detail: separate header from list data

Separate the header information into it's own adapter, and concatenate
it with the prior adapter.

This way, it can be updated separately without a jarring list update.

app/src/main/java/org/oxycblt/auxio/IntegerTable.kt

@@ -37,18 +37,12 @@ object IntegerTable {
     const val VIEW_TYPE_BASIC_HEADER = 0xA004
     /** SortHeaderViewHolder */
     const val VIEW_TYPE_SORT_HEADER = 0xA005
-    /** AlbumDetailViewHolder */
-    const val VIEW_TYPE_ALBUM_DETAIL = 0xA006
     /** AlbumSongViewHolder */
     const val VIEW_TYPE_ALBUM_SONG = 0xA007
-    /** ArtistDetailViewHolder */
-    const val VIEW_TYPE_ARTIST_DETAIL = 0xA008
     /** ArtistAlbumViewHolder */
     const val VIEW_TYPE_ARTIST_ALBUM = 0xA009
     /** ArtistSongViewHolder */
     const val VIEW_TYPE_ARTIST_SONG = 0xA00A
-    /** GenreDetailViewHolder */
-    const val VIEW_TYPE_GENRE_DETAIL = 0xA00B
     /** DiscHeaderViewHolder */
     const val VIEW_TYPE_DISC_HEADER = 0xA00C
     /** "Music playback" notification code */

app/src/main/java/org/oxycblt/auxio/detail/AlbumDetailFragment.kt

@@ -25,12 +25,15 @@ import android.view.View
 import androidx.fragment.app.activityViewModels
 import androidx.navigation.fragment.findNavController
 import androidx.navigation.fragment.navArgs
+import androidx.recyclerview.widget.ConcatAdapter
 import androidx.recyclerview.widget.LinearSmoothScroller
 import com.google.android.material.transition.MaterialSharedAxis
 import dagger.hilt.android.AndroidEntryPoint
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.databinding.FragmentDetailBinding
-import org.oxycblt.auxio.detail.recycler.AlbumDetailAdapter
+import org.oxycblt.auxio.detail.header.AlbumDetailHeaderAdapter
+import org.oxycblt.auxio.detail.list.AlbumDetailListAdapter
+import org.oxycblt.auxio.detail.list.DetailListAdapter
 import org.oxycblt.auxio.list.Item
 import org.oxycblt.auxio.list.ListFragment
 import org.oxycblt.auxio.list.Sort
@@ -49,10 +52,15 @@ import org.oxycblt.auxio.util.*
  * A [ListFragment] that shows information about an [Album].
  *
  * @author Alexander Capehart (OxygenCobalt)
+ *
+ * TODO: Split up list and header adapters, and then work from there. Header item works fine. Make
+ *   sure that other pos-dependent code functions
  */
 @AndroidEntryPoint
 class AlbumDetailFragment :
-    ListFragment<Song, FragmentDetailBinding>(), AlbumDetailAdapter.Listener {
+    ListFragment<Song, FragmentDetailBinding>(),
+    AlbumDetailHeaderAdapter.Listener,
+    DetailListAdapter.Listener<Song> {
     private val detailModel: DetailViewModel by activityViewModels()
     override val navModel: NavigationViewModel by activityViewModels()
     override val playbackModel: PlaybackViewModel by activityViewModels()
@@ -60,7 +68,8 @@ class AlbumDetailFragment :
     // Information about what album to display is initially within the navigation arguments
     // as a UID, as that is the only safe way to parcel an album.
     private val args: AlbumDetailFragmentArgs by navArgs()
-    private val detailAdapter = AlbumDetailAdapter(this)
+    private val albumHeaderAdapter = AlbumDetailHeaderAdapter(this)
+    private val albumListAdapter = AlbumDetailListAdapter(this)
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -87,7 +96,7 @@ class AlbumDetailFragment :
             setOnMenuItemClickListener(this@AlbumDetailFragment)
         }
 
-        binding.detailRecycler.adapter = detailAdapter
+        binding.detailRecycler.adapter = ConcatAdapter(albumHeaderAdapter, albumListAdapter)
 
         // -- VIEWMODEL SETUP ---
         // DetailViewModel handles most initialization from the navigation argument.
@@ -185,14 +194,15 @@ class AlbumDetailFragment :
             return
         }
         requireBinding().detailToolbar.title = album.resolveName(requireContext())
+        albumHeaderAdapter.setParent(album)
     }
 
     private fun updatePlayback(song: Song?, parent: MusicParent?, isPlaying: Boolean) {
         if (parent is Album && parent == unlikelyToBeNull(detailModel.currentAlbum.value)) {
-            detailAdapter.setPlaying(song, isPlaying)
+            albumListAdapter.setPlaying(song, isPlaying)
         } else {
             // Clear the ViewHolders if the mode isn't ALL_SONGS
-            detailAdapter.setPlaying(null, isPlaying)
+            albumListAdapter.setPlaying(null, isPlaying)
         }
     }
 
@@ -277,11 +287,11 @@ class AlbumDetailFragment :
     }
 
     private fun updateList(list: List<Item>) {
-        detailAdapter.update(list, detailModel.albumInstructions.consume())
+        albumListAdapter.update(list, detailModel.albumInstructions.consume())
     }
 
     private fun updateSelection(selected: List<Music>) {
-        detailAdapter.setSelected(selected.toSet())
+        albumListAdapter.setSelected(selected.toSet())
         requireBinding().detailSelectionToolbar.updateSelectionAmount(selected.size)
     }
 }

app/src/main/java/org/oxycblt/auxio/detail/ArtistDetailFragment.kt

@@ -25,12 +25,15 @@ import android.view.View
 import androidx.fragment.app.activityViewModels
 import androidx.navigation.fragment.findNavController
 import androidx.navigation.fragment.navArgs
+import androidx.recyclerview.widget.ConcatAdapter
 import com.google.android.material.transition.MaterialSharedAxis
 import dagger.hilt.android.AndroidEntryPoint
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.databinding.FragmentDetailBinding
-import org.oxycblt.auxio.detail.recycler.ArtistDetailAdapter
+import org.oxycblt.auxio.detail.header.ArtistDetailHeaderAdapter
-import org.oxycblt.auxio.detail.recycler.DetailAdapter
+import org.oxycblt.auxio.detail.header.DetailHeaderAdapter
+import org.oxycblt.auxio.detail.list.ArtistDetailListAdapter
+import org.oxycblt.auxio.detail.list.DetailListAdapter
 import org.oxycblt.auxio.list.Item
 import org.oxycblt.auxio.list.ListFragment
 import org.oxycblt.auxio.list.Sort
@@ -51,7 +54,9 @@ import org.oxycblt.auxio.util.*
  */
 @AndroidEntryPoint
 class ArtistDetailFragment :
-    ListFragment<Music, FragmentDetailBinding>(), DetailAdapter.Listener<Music> {
+    ListFragment<Music, FragmentDetailBinding>(),
+    DetailHeaderAdapter.Listener,
+    DetailListAdapter.Listener<Music> {
     private val detailModel: DetailViewModel by activityViewModels()
     override val navModel: NavigationViewModel by activityViewModels()
     override val playbackModel: PlaybackViewModel by activityViewModels()
@@ -59,7 +64,8 @@ class ArtistDetailFragment :
     // Information about what artist to display is initially within the navigation arguments
     // as a UID, as that is the only safe way to parcel an artist.
     private val args: ArtistDetailFragmentArgs by navArgs()
-    private val detailAdapter = ArtistDetailAdapter(this)
+    private val artistHeaderAdapter = ArtistDetailHeaderAdapter(this)
+    private val artistListAdapter = ArtistDetailListAdapter(this)
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -86,7 +92,7 @@ class ArtistDetailFragment :
             setOnMenuItemClickListener(this@ArtistDetailFragment)
         }
 
-        binding.detailRecycler.adapter = detailAdapter
+        binding.detailRecycler.adapter = ConcatAdapter(artistHeaderAdapter, artistListAdapter)
 
