub(crate) use crate::cursor::{
 pub(crate) use crate::icon::NoIcon as PlatformIcon;
 pub(crate) use crate::platform_impl::Fullscreen;
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct FingerId(usize);
-
-impl FingerId {
-    #[cfg(test)]
-    pub const fn dummy() -> Self {
-        FingerId(0)
-    }
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct KeyEventExtra {}
 

src/platform_impl/apple/uikit/view.rs

@@ -14,11 +14,10 @@ use objc2_ui_kit::{
 
 use super::app_state::{self, EventWrapper};
 use super::window::WinitUIWindow;
-use super::FingerId;
 use crate::dpi::PhysicalPosition;
 use crate::event::{
-    ButtonSource, ElementState, Event, FingerId as RootFingerId, Force, KeyEvent, PointerKind,
-    PointerSource, TouchPhase, WindowEvent,
+    ButtonSource, ElementState, Event, FingerId, Force, KeyEvent, PointerKind, PointerSource,
+    TouchPhase, WindowEvent,
 };
 use crate::keyboard::{Key, KeyCode, KeyLocation, NamedKey, NativeKeyCode, PhysicalKey};
 use crate::platform_impl::KeyEventExtra;
@@ -35,7 +34,7 @@ pub struct WinitViewState {
     pinch_last_delta: Cell<CGFloat>,
     pan_last_delta: Cell<CGPoint>,
 
-    primary_finger: Cell<Option<usize>>,
+    primary_finger: Cell<Option<FingerId>>,
     fingers: Cell<u8>,
 }
 
@@ -519,7 +518,7 @@ impl WinitView {
                 )
             };
             let window_id = window.id();
-            let finger_id = RootFingerId(FingerId(touch_id));
+            let finger_id = FingerId::from_raw(touch_id);
 
             let ivars = self.ivars();
 
@@ -529,15 +528,17 @@ impl WinitView {
                         true
                     } else {
                         ivars.fingers.set(ivars.fingers.get() + 1);
+                        // Keep the primary finger around until we clear all the fingers to
+                        // recognize it when user briefly removes it.
                         match ivars.primary_finger.get() {
-                            Some(primary_id) => primary_id == touch_id,
+                            Some(primary_id) => primary_id == finger_id,
                             None => {
                                 debug_assert_eq!(
                                     ivars.fingers.get(),
                                     1,
                                     "number of fingers were not counted correctly"
                                 );
-                                ivars.primary_finger.set(Some(touch_id));
+                                ivars.primary_finger.set(Some(finger_id));
                                 true
                             },
                         }
@@ -575,7 +576,7 @@ impl WinitView {
                     let (primary, source) = if let UITouchType::Pencil = touch_type {
                         (true, PointerSource::Unknown)
                     } else {
-                        (ivars.primary_finger.get().unwrap() == touch_id, PointerSource::Touch {
+                        (ivars.primary_finger.get().unwrap() == finger_id, PointerSource::Touch {
                             finger_id,
                             force,
                         })
@@ -597,7 +598,7 @@ impl WinitView {
                         true
                     } else {
                         ivars.fingers.set(ivars.fingers.get() - 1);
-                        let primary = ivars.primary_finger.get().unwrap() == touch_id;
+                        let primary = ivars.primary_finger.get().unwrap() == finger_id;
                         if ivars.fingers.get() == 0 {
                             ivars.primary_finger.set(None);
                         }

src/platform_impl/linux/mod.rs

@@ -107,24 +107,6 @@ impl Default for PlatformSpecificWindowAttributes {
 pub(crate) static X11_BACKEND: Lazy<Mutex<Result<Arc<XConnection>, XNotSupported>>> =
     Lazy::new(|| Mutex::new(XConnection::new(Some(x_error_callback)).map(Arc::new)));
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub enum FingerId {
-    #[cfg(x11_platform)]
-    X(x11::FingerId),
-    #[cfg(wayland_platform)]
-    Wayland(wayland::FingerId),
-}
-
-impl FingerId {
-    #[cfg(test)]
-    pub const fn dummy() -> Self {
-        #[cfg(wayland_platform)]
-        return FingerId::Wayland(wayland::FingerId::dummy());
-        #[cfg(all(not(wayland_platform), x11_platform))]
-        return FingerId::X(x11::FingerId::dummy());
-    }
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub enum MonitorHandle {
     #[cfg(x11_platform)]

src/platform_impl/linux/wayland/mod.rs

@@ -17,16 +17,6 @@ mod state;
 mod types;
 mod window;
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct FingerId(i32);
-
-impl FingerId {
-    #[cfg(test)]
-    pub const fn dummy() -> Self {
-        FingerId(0)
-    }
-}
-
 /// Get the WindowId out of the surface.
 #[inline]
 fn make_wid(surface: &WlSurface) -> WindowId {

src/platform_impl/linux/wayland/seat/touch/mod.rs

@@ -8,9 +8,9 @@ use sctk::seat::touch::{TouchData, TouchHandler};
 use tracing::warn;
 
 use crate::dpi::LogicalPosition;
-use crate::event::{ButtonSource, ElementState, PointerKind, PointerSource, WindowEvent};
+use crate::event::{ButtonSource, ElementState, FingerId, PointerKind, PointerSource, WindowEvent};
+use crate::platform_impl::wayland;
 use crate::platform_impl::wayland::state::WinitState;
-use crate::platform_impl::wayland::{self, FingerId};
 
 impl TouchHandler for WinitState {
     fn down(
@@ -40,12 +40,15 @@ impl TouchHandler for WinitState {
 
