- From: Chris Wilson <cwilso@google.com>
- Date: Wed, 27 Jun 2012 09:22:39 -0700
- To: Adam Goode <agoode@google.com>
- Cc: Jussi Kalliokoski <jussi.kalliokoski@gmail.com>, Dominique Hazael-Massieux <dom@w3.org>, public-audio@w3.org
- Message-ID: <CAJK2wqUn9dO+MESpOx2v2hDeb0T39sVv83AA9CaubMWuZstuQg@mail.gmail.com>
Sorry, I/O has been taking all my attention lately - but I do want to underscore that there is a confusing difference between a "MIDIDevice" and a MIDI device (e.g. a rack-mount synthesizer unit). MIDIDevice represents a MIDI interface - so the enumeration, for example, is enumerating the MIDI interfaces available, NOT polling the MIDI devices plugged into those interfaces. Sometimes these are the same - e.g. my USB MIDI keyboard is an interface as well as a MIDI device - but sometimes they're not (e.g. the several synths and drum machines I have chained together from a single 4x4 MIDI interface. On Tue, Jun 26, 2012 at 8:44 AM, Adam Goode <agoode@google.com> wrote: > On Tue, Jun 26, 2012 at 11:34 AM, Jussi Kalliokoski < > jussi.kalliokoski@gmail.com> wrote: > >> The semantics here may be too strong, maybe SHOULD should be used instead >> of MUST, as forcing the browser to poll on the devices when the OS doesn't >> provide an API for this is a bad idea. And disconnect and connect are not >> applicable to MIDI ports anyway (as in, not direct USB connection). >> >> >>> > And the API does allow for (un)plugging. [1] >>> >>> But only for devices that the app already knows about and keeps track of >>> — or am I missing something? To be more concrete, how would a Web app >>> know that the new MIDI keyboard I just bought just got plugged in? >>> >> >> According to the current API, the only way would be polling. I've been >> thinking of a way to fix this, perhaps an event to MIDIAccess when any >> device is plugged in or out would suffice, but I'm not sure yet. >> >> >>> >>> > Putting the event on MIDIAccess seems like the right thing. Many MIDI > devices are USB, so you'll get that notification. I like the way CoreMIDI > does it on iOS, you get all sorts of notifications for various events: > > http://developer.apple.com/library/ios/#documentation/CoreMidi/Reference/MIDIServices_Reference/Reference/reference.html#//apple_ref/doc/c_ref/MIDINotificationMessageID > > > Adam >
Received on Wednesday, 27 June 2012 16:23:14 UTC