Support Trusted Web Activity

[yoasif]

QA team: steps to test are outlined in a comment below.

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Why/User Benefit/User Problem

Trusted Web Activities are a way to integrate your web-app content such as your PWA with your Android app using a protocol based on Custom Tabs.

User Story

As a user I want Progressive Web Apps installed from the Google Play store to use my default browser.

What / Requirements

https://docs.google.com/document/d/1XMMJNJO1VUEBn1jGGIf8b-lHZJuZUuZnjQoX5LSmq8c/edit#
https://developers.google.com/web/updates/2017/10/using-twa

Acceptance Criteria (how do I know when I’m done?)

• I can download a TWA from the Google Play Store and run it in Fenix.

┆Issue is synchronized with this Jira Task

[pocmo]

Related A-C meta bug:
mozilla-mobile/android-components#1819

[liuche]

I've added some more details about TWA in the AC bug.

[liuche]

After some discussion w/ the team, it sounds like TWAs are almost ready to ship. This allow users who download TWAs from the Google Play Store to use Fenix.

Things remaining:

• any remaining eng work (@NotWoods will be finishing this, Closes #394 - Trusted Web Activities #5391)
• Import the Digital Asset Links API key into Fenix (@jonalmeida)
• AC to upgrade to alpha APIs* (@NotWoods in AC, For #4444: Use AndroidX browser 1.2.0-alpha07 android-components#4440)
• File a PI request to test some common TWAs (@liuche)
• Get UX Feedback (@NotWoods will share an apk link here, and add gif how TWAs work on Chrome + instructions on how to install)
• signoff from Product - Notifications won't work until we support Push (WebPush?) but we're in Preview, so I'm not too worried Nightly only
• SUMO article?

* Most of the APIs that we're using are stable, but the mitigation plan is a) revert on AC, b) reach out to Google androidx team, who have been very responsive

[liuche]

@NotWoods question came up in triage, "what TWA features won't work?"

• Push
• what else?

Product says let's do this in Nightly only.

[NotWoods]

Splash screens also won't work yet. Both notifications and splash screens require APIs only present in the 1.2.0 library, and would make it harder to revert.

TWAs are pretty much custom tabs without the toolbar, so very few changes are needed. I wrote code for hiding the toolbar that’s shared with PWAs already. Generally if it works as a custom tab, it works as a TWA.

[NotWoods]

Updated the TODO list: We have an API key for TWAs ready but its not yet accessible in the codebase. @jonalmeida will be adding it in soon.

[sblatz]

I think we need follow-up from @liuche on the status of this ticket.

[apbitner]

I downloaded the first app along with the latest APK and launched the app. This work seems to be behind the scenes so I didn't notice anything that needs to be reviewed from a UX perspective, unless I'm missing something?

[NotWoods]

The UX would be very light, if any. All Chrome does here is display the "Running in Chrome" snackbar.

[apbitner]

If it's just staying on Nightly then it should be good for now. We may add a 'Running in Firefox' notification at some point.

[liuche]

Marking E2 for reviewing remaining work, since there's no additional ask from UX.

[NotWoods]

@liuche Should we put QA needed on this issue?

[liuche]

Yes please! But also include a comment with clear "Steps to Reproduce" (including which build flavor or channel they should be on).

[NotWoods]

Steps to reproduce

[sv-ohorvath]

@NotWoods Using the apks and steps from #394 (comment) I've found the following:

• The Oyo lite app doesn't launch on Fenix, returns an "App keeps stopping" error.

• Cannot open external links in any TWA, the links appear as visited in the browser history (i.e homescreen links to other apps in PWA directory).

• In the PWA directory app the notification alert button doesn't prompt the permission request (probably the same for location, cam or mic permissions, I haven't found any TWA examples for these yet).

• LE - New issue:

  1. kill Fenix
  2. open one of the following TWAs: https://play.google.com/store/apps/details?id=sdm.apps.twademo, https://play.google.com/store/apps/details?id=com.innovativedemoapps.twa.sample
  3. open link in Fenix
  4. switch Fenix to PB
  5. swipe to close Fenix
  6. reopen Fenix: shows the TWA, Fenix is in the background