music: automatically number new playlists

Automatically number new playlists, from Playlist 1, Playlist 2, etc. This comes with the additional requirement that all playlists have unique names.
2023-05-12 13:41:39 -06:00 · 2023-05-12 13:41:39 -06:00 · 763061c352
commit 763061c352
parent e01ea25d0b
14 changed files with 188 additions and 145 deletions
--- a/app/src/main/java/org/oxycblt/auxio/MainFragment.kt
+++ b/app/src/main/java/org/oxycblt/auxio/MainFragment.kt
@ -135,7 +135,7 @@ class MainFragment :
        collect(navModel.mainNavigationAction.flow, ::handleMainNavigation)
        collect(navModel.exploreNavigationItem.flow, ::handleExploreNavigation)
        collect(navModel.exploreArtistNavigationItem.flow, ::handleArtistNavigationPicker)
-        collect(musicModel.pendingPlaylistNaming.flow, ::handlePlaylistNaming)
+        collect(musicModel.pendingNewPlaylist.flow, ::handlePlaylistNaming)
        collectImmediately(playbackModel.song, ::updateSong)
        collect(playbackModel.artistPickerSong.flow, ::handlePlaybackArtistPicker)
        collect(playbackModel.genrePickerSong.flow, ::handlePlaybackGenrePicker)
@ -306,8 +306,8 @@ class MainFragment :

    private fun handlePlaylistNaming(args: PendingName.Args?) {
        if (args != null) {
-            findNavController().navigateSafe(MainFragmentDirections.actionNamePlaylist(args))
-            musicModel.pendingPlaylistNaming.consume()
+            findNavController().navigateSafe(MainFragmentDirections.actionNewPlaylist(args))
+            musicModel.pendingNewPlaylist.consume()
        }
    }

--- a/app/src/main/java/org/oxycblt/auxio/detail/PlaylistDetailFragment.kt
+++ b/app/src/main/java/org/oxycblt/auxio/detail/PlaylistDetailFragment.kt
@ -138,7 +138,6 @@ class PlaylistDetailFragment :
    }

    override fun onPlay() {
-        // TODO: Handle
        playbackModel.play(unlikelyToBeNull(detailModel.currentPlaylist.value))
    }

--- a/app/src/main/java/org/oxycblt/auxio/home/HomeFragment.kt
+++ b/app/src/main/java/org/oxycblt/auxio/home/HomeFragment.kt
@ -321,7 +321,7 @@ class HomeFragment :
            }
        } else {
            binding.homeFab.flipTo(R.drawable.ic_add_24, R.string.desc_new_playlist) {
-                musicModel.createPlaylist("New playlist")
+                musicModel.createPlaylist(requireContext())
            }
        }
    }
--- a/app/src/main/java/org/oxycblt/auxio/music/Music.kt
+++ b/app/src/main/java/org/oxycblt/auxio/music/Music.kt
@ -22,6 +22,7 @@ import android.content.Context
 import android.net.Uri
 import android.os.Parcelable
 import androidx.room.TypeConverter
+import java.security.MessageDigest
 import java.util.UUID
 import kotlin.math.max
 import kotlinx.parcelize.IgnoredOnParcel
@ -118,13 +119,47 @@ sealed interface Music : Item {