         // --- VIEWMODEL SETUP ---
         // DetailViewModel handles most initialization from the navigation argument.
@@ -194,8 +200,8 @@ class ArtistDetailFragment :
             findNavController().navigateUp()
             return
         }
-
         requireBinding().detailToolbar.title = artist.resolveName(requireContext())
+        artistHeaderAdapter.setParent(artist)
     }
 
     private fun updatePlayback(song: Song?, parent: MusicParent?, isPlaying: Boolean) {
@@ -210,7 +216,7 @@ class ArtistDetailFragment :
                 else -> null
             }
 
-        detailAdapter.setPlaying(playingItem, isPlaying)
+        artistListAdapter.setPlaying(playingItem, isPlaying)
     }
 
     private fun handleNavigation(item: Music?) {
@@ -249,11 +255,11 @@ class ArtistDetailFragment :
     }
 
     private fun updateList(list: List<Item>) {
-        detailAdapter.update(list, detailModel.artistInstructions.consume())
+        artistListAdapter.update(list, detailModel.artistInstructions.consume())
     }
 
     private fun updateSelection(selected: List<Music>) {
-        detailAdapter.setSelected(selected.toSet())
+        artistListAdapter.setSelected(selected.toSet())
         requireBinding().detailSelectionToolbar.updateSelectionAmount(selected.size)
     }
 }

app/src/main/java/org/oxycblt/auxio/detail/DetailViewModel.kt

@@ -30,7 +30,7 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.yield
 import org.oxycblt.auxio.R
-import org.oxycblt.auxio.detail.recycler.SortHeader
+import org.oxycblt.auxio.detail.list.SortHeader
 import org.oxycblt.auxio.list.BasicHeader
 import org.oxycblt.auxio.list.Item
 import org.oxycblt.auxio.list.Sort
@@ -270,7 +270,7 @@ constructor(
 
     private fun refreshAlbumList(album: Album, replace: Boolean = false) {
         logD("Refreshing album data")
-        val list = mutableListOf<Item>(album)
+        val list = mutableListOf<Item>()
         list.add(SortHeader(R.string.lbl_songs))
         val instructions =
             if (replace) {
@@ -302,7 +302,7 @@ constructor(
 
     private fun refreshArtistList(artist: Artist, replace: Boolean = false) {
         logD("Refreshing artist data")
-        val list = mutableListOf<Item>(artist)
+        val list = mutableListOf<Item>()
         val albums = Sort(Sort.Mode.ByDate, Sort.Direction.DESCENDING).albums(artist.albums)
 
         val byReleaseGroup =
@@ -351,7 +351,7 @@ constructor(
 
     private fun refreshGenreList(genre: Genre, replace: Boolean = false) {
         logD("Refreshing genre data")
-        val list = mutableListOf<Item>(genre)
+        val list = mutableListOf<Item>()
         // Genre is guaranteed to always have artists and songs.
         list.add(BasicHeader(R.string.lbl_artists))
         list.addAll(genre.artists)

app/src/main/java/org/oxycblt/auxio/detail/GenreDetailFragment.kt

@@ -25,12 +25,15 @@ import android.view.View
 import androidx.fragment.app.activityViewModels
 import androidx.navigation.fragment.findNavController
 import androidx.navigation.fragment.navArgs
+import androidx.recyclerview.widget.ConcatAdapter
 import com.google.android.material.transition.MaterialSharedAxis
 import dagger.hilt.android.AndroidEntryPoint
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.databinding.FragmentDetailBinding
-import org.oxycblt.auxio.detail.recycler.DetailAdapter
+import org.oxycblt.auxio.detail.header.DetailHeaderAdapter
-import org.oxycblt.auxio.detail.recycler.GenreDetailAdapter
+import org.oxycblt.auxio.detail.header.GenreDetailHeaderAdapter
+import org.oxycblt.auxio.detail.list.DetailListAdapter
+import org.oxycblt.auxio.detail.list.GenreDetailListAdapter
 import org.oxycblt.auxio.list.Item
 import org.oxycblt.auxio.list.ListFragment
 import org.oxycblt.auxio.list.Sort
@@ -52,7 +55,9 @@ import org.oxycblt.auxio.util.*
  */
 @AndroidEntryPoint
 class GenreDetailFragment :
-    ListFragment<Music, FragmentDetailBinding>(), DetailAdapter.Listener<Music> {
+    ListFragment<Music, FragmentDetailBinding>(),
+    DetailHeaderAdapter.Listener,
+    DetailListAdapter.Listener<Music> {
     private val detailModel: DetailViewModel by activityViewModels()
     override val navModel: NavigationViewModel by activityViewModels()
     override val playbackModel: PlaybackViewModel by activityViewModels()
@@ -60,7 +65,8 @@ class GenreDetailFragment :
     // Information about what genre to display is initially within the navigation arguments
     // as a UID, as that is the only safe way to parcel an genre.
     private val args: GenreDetailFragmentArgs by navArgs()
-    private val detailAdapter = GenreDetailAdapter(this)
+    private val genreHeaderAdapter = GenreDetailHeaderAdapter(this)
+    private val genreListAdapter = GenreDetailListAdapter(this)
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -85,7 +91,7 @@ class GenreDetailFragment :
             setOnMenuItemClickListener(this@GenreDetailFragment)
         }
 
-        binding.detailRecycler.adapter = detailAdapter
+        binding.detailRecycler.adapter = ConcatAdapter(genreHeaderAdapter, genreListAdapter)
 
         // --- VIEWMODEL SETUP ---
         // DetailViewModel handles most initialization from the navigation argument.
@@ -191,8 +197,8 @@ class GenreDetailFragment :
             findNavController().navigateUp()
             return
         }
-
         requireBinding().detailToolbar.title = genre.resolveName(requireContext())
+        genreHeaderAdapter.setParent(genre)
     }
 
     private fun updatePlayback(song: Song?, parent: MusicParent?, isPlaying: Boolean) {
@@ -204,7 +210,7 @@ class GenreDetailFragment :
         if (parent is Genre && parent.uid == unlikelyToBeNull(detailModel.currentGenre.value).uid) {
             playingMusic = song
         }
-        detailAdapter.setPlaying(playingMusic, isPlaying)
+        genreListAdapter.setPlaying(playingMusic, isPlaying)
     }
 
     private fun handleNavigation(item: Music?) {
@@ -232,11 +238,11 @@ class GenreDetailFragment :
     }
 
     private fun updateList(list: List<Item>) {
-        detailAdapter.update(list, detailModel.genreInstructions.consume())
+        genreListAdapter.update(list, detailModel.genreInstructions.consume())
     }
 
     private fun updateSelection(selected: List<Music>) {
-        detailAdapter.setSelected(selected.toSet())
+        genreListAdapter.setSelected(selected.toSet())
         requireBinding().detailSelectionToolbar.updateSelectionAmount(selected.size)
     }
 }

app/src/main/java/org/oxycblt/auxio/detail/SongDetailDialog.kt

@@ -29,8 +29,8 @@ import androidx.navigation.fragment.navArgs
 import dagger.hilt.android.AndroidEntryPoint
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.databinding.DialogSongDetailBinding
-import org.oxycblt.auxio.detail.recycler.SongProperty
+import org.oxycblt.auxio.detail.list.SongProperty
-import org.oxycblt.auxio.detail.recycler.SongPropertyAdapter
+import org.oxycblt.auxio.detail.list.SongPropertyAdapter
 import org.oxycblt.auxio.list.adapter.UpdateInstructions
 import org.oxycblt.auxio.music.Music
 import org.oxycblt.auxio.music.Song

