Bugzilla

(In reply to Henrik Skupin [:whimboo][⌚️UTC+2] from comment #14)
> Actually what I completely missed is the fact that sending events from the parent process only works when the browser to interact with is actually the foreground tab. When Marionette / Remote Agents has to interact with a background tab events no longer work given that they are still send to the foreground tab.
> 
> Masayuki or Hiro, do you know if there is or could be a way to work with EventUtils in the parent process and forward the event not only to the currently visible tab but a specific (top-level) browsing context? If that's not possible we won't be able to use parent process emitting of events.

I think trying to send events through APZ to a page in a background tab might cause other problems.

When APZ processes an event, it performs a hit-test on rendering-related state, such as the WebRender scene and other things derived from the display list. I think those pieces of rendering state are not created for background tabs.

(In reply to Henrik Skupin [:whimboo][⌚️UTC+2] from comment #14)
> Actually what I completely missed is the fact that sending events from the parent process only works when the browser to interact with is actually the foreground tab. When Marionette / Remote Agents has to interact with a background tab events no longer work given that they are still send to the foreground tab.
> 
> Masayuki or Hiro, do you know if there is or could be a way to work with EventUtils in the parent process and forward the event not only to the currently visible tab but a specific (top-level) browsing context? If that's not possible we won't be able to use parent process emitting of events.

I think trying to send events through APZ to a page in a background tab might cause other problems.

When APZ processes an event, it performs a hit-test using rendering-related state, such as the WebRender scene and other things derived from the display list. I think those pieces of rendering state are not created for background tabs.