[whatwg] communicating plugin state (primarily for click-to-play)

[Josh Aas]

Mozilla has been working on a click-to-play feature for plugins. The
feature currently breaks a large number of sites because it interacts
poorly with scripting and fallback schemes. For example, quite a bit
of plugin usage doesn't involve user-visible content but rather plugin
instances that exist for scripting alone. When instances aren't
created as expected for script calls, the resulting exceptions cause
problems.

In order for click-to-play to be a viable feature we'll probably need
to allow pages with complex plugin usage (i.e. scripting) to query for
click-to-play state.

This could be expressed via a Web IDL enum property on embed and
object elements. The property could be called something like
"pluginState". The states might be (with apologies for the rough
names):

- not-plugin (object/embed is some other type like image or document)
- active (plugin instance created, running)
- inactive (e.g. crashed)
- no-handler (e.g. missing plugin)
- click-to-play (click-to-play UI is diplayed, should become active upon click)

Thoughts?

--
Josh Aas
Mozilla Corporation