Show error screens in embedded widget mode

[robintown]

Implementation

This enhancement requires implementation in each of our clients.

• Show error screens in group calls element-web#29254
• Show error screens in group calls element-x-android#4297
• Show error screens in group calls element-x-ios#3856

These PRs are blocked until we are certain that we'll have a stable release up on call.element.io which sends 'close' actions within the current release cycles of EW and EX. To unblock and roll them out sooner, the plan is to backport the sending of the 'close' action to a v0.7 release.

Your use case

element-hq/element-x-ios#3813

What would you like to do?

Make sure that the error screens we're adding to the application can be shown in embedded mode as well, without the client immediately hiding the widget.

Why would you like to do it?

Because we're putting effort into creating helpful error screens, and it would be a shame for the experience in embedded mode to still just be:

1. An error occurs
2. The widget closes immediately
3. ??? Confusion

• Reconsider actionable error screen actions in widget mode. (if we are not connected to the RTC session EW should display a X icon)

How would you like to achieve it?

When an error occurs, tell the widget to no longer be "always on screen", so that it can be closed, but at the same time make sure Element Web etc. won't just react to the disconnection by closing it immediately.

Have you considered any alternatives?

No response

Additional context

No response

[fkwp]

Is there a block diagram of the lifecycle of a widget?

[hughns]

#3011 changes Element Call so that it sends a hangup and close action to the widget host.

Old messenger clients will continue to behave the same with new EC (because EC is sending both actions).

We then change the messenger widget hosts so that they ignore the hangup and only close the widget on a close:

• Show error screens in group calls element-web#29254
• Show error screens in group calls element-x-ios#3813
• Show error screens in group calls element-x-android#4297

When these PRs land older EC versions (pre #3011) will then have a broken UX when the user hangs up. They get left on a blank EC screen.

Because of this broken UX we don't want to merge the messenger changes until we have a newer version of EC running on call.element.io.

[hughns]

During discussion today the idea of making a change to EC 0.7.x so that it isn't broken with the new EX/EW PRs came up. This would mean that we can decouple the rollout of this somewhat. @robintown will look at this.

[fkwp]

@robintown please update the roll-out plan including the 0.7.2 release unblocking the messenger PRs

[robintown]

@fkwp done