Implement EventTarget builtin

Author: andreiltd

builtins/web/event/event-target.cpp

@@ -0,0 +1,70 @@
+#ifndef BUILTINS_WEB_EVENT_TARGET_H_
+#define BUILTINS_WEB_EVENT_TARGET_H_
+
+#include "builtin.h"
+#include "extension-api.h"
+
+namespace builtins {
+namespace web {
+namespace event {
+
+struct EventListener {
+  void trace(JSTracer *trc) {
+    TraceEdge(trc, &callback, "EventListener callback");
+    TraceEdge(trc, &signal, "EventListener signal");
+  }
+
+  JS::Heap<JS::Value> callback;
+  JS::Heap<JS::Value> signal;
+
+  std::string type;
+
+  bool passive;
+  bool capture;
+  bool once;
+  bool removed;
+
+  // Define equality: only callback, type, and capture matter.
+  bool operator==(const EventListener &other) const {
+    return (callback == other.callback) && (type == other.type) && (capture == other.capture);
+  }
+};
+
+class EventTarget : public TraceableBuiltinImpl<EventTarget> {
+  static bool addEventListener(JSContext *cx, unsigned argc, JS::Value *vp);
+  static bool removeEventListener(JSContext *cx, unsigned argc, JS::Value *vp);
+  static bool dispatchEvent(JSContext *cx, unsigned argc, JS::Value *vp);
+
+  using ListenerList = JS::GCVector<EventListener, 0, js::SystemAllocPolicy>;
+  static ListenerList *listeners(JSObject *self);
+
+  static bool dispatch(JSContext *cx, HandleObject self, HandleObject event,
+                       HandleObject target_override, MutableHandleValue rval);
+
+  static bool inner_invoke(JSContext *cx, HandleObject event, JS::HandleVector<EventListener> list,
+                           bool *found);
+
+  static bool invoke_listeners(JSContext *cx, HandleObject target, HandleObject event);
+
+public:
+  static constexpr const char *class_name = "EventTarget";
+  static constexpr unsigned ctor_length = 0;
+
+  static const JSFunctionSpec static_methods[];
+  static const JSPropertySpec static_properties[];
+  static const JSFunctionSpec methods[];
+  static const JSPropertySpec properties[];
+
+  enum Slots { Listeners, Count };
+
+  static bool init_class(JSContext *cx, HandleObject global);
+  static bool constructor(JSContext *cx, unsigned argc, Value *vp);
+  static void finalize(JS::GCContext *gcx, JSObject *self);
+  static void trace(JSTracer *trc, JSObject *self);
+};
+
+} // namespace event
+} // namespace web
+} // namespace builtins
+
+#endif // BUILTINS_WEB_EVENT_TARGET_H_