Recommend App: Add presenter to encapsulate display logic

[dvdchr]

Refs #16995
Closes #17003
Based on #17005

Summary

This change introduces a presenter object that encapsulates content fetching and presentation logic for the share app flow, along with a subclass of UIActivityItemSource to help format the text contents depending on the activity type. As described in #17003, I think it's worth it to encapsulate this since it's possible to have multiple entry points in the future.

Some notes for this change:

• The presenter exposes a delegate that gets called on every loading state changes. This is useful for the caller to update their display to show e.g. a loading indicator while the content is being fetched.
• Other than formatting needs, a UIActivityItemSource subclass is necessary to provide additional information – specifically a subject string provided through activityViewController:subjectForActivityType. This information is used when sharing to mail. I'll share some screenshots below on how it looks when it's shared in various apps.
• Lastly, this adds a new feature flag for the recommend button.

Screenshots

Share Destination	Screenshot
Messages
Mail
Twitter
WordPress (Save as Draft) – Note: Not sure why the text contents are not carried, but I suspect this needs to be fixed from the WP side.
Copy (Pasteboard)
Chrome
Slack – Not sure why the text is not present, but this is usually due to the destination's Share Extension not picking up multiple activity items.
WhatsApp

To Test

Manually editing the source + compiling to device

Since there are no visual components hooked up to this component, we'll have to wire this up manually in Xcode AND compile it to a device 😅 .

Here's how I modified the code to test the share functionality:

• In the MeViewController, add a private instance variable like so:

  private let sharePresenter = ShareAppContentPresenter(account: nil)

• Find the pushHelp() method, comment out the code in the return block, and change it to this:

  return { [unowned self] row in
      defer { self.tableView.deselectSelectedRowWithAnimation(true) }
      guard let indexPath = self.tableView.indexPathForSelectedRow,
            let selectedCell = self.tableView.cellForRow(at: selectedIndexPath) else {
          return
      }
      sharePresenter.present(for: .wordpress, in: self, sourceView: selectedCell)
  }

• Since there's no loading indicator yet, just wait for one or two seconds and the share sheet should appear shortly after tapping the help button on the Me screen.
• Lastly, try logging in to a self-hosted site (without WP account) and make sure that you can still prompt the share sheet.

Unit tests

Make sure that the tests are 🟢 !

Regression Notes

1. Potential unintended areas of impact
   None.

2. What I did to test those areas of impact (or what existing automated tests I relied on)
   This component is not used yet.

3. What automated tests I added (or what prevented me from doing so)
   Added some unit tests for the presenter.

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding unit tests for my changes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

[peril-wordpress-mobile]

You can trigger an installable build for these changes by visiting CircleCI here.

[peril-wordpress-mobile]

You can trigger optional UI/connected tests for these changes by visiting CircleCI here.

[aerych]

Howdy @dvdchr 👋
I tested on my iPhone X and everything worked great. Thanks for showing all the examples in the PR description. It was nice to have something to compare my results to. :)
Code looks good to me. I had just one suggestion about the subject text.
Otherwise :)

[aerych]

Spotted an issue so I've added another note and marked this request changes since we need to address an exception. Sorry I missed it in the first round!

[aerych]

Heya @dvdchr 👋
The exception is resolved. Thanks for the changes! Marking approved so as to not block the rest of the work.

However, I think we might want to see if we can improve the popover presentation on iPad. The solution I suggested was something I hadn't tested, and now that I see it in action I think we might need to make an adjustment.

Depending on which way I orient the iPad, the popover appears away from where I tapped. The size also varies depending on orientation so sometimes there are more visible options than others. I'm wondering if sharing the frame of the cell (or maybe just the cell as the view) that was tapped rather than the controller view would help improve the experience. We'd also need to make the change before the code freeze. What do you think?

[dvdchr]

Hey @aerych. I wasn't very aware of the design guidelines for iPad before, so thank you for the help and tips on this. Really appreciate it! 🙂

Depending on which way I orient the iPad, the popover appears away from where I tapped. The size also varies depending on orientation so sometimes there are more visible options than others. I'm wondering if sharing the frame of the cell (or maybe just the cell as the view) that was tapped rather than the controller view would help improve the experience.

Noted. I just realized that since the popover is anchored to the view controller's view, there's not enough space on the side and the system puts the popover on the top side, which makes the content a bit cramped.

Addressed in 6a07b6d, I've confirmed that passing the cell as the sourceView correctly anchors the popover to the tapped cell, and indeed the share sheet is displayed better. Here's a preview:

Portrait	Landscape

We'd also need to make the change before the code freeze. What do you think?

Since the code review for #17007 and #17020 is blocked by this one, I'll apply the changes on this PR. Then, I'll merge up the changes to both #17007 and #17020, so you can proceed with reviewing both of them.

I'll aim to merge everything to develop tomorrow (provided that you approved them all, of course 😄 ). If there's any new major issue on the PRs, I will address it on a separate PR (since the feature flag is still false).

---

P.S.: I've updated the code sample in the description to fill the sourceView parameter if you decided to give this another look! 🙂

[peril-wordpress-mobile]

	Warnings
⚠️	This PR is assigned to a milestone which is closing in less than 4 days Please, make sure to get it merged by then or assign it to a later expiring milestone

Generated by 🚫 dangerJS

[aerych]

Tested with the changes and they look great! Thanks @dvdchr! again!

[dvdchr]

Thanks @aerych !