[fenix] Closes https://github.com/mozilla-mobile/fenix/issues/24276

– capitalize and stylize comments
– fix history items duplication
– fix refresh glitching after removing multiple history items

app/src/main/java/org/mozilla/fenix/library/history/HistoryDataSource.kt

@@ -19,7 +19,7 @@ class HistoryDataSource(
     override fun getRefreshKey(state: PagingState<Int, History>): Int? = null
 
     override suspend fun load(params: LoadParams<Int>): LoadResult<Int, History> {
-        // Get the offset of the last loaded page or default to 0 when it is null, on the initial
+        // Get the offset of the last loaded page or default to 0 when it is null on the initial
         // load or a refresh.
         val offset = params.key ?: 0
         val historyItems = historyProvider.getHistory(offset, params.loadSize).run {
@@ -28,7 +28,7 @@ class HistoryDataSource(
         val nextOffset = if (historyItems.isEmpty()) {
             null
         } else {
-            (offset + historyItems.size) + 1
+            historyItems.last().position + 1
         }
         return LoadResult.Page(
             data = historyItems,

app/src/main/java/org/mozilla/fenix/library/history/HistoryView.kt

@@ -35,13 +35,12 @@ class HistoryView(
 
     val historyAdapter = HistoryAdapter(interactor).apply {
         addLoadStateListener {
-            // first call will always have itemCount == 0, but we want to keep adapterItemCount
+            // First call will always have itemCount == 0, but we want to keep adapterItemCount
             // as null until we can distinguish an empty list from populated, so updateEmptyState()
-            // could work correctly
+            // could work correctly.
-            if (itemCount != 0) {
+            if (itemCount > 0) {
                 adapterItemCount = itemCount
-            }
+            } else if (it.source.refresh is LoadState.NotLoading &&
-            if (it.source.refresh is LoadState.NotLoading &&
                 it.append.endOfPaginationReached &&
                 itemCount < 1
             ) {

app/src/main/res/layout/component_history.xml

@@ -25,7 +25,7 @@
         layout="@layout/recently_closed_nav_item"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        app:layout_constraintTop_toBottomOf="@id/progress_bar" />
+        app:layout_constraintTop_toTopOf="parent" />
 
     <TextView
         android:id="@+id/history_empty_view"