Implement user suggestion when inviting users to a room, as on web

[jakewb-b]

On Element Web, when inviting users to a room, I see a short list of users I have recently DMd, and then a list of other suggested users.

This is much more user-friendly than the experience on iOS, where by default I see my local contacts (most of whom are not on Matrix) and have to search for users by their Matrix ID.

Can we implement Eleweb’s smart handling of suggested people to invite in a room on iOS?

[giomfo]

I decided to reuse this issue to start working on element-hq/element-meta#83

Because the same contacts picker is used to create a new DM or to invite users to a room, I would like to consider separately the 2 kinds of suggestion:

• short list of users I have recently DMd: this suggestion should appeared only when the end user wants to invite users to an existing room. I consider irrelevant on web this short list in case of a new DM creation. Note: this short list doesn't exist in Element-Android.
  We (@jakewb-b, @gaelledel and I) agreed to create dedicated issues to add "this short list of users I have recently DMd" in Element-iOS and in Element-Android, and keep using this one to add the list of suggested/known users.
• list of "known users": I use here on purpose the wording of Element-Android for this second list. I think this is more relevant than "suggestions"
  The plan would be to implement in Element-iOS the following design:

About this design:

• @gaelledel: what do you think about "known users"? do you prefer to keep "Suggested"? I let you decide
  • this point is still under discussion
• How to manage the "Local Contacts" which appears when the end user grants access to their phonebook?

Don't you think we should merge the matrix user discovered in the phone book in the suggested list and ignore the local contacts who don't match with a matrix account?

In the current suggested design, this list of local contacts is accessible via the icon displayed at the top right corner. This button displays a list of actions which correspond to the curent Android options

About the search:
When the end user starts searching, the application is filtering the suggested/known users by considering their display name and/or their matrixId. Note the search on matrixId should be optional in the implementation (some fork of Element don't want to display matrixId). A new section is added to display the result of the search in the users directory. The suggested design is:

Note:

• 1st section “Suggested” shows results based on shared spaces and rooms
• 2nd section “user directory” shows results based on the whole directory
• The results should only be reflecting to the begining of a word with from the Display name or matrix ID
• If a contact was already shown in the “suggested” section, it should not appear in the user directory

[rufuskahler]

Removing 'Needs-Design' as will be resolved through EX work.