Closed Bug 870219 Opened 8 years ago Closed 8 years ago

Add a way for JS-implemented WebIDL objects to sanely do event handlers


(Core :: DOM: Events, defect)

Not set





(Reporter: bzbarsky, Assigned: bzbarsky)



(Keywords: dev-doc-needed)


(2 files)

Without having to reinvent the wheel, that is.
With the upcoming patch, implementing something like this:

  attribute EventHandler onaddstream;

would look like this:

  get onaddstream() {
    return this.__DOM_IMPL__.getEventHandler("addstream");
  set onaddstream(handler) {
    return this.__DOM_IMPL__.setEventHandler("addstream", handler);

which is not as cool as if we autogenerated it in the binding code, but better than nothing...

Of course the other option is we could just special-case event handlers in the binding codegen: for things inheriting from EventTarget, attributes of type EventHandler, named on*, just generate calls into the superclass...  Not sure whether it's worth the bother.
Blocks: 823512
No longer blocks: 858741
Blocks: 850430
Attachment #747293 - Flags: review?(bugs) → review+
Flags: in-testsuite-
Whiteboard: [need review]
Target Milestone: --- → mozilla23
Any reason you called it setEventHandler rather than setEventListener?
Yes they're different things.  An event listener is something that gets invoked when an event fires.  An event handler is a callback that a very special kinds of event listener can call...
addEventListener handles event listeners, onfoo properties are event handlers.
And backed out:

The problem is that worker code is crashing at startup with:

  ###!!! ASSERTION: Wrong thread!: '!NS_IsMainThread()', file ../../../dom/workers/WorkerPrivate.cpp, line 4257

with the stack showing JS running under the component loader and doing:

mozilla::dom::EventTargetBinding_workers::CreateInterfaceObjects(JSContext*, JS::Handle<JSObject*>, JSObject**)+0x00000063 [/builds/slave/m-in-osx64-d-00000000000000000/build/obj-firefox/dist/ +0x01882423]
mozilla::dom::workers::ResolveWorkerClasses(JSContext*, JS::Handle<JSObject*>, JS::Handle<jsid>, unsigned int, JS::MutableHandle<JSObject*>)+0x000001BF [/builds/slave/m-in-osx64-d-00000000000000000/build/obj-firefox/dist/ +0x00D1679F]
BackstagePass::NewResolve(nsIXPConnectWrappedNative*, JSContext*, JSObject*, jsid, unsigned int, JSObject**, bool*)+0x00000086 [/builds/slave/m-in-osx64-d-00000000000000000/build/obj-firefox/dist/ +0x010FAC86]
Comment on attachment 747539 [details] [diff] [review]
part 1.  Fix the chrome-scope checking for workers to work even if we incorrectly set up worker interface objects on the main thread.

Are we guaranteed that nsThreadUtils.h is included somewhere?
Attachment #747539 - Flags: review?(bent.mozilla) → review+
> Are we guaranteed that nsThreadUtils.h is included somewhere?

I'll add it to the list of binding includes, just in case.
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