app/src/main/java/org/oxycblt/auxio/detail/header/AlbumDetailHeaderAdapter.kt

@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2023 Auxio Project
+ * AlbumDetailHeaderAdapter.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
+package org.oxycblt.auxio.detail.header
+
+import android.view.View
+import android.view.ViewGroup
+import androidx.recyclerview.widget.RecyclerView
+import org.oxycblt.auxio.R
+import org.oxycblt.auxio.databinding.ItemDetailHeaderBinding
+import org.oxycblt.auxio.music.Album
+import org.oxycblt.auxio.music.resolveNames
+import org.oxycblt.auxio.playback.formatDurationMs
+import org.oxycblt.auxio.util.context
+import org.oxycblt.auxio.util.getPlural
+import org.oxycblt.auxio.util.inflater
+
+/**
+ * A [DetailHeaderAdapter] that shows [Album] information.
+ * @author Alexander Capehart (OxygenCobalt)
+ */
+class AlbumDetailHeaderAdapter(private val listener: Listener) :
+    DetailHeaderAdapter<Album, AlbumDetailHeaderViewHolder>() {
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
+        AlbumDetailHeaderViewHolder.from(parent)
+
+    override fun onBindHeader(holder: AlbumDetailHeaderViewHolder, parent: Album) =
+        holder.bind(parent, listener)
+
+    /** An extended listener for [DetailHeaderAdapter] implementations. */
+    interface Listener : DetailHeaderAdapter.Listener {
+
+        /**
+         * Called when the artist name in the [Album] header was clicked, requesting navigation to
+         * it's parent artist.
+         */
+        fun onNavigateToParentArtist()
+    }
+}
+
+/**
+ * A [RecyclerView.ViewHolder] that displays the [Album] header in the detail view. Use [from] to
+ * create an instance.
+ *
+ * @author Alexander Capehart (OxygenCobalt)
+ */
+class AlbumDetailHeaderViewHolder
+private constructor(private val binding: ItemDetailHeaderBinding) :
+    RecyclerView.ViewHolder(binding.root) {
+
+    /**
+     * Bind new data to this instance.
+     *
+     * @param album The new [Album] to bind.
+     * @param listener A [AlbumDetailHeaderAdapter.Listener] to bind interactions to.
+     */
+    fun bind(album: Album, listener: AlbumDetailHeaderAdapter.Listener) {
+        binding.detailCover.bind(album)
+
+        // The type text depends on the release type (Album, EP, Single, etc.)
+        binding.detailType.text = binding.context.getString(album.releaseType.stringRes)
+
+        binding.detailName.text = album.resolveName(binding.context)
+
+        // Artist name maps to the subhead text
+        binding.detailSubhead.apply {
+            text = album.artists.resolveNames(context)
+
+            // Add a QoL behavior where navigation to the artist will occur if the artist
+            // name is pressed.
+            setOnClickListener { listener.onNavigateToParentArtist() }
+        }
+
+        // Date, song count, and duration map to the info text
+        binding.detailInfo.apply {
+            // Fall back to a friendlier "No date" text if the album doesn't have date information
+            val date = album.dates?.resolveDate(context) ?: context.getString(R.string.def_date)
+            val songCount = context.getPlural(R.plurals.fmt_song_count, album.songs.size)
+            val duration = album.durationMs.formatDurationMs(true)
+            text = context.getString(R.string.fmt_three, date, songCount, duration)
+        }
+
+        binding.detailPlayButton.setOnClickListener { listener.onPlay() }
+        binding.detailShuffleButton.setOnClickListener { listener.onShuffle() }
+    }
+
+    companion object {
+        /**
+         * Create a new instance.
+         *
+         * @param parent The parent to inflate this instance from.
+         * @return A new instance.
+         */
+        fun from(parent: View) =
+            AlbumDetailHeaderViewHolder(ItemDetailHeaderBinding.inflate(parent.context.inflater))
+    }
+}

app/src/main/java/org/oxycblt/auxio/detail/header/ArtistDetailHeaderAdapter.kt

@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2023 Auxio Project
+ * ArtistDetailHeaderAdapter.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
+package org.oxycblt.auxio.detail.header
+
+import android.view.View
+import android.view.ViewGroup
+import androidx.core.view.isVisible
+import androidx.recyclerview.widget.RecyclerView
+import org.oxycblt.auxio.R
+import org.oxycblt.auxio.databinding.ItemDetailHeaderBinding
+import org.oxycblt.auxio.music.Artist
+import org.oxycblt.auxio.music.resolveNames
+import org.oxycblt.auxio.util.context
+import org.oxycblt.auxio.util.getPlural
+import org.oxycblt.auxio.util.inflater
+
+/**
+ * A [DetailHeaderAdapter] that shows [Artist] information.
+ * @author Alexander Capehart (OxygenCobalt)
+ */
+class ArtistDetailHeaderAdapter(private val listener: Listener) :
+    DetailHeaderAdapter<Artist, ArtistDetailHeaderViewHolder>() {
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
+        ArtistDetailHeaderViewHolder.from(parent)
+    override fun onBindHeader(holder: ArtistDetailHeaderViewHolder, parent: Artist) =
+        holder.bind(parent, listener)
+}
+
+/**
+ * A [RecyclerView.ViewHolder] that displays the [Artist] header in the detail view. Use [from] to
+ * create an instance.
+ *
+ * @author Alexander Capehart (OxygenCobalt)
+ */
+class ArtistDetailHeaderViewHolder
+private constructor(private val binding: ItemDetailHeaderBinding) :
+    RecyclerView.ViewHolder(binding.root) {
+
+    /**
+     * Bind new data to this instance.
+     *
+     * @param artist The new [Artist] to bind.
+     * @param listener A [DetailHeaderAdapter.Listener] to bind interactions to.
+     */
+    fun bind(artist: Artist, listener: DetailHeaderAdapter.Listener) {
+        binding.detailCover.bind(artist)
+        binding.detailType.text = binding.context.getString(R.string.lbl_artist)
+        binding.detailName.text = artist.resolveName(binding.context)
+
+        if (artist.songs.isNotEmpty()) {
+            // Information about the artist's genre(s) map to the sub-head text
+            binding.detailSubhead.apply {
+                isVisible = true
+                text = artist.genres.resolveNames(context)
+            }
+
+            // Song and album counts map to the info
+            binding.detailInfo.text =
+                binding.context.getString(
+                    R.string.fmt_two,
+                    binding.context.getPlural(R.plurals.fmt_album_count, artist.albums.size),
+                    binding.context.getPlural(R.plurals.fmt_song_count, artist.songs.size))
+
+            // In the case that this header used to he configured to have no songs,
+            // we want to reset the visibility of all information that was hidden.
+            binding.detailPlayButton.isVisible = true
+            binding.detailShuffleButton.isVisible = true
+        } else {
+            // The artist does not have any songs, so hide functionality that makes no sense.
+            // ex. Play and Shuffle, Song Counts, and Genre Information.
+            // Artists are always guaranteed to have albums however, so continue to show those.
+            binding.detailSubhead.isVisible = false
+            binding.detailInfo.text =
+                binding.context.getPlural(R.plurals.fmt_album_count, artist.albums.size)
+            binding.detailPlayButton.isVisible = false
+            binding.detailShuffleButton.isVisible = false
+        }
+
+        binding.detailPlayButton.setOnClickListener { listener.onPlay() }
+        binding.detailShuffleButton.setOnClickListener { listener.onShuffle() }
+    }
+
+    companion object {
+        /**
+         * Create a new instance.
+         *
+         * @param parent The parent to inflate this instance from.
+         * @return A new instance.
+         */
+        fun from(parent: View) =
+            ArtistDetailHeaderViewHolder(ItemDetailHeaderBinding.inflate(parent.context.inflater))
+    }
+}

