Re: Intent to implement and ship: "passive" option for AddEventListenerOptions

2016-05-06 Thread Eric Shepherd
That's what I figured, but the articles about it didn't seem to say, and the late hour caused me not to think to look at the spec itself. Good deal. > That's a no-op per https://dom.spec.whatwg.org/#dom-event-preventdefault. -- Eric Shepherd Senior Technical Writer Mozilla Developer Network

Re: Intent to implement and ship: "passive" option for AddEventListenerOptions

2016-05-06 Thread Kartikaya Gupta
Correct, the preventDefault() is ignored from a passive listener, and we will probably log a warning to the console (I have a patch up for review that does that, let's see what smaug says). On Fri, May 6, 2016 at 1:01 AM, Anne van Kesteren wrote: > On Fri, May 6, 2016 at 4:43 AM, Eric Shepherd w

Re: Intent to implement and ship: "passive" option for AddEventListenerOptions

2016-05-05 Thread Anne van Kesteren
On Fri, May 6, 2016 at 4:43 AM, Eric Shepherd wrote: > What happens if the developer specifies passive yet calls > preventDefault() anyway? That's a no-op per https://dom.spec.whatwg.org/#dom-event-preventdefault. -- https://annevankesteren.nl/ ___ d

Re: Intent to implement and ship: "passive" option for AddEventListenerOptions

2016-05-05 Thread Eric Shepherd
ship: "passive" option for AddEventListenerOptions > Summary: Authors can declare in their addEventListener call that the > listener will not be calling preventDefault() on the event. This > unlocks certain performance optimizations. -- Eric Shepherd Senior Technical Write

Re: Intent to implement and ship: "passive" option for AddEventListenerOptions

2016-05-05 Thread Markus Stange
On 2016-05-05 3:21 PM, Justin Dolske wrote: How will a developer know when it would be worthwhile to mark their event listener as passive? Do we perhaps log something to the console? The Chrome devtools have two features to help with this: They have a checkbox for "Show scrolling perf issues"

Re: Intent to implement and ship: "passive" option for AddEventListenerOptions

2016-05-05 Thread Kartikaya Gupta
In general developers should probably default to marking their listeners as passive, unless their listeners are actually going to call preventDefault(). We don't have a console log for saying "use a passive listener", no. We can easily detect listeners that are not marked passive and that are impac

Re: Intent to implement and ship: "passive" option for AddEventListenerOptions

2016-05-05 Thread Justin Dolske
How will a developer know when it would be worthwhile to mark their event listener as passive? Do we perhaps log something to the console? Justin On Wed, May 4, 2016 at 3:19 PM, Kartikaya Gupta wrote: > Summary: Authors can declare in their addEventListener call that the > listener will not be

Intent to implement and ship: "passive" option for AddEventListenerOptions

2016-05-05 Thread Kartikaya Gupta
Summary: Authors can declare in their addEventListener call that the listener will not be calling preventDefault() on the event. This unlocks certain performance optimizations. Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1266066 Link to standard: https://dom.spec.whatwg.org/#dom-addeventlis