Wayland: Switched to using a reference to relative_pointer_manager_proxy when creating SeatData (#1179)

* Fixed relative_pointer not being set up when the "zwp_relative_pointer_manager_v1" callback comes after the "wl_seat" callback

* Ran cargo fmt

* Updated changelog

* Improved CHANGELOG

* Switched to using Rc<RefCell> instead of Arc<Mutex> since all accesses to the relative_pointer_manager_proxy will happen on the same thread.

* Forgot to run cargo fmt

CHANGELOG.md

@@ -20,6 +20,7 @@
 - On X11, return dummy monitor data to avoid panicking when no monitors exist.
 - On X11, prevent stealing input focus when creating a new window.
   Only steal input focus when entering fullscreen mode.
+- On Wayland, fixed DeviceEvents for relative mouse movement is not always produced
 
 # 0.20.0 Alpha 3 (2019-08-14)
 

src/platform_impl/linux/wayland/event_loop.rs

@@ -148,7 +148,7 @@ impl<T: 'static> EventLoop<T> {
 
         let mut seat_manager = SeatManager {
             sink: sink.clone(),
-            relative_pointer_manager_proxy: None,
+            relative_pointer_manager_proxy: Rc::new(RefCell::new(None)),
             store: store.clone(),
             seats: seats.clone(),
             kbd_sender,
@@ -164,13 +164,16 @@ impl<T: 'static> EventLoop<T> {
                     version,
                 } => {
                     if interface == "zwp_relative_pointer_manager_v1" {
-                        seat_manager.relative_pointer_manager_proxy = Some(
-                            registry
+                        let relative_pointer_manager_proxy = registry
                             .bind(version, id, move |pointer_manager| {
                                 pointer_manager.implement_closure(|_, _| (), ())
                             })
-                                .unwrap(),
-                        )
+                            .unwrap();
+
+                        *seat_manager
+                            .relative_pointer_manager_proxy
+                            .try_borrow_mut()
+                            .unwrap() = Some(relative_pointer_manager_proxy);
                     }
                     if interface == "wl_seat" {
                         seat_manager.add_seat(id, version, registry)
@@ -493,7 +496,7 @@ struct SeatManager<T: 'static> {
     store: Arc<Mutex<WindowStore>>,
     seats: Arc<Mutex<Vec<(u32, wl_seat::WlSeat)>>>,
     kbd_sender: ::calloop::channel::Sender<(crate::event::WindowEvent, super::WindowId)>,
-    relative_pointer_manager_proxy: Option<ZwpRelativePointerManagerV1>,
+    relative_pointer_manager_proxy: Rc<RefCell<Option<ZwpRelativePointerManagerV1>>>,
 }
 
 impl<T: 'static> SeatManager<T> {
@@ -505,7 +508,7 @@ impl<T: 'static> SeatManager<T> {
             store: self.store.clone(),
             pointer: None,
             relative_pointer: None,
-            relative_pointer_manager_proxy: self.relative_pointer_manager_proxy.as_ref().cloned(),
+            relative_pointer_manager_proxy: self.relative_pointer_manager_proxy.clone(),
             keyboard: None,
             touch: None,
             kbd_sender: self.kbd_sender.clone(),
@@ -537,7 +540,7 @@ struct SeatData<T> {
     kbd_sender: ::calloop::channel::Sender<(crate::event::WindowEvent, super::WindowId)>,
     pointer: Option<wl_pointer::WlPointer>,
     relative_pointer: Option<ZwpRelativePointerV1>,
-    relative_pointer_manager_proxy: Option<ZwpRelativePointerManagerV1>,
+    relative_pointer_manager_proxy: Rc<RefCell<Option<ZwpRelativePointerManagerV1>>>,
     keyboard: Option<wl_keyboard::WlKeyboard>,
     touch: Option<wl_touch::WlTouch>,
     modifiers_tracker: Arc<Mutex<ModifiersState>>,
@@ -557,8 +560,10 @@ impl<T: 'static> SeatData<T> {
                         self.modifiers_tracker.clone(),
                     ));
 
-                    self.relative_pointer =
-                        self.relative_pointer_manager_proxy
+                    self.relative_pointer = self
+                        .relative_pointer_manager_proxy
+                        .try_borrow()
+                        .unwrap()
                         .as_ref()
                         .and_then(|manager| {
                             super::pointer::implement_relative_pointer(