list: make sorting direction explicit

Make sorting direction (ascending/descending) explicit in the UI and in
the code.

Instead of a boolean flag, two distinct "ascending" and "descending"
options are used instead. This should be much clearer.

CHANGELOG.md

@@ -8,6 +8,8 @@
 #### What's Improved
 - Auxio will now accept zeroed track/disc numbers in the presence of non-zero total
 track/disc fields
+- Music loading has been made slightly faster
+- Improved sort menu usability
 
 #### What's Fixed
 - Fixed non-functioning "repeat all" repeat mode

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

@@ -40,7 +40,7 @@ import org.oxycblt.auxio.music.Music
 import org.oxycblt.auxio.music.MusicMode
 import org.oxycblt.auxio.music.MusicParent
 import org.oxycblt.auxio.music.Song
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.ui.NavigationViewModel
 import org.oxycblt.auxio.util.*
@@ -151,14 +151,19 @@ class AlbumDetailFragment :
         openMenu(anchor, R.menu.menu_album_sort) {
             val sort = detailModel.albumSongSort
             unlikelyToBeNull(menu.findItem(sort.mode.itemId)).isChecked = true
-            unlikelyToBeNull(menu.findItem(R.id.option_sort_asc)).isChecked = sort.isAscending
+            val directionItemId =
+                when (sort.direction) {
+                    Sort.Direction.ASCENDING -> R.id.option_sort_asc
+                    Sort.Direction.DESCENDING -> R.id.option_sort_dec
+                }
+            unlikelyToBeNull(menu.findItem(directionItemId)).isChecked = true
             setOnMenuItemClickListener { item ->
                 item.isChecked = !item.isChecked
                 detailModel.albumSongSort =
-                    if (item.itemId == R.id.option_sort_asc) {
-                        sort.withAscending(item.isChecked)
-                    } else {
-                        sort.withMode(unlikelyToBeNull(Sort.Mode.fromItemId(item.itemId)))
+                    when (item.itemId) {
+                        R.id.option_sort_asc -> sort.withDirection(Sort.Direction.ASCENDING)
+                        R.id.option_sort_dec -> sort.withDirection(Sort.Direction.DESCENDING)
+                        else -> sort.withMode(unlikelyToBeNull(Sort.Mode.fromItemId(item.itemId)))
                     }
                 true
             }

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

@@ -39,7 +39,7 @@ import org.oxycblt.auxio.music.Artist
 import org.oxycblt.auxio.music.Music
 import org.oxycblt.auxio.music.MusicParent
 import org.oxycblt.auxio.music.Song
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.ui.NavigationViewModel
 import org.oxycblt.auxio.util.collect
@@ -167,15 +167,20 @@ class ArtistDetailFragment :
         openMenu(anchor, R.menu.menu_artist_sort) {
             val sort = detailModel.artistSongSort
             unlikelyToBeNull(menu.findItem(sort.mode.itemId)).isChecked = true
-            unlikelyToBeNull(menu.findItem(R.id.option_sort_asc)).isChecked = sort.isAscending
+            val directionItemId =
+                when (sort.direction) {
+                    Sort.Direction.ASCENDING -> R.id.option_sort_asc
+                    Sort.Direction.DESCENDING -> R.id.option_sort_dec
+                }
+            unlikelyToBeNull(menu.findItem(directionItemId)).isChecked = true
             setOnMenuItemClickListener { item ->
                 item.isChecked = !item.isChecked
 
                 detailModel.artistSongSort =
-                    if (item.itemId == R.id.option_sort_asc) {
-                        sort.withAscending(item.isChecked)
-                    } else {
-                        sort.withMode(unlikelyToBeNull(Sort.Mode.fromItemId(item.itemId)))
+                    when (item.itemId) {
+                        R.id.option_sort_asc -> sort.withDirection(Sort.Direction.ASCENDING)
+                        R.id.option_sort_dec -> sort.withDirection(Sort.Direction.DESCENDING)
+                        else -> sort.withMode(unlikelyToBeNull(Sort.Mode.fromItemId(item.itemId)))
                     }
 
                 true

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

@@ -34,7 +34,7 @@ import org.oxycblt.auxio.list.BasicHeader
 import org.oxycblt.auxio.list.Item
 import org.oxycblt.auxio.music.*
 import org.oxycblt.auxio.music.library.Library
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.music.metadata.AudioInfo
 import org.oxycblt.auxio.music.metadata.Disc
 import org.oxycblt.auxio.music.metadata.ReleaseType
@@ -280,7 +280,7 @@ constructor(
     private fun refreshArtistList(artist: Artist) {
         logD("Refreshing artist data")
         val data = mutableListOf<Item>(artist)
-        val albums = Sort(Sort.Mode.ByDate, false).albums(artist.albums)
+        val albums = Sort(Sort.Mode.ByDate, Sort.Direction.DESCENDING).albums(artist.albums)
 
