Correctly display the folder header also in album view

Also fix a number of smaller issues

ultrasonic/src/main/kotlin/org/moire/ultrasonic/fragment/AlbumListFragment.kt

@@ -9,7 +9,6 @@ import androidx.recyclerview.widget.RecyclerView
 import org.koin.core.component.KoinApiExtension
 import org.moire.ultrasonic.R
 import org.moire.ultrasonic.domain.MusicDirectory
-import org.moire.ultrasonic.domain.MusicFolder
 import org.moire.ultrasonic.util.Constants
 
 /**
@@ -45,11 +44,6 @@ class AlbumListFragment : GenericListFragment<MusicDirectory.Entry, AlbumRowAdap
      */
     override val itemClickTarget: Int = R.id.trackCollectionFragment
 
-    /**
-     * Whether to show the folder selector
-     */
-    override var folderHeaderEnabled = false
-
     /**
      * The central function to pass a query to the model and return a LiveData object
      */
@@ -103,8 +97,4 @@ class AlbumListFragment : GenericListFragment<MusicDirectory.Entry, AlbumRowAdap
         bundle.putString(Constants.INTENT_EXTRA_NAME_PARENT_ID, item.parent)
         findNavController().navigate(itemClickTarget, bundle)
     }
-
-    override val musicFolderObserver = { _: List<MusicFolder> ->
-        // Do nothing
-    }
 }

ultrasonic/src/main/kotlin/org/moire/ultrasonic/fragment/AlbumListModel.kt

@@ -35,19 +35,19 @@ class AlbumListModel(application: Application) : GenericListModel(application) {
         refresh: Boolean,
         args: Bundle
     ) {
-        val musicDirectory: MusicDirectory
+        super.load(isOffline, useId3Tags, musicService, refresh, args)
-        val musicFolderId = if (showSelectFolderHeader) {
-            activeServerProvider.getActiveServer().musicFolderId
-        } else {
-            null
-        }
 
         val albumListType = args.getString(Constants.INTENT_EXTRA_NAME_ALBUM_LIST_TYPE)!!
         val size = args.getInt(Constants.INTENT_EXTRA_NAME_ALBUM_LIST_SIZE, 0)
         var offset = args.getInt(Constants.INTENT_EXTRA_NAME_ALBUM_LIST_OFFSET, 0)
         val append = args.getBoolean(Constants.INTENT_EXTRA_NAME_APPEND, false)
 
-        showHeader = showHeader(albumListType)
+        val musicDirectory: MusicDirectory
+        val musicFolderId = if (showSelectFolderHeader(args)) {
+            activeServerProvider.getActiveServer().musicFolderId
+        } else {
+            null
+        }
 
         // Handle the logic for endless scrolling:
         // If appending the existing list, set the offset from where to load
@@ -65,7 +65,7 @@ class AlbumListModel(application: Application) : GenericListModel(application) {
             )
         }
 
-        currentListIsSortable = sortableCollection(albumListType)
+        currentListIsSortable = isCollectionSortable(albumListType)
 
         if (append && albumList.value != null) {
             val list = ArrayList<MusicDirectory.Entry>()
@@ -79,14 +79,18 @@ class AlbumListModel(application: Application) : GenericListModel(application) {
         loadedUntil = offset
     }
 
-    private fun showHeader(albumListType: String): Boolean {
+    override fun showSelectFolderHeader(args: Bundle?): Boolean {
+        if (args == null) return false
+
+        val albumListType = args.getString(Constants.INTENT_EXTRA_NAME_ALBUM_LIST_TYPE)!!
+
         val isAlphabetical = (albumListType == AlbumListType.SORTED_BY_NAME.toString()) ||
             (albumListType == AlbumListType.SORTED_BY_ARTIST.toString())
 
         return !isOffline() && !Util.getShouldUseId3Tags() && isAlphabetical
     }
 
-    private fun sortableCollection(albumListType: String): Boolean {
+    private fun isCollectionSortable(albumListType: String): Boolean {
         return albumListType != "newest" && albumListType != "random" &&
             albumListType != "highest" && albumListType != "recent" &&
             albumListType != "frequent"

ultrasonic/src/main/kotlin/org/moire/ultrasonic/fragment/AlbumRowAdapter.kt

@@ -1,5 +1,5 @@
 /*
- * ArtistRowAdapter.kt
+ * AlbumRowAdapter.kt
  * Copyright (C) 2009-2021 Ultrasonic developers
  *
  * Distributed under terms of the GNU GPLv3 license.
@@ -21,7 +21,7 @@ import org.moire.ultrasonic.util.ImageLoader
 import org.moire.ultrasonic.view.SelectMusicFolderView
 
