Make poses nullable

components/script/dom/mod.rs

@@ -549,6 +549,7 @@ pub mod xmlserializer;
 pub mod xr;
 pub mod xrframe;
 pub mod xrinputsource;
+pub mod xrinputsourceevent;
 pub mod xrpose;
 pub mod xrreferencespace;
 pub mod xrrenderstate;

components/script/dom/xrframe.rs

@@ -93,8 +93,16 @@ impl XRFrameMethods for XRFrame {
         if !self.active.get() {
             return Err(Error::InvalidState);
         }
-        let space = space.get_pose(&self.data);
+        let space = if let Some(space) = space.get_pose(&self.data) {
-        let relative_to = relative_to.get_pose(&self.data);
+            space
+        } else {
+            return Ok(None);
+        };
+        let relative_to = if let Some(r) = relative_to.get_pose(&self.data) {
+            r
+        } else {
+            return Ok(None);
+        };
         let pose = relative_to.inverse().pre_transform(&space);
         Ok(Some(XRPose::new(&self.global(), pose)))
     }

components/script/dom/xrspace.rs

@@ -57,9 +57,9 @@ impl XRSpace {
     /// The reference origin used is common between all
     /// get_pose calls for spaces from the same device, so this can be used to compare
     /// with other spaces
-    pub fn get_pose(&self, base_pose: &Frame) -> ApiPose {
+    pub fn get_pose(&self, base_pose: &Frame) -> Option<ApiPose> {
         if let Some(reference) = self.downcast::<XRReferenceSpace>() {
-            reference.get_pose(base_pose)
+            Some(reference.get_pose(base_pose))
         } else if let Some(source) = self.input_source.get() {
             // XXXManishearth we should be able to request frame information
             // for inputs when necessary instead of always loading it
@@ -72,7 +72,7 @@ impl XRSpace {
                 .iter()
                 .find(|i| i.id == id)
                 .expect("no input found");
-            cast_transform(frame.target_ray_origin)
+            Some(cast_transform(frame.target_ray_origin))
         } else {
             unreachable!()
         }