         val byReleaseGroup =
             albums.groupBy {

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

@@ -40,7 +40,7 @@ import org.oxycblt.auxio.music.Genre
 import org.oxycblt.auxio.music.Music
 import org.oxycblt.auxio.music.MusicParent
 import org.oxycblt.auxio.music.Song
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.ui.NavigationViewModel
 import org.oxycblt.auxio.util.collect
@@ -166,14 +166,19 @@ class GenreDetailFragment :
         openMenu(anchor, R.menu.menu_genre_sort) {
             val sort = detailModel.genreSongSort
             unlikelyToBeNull(menu.findItem(sort.mode.itemId)).isChecked = true
-            unlikelyToBeNull(menu.findItem(R.id.option_sort_asc)).isChecked = sort.isAscending
+            val directionItemId =
+                when (sort.direction) {
+                    Sort.Direction.ASCENDING -> R.id.option_sort_asc
+                    Sort.Direction.DESCENDING -> R.id.option_sort_dec
+                }
+            unlikelyToBeNull(menu.findItem(directionItemId)).isChecked = true
             setOnMenuItemClickListener { item ->
                 item.isChecked = !item.isChecked
                 detailModel.genreSongSort =
-                    if (item.itemId == R.id.option_sort_asc) {
-                        sort.withAscending(item.isChecked)
-                    } else {
-                        sort.withMode(unlikelyToBeNull(Sort.Mode.fromItemId(item.itemId)))
+                    when (item.itemId) {
+                        R.id.option_sort_asc -> sort.withDirection(Sort.Direction.ASCENDING)
+                        R.id.option_sort_dec -> sort.withDirection(Sort.Direction.DESCENDING)
+                        else -> sort.withMode(unlikelyToBeNull(Sort.Mode.fromItemId(item.itemId)))
                     }
                 true
             }

app/src/main/java/org/oxycblt/auxio/home/HomeFragment.kt

@@ -23,6 +23,7 @@ import android.view.MenuItem
 import android.view.View
 import androidx.activity.result.ActivityResultLauncher
 import androidx.activity.result.contract.ActivityResultContracts
+import androidx.core.view.MenuCompat
 import androidx.core.view.isVisible
 import androidx.core.view.iterator
 import androidx.core.view.updatePadding
@@ -53,7 +54,7 @@ import org.oxycblt.auxio.list.selection.SelectionFragment
 import org.oxycblt.auxio.list.selection.SelectionViewModel
 import org.oxycblt.auxio.music.*
 import org.oxycblt.auxio.music.library.Library
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.music.system.Indexer
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.ui.MainNavigationAction
@@ -104,7 +105,10 @@ class HomeFragment :
 
         // --- UI SETUP ---
         binding.homeAppbar.addOnOffsetChangedListener(this)
-        binding.homeToolbar.setOnMenuItemClickListener(this)
+        binding.homeToolbar.apply {
+            setOnMenuItemClickListener(this@HomeFragment)
+            MenuCompat.setGroupDividerEnabled(menu, true)
+        }
 
         // Load the track color in manually as it's unclear whether the track actually supports
         // using a ColorStateList in the resources
@@ -213,11 +217,18 @@ class HomeFragment :
                 // Junk click event when opening the menu
             }
             R.id.option_sort_asc -> {
-                item.isChecked = !item.isChecked
+                item.isChecked = true
                 homeModel.setSortForCurrentTab(
                     homeModel
                         .getSortForTab(homeModel.currentTabMode.value)
-                        .withAscending(item.isChecked))
+                        .withDirection(Sort.Direction.ASCENDING))
+            }
+            R.id.option_sort_dec -> {
+                item.isChecked = true
+                homeModel.setSortForCurrentTab(
+                    homeModel
+                        .getSortForTab(homeModel.currentTabMode.value)
+                        .withDirection(Sort.Direction.DESCENDING))
             }
             else -> {
                 // Sorting option was selected, mark it as selected and update the mode
@@ -270,6 +281,7 @@ class HomeFragment :
                 // Only allow sorting by name, count, and duration for artists
                 MusicMode.ARTISTS -> { id ->
                         id == R.id.option_sort_asc ||
+                            id == R.id.option_sort_dec ||
                             id == R.id.option_sort_name ||
                             id == R.id.option_sort_count ||
                             id == R.id.option_sort_duration
@@ -277,6 +289,7 @@ class HomeFragment :
                 // Only allow sorting by name, count, and duration for genres
                 MusicMode.GENRES -> { id ->
                         id == R.id.option_sort_asc ||
+                            id == R.id.option_sort_dec ||
                             id == R.id.option_sort_name ||
                             id == R.id.option_sort_count ||
                             id == R.id.option_sort_duration
@@ -292,7 +305,10 @@ class HomeFragment :
             // Check the ascending option and corresponding sort option to align with
             // the current sort of the tab.
             if (option.itemId == toHighlight.mode.itemId ||
-                (option.itemId == R.id.option_sort_asc && toHighlight.isAscending)) {
+                (option.itemId == R.id.option_sort_asc &&
+                    toHighlight.direction == Sort.Direction.ASCENDING) ||
+                (option.itemId == R.id.option_sort_dec &&
+                    toHighlight.direction == Sort.Direction.DESCENDING)) {
                 option.isChecked = true
             }
 

app/src/main/java/org/oxycblt/auxio/home/HomeViewModel.kt

@@ -25,7 +25,7 @@ import kotlinx.coroutines.flow.StateFlow
 import org.oxycblt.auxio.home.tabs.Tab
 import org.oxycblt.auxio.music.*
 import org.oxycblt.auxio.music.library.Library
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.playback.PlaybackSettings
 import org.oxycblt.auxio.util.logD
 

app/src/main/java/org/oxycblt/auxio/home/list/AlbumListFragment.kt

@@ -37,7 +37,7 @@ import org.oxycblt.auxio.list.adapter.SelectionIndicatorAdapter
 import org.oxycblt.auxio.list.recycler.AlbumViewHolder
 import org.oxycblt.auxio.list.selection.SelectionViewModel
 import org.oxycblt.auxio.music.*
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.playback.formatDurationMs
 import org.oxycblt.auxio.playback.secsToMs

app/src/main/java/org/oxycblt/auxio/home/list/ArtistListFragment.kt

@@ -38,7 +38,7 @@ import org.oxycblt.auxio.music.Artist
 import org.oxycblt.auxio.music.Music
 import org.oxycblt.auxio.music.MusicMode
 import org.oxycblt.auxio.music.MusicParent
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.playback.formatDurationMs
 import org.oxycblt.auxio.ui.NavigationViewModel

