Use a ViewModel for the CommentsSheet

app/src/main/java/com/github/libretube/api/obj/CommentsPage.kt

@@ -4,7 +4,7 @@ import com.fasterxml.jackson.annotation.JsonIgnoreProperties
 
 @JsonIgnoreProperties(ignoreUnknown = true)
 data class CommentsPage(
-    val comments: MutableList<Comment> = arrayListOf(),
+    var comments: MutableList<Comment> = arrayListOf(),
     val disabled: Boolean? = null,
     val nextpage: String? = null
 )

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

@@ -36,7 +36,6 @@ import com.github.libretube.R
 import com.github.libretube.api.CronetHelper
 import com.github.libretube.api.RetrofitInstance
 import com.github.libretube.api.obj.ChapterSegment
-import com.github.libretube.api.obj.Comment
 import com.github.libretube.api.obj.PipedStream
 import com.github.libretube.api.obj.Segment
 import com.github.libretube.api.obj.SegmentData
@@ -76,6 +75,7 @@ import com.github.libretube.ui.extensions.setFormattedHtml
 import com.github.libretube.ui.extensions.setInvisible
 import com.github.libretube.ui.extensions.setupSubscriptionButton
 import com.github.libretube.ui.interfaces.OnlinePlayerOptions
+import com.github.libretube.ui.models.CommentsViewModel
 import com.github.libretube.ui.models.PlayerViewModel
 import com.github.libretube.ui.sheets.BaseBottomSheet
 import com.github.libretube.ui.sheets.CommentsSheet
@@ -124,6 +124,7 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
     private lateinit var doubleTapOverlayBinding: DoubleTapOverlayBinding
     private lateinit var playerGestureControlsViewBinding: PlayerGestureControlsViewBinding
     private val viewModel: PlayerViewModel by activityViewModels()
+    private val commentsViewModel: CommentsViewModel by activityViewModels()
 
     /**
      * video information
@@ -152,8 +153,6 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
      * Chapters and comments
      */
     private lateinit var chapters: List<ChapterSegment>
-    private val comments: MutableList<Comment> = mutableListOf()
-    private var commentsNextPage: String? = null
 
     /**
      * for the player view
@@ -330,15 +329,11 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
         }
 
         binding.commentsToggle.setOnClickListener {
-            CommentsSheet(
+            videoId ?: return@setOnClickListener
-                videoId!!,
+            // set the max height to not cover the currently playing video
-                comments,
+            commentsViewModel.maxHeight = binding.root.height - binding.player.height
-                commentsNextPage,
+            commentsViewModel.videoId = videoId
-                binding.root.height - binding.player.height
+            CommentsSheet().show(childFragmentManager)
-            ) { comments, nextPage ->
-                this.comments.addAll(comments)
-                this.commentsNextPage = nextPage
-            }.show(childFragmentManager)
         }
 
         playerBinding.queueToggle.visibility = View.VISIBLE
@@ -604,6 +599,9 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
         playerBinding.exoProgress.clearSegments()
         playerBinding.sbToggle.visibility = View.GONE
 
+        // reset the comments to become reloaded later
+        commentsViewModel.reset()
+
         lifecycleScope.launchWhenCreated {
             streams = try {
                 RetrofitInstance.api.getStreams(videoId!!)
@@ -754,10 +752,6 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
         if (nextVideoId != null) {
             videoId = nextVideoId
 
-            // reset the comments to be reloaded later
-            comments.clear()
-            commentsNextPage = null
-
             // play the next video
             playVideo()
         }

app/src/main/java/com/github/libretube/ui/models/CommentsViewModel.kt

@@ -0,0 +1,65 @@
+package com.github.libretube.ui.models
+
+import android.util.Log
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import com.github.libretube.api.RetrofitInstance
+import com.github.libretube.api.obj.CommentsPage
+import com.github.libretube.extensions.TAG
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+
+class CommentsViewModel : ViewModel() {
+    private val scope = CoroutineScope(Dispatchers.IO)
+    private var isLoading = false
+
+    val commentsPage = MutableLiveData<CommentsPage?>()
+
+    private var nextPage: String? = null
+
+    var videoId: String? = null
+    var maxHeight: Int = 0
+
+    fun fetchComments() {
+        videoId ?: return
+        scope.launch {
+            isLoading = true
+            val response = try {
+                RetrofitInstance.api.getComments(videoId!!)
+            } catch (e: Exception) {
+                Log.e(TAG(), e.toString())
+                return@launch
+            }
+            nextPage = response.nextpage
+            commentsPage.postValue(response)
+            isLoading = false
+        }
+    }
+
+    fun fetchNextComments() {
+        if (isLoading || nextPage == null || videoId == null) return
+        scope.launch {
+            isLoading = true
+            val response = try {
+                RetrofitInstance.api.getCommentsNextPage(videoId!!, nextPage!!)
+            } catch (e: Exception) {
+                Log.e(TAG(), e.toString())
+                return@launch
+            }
+            val updatedPage = commentsPage.value?.apply {
+                comments = comments.plus(response.comments).toMutableList()
+            }
+            nextPage = response.nextpage
+            commentsPage.postValue(updatedPage)
+            isLoading = false
+        }
+    }
+
+    fun reset() {
+        isLoading = false
+        nextPage = null
+        commentsPage.value = null
+        videoId = null
+    }
+}

