- From: Anssi Kostiainen <anssi.kostiainen@nokia.com>
- Date: Mon, 11 Apr 2011 15:59:09 +0300
- To: ext Rich Tibbett <richt@opera.com>
- CC: "public-device-apis@w3.org Group WG" <public-device-apis@w3.org>
Hi, On 8.4.2011, at 13.59, ext Rich Tibbett wrote: > The only absolutely locked-in, useful use case I see is the following: > > if(event.level > 20) { > // No problem! > } else { > // you're running on low battery so we'll disable the > // power-hungry feature z to save the battery > // (of course, you can enable z manually if you wish) > // + we'll step up the automatic saving of your ongoing > // session just in case your machine dies mid-sentence. > } > > Every other method or property is negotiable. I don't see the need to know which power source I'm currently connected to hence the proposal to remove isBattery and isCharging. In fact, I could infer that I'm connected to the wall if I don't receive any subsequent callbacks after an initial power source event has been fired (with event.level = 100). > > Furthermore, it should be easy to produce a timeRemaining guesstimate based on event callbacks that don't contain this data. As an example, if an event starts at time t and I receive an event.level = 99 at t+180 seconds and then an event.level = 98 at t+120 seconds and then an event.level = 97 at t+120 seconds I can make a guesstimate, via Javascript, that at time t+420 the machine is likely to remain responsive for the next 3 hours and 12 minutes at current battery consumption levels. There's little need to provide that data (and have two separate power level attributes) in the returned event itself. > > Based on that, I'd propose to also drop the timeRemaining attribute, leaving only the 'level' attribute in an event callback. Thanks again for the feedback. I added a note to the spec that the inclusion of those properties (isBattery, isCharging, and timeRemaining) is under consideration. > Dzung's proposal to rename the event to PowerSourceEvent also makes a lot of sense for this also. I did not yet rename the event as I believe that the BatteryStatusEvent more concretely conveys the meaning than the PowerSourceEvent and maps to the spec name. "Power Source Event Specification" sounds a bit too abstract to me. That said, lets bikeshed the naming once we have all the hard problems solved -- if that's fine with you guys :) -Anssi
Received on Monday, 11 April 2011 12:59:44 UTC