app/src/main/java/org/oxycblt/auxio/home/list/GenreListFragment.kt

@@ -38,7 +38,7 @@ import org.oxycblt.auxio.music.Genre
 import org.oxycblt.auxio.music.Music
 import org.oxycblt.auxio.music.MusicMode
 import org.oxycblt.auxio.music.MusicParent
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.playback.formatDurationMs
 import org.oxycblt.auxio.ui.NavigationViewModel

app/src/main/java/org/oxycblt/auxio/home/list/SongListFragment.kt

@@ -40,7 +40,7 @@ import org.oxycblt.auxio.music.Music
 import org.oxycblt.auxio.music.MusicMode
 import org.oxycblt.auxio.music.MusicParent
 import org.oxycblt.auxio.music.Song
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.playback.formatDurationMs
 import org.oxycblt.auxio.playback.secsToMs

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

@@ -35,7 +35,7 @@ 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.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 
 /**
  * A [Keyer] implementation for [Music] data.
@@ -91,7 +91,7 @@ private constructor(
 ) : Fetcher {
     override suspend fun fetch(): FetchResult? {
         // Pick the "most prominent" albums (i.e albums with the most songs) to show in the image.
-        val albums = Sort(Sort.Mode.ByCount, false).albums(artist.albums)
+        val albums = Sort(Sort.Mode.ByCount, Sort.Direction.DESCENDING).albums(artist.albums)
         val results = albums.mapAtMostNotNull(4) { album -> Covers.fetch(context, album) }
         return Images.createMosaic(context, results, size)
     }

app/src/main/java/org/oxycblt/auxio/list/ListFragment.kt

@@ -21,6 +21,8 @@ import android.view.MenuItem
 import android.view.View
 import androidx.annotation.MenuRes
 import androidx.appcompat.widget.PopupMenu
+import androidx.core.internal.view.SupportMenu
+import androidx.core.view.MenuCompat
 import androidx.recyclerview.widget.RecyclerView
 import androidx.viewbinding.ViewBinding
 import org.oxycblt.auxio.MainFragmentDirections
@@ -237,6 +239,8 @@ abstract class ListFragment<in T : Music, VB : ViewBinding> :
         currentMenu =
             PopupMenu(requireContext(), anchor).apply {
                 inflate(menuRes)
+                logD(menu is SupportMenu)
+                MenuCompat.setGroupDividerEnabled(menu, true)
                 block()
                 setOnDismissListener { currentMenu = null }
                 show()

app/src/main/java/org/oxycblt/auxio/list/Sort.kt

@@ -15,14 +15,14 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
  
-package org.oxycblt.auxio.music.library
+package org.oxycblt.auxio.list
 
 import androidx.annotation.IdRes
 import kotlin.math.max
 import org.oxycblt.auxio.IntegerTable
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.music.*
-import org.oxycblt.auxio.music.library.Sort.Mode
+import org.oxycblt.auxio.list.Sort.Mode
 import org.oxycblt.auxio.music.metadata.Date
 import org.oxycblt.auxio.music.metadata.Disc
 
@@ -32,23 +32,23 @@ import org.oxycblt.auxio.music.metadata.Disc
  * This can be used not only to sort items, but also represent a sorting mode within the UI.
  *
  * @param mode A [Mode] dictating how to sort the list.
- * @param isAscending Whether to sort in ascending or descending order.
+ * @param direction The [Direction] to sort in.
  * @author Alexander Capehart (OxygenCobalt)
  */
-data class Sort(val mode: Mode, val isAscending: Boolean) {
+data class Sort(val mode: Mode, val direction: Direction) {
     /**
-     * Create a new [Sort] with the same [mode], but different [isAscending] value.
-     * @param isAscending Whether the new sort should be in ascending order or not.
-     * @return A new sort with the same mode, but with the new [isAscending] value applied.
+     * Create a new [Sort] with the same [mode], but a different [Direction].
+     * @param direction The new [Direction] to sort in.
+     * @return A new sort with the same mode, but with the new [Direction] value applied.
      */
-    fun withAscending(isAscending: Boolean) = Sort(mode, isAscending)
+    fun withDirection(direction: Direction) = Sort(mode, direction)
 
     /**
-     * Create a new [Sort] with the same [isAscending] value, but different [mode] value.
+     * Create a new [Sort] with the same [direction] value, but different [mode] value.
      * @param mode Tbe new mode to use for the Sort.
-     * @return A new sort with the same [isAscending] value, but with the new [mode] applied.
+     * @return A new sort with the same [direction] value, but with the new [mode] applied.
      */
-    fun withMode(mode: Mode) = Sort(mode, isAscending)
+    fun withMode(mode: Mode) = Sort(mode, direction)
 
     /**
      * Sort a list of [Song]s.
@@ -99,7 +99,7 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
      * @param songs The [Song]s to sort.
      */
     private fun songsInPlace(songs: MutableList<out Song>) {
-        songs.sortWith(mode.getSongComparator(isAscending))
+        songs.sortWith(mode.getSongComparator(direction))
     }
 
     /**
@@ -107,7 +107,7 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
      * @param albums The [Album]s to sort.
      */
     private fun albumsInPlace(albums: MutableList<out Album>) {
-        albums.sortWith(mode.getAlbumComparator(isAscending))
+        albums.sortWith(mode.getAlbumComparator(direction))
     }
 
     /**
@@ -115,7 +115,7 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
      * @param artists The [Album]s to sort.
      */
     private fun artistsInPlace(artists: MutableList<out Artist>) {
-        artists.sortWith(mode.getArtistComparator(isAscending))
+        artists.sortWith(mode.getArtistComparator(direction))
     }
 
