Implement WebIDL sequence return values

2 files changed, 40 insertions, 3 deletions

diff --git a/components/script/dom/bindings/codegen/CodegenRust.py b/components/script/dom/bindings/codegen/CodegenRust.py
index 5ac6c455e39..260ef1e9006 100644
--- a/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/components/script/dom/bindings/codegen/CodegenRust.py
@@ -1295,7 +1295,12 @@ def getRetvalDeclarationForType(returnType, descriptorProvider):
     if returnType.isObject() or returnType.isSpiderMonkeyInterface():
         return CGGeneric("*mut JSObject")
     if returnType.isSequence():
-        raise TypeError("We don't support sequence return values")
+        inner = returnType.unroll()
+        result = getRetvalDeclarationForType(inner, descriptorProvider)
+        result = CGWrapper(result, pre="Vec<", post=">")
+        if returnType.nullable():
+            result = CGWrapper(result, pre="Option<", post=">")
+        return result
     if returnType.isDictionary():
         nullable = returnType.nullable()
         dictName = returnType.inner.name if nullable else returnType.name
diff --git a/components/script/dom/bindings/conversions.rs b/components/script/dom/bindings/conversions.rs
index 45279e7a966..3f4da2199db 100644
--- a/components/script/dom/bindings/conversions.rs
+++ b/components/script/dom/bindings/conversions.rs
@@ -38,14 +38,16 @@ use dom::bindings::js::Root;
 use dom::bindings::num::Finite;
 use dom::bindings::reflector::{Reflectable, Reflector};
 use dom::bindings::str::{ByteString, USVString};
+use dom::bindings::trace::RootedVec;
 use dom::bindings::utils::DOMClass;
 use js;
 use js::glue::{GetProxyPrivate, IsWrapper, RUST_JS_NumberValue};
 use js::glue::{RUST_JSID_IS_STRING, RUST_JSID_TO_STRING, UnwrapObject};
-use js::jsapi::{HandleId, HandleObject, HandleValue, JS_GetClass};
+use js::jsapi::{HandleId, HandleObject, HandleValue, Heap, JS_GetClass};
 use js::jsapi::{JSClass, JSContext, JSObject, JSString, MutableHandleValue};
 use js::jsapi::{JS_GetLatin1StringCharsAndLength, JS_GetReservedSlot};
 use js::jsapi::{JS_GetTwoByteStringCharsAndLength, JS_NewStringCopyN};
+use js::jsapi::{JS_NewArrayObject, HandleValueArray, RootedValue};
 use js::jsapi::{JS_NewUCStringCopyN, JS_StringHasLatin1Chars, JS_WrapValue};
 use js::jsval::{BooleanValue, Int32Value, NullValue, UInt32Value, UndefinedValue};
 use js::jsval::{JSVal, ObjectOrNullValue, ObjectValue, StringValue};
@@ -56,7 +58,7 @@ use libc;
 use num::Float;
 use num::traits::{Bounded, Zero};
 use std::rc::Rc;
-use std::{char, ptr, slice};
+use std::{char, mem, ptr, slice};
 use util::str::DOMString;
 
 trait As<O>: Copy {
@@ -811,6 +813,36 @@ impl<T: FromJSValConvertible> FromJSValConvertible for Option<T> {
     }
 }
 
+impl<T: ToJSValConvertible> ToJSValConvertible for Vec<T> {
+    fn to_jsval(&self, cx: *mut JSContext, rval: MutableHandleValue) {
+        let mut js_objects = RootedVec::new();
+
+        for obj in self.iter() {
+            let mut heap = Heap::default();
+            let mut val = RootedValue::new(cx, UndefinedValue());
+            obj.to_jsval(cx, val.handle_mut());
+            heap.set(val.handle().get());
+            js_objects.push(heap);
+        }
+
+        let values: Vec<JSVal> = js_objects.iter()
+                                           .map(|heap| heap.handle().get())
+                                           .collect();
+
+        let handle = HandleValueArray {
+            length_: values.len() as u64,
+            elements_: values.as_ptr(),
+        };
+
+        unsafe {
+            let js_array = JS_NewArrayObject(cx, &handle);
+            assert!(!js_array.is_null());
+
+            rval.set(ObjectValue(mem::transmute(js_array)));
+        }
+    }
+}
+
 //http://heycam.github.io/webidl/#es-object
 impl ToJSValConvertible for *mut JSObject {
     fn to_jsval(&self, cx: *mut JSContext, rval: MutableHandleValue) {