         // Update the state of the point.
         let location = LogicalPosition::<f64>::from(position);
+        // Only update primary finger once we don't have any touch.
+        if seat_state.touch_map.is_empty() {
+            seat_state.first_touch_id = Some(id);
+        }
+        let primary = seat_state.first_touch_id == Some(id);
         seat_state.touch_map.insert(id, TouchPoint { surface, location });
-        let primary = seat_state.first_touch_id.get_or_insert(id) == &id;
 
         let position = location.to_physical(scale_factor);
-        let finger_id =
-            crate::event::FingerId(crate::platform_impl::FingerId::Wayland(FingerId(id)));
+        let finger_id = FingerId::from_raw(id as usize);
 
         self.events_sink.push_window_event(
             WindowEvent::PointerEntered {
@@ -93,7 +96,10 @@ impl TouchHandler for WinitState {
 
         // Update the primary touch point.
         let primary = seat_state.first_touch_id == Some(id);
-        if primary {
+        // Reset primary finger once all the other fingers are lifted to not transfer primary
+        // finger to some other finger and still accept it when it's briefly moved between the
+        // windows.
+        if seat_state.touch_map.is_empty() {
             seat_state.first_touch_id = None;
         }
 
@@ -104,8 +110,7 @@ impl TouchHandler for WinitState {
         };
 
         let position = touch_point.location.to_physical(scale_factor);
-        let finger_id =
-            crate::event::FingerId(crate::platform_impl::FingerId::Wayland(FingerId(id)));
+        let finger_id = FingerId::from_raw(id as usize);
 
         self.events_sink.push_window_event(
             WindowEvent::PointerButton {
@@ -167,9 +172,7 @@ impl TouchHandler for WinitState {
                 primary,
                 position: touch_point.location.to_physical(scale_factor),
                 source: PointerSource::Touch {
-                    finger_id: crate::event::FingerId(crate::platform_impl::FingerId::Wayland(
-                        FingerId(id),
-                    )),
+                    finger_id: FingerId::from_raw(id as usize),
                     force: None,
                 },
             },
@@ -201,9 +204,7 @@ impl TouchHandler for WinitState {
                     device_id: None,
                     primary,
                     position: Some(position),
-                    kind: PointerKind::Touch(crate::event::FingerId(
-                        crate::platform_impl::FingerId::Wayland(FingerId(id)),
-                    )),
+                    kind: PointerKind::Touch(FingerId::from_raw(id as usize)),
                 },
                 window_id,
             );

src/platform_impl/linux/x11/event_processor.rs

@@ -22,8 +22,9 @@ use xkbcommon_dl::xkb_mod_mask_t;
 
 use crate::dpi::{PhysicalPosition, PhysicalSize};
 use crate::event::{
-    ButtonSource, DeviceEvent, DeviceId, ElementState, Event, Ime, MouseButton, MouseScrollDelta,
-    PointerKind, PointerSource, RawKeyEvent, SurfaceSizeWriter, TouchPhase, WindowEvent,
+    ButtonSource, DeviceEvent, DeviceId, ElementState, Event, FingerId, Ime, MouseButton,
+    MouseScrollDelta, PointerKind, PointerSource, RawKeyEvent, SurfaceSizeWriter, TouchPhase,
+    WindowEvent,
 };
 use crate::keyboard::ModifiersState;
 use crate::platform_impl::common::xkb::{self, XkbState};
@@ -33,7 +34,7 @@ use crate::platform_impl::platform::x11::ActiveEventLoop;
 use crate::platform_impl::x11::atoms::*;
 use crate::platform_impl::x11::util::cookie::GenericEventCookie;
 use crate::platform_impl::x11::{
-    mkdid, mkfid, mkwid, util, CookieResultExt, Device, DeviceInfo, Dnd, DndState, ImeReceiver,
+    mkdid, mkwid, util, CookieResultExt, Device, DeviceInfo, Dnd, DndState, ImeReceiver,
     ScrollOrientation, UnownedWindow, WindowId,
 };
 
@@ -1390,7 +1391,7 @@ impl EventProcessor {
             }
 
             let device_id = Some(mkdid(xev.deviceid as xinput::DeviceId));
-            let finger_id = mkfid(id);
+            let finger_id = FingerId::from_raw(id as usize);
 
             match phase {
                 xinput2::XI_TouchBegin => {