[whatwg] Some media element details
ian at hixie.ch
Wed Jun 11 17:42:25 PDT 2008
On Fri, 16 May 2008, James Justin Harrell wrote:
> The current HTMLMediaElement interface is inconsistent and is designed
> in such a way that making changes to it will be extremely difficult.
> The network state is given by the "networkState" attribute, and is one
> of: EMPTY, LOADING, LOADED_METADATA, LOADED_FIRST_FRAME, LOADED
> The ready state is given by the "readyState" attribute, and is one of:
> DATA_UNAVAILABLE, CAN_SHOW_CURRENT_FRAME, CAN_PLAY, CAN_PLAY_THROUGH
> Although adding states for either of these would not be fun, it could be
> done. But the playback state is different.
> The consistent and upgradeable design would be to have a "playbackState"
> attribute that is one of: PAUSED, PLAYING
> But because there are currently only two states, we instead have a
> single boolean attribute. Boolean attributes are great when you're sure
> there will always be only two states, but they're terrible if there's a
> chance you'll want to add additional states.
> It isn't difficult to imagine all kinds of additional playback states.
> For example, what if there was great demand for forward-seeking and
> backward-seeking states? (e.g. the states that are usually associated
> with those >> and << buttons) How could those states be added?
This is already supported, and is independent of the pause state. (You
could easily imagine a UI where you could pause while fast-forwarding.)
> The media error state is also inconsistent, and this time for no
> apparent reason, although it would at least be easy to update. A more
> consistent design would be to have an "errorState" attribute that is one
> of: NO_ERROR, ABORTED, NETWORK_ERROR, DECODING_ERROR
We want to be able to include much more information, hence the use of an
object for now.
> And why are the error state names prefixed with "MEDIA_ERR" when the
> names for the other states are not prefixed? e.g. LOADING instead of
The other state constants are prefixed (LOAD and CAN_ respectively) except
for the zero state (which doesn't have a constant at all for errors).
On Fri, 16 May 2008, Maciej Stachowiak wrote:
> > But because there are currently only two states, we instead have a
> > single boolean attribute. Boolean attributes are great when you're
> > sure there will always be only two states, but they're terrible if
> > there's a chance you'll want to add additional states.
> I'm not sure adding states is all that safe. Any code that does a switch
> on the state would now fall through to an untested code path.
Indeed, we're unlikely to ever add states, we're more likely to add
Ian Hickson U+1047E )\._.,--....,'``. fL
http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,.
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