app/src/main/java/org/oxycblt/auxio/detail/header/DetailHeaderAdapter.kt

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2023 Auxio Project
+ * DetailHeaderAdapter.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
+package org.oxycblt.auxio.detail.header
+
+import androidx.recyclerview.widget.RecyclerView
+import org.oxycblt.auxio.music.MusicParent
+
+/**
+ * A [RecyclerView.Adapter] that implements shared behavior between each parent header view.
+ *
+ * @author Alexander Capehart (OxygenCobalt)
+ */
+abstract class DetailHeaderAdapter<T : MusicParent, VH : RecyclerView.ViewHolder> :
+    RecyclerView.Adapter<VH>() {
+    private var currentParent: T? = null
+    final override fun getItemCount() = 1
+    final override fun onBindViewHolder(holder: VH, position: Int) =
+        onBindHeader(holder, requireNotNull(currentParent))
+
+    /**
+     * Bind the created header [RecyclerView.ViewHolder] with the current [parent].
+     * @param holder The [RecyclerView.ViewHolder] to bind.
+     * @param parent The current [MusicParent] to bind.
+     */
+    abstract fun onBindHeader(holder: VH, parent: T)
+
+    /**
+     * Update the [MusicParent] shown in the header.
+     * @param parent The new [MusicParent] to show.
+     */
+    fun setParent(parent: T) {
+        currentParent = parent
+        notifyItemChanged(0, PAYLOAD_UPDATE_HEADER)
+    }
+
+    /** An extended listener for [DetailHeaderAdapter] implementations. */
+    interface Listener {
+        /**
+         * Called when the play button in a detail header is pressed, requesting that the current
+         * item should be played.
+         */
+        fun onPlay()
+
+        /**
+         * Called when the shuffle button in a detail header is pressed, requesting that the current
+         * item should be shuffled
+         */
+        fun onShuffle()
+    }
+
+    private companion object {
+        val PAYLOAD_UPDATE_HEADER = Any()
+    }
+}

app/src/main/java/org/oxycblt/auxio/detail/header/GenreDetailHeaderAdapter.kt

@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2023 Auxio Project
+ * GenreDetailHeaderAdapter.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
+package org.oxycblt.auxio.detail.header
+
+import android.view.View
+import android.view.ViewGroup
+import androidx.core.view.isVisible
+import androidx.recyclerview.widget.RecyclerView
+import org.oxycblt.auxio.R
+import org.oxycblt.auxio.databinding.ItemDetailHeaderBinding
+import org.oxycblt.auxio.detail.list.DetailListAdapter
+import org.oxycblt.auxio.music.Genre
+import org.oxycblt.auxio.util.context
+import org.oxycblt.auxio.util.getPlural
+import org.oxycblt.auxio.util.inflater
+
+/**
+ * A [DetailHeaderAdapter] that shows [Genre] information.
+ * @author Alexander Capehart (OxygenCobalt)
+ */
+class GenreDetailHeaderAdapter(private val listener: Listener) :
+    DetailHeaderAdapter<Genre, GenreDetailHeaderViewHolder>() {
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
+        GenreDetailHeaderViewHolder.from(parent)
+
+    override fun onBindHeader(holder: GenreDetailHeaderViewHolder, parent: Genre) =
+        holder.bind(parent, listener)
+}
+
+/**
+ * A [RecyclerView.ViewHolder] that displays the [Genre] header in the detail view. Use [from] to
+ * create an instance.
+ *
+ * @author Alexander Capehart (OxygenCobalt)
+ */
+class GenreDetailHeaderViewHolder
+private constructor(private val binding: ItemDetailHeaderBinding) :
+    RecyclerView.ViewHolder(binding.root) {
+    /**
+     * Bind new data to this instance.
+     *
+     * @param genre The new [Genre] to bind.
+     * @param listener A [DetailListAdapter.Listener] to bind interactions to.
+     */
+    fun bind(genre: Genre, listener: DetailHeaderAdapter.Listener) {
+        binding.detailCover.bind(genre)
+        binding.detailType.text = binding.context.getString(R.string.lbl_genre)
+        binding.detailName.text = genre.resolveName(binding.context)
+        // Nothing about a genre is applicable to the sub-head text.
+        binding.detailSubhead.isVisible = false
+        // The song count of the genre maps to the info text.
+        binding.detailInfo.text =
+            binding.context.getString(
+                R.string.fmt_two,
+                binding.context.getPlural(R.plurals.fmt_artist_count, genre.artists.size),
+                binding.context.getPlural(R.plurals.fmt_song_count, genre.songs.size))
+        binding.detailPlayButton.setOnClickListener { listener.onPlay() }
+        binding.detailShuffleButton.setOnClickListener { listener.onShuffle() }
+    }
+
+    companion object {
+        /**
+         * Create a new instance.
+         *
+         * @param parent The parent to inflate this instance from.
+         * @return A new instance.
+         */
+        fun from(parent: View) =
+            GenreDetailHeaderViewHolder(ItemDetailHeaderBinding.inflate(parent.context.inflater))
+    }
+}

app/src/main/java/org/oxycblt/auxio/detail/list/AlbumDetailListAdapter.kt

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2021 Auxio Project
- * AlbumDetailAdapter.kt is part of Auxio.
+ * AlbumDetailListAdapter.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,7 +16,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
  
-package org.oxycblt.auxio.detail.recycler
+package org.oxycblt.auxio.detail.list
 
 import android.view.View
 import android.view.ViewGroup
@@ -26,7 +26,6 @@ import androidx.recyclerview.widget.RecyclerView
 import org.oxycblt.auxio.IntegerTable
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.databinding.ItemAlbumSongBinding
-import org.oxycblt.auxio.databinding.ItemDetailBinding
 import org.oxycblt.auxio.databinding.ItemDiscHeaderBinding
 import org.oxycblt.auxio.list.Item
 import org.oxycblt.auxio.list.SelectableListListener
@@ -34,37 +33,22 @@ import org.oxycblt.auxio.list.adapter.SelectionIndicatorAdapter
 import org.oxycblt.auxio.list.adapter.SimpleDiffCallback
 import org.oxycblt.auxio.music.Album
 import org.oxycblt.auxio.music.Song
-import org.oxycblt.auxio.music.areRawNamesTheSame
 import org.oxycblt.auxio.music.metadata.Disc
-import org.oxycblt.auxio.music.resolveNames
 import org.oxycblt.auxio.playback.formatDurationMs
 import org.oxycblt.auxio.util.context
-import org.oxycblt.auxio.util.getPlural
 import org.oxycblt.auxio.util.inflater
 
 /**
- * An [DetailAdapter] implementing the header and sub-items for the [Album] detail view.
+ * An [DetailListAdapter] implementing the header and sub-items for the [Album] detail view.
  *
- * @param listener A [Listener] to bind interactions to.
+ * @param listener A [DetailListAdapter.Listener] to bind interactions to.
  * @author Alexander Capehart (OxygenCobalt)
  */
-class AlbumDetailAdapter(private val listener: Listener) : DetailAdapter(listener, DIFF_CALLBACK) {
+class AlbumDetailListAdapter(private val listener: Listener<Song>) :
-    /**
+    DetailListAdapter(listener, DIFF_CALLBACK) {
-     * An extension to [DetailAdapter.Listener] that enables interactions specific to the album
-     * detail view.
-     */
-    interface Listener : DetailAdapter.Listener<Song> {
-        /**
-         * Called when the artist name in the [Album] header was clicked, requesting navigation to
-         * it's parent artist.
-         */
-        fun onNavigateToParentArtist()
-    }
-
     override fun getItemViewType(position: Int) =
         when (getItem(position)) {
-            // Support the Album header, sub-headers for each disc, and special album songs.
+            // Support sub-headers for each disc, and special album songs.
-            is Album -> AlbumDetailViewHolder.VIEW_TYPE
             is Disc -> DiscViewHolder.VIEW_TYPE
             is Song -> AlbumSongViewHolder.VIEW_TYPE
             else -> super.getItemViewType(position)
@@ -72,7 +56,6 @@ class AlbumDetailAdapter(private val listener: Listener) : DetailAdapter(listene
 