        companion object {
            /**
-             * Creates an Auxio-style [UID] with a [UUID] generated by internal Auxio code.
+             * Creates an Auxio-style [UID] with a [UUID] composed of a hash of the non-subjective,
+             * unlikely-to-change metadata of the music.
             *
             * @param mode The analogous [MusicMode] of the item that created this [UID].
-             * @param uuid The generated [UUID] for this item.
+             * @param updates Block to update the [MessageDigest] hash with the metadata of the
+             *   item. Make sure the metadata hashed semantically aligns with the format
+             *   specification.
             * @return A new auxio-style [UID].
             */
-            fun auxio(mode: MusicMode, uuid: UUID) = UID(Format.AUXIO, mode, uuid)
+            fun auxio(mode: MusicMode, updates: MessageDigest.() -> Unit): UID {
+                val digest =
+                    MessageDigest.getInstance("SHA-256").run {
+                        updates()
+                        digest()
+                    }
+                // Convert the digest to a UUID. This does cleave off some of the hash, but this
+                // is considered okay.
+                val uuid =
+                    UUID(
+                        digest[0]
+                            .toLong()
+                            .shl(56)
+                            .or(digest[1].toLong().and(0xFF).shl(48))
+                            .or(digest[2].toLong().and(0xFF).shl(40))
+                            .or(digest[3].toLong().and(0xFF).shl(32))
+                            .or(digest[4].toLong().and(0xFF).shl(24))
+                            .or(digest[5].toLong().and(0xFF).shl(16))
+                            .or(digest[6].toLong().and(0xFF).shl(8))
+                            .or(digest[7].toLong().and(0xFF)),
+                        digest[8]
+                            .toLong()
+                            .shl(56)
+                            .or(digest[9].toLong().and(0xFF).shl(48))
+                            .or(digest[10].toLong().and(0xFF).shl(40))
+                            .or(digest[11].toLong().and(0xFF).shl(32))
+                            .or(digest[12].toLong().and(0xFF).shl(24))
+                            .or(digest[13].toLong().and(0xFF).shl(16))
+                            .or(digest[14].toLong().and(0xFF).shl(8))
+                            .or(digest[15].toLong().and(0xFF)))
+                return UID(Format.AUXIO, mode, uuid)
+            }

            /**
             * Creates a MusicBrainz-style [UID] with a [UUID] derived from the MusicBrainz ID
--- a/app/src/main/java/org/oxycblt/auxio/music/MusicViewModel.kt
+++ b/app/src/main/java/org/oxycblt/auxio/music/MusicViewModel.kt
@ -18,11 +18,13 @@
 
 package org.oxycblt.auxio.music

+import android.content.Context
 import androidx.lifecycle.ViewModel
 import dagger.hilt.android.lifecycle.HiltViewModel
 import javax.inject.Inject
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
+import org.oxycblt.auxio.R
 import org.oxycblt.auxio.music.dialog.PendingName
 import org.oxycblt.auxio.util.Event
 import org.oxycblt.auxio.util.MutableEvent
@ -45,8 +47,8 @@ class MusicViewModel @Inject constructor(private val musicRepository: MusicRepos
    val statistics: StateFlow<Statistics?>
        get() = _statistics

-    private val _pendingPlaylistNaming = MutableEvent<PendingName.Args?>()
-    val pendingPlaylistNaming: Event<PendingName.Args?> = _pendingPlaylistNaming
+    private val _pendingNewPlaylist = MutableEvent<PendingName.Args?>()
+    val pendingNewPlaylist: Event<PendingName.Args?> = _pendingNewPlaylist

    init {
        musicRepository.addUpdateListener(this)
@ -84,16 +86,37 @@ class MusicViewModel @Inject constructor(private val musicRepository: MusicRepos
        musicRepository.requestIndex(false)
    }

+    /**
+     * Create a new generic playlist. This will automatically generate a playlist name and then
+     * prompt the user to edit the name before the creation finished.
+     *
+     * @param context The [Context] required to generate the playlist name.
+     * @param songs The [Song]s to be contained in the new playlist.
+     */
+    fun createPlaylist(context: Context, songs: List<Song> = listOf()) {
+        val userLibrary = musicRepository.userLibrary ?: return
+        var i = 1
+        while (true) {
+            val possibleName = context.getString(R.string.fmt_def_playlist, i)
+            if (userLibrary.playlists.none { it.name.resolve(context) == possibleName }) {
+                createPlaylist(possibleName, songs)
+                return
+            }
+            ++i
+        }
+    }
+
    /**
     * Create a new generic playlist. This will prompt the user to edit the name before the creation
     * finishes.
     *
     * @param name The preferred name of the new playlist.
+     * @param songs The [Song]s to be contained in the new playlist.
     */
    fun createPlaylist(name: String, songs: List<Song> = listOf()) {
        // TODO: Default to something like "Playlist 1", "Playlist 2", etc.
        // TODO: Attempt to unify playlist creation flow with dialog model
-        _pendingPlaylistNaming.put(PendingName.Args(name, songs.map { it.uid }))
+        _pendingNewPlaylist.put(PendingName.Args(name, songs.map { it.uid }))
    }

