1400955 - Dispatch JS tab events without depending on a <browser> being present

Status: RESOLVED INCOMPLETE

(Firefox for Android Graveyard :: General, enhancement, P5)

Description

[Jan Henning [:JanH]]

As described in bug 1343090 comment 5:
We don't have any XUL-side <tab>s (since that part of our UI is implemented natively in Java, so at a first glance we don't have any need of them), so unlike Desktop we dispatch any JS-side tab events via the individual <browser> element itself, which naturally poses a problem if we're attempting to make lazily-loaded ("zombified") tabs completely <browser>-less.

This is also causing some problems even today, because tab zombification already involves destroying the original <browser> and replacing it by a fresh one showing about:blank [1], so everybody listening to events on the old browser needs to listen to the corresponding tab zombification events and then move their event listeners across - failure to do so led e.g. to the infamous session history loss in bug 1044556.

I'm not sure what the best solution here would be - my naive solution would be creating an additional <tabs> element with corresponding <tab> children that would be solely used for dispatching and listening to tab events, so anybody listening to (or wanting to dispatch) tab events would be totally unaffected by whatever unspeakable things we'd be doing to the actual <browser> element.

[1] https://dxr.mozilla.org/mozilla-central/rev/ae39864562c6048fdc2950c5dfedb48e247c3300/mobile/android/chrome/content/browser.js#3827

Comment 1

[Firefox Bug Husbandry Bot]

Re-triaging per https://bugzilla.mozilla.org/show_bug.cgi?id=1473195

Needinfo :susheel if you think this bug should be re-triaged.

Comment 2

[BMO Automation]

We have completed our launch of our new Firefox on Android. The development of the new versions use GitHub for issue tracking. If the bug report still reproduces in a current version of [Firefox on Android nightly](https://play.google.com/store/apps/details?id=org.mozilla.fenix) an issue can be reported at the [Fenix GitHub project](https://github.com/mozilla-mobile/fenix/). If you want to discuss your report please use [Mozilla's chat](https://wiki.mozilla.org/Matrix#Connect_to_Matrix) server https://chat.mozilla.org and join the [#fenix](https://chat.mozilla.org/#/room/#fenix:mozilla.org) channel.