Handle AddInput/RemoveInput events

components/atoms/static_atoms.txt

@@ -44,6 +44,7 @@ iceconnectionstatechange
 icegatheringstatechange
 image
 input
+inputsourceschange
 invalid
 keydown
 keypress

components/script/dom/webidls/XRSession.webidl

@@ -40,7 +40,7 @@ interface XRSession : EventTarget {
   attribute EventHandler onend;
   attribute EventHandler onselect;
   attribute EventHandler onsqueeze;
-  // attribute EventHandler oninputsourceschange;
+  attribute EventHandler oninputsourceschange;
   attribute EventHandler onselectstart;
   attribute EventHandler onselectend;
   attribute EventHandler onsqueezestart;

components/script/dom/xrinputsourcearray.rs

@@ -5,13 +5,16 @@
 use crate::dom::bindings::cell::DomRefCell;
 use crate::dom::bindings::codegen::Bindings::XRInputSourceArrayBinding;
 use crate::dom::bindings::codegen::Bindings::XRInputSourceArrayBinding::XRInputSourceArrayMethods;
+use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
 use crate::dom::bindings::root::{Dom, DomRoot};
+use crate::dom::event::Event;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::xrinputsource::XRInputSource;
+use crate::dom::xrinputsourceschangeevent::XRInputSourcesChangeEvent;
 use crate::dom::xrsession::XRSession;
 use dom_struct::dom_struct;
-use webxr_api::InputId;
+use webxr_api::{InputId, InputSource};
 
 #[dom_struct]
 pub struct XRInputSourceArray {
@@ -48,6 +51,56 @@ impl XRInputSourceArray {
         });
     }
 
+    pub fn add_input_source(&self, session: &XRSession, info: InputSource) {
+        let mut input_sources = self.input_sources.borrow_mut();
+        let global = self.global();
+        let input = XRInputSource::new(&global, &session, info);
+        debug_assert!(
+            input_sources.iter().find(|i| i.id() == info.id).is_none(),
+            "Should never add a duplicate input id!"
+        );
+        input_sources.push(Dom::from_ref(&input));
+
+        let added = [input];
+
+        let event = XRInputSourcesChangeEvent::new(
+            &global,
+            atom!("inputsourceschange"),
+            false,
+            true,
+            session,
+            &added,
+            &[],
+        );
+        // Release the refcell guard
+        drop(input_sources);
+        event.upcast::<Event>().fire(session.upcast());
+    }
+
+    pub fn remove_input_source(&self, session: &XRSession, id: InputId) {
+        let mut input_sources = self.input_sources.borrow_mut();
+        let global = self.global();
+        let removed = if let Some(i) = input_sources.iter().find(|i| i.id() == id) {
+            [DomRoot::from_ref(&**i)]
+        } else {
+            return;
+        };
+
+        let event = XRInputSourcesChangeEvent::new(
+            &global,
+            atom!("inputsourceschange"),
+            false,
+            true,
+            session,
+            &[],
+            &removed,
+        );
+        input_sources.retain(|i| i.id() != id);
+        // release the refcell guard
+        drop(input_sources);
+        event.upcast::<Event>().fire(session.upcast());
+    }
+
     pub fn find(&self, id: InputId) -> Option<DomRoot<XRInputSource>> {
         self.input_sources
             .borrow()

components/script/dom/xrinputsourceschangeevent.rs

@@ -66,10 +66,10 @@ impl XRInputSourcesChangeEvent {
         let cx = global.get_cx();
         unsafe {
             rooted!(in(*cx) let mut added_val = UndefinedValue());
-            rooted!(in(*cx) let mut removed_val  = UndefinedValue());
             added.to_jsval(*cx, added_val.handle_mut());
-            removed.to_jsval(*cx, removed_val.handle_mut());
             changeevent.added.set(added_val.get());
+            rooted!(in(*cx) let mut removed_val = UndefinedValue());
+            removed.to_jsval(*cx, removed_val.handle_mut());
             changeevent.added.set(removed_val.get());
         }
 

components/script/dom/xrsession.rs

@@ -289,7 +289,12 @@ impl XRSession {
                 );
                 event.upcast::<Event>().fire(self.upcast());
             },
-            _ => (), // XXXManishearth TBD
+            XREvent::AddInput(info) => {
+                self.input_sources.add_input_source(self, info);
+            },
+            XREvent::RemoveInput(id) => {
+                self.input_sources.remove_input_source(self, id);
+            },
         }
     }
 
@@ -432,6 +437,13 @@ impl XRSessionMethods for XRSession {
         SetOnvisibilitychange
     );
 
+    /// https://immersive-web.github.io/webxr/#eventdef-xrsession-inputsourceschange
+    event_handler!(
+        inputsourceschange,
+        GetOninputsourceschange,
+        SetOninputsourceschange
+    );
+
     // https://immersive-web.github.io/webxr/#dom-xrsession-renderstate
     fn RenderState(&self) -> DomRoot<XRRenderState> {
         self.active_render_state.get()