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
         when (viewType) {
-            AlbumDetailViewHolder.VIEW_TYPE -> AlbumDetailViewHolder.from(parent)
             DiscViewHolder.VIEW_TYPE -> DiscViewHolder.from(parent)
             AlbumSongViewHolder.VIEW_TYPE -> AlbumSongViewHolder.from(parent)
             else -> super.onCreateViewHolder(parent, viewType)
@@ -81,7 +64,6 @@ class AlbumDetailAdapter(private val listener: Listener) : DetailAdapter(listene
     override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
         super.onBindViewHolder(holder, position)
         when (val item = getItem(position)) {
-            is Album -> (holder as AlbumDetailViewHolder).bind(item, listener)
             is Disc -> (holder as DiscViewHolder).bind(item)
             is Song -> (holder as AlbumSongViewHolder).bind(item, listener)
         }
@@ -100,91 +82,16 @@ class AlbumDetailAdapter(private val listener: Listener) : DetailAdapter(listene
         /** A comparator that can be used with DiffUtil. */
         val DIFF_CALLBACK =
             object : SimpleDiffCallback<Item>() {
-                override fun areContentsTheSame(oldItem: Item, newItem: Item): Boolean {
+                override fun areContentsTheSame(oldItem: Item, newItem: Item) =
-                    return when {
+                    when {
-                        oldItem is Album && newItem is Album ->
-                            AlbumDetailViewHolder.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
                         oldItem is Disc && newItem is Disc ->
                             DiscViewHolder.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
                         oldItem is Song && newItem is Song ->
                             AlbumSongViewHolder.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
 
                         // Fall back to DetailAdapter's differ to handle other headers.
-                        else -> DetailAdapter.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
+                        else -> DetailListAdapter.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
                     }
-                }
-            }
-    }
-}
-
-/**
- * A [RecyclerView.ViewHolder] that displays the [Album] header in the detail view. Use [from] to
- * create an instance.
- *
- * @author Alexander Capehart (OxygenCobalt)
- */
-private class AlbumDetailViewHolder private constructor(private val binding: ItemDetailBinding) :
-    RecyclerView.ViewHolder(binding.root) {
-
-    /**
-     * Bind new data to this instance.
-     *
-     * @param album The new [Album] to bind.
-     * @param listener A [AlbumDetailAdapter.Listener] to bind interactions to.
-     */
-    fun bind(album: Album, listener: AlbumDetailAdapter.Listener) {
-        binding.detailCover.bind(album)
-
-        // The type text depends on the release type (Album, EP, Single, etc.)
-        binding.detailType.text = binding.context.getString(album.releaseType.stringRes)
-
-        binding.detailName.text = album.resolveName(binding.context)
-
-        // Artist name maps to the subhead text
-        binding.detailSubhead.apply {
-            text = album.artists.resolveNames(context)
-
-            // Add a QoL behavior where navigation to the artist will occur if the artist
-            // name is pressed.
-            setOnClickListener { listener.onNavigateToParentArtist() }
-        }
-
-        // Date, song count, and duration map to the info text
-        binding.detailInfo.apply {
-            // Fall back to a friendlier "No date" text if the album doesn't have date information
-            val date = album.dates?.resolveDate(context) ?: context.getString(R.string.def_date)
-            val songCount = context.getPlural(R.plurals.fmt_song_count, album.songs.size)
-            val duration = album.durationMs.formatDurationMs(true)
-            text = context.getString(R.string.fmt_three, date, songCount, duration)
-        }
-
-        binding.detailPlayButton.setOnClickListener { listener.onPlay() }
-        binding.detailShuffleButton.setOnClickListener { listener.onShuffle() }
-    }
-
-    companion object {
-        /** A unique ID for this [RecyclerView.ViewHolder] type. */
-        const val VIEW_TYPE = IntegerTable.VIEW_TYPE_ALBUM_DETAIL
-
-        /**
-         * Create a new instance.
-         *
-         * @param parent The parent to inflate this instance from.
-         * @return A new instance.
-         */
-        fun from(parent: View) =
-            AlbumDetailViewHolder(ItemDetailBinding.inflate(parent.context.inflater))
-
-        /** A comparator that can be used with DiffUtil. */
-        val DIFF_CALLBACK =
-            object : SimpleDiffCallback<Album>() {
-                override fun areContentsTheSame(oldItem: Album, newItem: Album) =
-                    oldItem.rawName == newItem.rawName &&
-                        oldItem.artists.areRawNamesTheSame(newItem.artists) &&
-                        oldItem.dates == newItem.dates &&
-                        oldItem.songs.size == newItem.songs.size &&
-                        oldItem.durationMs == newItem.durationMs &&
-                        oldItem.releaseType == newItem.releaseType
             }
     }
 }

app/src/main/java/org/oxycblt/auxio/detail/list/ArtistDetailListAdapter.kt

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2021 Auxio Project
- * ArtistDetailAdapter.kt is part of Auxio.
+ * ArtistDetailListAdapter.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,15 +16,13 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
  
-package org.oxycblt.auxio.detail.recycler
+package org.oxycblt.auxio.detail.list
 
 import android.view.View
 import android.view.ViewGroup
-import androidx.core.view.isVisible
 import androidx.recyclerview.widget.RecyclerView
 import org.oxycblt.auxio.IntegerTable
 import org.oxycblt.auxio.R
-import org.oxycblt.auxio.databinding.ItemDetailBinding
 import org.oxycblt.auxio.databinding.ItemParentBinding
 import org.oxycblt.auxio.databinding.ItemSongBinding
 import org.oxycblt.auxio.list.Item
@@ -33,21 +31,19 @@ import org.oxycblt.auxio.list.adapter.SelectionIndicatorAdapter
 import org.oxycblt.auxio.list.adapter.SimpleDiffCallback
 import org.oxycblt.auxio.music.*
 import org.oxycblt.auxio.util.context
-import org.oxycblt.auxio.util.getPlural
 import org.oxycblt.auxio.util.inflater
 
 /**
- * A [DetailAdapter] implementing the header and sub-items for the [Artist] detail view.
+ * A [DetailListAdapter] implementing the header and sub-items for the [Artist] detail view.
  *
- * @param listener A [DetailAdapter.Listener] to bind interactions to.
+ * @param listener A [DetailListAdapter.Listener] to bind interactions to.
  * @author Alexander Capehart (OxygenCobalt)
  */
-class ArtistDetailAdapter(private val listener: Listener<Music>) :
+class ArtistDetailListAdapter(private val listener: Listener<Music>) :
-    DetailAdapter(listener, DIFF_CALLBACK) {
+    DetailListAdapter(listener, DIFF_CALLBACK) {
     override fun getItemViewType(position: Int) =
         when (getItem(position)) {
-            // Support an artist header, and special artist albums/songs.
+            // Support a special artist albums/songs.
-            is Artist -> ArtistDetailViewHolder.VIEW_TYPE
             is Album -> ArtistAlbumViewHolder.VIEW_TYPE
             is Song -> ArtistSongViewHolder.VIEW_TYPE
             else -> super.getItemViewType(position)
@@ -55,7 +51,6 @@ class ArtistDetailAdapter(private val listener: Listener<Music>) :
 
