Plumbing for fullscreen change event notification for plugins.

Plumbing for fullscreen change event notification for plugins.


BUG=98477

[koz (OOO until 15th September), 2011-09-29 05:48:38]

Jeremy and I have plumbed OnFullscreenChanged down to ppapi_plugin_instance.cc
from WebKit, but we don't know what to do from here. Can you point us in the
right direction?

[koz (OOO until 15th September), 2011-09-29 06:44:38]

On 2011/09/29 05:48:38, koz wrote:
> Jeremy and I have plumbed OnFullscreenChanged down to ppapi_plugin_instance.cc
> from WebKit, but we don't know what to do from here. Can you point us in the
> right direction?

WebKit side: https://bugs.webkit.org/show_bug.cgi?id=69063

[polina, 2011-09-29 23:15:42]

When do these fire, especially in relationship to ViewChanged, which is where we
update the fullscreen state variables?

[jeremya, 2011-09-29 23:27:09]

On 2011/09/29 23:15:42, polina wrote:
> When do these fire, especially in relationship to ViewChanged, which is where
we
> update the fullscreen state variables?

These should fire after ViewChanged.

[brettw, 2011-10-01 05:09:27]

> These should fire after ViewChanged.

Is it possible to make this fire before? The typical pattern will be to query
the fullscreen state from within DidChangeView and update your plugin UI
accordingly.

The workaround in the Pepper side would be to eat DidChangeView while we're
waiting for a fullscreen transition, and then fire one when we finally get the
fullscreen ack. This has the danger that if there's some problem going into
fullscreen, we better get some notification of that or the plugin will never be
issued a didChangeView again!

BUT then I was thinking that our fullscreen spec says the fullscreen transition
ends at the next didChangeView. This isn't guaranteed today, WebKit likes to do
various layouts and I'm not sure anything guarantees that they won't happen
before fullscreen is complete. Plus, when we move to an async proxy, a
didChangeView could have already been sent. For that case, we'd have to add
extra logic to the plugin to drop intermediate didChangeViews.

koz and jeremya: Knowing the implementation, do you think it's possible that
we'll lose a fullscreen request? Like what happens if there's an error
somewhere? I'm a little worried about this since I think it sounds like an easy
error to make and it will be so detrimental to plugins. If this is reasonably
assured, it doesn't really matter when we get the notification in relation to
didChangeView, we'll fix it on the Chrome side to reorder things.

[polina, 2011-10-03 21:48:18]

On 2011/10/01 05:09:27, brettw wrote:
> > These should fire after ViewChanged.
> 
> Is it possible to make this fire before? The typical pattern will be to query
> the fullscreen state from within DidChangeView and update your plugin UI
> accordingly.
> 
> The workaround in the Pepper side would be to eat DidChangeView while we're
> waiting for a fullscreen transition, and then fire one when we finally get the
> fullscreen ack. This has the danger that if there's some problem going into
> fullscreen, we better get some notification of that or the plugin will never
be
> issued a didChangeView again!
> 
> BUT then I was thinking that our fullscreen spec says the fullscreen
transition
> ends at the next didChangeView. This isn't guaranteed today, WebKit likes to
do
> various layouts and I'm not sure anything guarantees that they won't happen
> before fullscreen is complete. Plus, when we move to an async proxy, a
> didChangeView could have already been sent. For that case, we'd have to add
> extra logic to the plugin to drop intermediate didChangeViews.
> 
> koz and jeremya: Knowing the implementation, do you think it's possible that
> we'll lose a fullscreen request? Like what happens if there's an error
> somewhere? I'm a little worried about this since I think it sounds like an
easy
> error to make and it will be so detrimental to plugins. If this is reasonably
> assured, it doesn't really matter when we get the notification in relation to
> didChangeView, we'll fix it on the Chrome side to reorder things.

I have patched this CL to see how we can take advantage of this feature. But
unfortunately, I am not getting the any OnFullscreenChanged calls when running
Fullscreen ppapi_test. Do I need anything else besides these changes?