     /**
@@ -123,7 +123,7 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
      * @param genres The [Genre]s to sort.
      */
     private fun genresInPlace(genres: MutableList<out Genre>) {
-        genres.sortWith(mode.getGenreComparator(isAscending))
+        genres.sortWith(mode.getGenreComparator(direction))
     }
 
     /**
@@ -134,8 +134,14 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
         // Sort's integer representation is formatted as AMMMM, where A is a bitflag
         // representing if the sort is in ascending or descending order, and M is the
         // integer representation of the sort mode.
-        get() = mode.intCode.shl(1) or if (isAscending) 1 else 0
+        get() =
+            mode.intCode.shl(1) or
+                when (direction) {
+                    Direction.ASCENDING -> 1
+                    Direction.DESCENDING -> 0
+                }
 
+    /** Describes the type of data to sort with. */
     sealed class Mode {
         /** The integer representation of this sort mode. */
         abstract val intCode: Int
@@ -144,37 +150,37 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
 
         /**
          * Get a [Comparator] that sorts [Song]s according to this [Mode].
-         * @param isAscending Whether to sort in ascending or descending order.
+         * @param direction The direction to sort in.
          * @return A [Comparator] that can be used to sort a [Song] list according to this [Mode].
          */
-        open fun getSongComparator(isAscending: Boolean): Comparator<Song> {
+        open fun getSongComparator(direction: Direction): Comparator<Song> {
             throw UnsupportedOperationException()
         }
 
         /**
          * Get a [Comparator] that sorts [Album]s according to this [Mode].
-         * @param isAscending Whether to sort in ascending or descending order.
+         * @param direction The direction to sort in.
          * @return A [Comparator] that can be used to sort a [Album] list according to this [Mode].
          */
-        open fun getAlbumComparator(isAscending: Boolean): Comparator<Album> {
+        open fun getAlbumComparator(direction: Direction): Comparator<Album> {
             throw UnsupportedOperationException()
         }
 
         /**
          * Return a [Comparator] that sorts [Artist]s according to this [Mode].
-         * @param isAscending Whether to sort in ascending or descending order.
+         * @param direction The direction to sort in.
          * @return A [Comparator] that can be used to sort a [Artist] list according to this [Mode].
          */
-        open fun getArtistComparator(isAscending: Boolean): Comparator<Artist> {
+        open fun getArtistComparator(direction: Direction): Comparator<Artist> {
             throw UnsupportedOperationException()
         }
 
         /**
          * Return a [Comparator] that sorts [Genre]s according to this [Mode].
-         * @param isAscending Whether to sort in ascending or descending order.
+         * @param direction The direction to sort in.
          * @return A [Comparator] that can be used to sort a [Genre] list according to this [Mode].
          */
-        open fun getGenreComparator(isAscending: Boolean): Comparator<Genre> {
+        open fun getGenreComparator(direction: Direction): Comparator<Genre> {
             throw UnsupportedOperationException()
         }
 
@@ -189,17 +195,17 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
             override val itemId: Int
                 get() = R.id.option_sort_name
 
-            override fun getSongComparator(isAscending: Boolean) =
-                compareByDynamic(isAscending, BasicComparator.SONG)
+            override fun getSongComparator(direction: Direction) =
+                compareByDynamic(direction, BasicComparator.SONG)
 
-            override fun getAlbumComparator(isAscending: Boolean) =
-                compareByDynamic(isAscending, BasicComparator.ALBUM)
+            override fun getAlbumComparator(direction: Direction) =
+                compareByDynamic(direction, BasicComparator.ALBUM)
 
-            override fun getArtistComparator(isAscending: Boolean) =
-                compareByDynamic(isAscending, BasicComparator.ARTIST)
+            override fun getArtistComparator(direction: Direction) =
+                compareByDynamic(direction, BasicComparator.ARTIST)
 
-            override fun getGenreComparator(isAscending: Boolean) =
-                compareByDynamic(isAscending, BasicComparator.GENRE)
+            override fun getGenreComparator(direction: Direction) =
+                compareByDynamic(direction, BasicComparator.GENRE)
         }
 
         /**
@@ -213,9 +219,9 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
             override val itemId: Int
                 get() = R.id.option_sort_album
 
-            override fun getSongComparator(isAscending: Boolean): Comparator<Song> =
+            override fun getSongComparator(direction: Direction): Comparator<Song> =
                 MultiComparator(
-                    compareByDynamic(isAscending, BasicComparator.ALBUM) { it.album },
+                    compareByDynamic(direction, BasicComparator.ALBUM) { it.album },
                     compareBy(NullableComparator.DISC) { it.disc },
                     compareBy(NullableComparator.INT) { it.track },
                     compareBy(BasicComparator.SONG))
@@ -232,18 +238,18 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
             override val itemId: Int
                 get() = R.id.option_sort_artist
 
-            override fun getSongComparator(isAscending: Boolean): Comparator<Song> =
+            override fun getSongComparator(direction: Direction): Comparator<Song> =
                 MultiComparator(
-                    compareByDynamic(isAscending, ListComparator.ARTISTS) { it.artists },
+                    compareByDynamic(direction, ListComparator.ARTISTS) { it.artists },
                     compareByDescending(NullableComparator.DATE_RANGE) { it.album.dates },
                     compareByDescending(BasicComparator.ALBUM) { it.album },
                     compareBy(NullableComparator.DISC) { it.disc },
                     compareBy(NullableComparator.INT) { it.track },
                     compareBy(BasicComparator.SONG))
 