 /**
- * Creates a Row in a RecyclerView which contains the details of an Artist
+ * Creates a Row in a RecyclerView which contains the details of an Album
  */
 class AlbumRowAdapter(
     albumList: List<MusicDirectory.Entry>,

ultrasonic/src/main/kotlin/org/moire/ultrasonic/fragment/ArtistListFragment.kt

@@ -6,7 +6,6 @@ import androidx.lifecycle.LiveData
 import org.koin.core.component.KoinApiExtension
 import org.moire.ultrasonic.R
 import org.moire.ultrasonic.domain.Artist
-import org.moire.ultrasonic.domain.MusicFolder
 import org.moire.ultrasonic.util.Constants
 
 /**
@@ -61,12 +60,4 @@ class ArtistListFragment : GenericListFragment<Artist, ArtistRowAdapter>() {
             imageLoaderProvider.getImageLoader()
         )
     }
-
-    override val musicFolderObserver = { changedFolders: List<MusicFolder> ->
-        viewAdapter.notifyDataSetChanged()
-        selectFolderHeader!!.setData(
-            activeServerProvider.getActiveServer().musicFolderId,
-            changedFolders
-        )
-    }
 }

ultrasonic/src/main/kotlin/org/moire/ultrasonic/fragment/ArtistListModel.kt

@@ -49,11 +49,7 @@ class ArtistListModel(application: Application) : GenericListModel(application)
         refresh: Boolean,
         args: Bundle
     ) {
-        if (!isOffline && !useId3Tags) {
+        super.load(isOffline, useId3Tags, musicService, refresh, args)
-            musicFolders.postValue(
-                musicService.getMusicFolders(refresh)
-            )
-        }
 
         val musicFolderId = activeServer.musicFolderId
 

ultrasonic/src/main/kotlin/org/moire/ultrasonic/fragment/GenericListFragment.kt

@@ -88,15 +88,21 @@ abstract class GenericListFragment<T : GenericEntry, TA : GenericRowAdapter<T>>
     /**
      * The observer to be called if the available music folders have changed
      */
-    abstract val musicFolderObserver: (List<MusicFolder>) -> Unit
+    val musicFolderObserver = { changedFolders: List<MusicFolder> ->
+        viewAdapter.notifyDataSetChanged()
+        selectFolderHeader?.setData(
+            activeServerProvider.getActiveServer().musicFolderId,
+            changedFolders
+        )
+        Unit
+    }
 
     /**
      * Whether to show the folder selector
      */
-    internal open var folderHeaderEnabled: Boolean = true
-
     fun showFolderHeader(): Boolean {
-        return folderHeaderEnabled && listModel.isOffline() && !Util.getShouldUseId3Tags()
+        return listModel.showSelectFolderHeader(arguments) &&
+            !listModel.isOffline() && !Util.getShouldUseId3Tags()
     }
 
     fun setTitle(title: String?) {

ultrasonic/src/main/kotlin/org/moire/ultrasonic/fragment/GenericListModel.kt

@@ -29,7 +29,7 @@ import org.moire.ultrasonic.util.Util
 * An abstract Model, which can be extended to retrieve a list of items from the API
 */
 @KoinApiExtension
-abstract class GenericListModel(application: Application) :
+open class GenericListModel(application: Application) :
     AndroidViewModel(application), KoinComponent {
 
     val activeServerProvider: ActiveServerProvider by inject()
@@ -42,7 +42,11 @@ abstract class GenericListModel(application: Application) :
 
     var currentListIsSortable = true
     var showHeader = true
-    var showSelectFolderHeader = false
+
+    @Suppress("UNUSED_PARAMETER")
+    open fun showSelectFolderHeader(args: Bundle?): Boolean {
+        return true
+    }
 
     internal val musicFolders: MutableLiveData<List<MusicFolder>> = MutableLiveData()
 
@@ -96,13 +100,20 @@ abstract class GenericListModel(application: Application) :
     /**
      * This is the central function you need to implement if you want to extend this class
      */
-    abstract fun load(
+    open fun load(
         isOffline: Boolean,
         useId3Tags: Boolean,
         musicService: MusicService,
         refresh: Boolean,
         args: Bundle
+    ) {
+        // Update the list of available folders if enabled
+        if (showSelectFolderHeader(args) && !isOffline && !useId3Tags) {
+            musicFolders.postValue(
+                musicService.getMusicFolders(refresh)
             )
+        }
+    }
 
     /**
      * Retrieves the available Music Folders in a LiveData

ultrasonic/src/main/kotlin/org/moire/ultrasonic/fragment/TrackCollectionFragment.kt

@@ -232,7 +232,6 @@ class TrackCollectionFragment : Fragment() {
     }
 
     val handler = CoroutineExceptionHandler { _, exception ->
-        println("CoroutineExceptionHandler got $exception")
         Handler(Looper.getMainLooper()).post {
             context?.let { CommunicationErrorHandler.handleError(exception, it) }
         }
@@ -727,7 +726,7 @@ class TrackCollectionFragment : Fragment() {
                 }
             }
         } else {
-            if (model.showSelectFolderHeader) {
+            if (model.showSelectFolderHeader(arguments)) {
                 if (albumListView!!.headerViewsCount == 0) {
                     albumListView!!.addHeaderView(selectFolderHeader!!.itemView, null, false)
                 }