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
         when (viewType) {
-            ArtistDetailViewHolder.VIEW_TYPE -> ArtistDetailViewHolder.from(parent)
             ArtistAlbumViewHolder.VIEW_TYPE -> ArtistAlbumViewHolder.from(parent)
             ArtistSongViewHolder.VIEW_TYPE -> ArtistSongViewHolder.from(parent)
             else -> super.onCreateViewHolder(parent, viewType)
@@ -65,7 +60,6 @@ class ArtistDetailAdapter(private val listener: Listener<Music>) :
         super.onBindViewHolder(holder, position)
         // Re-binding an item with new data and not just a changed selection/playing state.
         when (val item = getItem(position)) {
-            is Artist -> (holder as ArtistDetailViewHolder).bind(item, listener)
             is Album -> (holder as ArtistAlbumViewHolder).bind(item, listener)
             is Song -> (holder as ArtistSongViewHolder).bind(item, listener)
         }
@@ -83,96 +77,14 @@ class ArtistDetailAdapter(private val listener: Listener<Music>) :
         /** A comparator that can be used with DiffUtil. */
         val DIFF_CALLBACK =
             object : SimpleDiffCallback<Item>() {
-                override fun areContentsTheSame(oldItem: Item, newItem: Item): Boolean {
+                override fun areContentsTheSame(oldItem: Item, newItem: Item) =
-                    return when {
+                    when {
-                        oldItem is Artist && newItem is Artist ->
-                            ArtistDetailViewHolder.DIFF_CALLBACK.areContentsTheSame(
-                                oldItem, newItem)
                         oldItem is Album && newItem is Album ->
                             ArtistAlbumViewHolder.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
                         oldItem is Song && newItem is Song ->
                             ArtistSongViewHolder.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
-                        else -> DetailAdapter.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
+                        else -> DetailListAdapter.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
                     }
-                }
-            }
-    }
-}
-
-/**
- * A [RecyclerView.ViewHolder] that displays the [Artist] header in the detail view. Use [from] to
- * create an instance.
- *
- * @author Alexander Capehart (OxygenCobalt)
- */
-private class ArtistDetailViewHolder private constructor(private val binding: ItemDetailBinding) :
-    RecyclerView.ViewHolder(binding.root) {
-
-    /**
-     * Bind new data to this instance.
-     *
-     * @param artist The new [Artist] to bind.
-     * @param listener A [DetailAdapter.Listener] to bind interactions to.
-     */
-    fun bind(artist: Artist, listener: DetailAdapter.Listener<*>) {
-        binding.detailCover.bind(artist)
-        binding.detailType.text = binding.context.getString(R.string.lbl_artist)
-        binding.detailName.text = artist.resolveName(binding.context)
-
-        if (artist.songs.isNotEmpty()) {
-            // Information about the artist's genre(s) map to the sub-head text
-            binding.detailSubhead.apply {
-                isVisible = true
-                text = artist.genres.resolveNames(context)
-            }
-
-            // Song and album counts map to the info
-            binding.detailInfo.text =
-                binding.context.getString(
-                    R.string.fmt_two,
-                    binding.context.getPlural(R.plurals.fmt_album_count, artist.albums.size),
-                    binding.context.getPlural(R.plurals.fmt_song_count, artist.songs.size))
-
-            // In the case that this header used to he configured to have no songs,
-            // we want to reset the visibility of all information that was hidden.
-            binding.detailPlayButton.isVisible = true
-            binding.detailShuffleButton.isVisible = true
-        } else {
-            // The artist does not have any songs, so hide functionality that makes no sense.
-            // ex. Play and Shuffle, Song Counts, and Genre Information.
-            // Artists are always guaranteed to have albums however, so continue to show those.
-            binding.detailSubhead.isVisible = false
-            binding.detailInfo.text =
-                binding.context.getPlural(R.plurals.fmt_album_count, artist.albums.size)
-            binding.detailPlayButton.isVisible = false
-            binding.detailShuffleButton.isVisible = false
-        }
-
-        binding.detailPlayButton.setOnClickListener { listener.onPlay() }
-        binding.detailShuffleButton.setOnClickListener { listener.onShuffle() }
-    }
-
-    companion object {
-        /** A unique ID for this [RecyclerView.ViewHolder] type. */
-        const val VIEW_TYPE = IntegerTable.VIEW_TYPE_ARTIST_DETAIL
-
-        /**
-         * Create a new instance.
-         *
-         * @param parent The parent to inflate this instance from.
-         * @return A new instance.
-         */
-        fun from(parent: View) =
-            ArtistDetailViewHolder(ItemDetailBinding.inflate(parent.context.inflater))
-
-        /** A comparator that can be used with DiffUtil. */
-        val DIFF_CALLBACK =
-            object : SimpleDiffCallback<Artist>() {
-                override fun areContentsTheSame(oldItem: Artist, newItem: Artist) =
-                    oldItem.rawName == newItem.rawName &&
-                        oldItem.genres.areRawNamesTheSame(newItem.genres) &&
-                        oldItem.albums.size == newItem.albums.size &&
-                        oldItem.songs.size == newItem.songs.size
             }
     }
 }

app/src/main/java/org/oxycblt/auxio/detail/list/DetailListAdapter.kt

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2022 Auxio Project
- * DetailAdapter.kt is part of Auxio.
+ * DetailListAdapter.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,7 +16,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
  
-package org.oxycblt.auxio.detail.recycler
+package org.oxycblt.auxio.detail.list
 
 import android.view.View
 import android.view.ViewGroup
@@ -37,13 +37,14 @@ import org.oxycblt.auxio.util.context
 import org.oxycblt.auxio.util.inflater
 
 /**
- * A [RecyclerView.Adapter] that implements behavior shared across each detail view's adapters.
+ * A [RecyclerView.Adapter] that implements shared behavior between lists of child items in the
+ * detail views.
  *
  * @param listener A [Listener] to bind interactions to.
  * @param diffCallback A [DiffUtil.ItemCallback] to compare list updates with.
  * @author Alexander Capehart (OxygenCobalt)
  */
-abstract class DetailAdapter(
+abstract class DetailListAdapter(
     private val listener: Listener<*>,
     private val diffCallback: DiffUtil.ItemCallback<Item>
 ) :
@@ -78,21 +79,8 @@ abstract class DetailAdapter(
         return item is BasicHeader || item is SortHeader
     }
 
-    /** An extended [SelectableListListener] for [DetailAdapter] implementations. */
+    /** An extended [SelectableListListener] for [DetailListAdapter] implementations. */
     interface Listener<in T : Music> : SelectableListListener<T> {
-        // TODO: Split off into sub-listeners if a collapsing toolbar is implemented.
-        /**
-         * Called when the play button in a detail header is pressed, requesting that the current
-         * item should be played.
-         */
-        fun onPlay()
-
-        /**
-         * Called when the shuffle button in a detail header is pressed, requesting that the current
-         * item should be shuffled
-         */
-        fun onShuffle()
-
         /**
          * Called when the button in a [SortHeader] item is pressed, requesting that the sort menu
          * should be opened.
@@ -137,9 +125,9 @@ private class SortHeaderViewHolder(private val binding: ItemSortHeaderBinding) :
      * Bind new data to this instance.
      *
      * @param sortHeader The new [SortHeader] to bind.
-     * @param listener An [DetailAdapter.Listener] to bind interactions to.
+     * @param listener An [DetailListAdapter.Listener] to bind interactions to.
      */
-    fun bind(sortHeader: SortHeader, listener: DetailAdapter.Listener<*>) {
+    fun bind(sortHeader: SortHeader, listener: DetailListAdapter.Listener<*>) {
         binding.headerTitle.text = binding.context.getString(sortHeader.titleRes)
         binding.headerButton.apply {
             // Add a Tooltip based on the content description so that the purpose of this

app/src/main/java/org/oxycblt/auxio/detail/list/GenreDetailListAdapter.kt

@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2021 Auxio Project
+ * GenreDetailListAdapter.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
+package org.oxycblt.auxio.detail.list
+
+import android.view.ViewGroup
+import androidx.recyclerview.widget.RecyclerView
+import org.oxycblt.auxio.list.Item
+import org.oxycblt.auxio.list.adapter.SimpleDiffCallback
+import org.oxycblt.auxio.list.recycler.ArtistViewHolder
+import org.oxycblt.auxio.list.recycler.SongViewHolder
+import org.oxycblt.auxio.music.Artist
+import org.oxycblt.auxio.music.Genre
+import org.oxycblt.auxio.music.Music
+import org.oxycblt.auxio.music.Song
+
+/**
+ * An [DetailListAdapter] implementing the header and sub-items for the [Genre] detail view.
+ *
+ * @param listener A [DetailListAdapter.Listener] to bind interactions to.
+ * @author Alexander Capehart (OxygenCobalt)
+ */
+class GenreDetailListAdapter(private val listener: Listener<Music>) :
+    DetailListAdapter(listener, DIFF_CALLBACK) {
+    override fun getItemViewType(position: Int) =
+        when (getItem(position)) {
+            // Support generic Artist/Song items.
+            is Artist -> ArtistViewHolder.VIEW_TYPE
+            is Song -> SongViewHolder.VIEW_TYPE
+            else -> super.getItemViewType(position)
+        }
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
+        when (viewType) {
+            ArtistViewHolder.VIEW_TYPE -> ArtistViewHolder.from(parent)
+            SongViewHolder.VIEW_TYPE -> SongViewHolder.from(parent)
+            else -> super.onCreateViewHolder(parent, viewType)
+        }
+
+    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
+        super.onBindViewHolder(holder, position)
+        when (val item = getItem(position)) {
+            is Artist -> (holder as ArtistViewHolder).bind(item, listener)
+            is Song -> (holder as SongViewHolder).bind(item, listener)
+        }
+    }
+
+    override fun isItemFullWidth(position: Int): Boolean {
+        if (super.isItemFullWidth(position)) {
+            return true
+        }
+        // Genre headers should be full-width in all configurations
+        return getItem(position) is Genre
+    }
+
+    private companion object {
+        val DIFF_CALLBACK =
+            object : SimpleDiffCallback<Item>() {
+                override fun areContentsTheSame(oldItem: Item, newItem: Item) =
+                    when {
+                        oldItem is Artist && newItem is Artist ->
+                            ArtistViewHolder.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
+                        oldItem is Song && newItem is Song ->
+                            SongViewHolder.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
+                        else -> DetailListAdapter.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
+                    }
+            }
+    }
+}

