[APP-549] Language controls for Whats Hot (#563)

* Add a content-language preference control

* Update whats hot to only show the selected languages and to refresh on lang pref changes

* Fix lint

* Fix tests

* Add missing accessibility role

src/state/models/feeds/posts.ts

@@ -297,6 +297,9 @@ export class PostsFeedModel {
   // used to linearize async modifications to state
   lock = new AwaitLock()
 
+  // used to track if what's hot is coming up empty
+  emptyFetches = 0
+
   // data
   slices: PostsFeedSliceModel[] = []
 
@@ -603,6 +606,9 @@ export class PostsFeedModel {
   ) {
     this.loadMoreCursor = res.data.cursor
     this.hasMore = !!this.loadMoreCursor
+    if (replace) {
+      this.emptyFetches = 0
+    }
 
     this.rootStore.me.follows.hydrateProfiles(
       res.data.feed.map(item => item.post.author),
@@ -625,6 +631,12 @@ export class PostsFeedModel {
       } else {
         this.slices = this.slices.concat(toAppend)
       }
+      if (toAppend.length === 0) {
+        this.emptyFetches++
+        if (this.emptyFetches >= 10) {
+          this.hasMore = false
+        }
+      }
     })
   }