-            override fun getAlbumComparator(isAscending: Boolean): Comparator<Album> =
+            override fun getAlbumComparator(direction: Direction): Comparator<Album> =
                 MultiComparator(
-                    compareByDynamic(isAscending, ListComparator.ARTISTS) { it.artists },
+                    compareByDynamic(direction, ListComparator.ARTISTS) { it.artists },
                     compareByDescending(NullableComparator.DATE_RANGE) { it.dates },
                     compareBy(BasicComparator.ALBUM))
         }
@@ -260,17 +266,17 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
             override val itemId: Int
                 get() = R.id.option_sort_year
 
-            override fun getSongComparator(isAscending: Boolean): Comparator<Song> =
+            override fun getSongComparator(direction: Direction): Comparator<Song> =
                 MultiComparator(
-                    compareByDynamic(isAscending, NullableComparator.DATE_RANGE) { it.album.dates },
+                    compareByDynamic(direction, NullableComparator.DATE_RANGE) { it.album.dates },
                     compareByDescending(BasicComparator.ALBUM) { it.album },
                     compareBy(NullableComparator.DISC) { it.disc },
                     compareBy(NullableComparator.INT) { it.track },
                     compareBy(BasicComparator.SONG))
 
-            override fun getAlbumComparator(isAscending: Boolean): Comparator<Album> =
+            override fun getAlbumComparator(direction: Direction): Comparator<Album> =
                 MultiComparator(
-                    compareByDynamic(isAscending, NullableComparator.DATE_RANGE) { it.dates },
+                    compareByDynamic(direction, NullableComparator.DATE_RANGE) { it.dates },
                     compareBy(BasicComparator.ALBUM))
         }
 
@@ -282,25 +288,22 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
             override val itemId: Int
                 get() = R.id.option_sort_duration
 
-            override fun getSongComparator(isAscending: Boolean): Comparator<Song> =
+            override fun getSongComparator(direction: Direction): Comparator<Song> =
                 MultiComparator(
-                    compareByDynamic(isAscending) { it.durationMs },
-                    compareBy(BasicComparator.SONG))
+                    compareByDynamic(direction) { it.durationMs }, compareBy(BasicComparator.SONG))
 
-            override fun getAlbumComparator(isAscending: Boolean): Comparator<Album> =
+            override fun getAlbumComparator(direction: Direction): Comparator<Album> =
                 MultiComparator(
-                    compareByDynamic(isAscending) { it.durationMs },
-                    compareBy(BasicComparator.ALBUM))
+                    compareByDynamic(direction) { it.durationMs }, compareBy(BasicComparator.ALBUM))
 
-            override fun getArtistComparator(isAscending: Boolean): Comparator<Artist> =
+            override fun getArtistComparator(direction: Direction): Comparator<Artist> =
                 MultiComparator(
-                    compareByDynamic(isAscending, NullableComparator.LONG) { it.durationMs },
+                    compareByDynamic(direction, NullableComparator.LONG) { it.durationMs },
                     compareBy(BasicComparator.ARTIST))
 
-            override fun getGenreComparator(isAscending: Boolean): Comparator<Genre> =
+            override fun getGenreComparator(direction: Direction): Comparator<Genre> =
                 MultiComparator(
-                    compareByDynamic(isAscending) { it.durationMs },
-                    compareBy(BasicComparator.GENRE))
+                    compareByDynamic(direction) { it.durationMs }, compareBy(BasicComparator.GENRE))
         }
 
         /**
@@ -314,20 +317,18 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
             override val itemId: Int
                 get() = R.id.option_sort_count
 
-            override fun getAlbumComparator(isAscending: Boolean): Comparator<Album> =
+            override fun getAlbumComparator(direction: Direction): Comparator<Album> =
                 MultiComparator(
-                    compareByDynamic(isAscending) { it.songs.size },
-                    compareBy(BasicComparator.ALBUM))
+                    compareByDynamic(direction) { it.songs.size }, compareBy(BasicComparator.ALBUM))
 
-            override fun getArtistComparator(isAscending: Boolean): Comparator<Artist> =
+            override fun getArtistComparator(direction: Direction): Comparator<Artist> =
                 MultiComparator(
-                    compareByDynamic(isAscending, NullableComparator.INT) { it.songs.size },
+                    compareByDynamic(direction, NullableComparator.INT) { it.songs.size },
                     compareBy(BasicComparator.ARTIST))
 
-            override fun getGenreComparator(isAscending: Boolean): Comparator<Genre> =
+            override fun getGenreComparator(direction: Direction): Comparator<Genre> =
                 MultiComparator(
-                    compareByDynamic(isAscending) { it.songs.size },
-                    compareBy(BasicComparator.GENRE))
+                    compareByDynamic(direction) { it.songs.size }, compareBy(BasicComparator.GENRE))
         }
 
         /**
@@ -341,9 +342,9 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
             override val itemId: Int
                 get() = R.id.option_sort_disc
 
-            override fun getSongComparator(isAscending: Boolean): Comparator<Song> =
+            override fun getSongComparator(direction: Direction): Comparator<Song> =
                 MultiComparator(
-                    compareByDynamic(isAscending, NullableComparator.DISC) { it.disc },
+                    compareByDynamic(direction, NullableComparator.DISC) { it.disc },
                     compareBy(NullableComparator.INT) { it.track },
                     compareBy(BasicComparator.SONG))
         }
@@ -359,10 +360,10 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
             override val itemId: Int
                 get() = R.id.option_sort_track
 
-            override fun getSongComparator(isAscending: Boolean): Comparator<Song> =
+            override fun getSongComparator(direction: Direction): Comparator<Song> =
                 MultiComparator(
                     compareBy(NullableComparator.DISC) { it.disc },
-                    compareByDynamic(isAscending, NullableComparator.INT) { it.track },
+                    compareByDynamic(direction, NullableComparator.INT) { it.track },
                     compareBy(BasicComparator.SONG))
         }
 