app/src/main/java/org/oxycblt/auxio/detail/list/SongPropertyAdapter.kt

@@ -16,7 +16,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
  
-package org.oxycblt.auxio.detail.recycler
+package org.oxycblt.auxio.detail.list
 
 import android.view.View
 import android.view.ViewGroup

app/src/main/java/org/oxycblt/auxio/detail/recycler/GenreDetailAdapter.kt

@@ -1,154 +0,0 @@
-/*
- * Copyright (c) 2021 Auxio Project
- * GenreDetailAdapter.kt is part of Auxio.
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
- 
-package org.oxycblt.auxio.detail.recycler
-
-import android.view.View
-import android.view.ViewGroup
-import androidx.core.view.isVisible
-import androidx.recyclerview.widget.RecyclerView
-import org.oxycblt.auxio.IntegerTable
-import org.oxycblt.auxio.R
-import org.oxycblt.auxio.databinding.ItemDetailBinding
-import org.oxycblt.auxio.list.Item
-import org.oxycblt.auxio.list.adapter.SimpleDiffCallback
-import org.oxycblt.auxio.list.recycler.ArtistViewHolder
-import org.oxycblt.auxio.list.recycler.SongViewHolder
-import org.oxycblt.auxio.music.Artist
-import org.oxycblt.auxio.music.Genre
-import org.oxycblt.auxio.music.Music
-import org.oxycblt.auxio.music.Song
-import org.oxycblt.auxio.util.context
-import org.oxycblt.auxio.util.getPlural
-import org.oxycblt.auxio.util.inflater
-
-/**
- * An [DetailAdapter] implementing the header and sub-items for the [Genre] detail view.
- *
- * @param listener A [DetailAdapter.Listener] to bind interactions to.
- * @author Alexander Capehart (OxygenCobalt)
- */
-class GenreDetailAdapter(private val listener: Listener<Music>) :
-    DetailAdapter(listener, DIFF_CALLBACK) {
-    override fun getItemViewType(position: Int) =
-        when (getItem(position)) {
-            // Support the Genre header and generic Artist/Song items. There's nothing about
-            // a genre that will make the artists/songs specially formatted, so it doesn't matter
-            // what we use for their ViewHolders.
-            is Genre -> GenreDetailViewHolder.VIEW_TYPE
-            is Artist -> ArtistViewHolder.VIEW_TYPE
-            is Song -> SongViewHolder.VIEW_TYPE
-            else -> super.getItemViewType(position)
-        }
-
-    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
-        when (viewType) {
-            GenreDetailViewHolder.VIEW_TYPE -> GenreDetailViewHolder.from(parent)
-            ArtistViewHolder.VIEW_TYPE -> ArtistViewHolder.from(parent)
-            SongViewHolder.VIEW_TYPE -> SongViewHolder.from(parent)
-            else -> super.onCreateViewHolder(parent, viewType)
-        }
-
-    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
-        super.onBindViewHolder(holder, position)
-        when (val item = getItem(position)) {
-            is Genre -> (holder as GenreDetailViewHolder).bind(item, listener)
-            is Artist -> (holder as ArtistViewHolder).bind(item, listener)
-            is Song -> (holder as SongViewHolder).bind(item, listener)
-        }
-    }
-
-    override fun isItemFullWidth(position: Int): Boolean {
-        if (super.isItemFullWidth(position)) {
-            return true
-        }
-        // Genre headers should be full-width in all configurations
-        return getItem(position) is Genre
-    }
-
-    private companion object {
-        val DIFF_CALLBACK =
-            object : SimpleDiffCallback<Item>() {
-                override fun areContentsTheSame(oldItem: Item, newItem: Item): Boolean {
-                    return when {
-                        oldItem is Genre && newItem is Genre ->
-                            GenreDetailViewHolder.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
-                        oldItem is Artist && newItem is Artist ->
-                            ArtistViewHolder.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
-                        oldItem is Song && newItem is Song ->
-                            SongViewHolder.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
-                        else -> DetailAdapter.DIFF_CALLBACK.areContentsTheSame(oldItem, newItem)
-                    }
-                }
-            }
-    }
-}
-
-/**
- * A [RecyclerView.ViewHolder] that displays the [Genre] header in the detail view. Use [from] to
- * create an instance.
- *
- * @author Alexander Capehart (OxygenCobalt)
- */
-private class GenreDetailViewHolder private constructor(private val binding: ItemDetailBinding) :
-    RecyclerView.ViewHolder(binding.root) {
-    /**
-     * Bind new data to this instance.
-     *
-     * @param genre The new [Song] to bind.
-     * @param listener A [DetailAdapter.Listener] to bind interactions to.
-     */
-    fun bind(genre: Genre, listener: DetailAdapter.Listener<*>) {
-        binding.detailCover.bind(genre)
-        binding.detailType.text = binding.context.getString(R.string.lbl_genre)
-        binding.detailName.text = genre.resolveName(binding.context)
-        // Nothing about a genre is applicable to the sub-head text.
-        binding.detailSubhead.isVisible = false
-        // The song count of the genre maps to the info text.
-        binding.detailInfo.text =
-            binding.context.getString(
-                R.string.fmt_two,
-                binding.context.getPlural(R.plurals.fmt_artist_count, genre.artists.size),
-                binding.context.getPlural(R.plurals.fmt_song_count, genre.songs.size))
-        binding.detailPlayButton.setOnClickListener { listener.onPlay() }
-        binding.detailShuffleButton.setOnClickListener { listener.onShuffle() }
-    }
-
-    companion object {
-        /** A unique ID for this [RecyclerView.ViewHolder] type. */
-        const val VIEW_TYPE = IntegerTable.VIEW_TYPE_GENRE_DETAIL
-
-        /**
-         * Create a new instance.
-         *
-         * @param parent The parent to inflate this instance from.
-         * @return A new instance.
-         */
-        fun from(parent: View) =
-            GenreDetailViewHolder(ItemDetailBinding.inflate(parent.context.inflater))
-
-        /** A comparator that can be used with DiffUtil. */
-        val DIFF_CALLBACK =
-            object : SimpleDiffCallback<Genre>() {
-                override fun areContentsTheSame(oldItem: Genre, newItem: Genre) =
-                    oldItem.rawName == newItem.rawName &&
-                        oldItem.songs.size == newItem.songs.size &&
-                        oldItem.durationMs == newItem.durationMs
-            }
-    }
-}

app/src/main/java/org/oxycblt/auxio/image/ImageModule.kt

@@ -34,7 +34,6 @@ import org.oxycblt.auxio.image.extractor.*
 @InstallIn(SingletonComponent::class)
 interface ImageModule {
     @Binds fun settings(imageSettings: ImageSettingsImpl): ImageSettings
-    @Binds fun coverExtractor(coverExtractor: CoverExtractorImpl): CoverExtractor
 }
 
