The resize event isn't a UIEvent

[cvrebert]

In Safari, Firefox, and Chrome, resize events are instances of Event, not of UIEvent as this spec currently claims. Only MS Edge currently uses UIEvent for resize.

Also, CSSOM View specifies resize as a plain Event. Per https://drafts.csswg.org/cssom-view/#resizing-viewports :

[...] fire an event named resize at the Window object associated with doc

And per https://dom.spec.whatwg.org/#concept-event-fire

To "fire an event named e" means that a new event using the Event interface, [...]

[garykac]

It seems a bit odd to keep it in UIEvents if it is an instance of Event rather than UIEvent.

But I can't think of another place for it to live. If there are no objections or suggestions for an alternate location, I'll add a section for Event-based UIEvents.

[cvrebert]

Dunno. I suppose it could be moved to CSSOM View like the scroll event was.

[garykac]

@zcorpan @travisleithead Does moving resize into CSSOM (like we did with scroll) sound reasonable?

[zcorpan]

Yes, it's defined there already and integrates with HTML's event loop, so it should be well-defined when exactly it should be fired, and cover the same ground as the first two paragraphs in UIEvents.

The third paragraph:

The Window object SHOULD always be resizable. A host language MAY define certain elements to be resizable, and under what conditions (e.g., specific elements like <iframe>, or elements with particular characteristics like width and height). However, this specification does not define the behavior for elements.

...doesn't really make any sense to me.

[cvrebert]

Only MS Edge currently uses UIEvent for resize.

Filed https://connect.microsoft.com/IE/Feedback/Details/2455552

[plehegar]

This might help here: The resize event on touchscreen:
http://www.quirksmode.org/blog/archives/2016/03/the_resize_even_2.html
http://www.quirksmode.org/dom/events/resize_mobile.html

[travisleithead]

Edge had a pre-existing bug to switch resize to Event from UIEvent, but thanks for the extra feedback :-)

+1 for removing resize from UIEvents spec.

[garykac]

@zcorpan wrote:

The third paragraph:

The Window object SHOULD always be resizable. A host language MAY define certain elements to be resizable, and under what conditions (e.g., specific elements like <iframe>, or elements with particular characteristics like width and height). However, this specification does not define the behavior for elements.

doesn't really make any sense to me.

I read that as: "Windows are resizeable. Other things might be resizeable too, but we don't bother specifying them here."

That text looks like a catch-all to cover the case where some user agents are sending resize on non-Window objects and we didn't want the spec to disallow it. I don't think it adds much value unless we define what other objects can send resize, so I think it's safe to delete.