Fix miscellaneous bugs to Flow implementation.

app/src/main/java/com/github/apognu/otter/adapters/TracksAdapter.kt

@@ -82,8 +82,8 @@ class TracksAdapter(private val context: Context?, private val favoriteListener:
 
     context?.let {
       when (track.favorite) {
-        true -> holder.favorite.setColorFilter(context.resources.getColor(R.color.colorFavorite))
-        false -> holder.favorite.setColorFilter(context.resources.getColor(R.color.colorSelected))
+        true -> holder.favorite.setColorFilter(context.getColor(R.color.colorFavorite))
+        false -> holder.favorite.setColorFilter(context.getColor(R.color.colorSelected))
       }
 
       holder.favorite.setOnClickListener {

app/src/main/java/com/github/apognu/otter/fragments/FunkwhaleFragment.kt

@@ -10,7 +10,6 @@ import androidx.recyclerview.widget.RecyclerView
 import com.github.apognu.otter.repositories.HttpUpstream
 import com.github.apognu.otter.repositories.Repository
 import com.github.apognu.otter.utils.Cache
-import com.github.apognu.otter.utils.log
 import com.github.apognu.otter.utils.untilNetwork
 import com.google.gson.Gson
 import kotlinx.android.synthetic.main.fragment_artists.*
@@ -45,8 +44,8 @@ abstract class FunkwhaleFragment<D : Any, A : FunkwhaleAdapter<D, *>> : Fragment
 
     (repository.upstream as? HttpUpstream<*, *>)?.let { upstream ->
       if (upstream.behavior == HttpUpstream.Behavior.Progressive) {
-        recycler.setOnScrollChangeListener { _, _, y, _, _ ->
-          if (y > 0 && !recycler.canScrollVertically(1)) {
+        recycler.setOnScrollChangeListener { _, _, _, _, _ ->
+          if (recycler.computeVerticalScrollOffset() > 0 && !recycler.canScrollVertically(1)) {
             fetch(Repository.Origin.Network.origin, adapter.data.size)
           }
         }
@@ -67,41 +66,47 @@ abstract class FunkwhaleFragment<D : Any, A : FunkwhaleAdapter<D, *>> : Fragment
   open fun onDataFetched(data: List<D>) {}
 
   private fun fetch(upstreams: Int = (Repository.Origin.Network.origin and Repository.Origin.Cache.origin), size: Int = 0) {
-    var first = true
+    var first = size == 0
 
     swiper?.isRefreshing = true
 
     repository.fetch(upstreams, size).untilNetwork(IO) { data, isCache, hasMore ->
-      if (isCache) {
-        adapter.data = data.toMutableList()
-        adapter.notifyDataSetChanged()
-
-        return@untilNetwork
-      }
-
-      if (first) {
-        first = false
-
-        adapter.data.clear()
-      }
-
-      onDataFetched(data)
-
-      adapter.data.addAll(data)
-
-      if (!hasMore) {
-        swiper?.isRefreshing = false
-
-        repository.cacheId?.let { cacheId ->
-          Cache.set(
-            context,
-            cacheId,
-            Gson().toJson(repository.cache(adapter.data)).toByteArray()
-          )
-        }
-      }
-
       GlobalScope.launch(Main) {
+        if (isCache) {
+          adapter.data = data.toMutableList()
+          adapter.notifyDataSetChanged()
+
+          return@launch
+        }
+
+        if (first && data.isNotEmpty()) {
+          first = false
+
+          adapter.data.clear()
+        }
+
+        onDataFetched(data)
+
+        adapter.data.addAll(data)
+
+        if (!hasMore) {
+          swiper?.isRefreshing = false
+
+          GlobalScope.launch(IO) {
+            if (adapter.data.isNotEmpty()) {
+              try {
+                repository.cacheId?.let { cacheId ->
+                  Cache.set(
+                    context,
+                    cacheId,
+                    Gson().toJson(repository.cache(adapter.data)).toByteArray()
+                  )
+                }
+              } catch (e: ConcurrentModificationException) {}
+            }
+          }
+        }
+
         when (first) {
           true -> {
             adapter.notifyDataSetChanged()

app/src/main/java/com/github/apognu/otter/fragments/PlaylistTracksFragment.kt

@@ -100,10 +100,12 @@ class PlaylistTracksFragment : FunkwhaleFragment<PlaylistTrack, PlaylistTracksAd
         else -> cover_top_left
       }
 
-      GlobalScope.launch(Main) {
-        Picasso.get()
-          .maybeLoad(maybeNormalizeUrl(url))
-          .into(imageView)
+      imageView?.let { view ->
+        GlobalScope.launch(Main) {
+          Picasso.get()
+            .maybeLoad(maybeNormalizeUrl(url))
+            .into(view)
+        }
       }
     }
   }

app/src/main/java/com/github/apognu/otter/playback/PlayerService.kt

@@ -413,6 +413,7 @@ class PlayerService : Service() {
       )
 
       player.next()
+      player.playWhenReady = true
     }
   }
 

app/src/main/java/com/github/apognu/otter/repositories/HttpUpstream.kt

@@ -12,6 +12,7 @@ import com.google.gson.Gson
 import com.preference.PowerPreference
 import kotlinx.coroutines.Dispatchers.IO
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.flowOn
 import java.io.Reader
@@ -45,7 +46,7 @@ class HttpUpstream<D : Any, R : FunkwhaleResponse<D>>(val behavior: Behavior, pr
         } else {
           emit(Repository.Response(Repository.Origin.Network, data, true))
 
-          fetch(size + data.size)
+          fetch(size + data.size).collect { emit(it) }
         }
       },
       { error ->