Fix loading initial items of non-live timelines

[jmartinesp]

Content

Items in non-live timelines aren't loaded automatically anymore if they're not present in the cache. This is specially easy to spot when loading a thread timeline.

This was done automatically by the SDK in the past by returning a Reset timeline update, but this behaviour changed and now we have to do it.

Motivation and context

Fix the initial loading of timeline items when they're not cached after matrix-org/matrix-rust-sdk#6380.

Tests

Either clear the cache or make sure you're opening a thread you haven't loaded yet. Open the thread screen, if timelines appear, this should be fixed.

Tested devices

• Physical
• Emulator
• OS version(s): 13

Checklist

• This PR was made with the help of AI:
  • Yes. In this case, please request a review by Copilot.
  • No.
• Changes have been tested on an Android device or Android emulator with API 24
• 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 title will be used in the release note, it clearly defines what will change for the user
• Pull request includes screenshots or videos if containing UI changes
• You've made a self review of your PR

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[bmarty]

Thanks, I confirm that it fixes the issue of empty thread timeline on my side

[bmarty]

Is the test on timelineMode necessary here?

[jmartinesp]

It may not bee needed. Since live timelines are supposed to always have at least 1 item, the it.totalItemsCount == 0 check wouldn't be used and we wouldn't unnecessarily paginate.

[jmartinesp]

It worked fine when I tested this without the mode check: f43317b

[codecov]

Codecov Report

❌ Patch coverage is 66.66667% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 81.14%. Comparing base (d8c5409) to head (384f35e).
⚠️ Report is 2 commits behind head on develop.

Files with missing lines	Patch %	Lines
...id/features/messages/impl/timeline/TimelineView.kt	66.66%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #6598   +/-   ##
========================================
  Coverage    81.14%   81.14%           
========================================
  Files         2623     2623           
  Lines        72804    72806    +2     
  Branches      9418     9418           
========================================
+ Hits         59078    59080    +2     
  Misses       10254    10254           
  Partials      3472     3472           

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[bmarty]

Thanks!