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

@@ -1,32 +1,22 @@
 package com.github.libretube.ui.sheets
 
 import android.os.Bundle
-import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import androidx.lifecycle.lifecycleScope
+import androidx.fragment.app.activityViewModels
 import androidx.recyclerview.widget.LinearLayoutManager
 import com.github.libretube.R
-import com.github.libretube.api.RetrofitInstance
-import com.github.libretube.api.obj.Comment
 import com.github.libretube.databinding.CommentsSheetBinding
-import com.github.libretube.extensions.TAG
 import com.github.libretube.ui.adapters.CommentsAdapter
-import kotlinx.coroutines.Dispatchers
+import com.github.libretube.ui.models.CommentsViewModel
-import kotlinx.coroutines.withContext
 
-class CommentsSheet(
+class CommentsSheet : ExpandedBottomSheet() {
-    private val videoId: String,
-    private val comments: List<Comment>,
-    private var nextPage: String?,
-    private val maxHeight: Int,
-    private val onMoreComments: (comments: List<Comment>, nextPage: String?) -> Unit
-) : ExpandedBottomSheet() {
     private lateinit var binding: CommentsSheetBinding
 
     private lateinit var commentsAdapter: CommentsAdapter
-    private var isLoading = false
+
+    private val viewModel: CommentsViewModel by activityViewModels()
 
     override fun onCreateView(
         inflater: LayoutInflater,
@@ -35,7 +25,7 @@ class CommentsSheet(
     ): View {
         binding = CommentsSheetBinding.inflate(layoutInflater)
         // set a fixed maximum height
-        binding.root.maxHeight = maxHeight
+        binding.root.maxHeight = viewModel.maxHeight
         return binding.root
     }
 
@@ -48,62 +38,40 @@ class CommentsSheet(
         binding.commentsRV.viewTreeObserver
             .addOnScrollChangedListener {
                 if (!binding.commentsRV.canScrollVertically(1)) {
-                    fetchNextComments()
+                    viewModel.fetchNextComments()
                 }
             }
 
-        commentsAdapter = CommentsAdapter(videoId, comments.toMutableList()) {
+        commentsAdapter = CommentsAdapter(
+            viewModel.videoId!!,
+            viewModel.commentsPage.value?.comments.orEmpty().toMutableList()
+        ) {
             dialog?.dismiss()
         }
         binding.commentsRV.adapter = commentsAdapter
 
-        if (comments.isEmpty()) fetchComments()
+        if (viewModel.commentsPage.value?.comments.orEmpty().isEmpty()) {
-    }
+            binding.progress.visibility = View.VISIBLE
-
+            viewModel.fetchComments()
-    private fun fetchComments() {
-        binding.progress.visibility = View.VISIBLE
-        lifecycleScope.launchWhenCreated {
-            isLoading = true
-            val response = try {
-                RetrofitInstance.api.getComments(videoId)
-            } catch (e: Exception) {
-                return@launchWhenCreated
-            }
-            binding.progress.visibility = View.GONE
-            if (response.disabled == true) {
-                withContext(Dispatchers.Main) {
-                    binding.errorTV.visibility = View.VISIBLE
-                }
-                return@launchWhenCreated
-            }
-            if (response.comments.isEmpty()) {
-                withContext(Dispatchers.Main) {
-                    binding.errorTV.text = getString(R.string.no_comments_available)
-                    binding.errorTV.visibility = View.VISIBLE
-                }
-                return@launchWhenCreated
-            }
-            commentsAdapter.updateItems(response.comments)
-            nextPage = response.nextpage
-            onMoreComments.invoke(response.comments, response.nextpage)
-            isLoading = false
         }
-    }
 
-    private fun fetchNextComments() {
+        // listen for new comments to be loaded
-        if (isLoading || nextPage == null) return
+        viewModel.commentsPage.observe(viewLifecycleOwner) {
-        lifecycleScope.launchWhenCreated {
+            it ?: return@observe
-            isLoading = true
+            binding.progress.visibility = View.GONE
-            val response = try {
+            if (it.disabled == true) {
-                RetrofitInstance.api.getCommentsNextPage(videoId, nextPage!!)
+                binding.errorTV.visibility = View.VISIBLE
-            } catch (e: Exception) {
+                return@observe
-                Log.e(TAG(), e.toString())
-                return@launchWhenCreated
             }
-            nextPage = response.nextpage
+            if (it.comments.isEmpty()) {
-            commentsAdapter.updateItems(response.comments)
+                binding.errorTV.text = getString(R.string.no_comments_available)
-            onMoreComments.invoke(response.comments, response.nextpage)
+                binding.errorTV.visibility = View.VISIBLE
-            isLoading = false
+                return@observe
+            }
+            commentsAdapter.updateItems(
+                // only add the new comments to the recycler view
+                it.comments.subList(commentsAdapter.itemCount, it.comments.size)
+            )
         }
     }
 }