feat: add pagination to dearrow in feed

app/src/main/java/com/github/libretube/ui/adapters/VideosAdapter.kt

@@ -34,30 +34,14 @@ import com.github.libretube.util.TextUtils
 
 class VideosAdapter(
     private val streamItems: MutableList<StreamItem>,
-    private val showAllAtOnce: Boolean = true,
     private val forceMode: LayoutMode = LayoutMode.RESPECT_PREF
 ) : RecyclerView.Adapter<VideosViewHolder>() {
-
+    override fun getItemCount() = streamItems.size
-    private var visibleCount = minOf(10, streamItems.size)
-
-    override fun getItemCount(): Int {
-        return when {
-            showAllAtOnce -> streamItems.size
-            else -> minOf(streamItems.size, visibleCount)
-        }
-    }
 
     override fun getItemViewType(position: Int): Int {
         return if (streamItems[position].type == CAUGHT_UP_STREAM_TYPE) CAUGHT_UP_TYPE else NORMAL_TYPE
     }
 
-    fun updateItems() {
-        val oldSize = visibleCount
-        visibleCount += minOf(10, streamItems.size - oldSize)
-        if (visibleCount == oldSize) return
-        notifyItemRangeInserted(oldSize, visibleCount)
-    }
-
     fun insertItems(newItems: List<StreamItem>) {
         val feedSize = streamItems.size
         streamItems.addAll(newItems)
@@ -69,7 +53,7 @@ class VideosAdapter(
             it.url?.toID() == videoId
         }.takeIf { it > 0 } ?: return
         streamItems.removeAt(index)
-        visibleCount--
+
         notifyItemRemoved(index)
         notifyItemRangeChanged(index, itemCount)
     }

app/src/main/java/com/github/libretube/ui/fragments/SubscriptionsFragment.kt

@@ -45,9 +45,11 @@ import com.github.libretube.ui.sheets.ChannelGroupsSheet
 import com.github.libretube.ui.sheets.FilterSortBottomSheet
 import com.github.libretube.ui.sheets.FilterSortBottomSheet.Companion.FILTER_SORT_REQUEST_KEY
 import com.github.libretube.util.PlayingQueue
+import com.github.libretube.util.deArrow
 import com.google.android.material.chip.Chip
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 
 class SubscriptionsFragment : DynamicLayoutManagerFragment() {
     private var _binding: FragmentSubscriptionsBinding? = null
@@ -60,7 +62,9 @@ class SubscriptionsFragment : DynamicLayoutManagerFragment() {
     private var isCurrentTabSubChannels = false
     private var isAppBarFullyExpanded = true
 
-    var feedAdapter: VideosAdapter? = null
+    private var feedAdapter: VideosAdapter? = null
+    private val sortedFeed: MutableList<StreamItem> = mutableListOf()
+
     private var channelsAdapter: SubscriptionChannelAdapter? = null
     private var selectedSortOrder = PreferenceHelper.getInt(PreferenceKeys.FEED_SORT_ORDER, 0)
         set(value) {
@@ -153,13 +157,7 @@ class SubscriptionsFragment : DynamicLayoutManagerFragment() {
         }
 
         binding.subFeed.addOnBottomReachedListener {
-            val binding = _binding ?: return@addOnBottomReachedListener
+            loadNextFeedItems()
-
-            if (viewModel.videoFeed.value != null && !isCurrentTabSubChannels) {
-                binding.subRefresh.isRefreshing = true
-                feedAdapter?.updateItems()
-                binding.subRefresh.isRefreshing = false
-            }
         }
 
         // add some extra margin to the subscribed channels while the mini player is visible
@@ -205,6 +203,30 @@ class SubscriptionsFragment : DynamicLayoutManagerFragment() {
         }
     }
 
+    private fun loadNextFeedItems() {
+        val binding = _binding ?: return
+
+        val feedAdapter = feedAdapter ?: return
+
+        val hasMore = sortedFeed.size > feedAdapter.itemCount
+        if (viewModel.videoFeed.value != null && !isCurrentTabSubChannels && !binding.subRefresh.isRefreshing && hasMore) {
+            binding.subRefresh.isRefreshing = true
+
+            lifecycleScope.launch(Dispatchers.IO) {
+                val toIndex = minOf(feedAdapter.itemCount + 10, sortedFeed.size)
+
+                val streamItemsToInsert = sortedFeed
+                    .subList(feedAdapter.itemCount, toIndex)
+                    .deArrow()
+
+                withContext(Dispatchers.Main) {
+                    feedAdapter.insertItems(streamItemsToInsert)
+                    binding.subRefresh.isRefreshing = false
+                }
+            }
+        }
+    }
+
     private fun setupSortAndFilter() {
         binding.filterSort.setOnClickListener {
             val activityCompat = context as AppCompatActivity
@@ -332,9 +354,11 @@ class SubscriptionsFragment : DynamicLayoutManagerFragment() {
                 DatabaseHelper.filterByStatusAndWatchPosition(it, hideWatched)
             }
 
-        val sortedFeed = feed
+        val sorted = feed
             .sortedBySelectedOrder()
             .toMutableList()
+        sortedFeed.clear()
+        sortedFeed.addAll(sorted)
 
         // add an "all caught up item"
         if (selectedSortOrder == 0) {
@@ -355,10 +379,9 @@ class SubscriptionsFragment : DynamicLayoutManagerFragment() {
         binding.subFeed.isGone = notLoaded
         binding.emptyFeed.isVisible = notLoaded
 
-        feedAdapter = VideosAdapter(
+        feedAdapter = VideosAdapter(mutableListOf())
-            sortedFeed.toMutableList(),
+        loadNextFeedItems()
-            showAllAtOnce = false
+
-        )
         binding.subFeed.adapter = feedAdapter
         binding.toggleSubs.text = getString(R.string.subscriptions)
 
@@ -401,6 +424,11 @@ class SubscriptionsFragment : DynamicLayoutManagerFragment() {
         binding.toggleSubs.text = "${getString(R.string.subscriptions)} ($subCount)"
     }
 
+    fun removeItem(videoId: String) {
+        feedAdapter?.removeItemById(videoId)
+        sortedFeed.removeAll { it.url!!.toID() != videoId }
+    }
+
     override fun onConfigurationChanged(newConfig: Configuration) {
         super.onConfigurationChanged(newConfig)
         // manually restore the recyclerview state due to https://github.com/material-components/material-components-android/issues/3473

app/src/main/java/com/github/libretube/ui/sheets/VideoOptionsBottomSheet.kt

@@ -111,7 +111,7 @@ class VideoOptionsBottomSheet : BaseBottomSheet() {
                         // get the current fragment
                         val fragment = navHostFragment?.childFragmentManager?.fragments
                             ?.firstOrNull() as? SubscriptionsFragment
-                        fragment?.feedAdapter?.removeItemById(videoId)
+                        fragment?.removeItem(videoId)
                     }
                     setFragmentResult(VIDEO_OPTIONS_SHEET_REQUEST_KEY, bundleOf())
                 }