@@ -378,48 +379,47 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
             override val itemId: Int
                 get() = R.id.option_sort_date_added
 
-            override fun getSongComparator(isAscending: Boolean): Comparator<Song> =
+            override fun getSongComparator(direction: Direction): Comparator<Song> =
                 MultiComparator(
-                    compareByDynamic(isAscending) { it.dateAdded }, compareBy(BasicComparator.SONG))
+                    compareByDynamic(direction) { it.dateAdded }, compareBy(BasicComparator.SONG))
 
-            override fun getAlbumComparator(isAscending: Boolean): Comparator<Album> =
+            override fun getAlbumComparator(direction: Direction): Comparator<Album> =
                 MultiComparator(
-                    compareByDynamic(isAscending) { album -> album.dateAdded },
+                    compareByDynamic(direction) { album -> album.dateAdded },
                     compareBy(BasicComparator.ALBUM))
         }
 
         /**
-         * Utility function to create a [Comparator] in a dynamic way determined by [isAscending].
-         * @param isAscending Whether to sort in ascending or descending order.
+         * Utility function to create a [Comparator] in a dynamic way determined by [direction].
+         * @param direction The [Direction] to sort in.
          * @see compareBy
          * @see compareByDescending
          */
         protected inline fun <T : Music, K : Comparable<K>> compareByDynamic(
-            isAscending: Boolean,
+            direction: Direction,
             crossinline selector: (T) -> K
         ) =
-            if (isAscending) {
-                compareBy(selector)
-            } else {
-                compareByDescending(selector)
+            when (direction) {
+                Direction.ASCENDING -> compareBy(selector)
+                Direction.DESCENDING -> compareByDescending(selector)
             }
 
         /**
-         * Utility function to create a [Comparator] in a dynamic way determined by [isAscending]
-         * @param isAscending Whether to sort in ascending or descending order.
+         * Utility function to create a [Comparator] in a dynamic way determined by [direction]
+         * @param direction The [Direction] to sort in.
          * @param comparator A [Comparator] to wrap.
          * @return A new [Comparator] with the specified configuration.
          * @see compareBy
          * @see compareByDescending
          */
         protected fun <T : Music> compareByDynamic(
-            isAscending: Boolean,
+            direction: Direction,
             comparator: Comparator<in T>
-        ): Comparator<T> = compareByDynamic(isAscending, comparator) { it }
+        ): Comparator<T> = compareByDynamic(direction, comparator) { it }
 
         /**
-         * Utility function to create a [Comparator] a dynamic way determined by [isAscending]
-         * @param isAscending Whether to sort in ascending or descending order.
+         * Utility function to create a [Comparator] a dynamic way determined by [direction]
+         * @param direction The [Direction] to sort in.
          * @param comparator A [Comparator] to wrap.
          * @param selector Called to obtain a specific attribute to sort by.
          * @return A new [Comparator] with the specified configuration.
@@ -427,14 +427,13 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
          * @see compareByDescending
          */
         protected inline fun <T : Music, K> compareByDynamic(
-            isAscending: Boolean,
+            direction: Direction,
             comparator: Comparator<in K>,
             crossinline selector: (T) -> K
         ) =
-            if (isAscending) {
-                compareBy(comparator, selector)
-            } else {
-                compareByDescending(comparator, selector)
+            when (direction) {
+                Direction.ASCENDING -> compareBy(comparator, selector)
+                Direction.DESCENDING -> compareByDescending(comparator, selector)
             }
 
         /**
@@ -596,6 +595,12 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
         }
     }
 
+    /** The direction to sort items in. */
+    enum class Direction {
+        ASCENDING,
+        DESCENDING
+    }
+
     companion object {
         /**
          * Convert a [Sort] integer representation into an instance.
@@ -607,9 +612,9 @@ data class Sort(val mode: Mode, val isAscending: Boolean) {
             // Sort's integer representation is formatted as AMMMM, where A is a bitflag
             // representing on if the mode is ascending or descending, and M is the integer
             // representation of the sort mode.
-            val isAscending = (intCode and 1) == 1
+            val direction = if ((intCode and 1) == 1) Direction.ASCENDING else Direction.DESCENDING
             val mode = Mode.fromIntCode(intCode.shr(1)) ?: return null
-            return Sort(mode, isAscending)
+            return Sort(mode, direction)
         }
     }
 }