 @Module

app/src/main/java/org/oxycblt/auxio/image/extractor/CoverExtractor.kt

@@ -38,33 +38,15 @@ import org.oxycblt.auxio.music.Album
 import org.oxycblt.auxio.util.logD
 import org.oxycblt.auxio.util.logW
 
-/**
+class CoverExtractor
- * Stateless interface for loading [Album] cover image data.
- *
- * @author Alexander Capehart (OxygenCobalt)
- */
-interface CoverExtractor {
-    /**
-     * Fetch an album cover, respecting the current cover configuration.
-     *
-     * @param context [Context] required to load the image.
-     * @param imageSettings [ImageSettings] required to obtain configuration information.
-     * @param album [Album] to load the cover from.
-     * @return An [InputStream] of image data if the cover loading was successful, null if the cover
-     *   loading failed or should not occur.
-     */
-    suspend fun extract(album: Album): InputStream?
-}
-
-class CoverExtractorImpl
 @Inject
 constructor(
     @ApplicationContext private val context: Context,
     private val imageSettings: ImageSettings,
     private val mediaSourceFactory: MediaSource.Factory
-) : CoverExtractor {
+) {
 
-    override suspend fun extract(album: Album): InputStream? =
+    suspend fun extract(album: Album): InputStream? =
         try {
             when (imageSettings.coverMode) {
                 CoverMode.OFF -> null

app/src/main/java/org/oxycblt/auxio/list/adapter/FlexibleListAdapter.kt

@@ -35,6 +35,7 @@ import org.oxycblt.auxio.util.logD
 abstract class FlexibleListAdapter<T, VH : RecyclerView.ViewHolder>(
     diffCallback: DiffUtil.ItemCallback<T>
 ) : RecyclerView.Adapter<VH>() {
+    @Suppress("LeakingThis")
     private val differ = FlexibleListDiffer(this, diffCallback)
     final override fun getItemCount() = differ.currentList.size
     /** The current list stored by the adapter's differ instance. */
@@ -55,9 +56,7 @@ abstract class FlexibleListAdapter<T, VH : RecyclerView.ViewHolder>(
         instructions: UpdateInstructions?,
         callback: (() -> Unit)? = null
     ) =
-        differ.update(newData, instructions, callback).also {
+        differ.update(newData, instructions, callback)
-            logD("Update delivered: $instructions" + "")
-        }
 }
 
 /**

app/src/main/java/org/oxycblt/auxio/list/recycler/HeaderItemDecoration.kt

@@ -20,6 +20,7 @@ package org.oxycblt.auxio.list.recycler
 
 import android.content.Context
 import android.util.AttributeSet
+import androidx.recyclerview.widget.ConcatAdapter
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
 import com.google.android.material.divider.BackportMaterialDividerItemDecoration
@@ -41,12 +42,26 @@ constructor(
     defStyleAttr: Int = R.attr.materialDividerStyle,
     orientation: Int = LinearLayoutManager.VERTICAL
 ) : BackportMaterialDividerItemDecoration(context, attributeSet, defStyleAttr, orientation) {
-    override fun shouldDrawDivider(position: Int, adapter: RecyclerView.Adapter<*>?) =
+    override fun shouldDrawDivider(position: Int, adapter: RecyclerView.Adapter<*>?): Boolean {
+        if (adapter is ConcatAdapter) {
+            val adapterAndPosition =
+                try {
+                    adapter.getWrappedAdapterAndPosition(position + 1)
+                } catch (e: IllegalArgumentException) {
+                    return false
+                }
+            return hasHeaderAtPosition(adapterAndPosition.second, adapterAndPosition.first)
+        } else {
+            return hasHeaderAtPosition(position + 1, adapter)
+        }
+    }
+
+    private fun hasHeaderAtPosition(position: Int, adapter: RecyclerView.Adapter<*>?) =
         try {
             // Add a divider if the next item is a header. This organizes the divider to separate
             // the ends of content rather than the beginning of content, alongside an added benefit
             // of preventing top headers from having a divider applied.
-            (adapter as FlexibleListAdapter<*, *>).getItem(position + 1) is Header
+            (adapter as FlexibleListAdapter<*, *>).getItem(position) is Header
         } catch (e: ClassCastException) {
             false
         } catch (e: IndexOutOfBoundsException) {

app/src/main/res/color/sel_m3_switch_thumb.xml

@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-    <item android:alpha="0.12" android:color="?attr/colorOnSurface" android:state_enabled="false" />
-    <item android:color="?attr/colorOnPrimary" android:state_checked="true" />
-    <item android:color="?attr/colorSurfaceVariant" />
-</selector>

app/src/main/res/color/sel_m3_switch_track.xml

@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-    <item android:alpha="0.38" android:color="?attr/colorOnSurface" android:state_enabled="false" />
-    <item android:color="?attr/colorPrimary" android:state_checked="true" />
-    <item android:color="?attr/colorOnSurfaceVariant" />
-</selector>

app/src/main/res/drawable/ui_m3_switch_thumb.xml

@@ -1,15 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
-    <item
-        android:bottom="4dp"
-        android:left="4dp"
-        android:right="4dp"
-        android:top="4dp">
-        <shape android:shape="oval">
-            <solid android:color="#000000" />
-            <size
-                android:width="20dp"
-                android:height="20dp" />
-        </shape>
-    </item>
-</layer-list>

app/src/main/res/drawable/ui_m3_switch_track.xml

@@ -1,12 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
-    <item>
-        <shape android:shape="rectangle">
-            <solid android:color="#000000" />
-            <corners android:radius="56dp" />
-            <size
-                android:width="64dp"
-                android:height="28dp" />
-        </shape>
-    </item>
-</layer-list>

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

@@ -35,6 +35,6 @@
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         app:layout_behavior="com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior"
-        tools:listitem="@layout/item_detail" />
+        tools:listitem="@layout/item_detail_header" />
 
 </androidx.coordinatorlayout.widget.CoordinatorLayout>

app/src/main/res/values-gl/strings.xml

@@ -226,7 +226,7 @@
     <string name="fmt_db_pos">+%.1f dB</string>
     <string name="fmt_bitrate">%d kbps</string>
     <string name="fmt_sample_rate">%d Hz</string>
-    <string name="fmt_indexing">Cargando a túa biblioteca de música... (%1$d/%2$d)</string>
+    <string name="fmt_indexing">Cargando a túa biblioteca de música… (%1$d/%2$d)</string>
     <string name="fmt_lib_song_count">Cancións cargadas: %d</string>
     <string name="fmt_lib_album_count">Álbums cargados: %d</string>
     <string name="fmt_lib_artist_count">Artistas cargados: %d</string>

app/src/main/res/values/styles_core.xml

@@ -33,7 +33,7 @@
         <item name="textAppearanceHeadlineSmall">@style/TextAppearance.Auxio.HeadlineSmall</item>
 
         <item name="textAppearanceTitleLarge">@style/TextAppearance.Auxio.TitleLarge</item>
-        <item name="textAppearanceTitleMedium">@style/TextAppearance.Auxio.TitleMediumLowEmphasis
+        <item name="textAppearanceTitleMedium">@style/TextAppearance.Auxio.TitleMedium
         </item>
         <item name="textAppearanceTitleSmall">@style/TextAppearance.Auxio.TitleSmall</item>
 

app/src/main/res/values/typography.xml

@@ -72,13 +72,6 @@
     </style>
 
     <style name="TextAppearance.Auxio.TitleMedium" parent="TextAppearance.Material3.TitleMedium">
-        <item name="fontFamily">@font/inter_semibold</item>
-        <item name="android:fontFamily">@font/inter_semibold</item>
-        <item name="android:textStyle">bold</item>
-        <item name="android:letterSpacing">-0.00825</item>
-    </style>
-
-    <style name="TextAppearance.Auxio.TitleMediumLowEmphasis" parent="TextAppearance.Material3.TitleMedium">
         <item name="fontFamily">@font/inter_regular</item>
         <item name="android:fontFamily">@font/inter_regular</item>
         <item name="android:textStyle">normal</item>