feat: navigator

[alperozturk96]

Approach

Introduce NavigatorActivity shell activity that hosts fragments via FragmentContainerView. All screens that previously had their own activity are migrated to fragments and pushed through Navigator. NavigatorScreen sealed class represents each destination.

DrawerActivity launches NavigatorActivity with the target NavigatorScreen as a parcelable extra, keeping the call site clean with no per-screen logic.

Why FileDisplayActivity is not used?

Other activities like SettingsActivity and various non-drawer activities also trigger drawer navigation items. Wiring Navigator into FDA from the start would require every caller to hold a reference to FDA or route through it, which is not possible without a larger refactor. e.g. Navigating from CommunityActivity to some other activity.

This way any activity can launch NavigatorActivity via a simple Intent, no FDA dependency required. Once all navigation is consolidated into NavigatorActivity we can remove it and just use FDA

[github-actions]

Codacy

SpotBugs

Category	Base	New
Bad practice	40	40
Correctness	72	72
Dodgy code	237	237
Experimental	1	1
Internationalization	7	7
Malicious code vulnerability	2	2
Multithreaded correctness	34	34
Performance	43	43
Security	18	18
Total	454	454

[github-actions]

blue-Light-Screenshot test failed, but no output was generated. Maybe a preliminary stage failed.

[github-actions]

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/16652.apk



To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud app.

[alperozturk96]

Do not push same fragment.

[tobiasKaminsky]

👍 Fine to do it in another PR