app/src/main/java/org/oxycblt/auxio/music/MusicSettings.kt

@@ -21,7 +21,7 @@ import android.content.Context
 import android.os.storage.StorageManager
 import androidx.core.content.edit
 import org.oxycblt.auxio.R
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.music.storage.Directory
 import org.oxycblt.auxio.music.storage.MusicDirectories
 import org.oxycblt.auxio.settings.Settings
@@ -116,7 +116,7 @@ private class RealMusicSettings(context: Context) :
         get() =
             Sort.fromIntCode(
                 sharedPreferences.getInt(getString(R.string.set_key_songs_sort), Int.MIN_VALUE))
-                ?: Sort(Sort.Mode.ByName, true)
+                ?: Sort(Sort.Mode.ByName, Sort.Direction.ASCENDING)
         set(value) {
             sharedPreferences.edit {
                 putInt(getString(R.string.set_key_songs_sort), value.intCode)
@@ -128,7 +128,7 @@ private class RealMusicSettings(context: Context) :
         get() =
             Sort.fromIntCode(
                 sharedPreferences.getInt(getString(R.string.set_key_albums_sort), Int.MIN_VALUE))
-                ?: Sort(Sort.Mode.ByName, true)
+                ?: Sort(Sort.Mode.ByName, Sort.Direction.ASCENDING)
         set(value) {
             sharedPreferences.edit {
                 putInt(getString(R.string.set_key_albums_sort), value.intCode)
@@ -140,7 +140,7 @@ private class RealMusicSettings(context: Context) :
         get() =
             Sort.fromIntCode(
                 sharedPreferences.getInt(getString(R.string.set_key_artists_sort), Int.MIN_VALUE))
-                ?: Sort(Sort.Mode.ByName, true)
+                ?: Sort(Sort.Mode.ByName, Sort.Direction.ASCENDING)
         set(value) {
             sharedPreferences.edit {
                 putInt(getString(R.string.set_key_artists_sort), value.intCode)
@@ -152,7 +152,7 @@ private class RealMusicSettings(context: Context) :
         get() =
             Sort.fromIntCode(
                 sharedPreferences.getInt(getString(R.string.set_key_genres_sort), Int.MIN_VALUE))
-                ?: Sort(Sort.Mode.ByName, true)
+                ?: Sort(Sort.Mode.ByName, Sort.Direction.ASCENDING)
         set(value) {
             sharedPreferences.edit {
                 putInt(getString(R.string.set_key_genres_sort), value.intCode)
@@ -166,7 +166,7 @@ private class RealMusicSettings(context: Context) :
                 Sort.fromIntCode(
                     sharedPreferences.getInt(
                         getString(R.string.set_key_album_songs_sort), Int.MIN_VALUE))
-                    ?: Sort(Sort.Mode.ByDisc, true)
+                    ?: Sort(Sort.Mode.ByDisc, Sort.Direction.ASCENDING)
 
             // Correct legacy album sort modes to Disc
             if (sort.mode is Sort.Mode.ByName) {
@@ -187,7 +187,7 @@ private class RealMusicSettings(context: Context) :
             Sort.fromIntCode(
                 sharedPreferences.getInt(
                     getString(R.string.set_key_artist_songs_sort), Int.MIN_VALUE))
-                ?: Sort(Sort.Mode.ByDate, false)
+                ?: Sort(Sort.Mode.ByDate, Sort.Direction.DESCENDING)
         set(value) {
             sharedPreferences.edit {
                 putInt(getString(R.string.set_key_artist_songs_sort), value.intCode)
@@ -200,7 +200,7 @@ private class RealMusicSettings(context: Context) :
             Sort.fromIntCode(
                 sharedPreferences.getInt(
                     getString(R.string.set_key_genre_songs_sort), Int.MIN_VALUE))
-                ?: Sort(Sort.Mode.ByName, true)
+                ?: Sort(Sort.Mode.ByName, Sort.Direction.ASCENDING)
         set(value) {
             sharedPreferences.edit {
                 putInt(getString(R.string.set_key_genre_songs_sort), value.intCode)

app/src/main/java/org/oxycblt/auxio/music/library/Library.kt

@@ -20,6 +20,7 @@ package org.oxycblt.auxio.music.library
 import android.content.Context
 import android.net.Uri
 import android.provider.OpenableColumns
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.music.*
 import org.oxycblt.auxio.music.storage.contentResolverSafe
 import org.oxycblt.auxio.music.storage.useQuery
@@ -76,7 +77,7 @@ interface Library {
 
     companion object {
         /**
-         * Create a library-backed instance of [Library].
+         * Create an instance of [Library].
          * @param rawSongs [RawSong]s to create the library out of.
          * @param settings [MusicSettings] required.
          */
@@ -93,10 +94,10 @@ private class RealLibrary(rawSongs: List<RawSong>, settings: MusicSettings) : Li
 
     // Use a mapping to make finding information based on it's UID much faster.
     private val uidMap = buildMap {
-        songs.forEach { this[it.uid] = it.finalize() }
-        albums.forEach { this[it.uid] = it.finalize() }
-        artists.forEach { this[it.uid] = it.finalize() }
-        genres.forEach { this[it.uid] = it.finalize() }
+        songs.forEach { put(it.uid, it.finalize()) }
+        albums.forEach { put(it.uid, it.finalize()) }
+        artists.forEach { put(it.uid, it.finalize()) }
+        genres.forEach { put(it.uid, it.finalize()) }
     }
 
     /**
@@ -131,7 +132,8 @@ private class RealLibrary(rawSongs: List<RawSong>, settings: MusicSettings) : Li
      * grouping.
      */
     private fun buildSongs(rawSongs: List<RawSong>, settings: MusicSettings) =
-        Sort(Sort.Mode.ByName, true).songs(rawSongs.map { RealSong(it, settings) }.distinct())
+        Sort(Sort.Mode.ByName, Sort.Direction.ASCENDING)
+            .songs(rawSongs.map { RealSong(it, settings) }.distinct())
 
     /**
      * Build a list of [Album]s from the given [Song]s.

app/src/main/java/org/oxycblt/auxio/music/library/RealMusic.kt

@@ -24,6 +24,7 @@ import java.text.CollationKey
 import java.text.Collator
 import kotlin.math.max
 import org.oxycblt.auxio.R
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.music.Album
 import org.oxycblt.auxio.music.Artist
 import org.oxycblt.auxio.music.Genre
@@ -418,7 +419,7 @@ class RealArtist(private val rawArtist: RawArtist, songAlbums: List<Music>) : Ar
     fun finalize(): Artist {
         check(songs.isNotEmpty() || albums.isNotEmpty()) { "Malformed artist: Empty" }
         genres =
-            Sort(Sort.Mode.ByName, true)
+            Sort(Sort.Mode.ByName, Sort.Direction.ASCENDING)
                 .genres(songs.flatMapTo(mutableSetOf()) { it.genres })
                 .sortedByDescending { genre -> songs.count { it.genres.contains(genre) } }
         return this
@@ -458,10 +459,10 @@ class RealGenre(private val rawGenre: RawGenre, override val songs: List<RealSon
         }
 
