Do not display empty room list state before the loading one

[jmartinesp]

Type of change

• Feature
• Bugfix
• Technical
• Other :

Content

• Unify both room list summaries and the loadingState into a single value containing both (RoomList.State).
• Use this newly built RoomList.State to transparently decide whether to display the empty, loading, or loaded state with no flickers in the room list screen.

Motivation and context

When the room list took a bit longer than expected to load, the empty screen could be seen for a moment before the loading one appeared.

Tests

With an account having a single room in the room list, test:

• The loading state appears, then the room list does.
• When exiting and coming back to the screen there are no unexpected intermediate states.
• When leaving the room the empty state is displayed instead, even when restarting the app.
• If joining or creating a new room, the loaded state appears.

Tested devices

• Physical
• Emulator
• OS version(s): 14

Checklist

• Changes have been tested on an Android device or Android emulator with API 23
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request includes a new file under ./changelog.d. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#changelog
• Pull request includes screenshots or videos if containing UI changes
• Pull request includes a sign off
• You've made a self review of your PR

[github-actions]

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[codecov]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (4daf2b0) 72.31% compared to head (e2ff547) 72.32%.
Report is 11 commits behind head on develop.

Files	Patch %	Lines
...res/roomlist/impl/datasource/RoomListDataSource.kt	66.66%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #2402   +/-   ##
========================================
  Coverage    72.31%   72.32%           
========================================
  Files         1364     1364           
  Lines        32236    32232    -4     
  Branches      6297     6295    -2     
========================================
- Hits         23312    23311    -1     
+ Misses        5659     5658    -1     
+ Partials      3265     3263    -2     

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[jmartinesp]

I tried using a simpler solution and keeping the MutableStateFlow for room summaries, but I ran into matrix-org/matrix-rust-sdk#3135.

[frebib]

I pulled this in but noticed that my room list is truncated to only ~2 screens worth of rooms. Scrolling to the bottom doesn't load more. Also, strangely, many rooms are missing even when I search for them

[jmartinesp]

I pulled this in but noticed that my room list is truncated to only ~2 screens worth of rooms. Scrolling to the bottom doesn't load more. Also, strangely, many rooms are missing even when I search for them

The pagination logic was affected by the changes in the PR. I've rolled back those changes, since they caused some other side effects and went back to the initial implementation.

[sonarcloud]

Quality Gate passed

Issues
0 New issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud