Issue #2325: Remove PocketRepoCache; add comment explaining why it's not necessary.

Author: mcomella

app/src/main/java/org/mozilla/tv/firefox/architecture/ViewModelFactory.kt

@@ -39,7 +39,7 @@ class ViewModelFactory(
     override fun <T : ViewModel?> create(modelClass: Class<T>): T {
         return when (modelClass) {
             PocketViewModel::class.java -> PocketViewModel(
-                serviceLocator.pocketRepoCache
+                serviceLocator.pocketRepo
             ) as T
 
             ToolbarViewModel::class.java -> ToolbarViewModel(

app/src/main/java/org/mozilla/tv/firefox/pocket/PocketRepoCache.kt

@@ -29,6 +29,11 @@ open class PocketVideoRepo(
         .observeOn(AndroidSchedulers.mainThread())
         .distinctUntilChanged() // avoid churn because we may retrieve similar results in onStart.
 
+    /**
+     * Gets the latest Pocket videos from the store and pushes it to the UI. This is intentionally
+     * not reactive because a reactive update model might replace the content when the user is looking
+     * at it. This method is expected to be called when the user is not looking at the content (e.g. in onStart).
+     */
     @UiThread // not sure if this annotation is necessary anymore.
     fun updatePocketFromStore() {
         // If we have no API key, this will always be the state: there is nothing to do. In theory, now that we

app/src/main/java/org/mozilla/tv/firefox/pocket/PocketVideoRepo.kt

@@ -23,7 +23,7 @@ const val POCKET_VIDEO_COUNT = 20
  * view should not have to perform any transformations on this data).
  */
 class PocketViewModel(
-    pocketRepoCache: PocketRepoCache
+    pocketRepo: PocketVideoRepo
 ) : ViewModel() {
 
     sealed class State {
@@ -47,8 +47,7 @@ class PocketViewModel(
         }
     }
 
-    // #2297: the PocketRepoCache is broken and will not stop videos from updating when the user is looking at them.
-    val state: Observable<State> = pocketRepoCache.feedState
+    val state: Observable<State> = pocketRepo.feedState
         .map { repoState ->
             when (repoState) {
                 is PocketVideoRepo.FeedState.LoadComplete -> State.Feed(repoState.videos)

app/src/main/java/org/mozilla/tv/firefox/pocket/PocketViewModel.kt

@@ -27,7 +27,6 @@ import org.mozilla.tv.firefox.channels.pinnedtile.PinnedTileImageUtilWrapper
 import org.mozilla.tv.firefox.channels.pinnedtile.PinnedTileRepo
 import org.mozilla.tv.firefox.pocket.PocketEndpointRaw
 import org.mozilla.tv.firefox.pocket.PocketVideoFetchScheduler
-import org.mozilla.tv.firefox.pocket.PocketRepoCache
 import org.mozilla.tv.firefox.pocket.PocketVideoParser
 import org.mozilla.tv.firefox.pocket.PocketVideoRepo
 import org.mozilla.tv.firefox.pocket.PocketVideoStore
@@ -79,7 +78,6 @@ open class ServiceLocator(val app: Application) {
     val fretboardProvider: FretboardProvider by lazy { FretboardProvider(app) }
     val experimentsProvider by lazy { ExperimentsProvider(fretboardProvider.fretboard, app) }
     val turboMode: TurboMode by lazy { TurboMode(app) }
-    val pocketRepoCache by lazy { PocketRepoCache(pocketRepo) }
     val viewModelFactory by lazy { ViewModelFactory(this, app) }
     val screenController by lazy { ScreenController(sessionRepo) }
     val engineViewCache by lazy { EngineViewCache(sessionRepo) }

app/src/main/java/org/mozilla/tv/firefox/utils/ServiceLocator.kt

@@ -4,7 +4,6 @@
 
 package org.mozilla.tv.firefox.pocket
 
-import io.reactivex.Observable
 import io.reactivex.observers.TestObserver
 import io.reactivex.subjects.PublishSubject
 import io.reactivex.subjects.Subject
@@ -27,13 +26,9 @@ class PocketViewModelTest {
     fun setup() {
         repoCacheState = PublishSubject.create()
         val repo = mock(PocketVideoRepo::class.java)
-        `when`(repo.feedState).thenReturn(Observable.empty())
-        val repoCache = object : PocketRepoCache(repo) {
-            override val feedState
-                get() = repoCacheState
-        }
+        `when`(repo.feedState).thenReturn(repoCacheState)
 
-        viewModel = PocketViewModel(repoCache)
+        viewModel = PocketViewModel(repo)
         noKeyPlaceholders = PocketViewModel.noKeyPlaceholders
         testObserver = viewModel.state.test()
     }