         albums =
-            Sort(Sort.Mode.ByName, true).albums(distinctAlbums).sortedByDescending { album ->
-                album.songs.count { it.genres.contains(this) }
-            }
-        artists = Sort(Sort.Mode.ByName, true).artists(distinctArtists)
+            Sort(Sort.Mode.ByName, Sort.Direction.ASCENDING)
+                .albums(distinctAlbums)
+                .sortedByDescending { album -> album.songs.count { it.genres.contains(this) } }
+        artists = Sort(Sort.Mode.ByName, Sort.Direction.ASCENDING).artists(distinctArtists)
         durationMs = totalDuration
     }
 

app/src/main/java/org/oxycblt/auxio/search/SearchViewModel.kt

@@ -32,7 +32,7 @@ import org.oxycblt.auxio.list.BasicHeader
 import org.oxycblt.auxio.list.Item
 import org.oxycblt.auxio.music.*
 import org.oxycblt.auxio.music.library.Library
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.playback.PlaybackSettings
 import org.oxycblt.auxio.util.logD
 
@@ -176,6 +176,6 @@ constructor(
     }
 
     private companion object {
-        val SORT = Sort(Sort.Mode.ByName, true)
+        val SORT = Sort(Sort.Mode.ByName, Sort.Direction.ASCENDING)
     }
 }

app/src/main/res/menu/menu_album_sort.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <menu xmlns:android="http://schemas.android.com/apk/res/android">
-    <group android:checkableBehavior="single">
+    <group android:checkableBehavior="single"
+        android:id="@+id/sort_modes">
         <item
             android:id="@+id/option_sort_disc"
             android:title="@string/lbl_sort_disc" />
@@ -8,9 +9,13 @@
             android:id="@+id/option_sort_track"
             android:title="@string/lbl_sort_track" />
     </group>
-    <group android:checkableBehavior="all">
+    <group android:checkableBehavior="single"
+        android:id="@+id/sort_direction">
         <item
             android:id="@+id/option_sort_asc"
             android:title="@string/lbl_sort_asc" />
+        <item
+            android:id="@+id/option_sort_dec"
+            android:title="@string/lbl_sort_dec" />
     </group>
 </menu>

app/src/main/res/menu/menu_artist_sort.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <menu xmlns:android="http://schemas.android.com/apk/res/android">
-    <group android:checkableBehavior="single">
+    <group android:checkableBehavior="single"
+        android:id="@+id/sort_modes">
         <item
             android:id="@+id/option_sort_name"
             android:title="@string/lbl_sort_name" />
@@ -14,9 +15,13 @@
             android:id="@+id/option_sort_duration"
             android:title="@string/lbl_sort_duration" />
     </group>
-    <group android:checkableBehavior="all">
+    <group android:checkableBehavior="single"
+        android:id="@+id/sort_direction">
         <item
             android:id="@+id/option_sort_asc"
             android:title="@string/lbl_sort_asc" />
+        <item
+            android:id="@+id/option_sort_dec"
+            android:title="@string/lbl_sort_dec" />
     </group>
 </menu>

app/src/main/res/menu/menu_genre_sort.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <menu xmlns:android="http://schemas.android.com/apk/res/android">
-    <group android:checkableBehavior="single">
+    <group android:checkableBehavior="single"
+        android:id="@+id/sort_modes">
         <item
             android:id="@+id/option_sort_name"
             android:title="@string/lbl_sort_name" />
@@ -17,9 +18,13 @@
             android:id="@+id/option_sort_duration"
             android:title="@string/lbl_sort_duration" />
     </group>
-    <group android:checkableBehavior="all">
+    <group android:checkableBehavior="single"
+        android:id="@+id/sort_direction">
         <item
             android:id="@+id/option_sort_asc"
             android:title="@string/lbl_sort_asc" />
+        <item
+            android:id="@+id/option_sort_dec"
+            android:title="@string/lbl_sort_dec" />
     </group>
 </menu>

app/src/main/res/menu/menu_home.xml

@@ -14,7 +14,8 @@
         android:title="@string/lbl_sort"
         app:showAsAction="ifRoom">
         <menu>
-            <group android:checkableBehavior="single">
+            <group android:checkableBehavior="single"
+                android:id="@+id/sort_modes">
                 <item
                     android:id="@+id/option_sort_name"
                     android:title="@string/lbl_sort_name" />
@@ -37,10 +38,14 @@
                     android:id="@+id/option_sort_date_added"
                     android:title="@string/lbl_sort_date_added" />
             </group>
-            <group android:checkableBehavior="all">
+            <group android:checkableBehavior="single"
+                android:id="@+id/sort_direction">
                 <item
                     android:id="@+id/option_sort_asc"
                     android:title="@string/lbl_sort_asc" />
+                <item
+                    android:id="@+id/option_sort_dec"
+                    android:title="@string/lbl_sort_dec" />
             </group>
         </menu>
     </item>

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

@@ -92,6 +92,7 @@
     <string name="lbl_sort_track">Track</string>
     <string name="lbl_sort_date_added">Date added</string>
     <string name="lbl_sort_asc">Ascending</string>
+    <string name="lbl_sort_dec">Descending</string>
 
     <string name="lbl_playback">Now playing</string>
     <string name="lbl_equalizer">Equalizer</string>

app/src/test/java/org/oxycblt/auxio/music/FakeMusicSettings.kt

@@ -17,7 +17,7 @@
  
 package org.oxycblt.auxio.music
 
-import org.oxycblt.auxio.music.library.Sort
+import org.oxycblt.auxio.list.Sort
 import org.oxycblt.auxio.music.storage.MusicDirectories
 
 interface FakeMusicSettings : MusicSettings {