    /**
--- a/app/src/main/java/org/oxycblt/auxio/music/device/DeviceMusicImpl.kt
+++ b/app/src/main/java/org/oxycblt/auxio/music/device/DeviceMusicImpl.kt
@ -18,8 +18,6 @@
 
 package org.oxycblt.auxio.music.device

-import androidx.annotation.VisibleForTesting
-import java.security.MessageDigest
 import java.util.*
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.list.Sort
@ -35,6 +33,7 @@ import org.oxycblt.auxio.music.metadata.parseMultiValue
 import org.oxycblt.auxio.util.nonZeroOrNull
 import org.oxycblt.auxio.util.toUuidOrNull
 import org.oxycblt.auxio.util.unlikelyToBeNull
+import org.oxycblt.auxio.util.update

 /**
 * Library-backed implementation of [Song].
@ -47,7 +46,7 @@ class SongImpl(rawSong: RawSong, musicSettings: MusicSettings) : Song {
    override val uid =
        // Attempt to use a MusicBrainz ID first before falling back to a hashed UID.
        rawSong.musicBrainzId?.toUuidOrNull()?.let { Music.UID.musicBrainz(MusicMode.SONGS, it) }
-            ?: createHashedUid(MusicMode.SONGS) {
+            ?: Music.UID.auxio(MusicMode.SONGS) {
                // Song UIDs are based on the raw data without parsing so that they remain
                // consistent across music setting changes. Parents are not held up to the
                // same standard since grouping is already inherently linked to settings.
@ -231,7 +230,7 @@ class AlbumImpl(
    override val uid =
        // Attempt to use a MusicBrainz ID first before falling back to a hashed UID.
        rawAlbum.musicBrainzId?.let { Music.UID.musicBrainz(MusicMode.ALBUMS, it) }
-            ?: createHashedUid(MusicMode.ALBUMS) {
+            ?: Music.UID.auxio(MusicMode.ALBUMS) {
                // Hash based on only names despite the presence of a date to increase stability.
                // I don't know if there is any situation where an artist will have two albums with
                // the exact same name, but if there is, I would love to know.
@ -327,7 +326,7 @@ class ArtistImpl(
    override val uid =
        // Attempt to use a MusicBrainz ID first before falling back to a hashed UID.
        rawArtist.musicBrainzId?.let { Music.UID.musicBrainz(MusicMode.ARTISTS, it) }
-            ?: createHashedUid(MusicMode.ARTISTS) { update(rawArtist.name) }
+            ?: Music.UID.auxio(MusicMode.ARTISTS) { update(rawArtist.name) }
    override val name =
        rawArtist.name?.let { Name.Known.from(it, rawArtist.sortName, musicSettings) }
            ?: Name.Unknown(R.string.def_artist)
@ -411,7 +410,7 @@ class GenreImpl(
    musicSettings: MusicSettings,
    override val songs: List<SongImpl>
 ) : Genre {
-    override val uid = createHashedUid(MusicMode.GENRES) { update(rawGenre.name) }
+    override val uid = Music.UID.auxio(MusicMode.GENRES) { update(rawGenre.name) }
    override val name =
        rawGenre.name?.let { Name.Known.from(it, rawGenre.name, musicSettings) }
            ?: Name.Unknown(R.string.def_genre)
@ -467,98 +466,3 @@ class GenreImpl(
        return this
    }
 }
-
-/**
- * Generate a [Music.UID] derived from the hash of objective music metadata.
- *
- * @param mode The analogous [MusicMode] of the item that created this [UID].
- * @param updates Block to update the [MessageDigest] hash with the metadata of the item. Make sure
- *   the metadata hashed semantically aligns with the format specification.
- * @return A new [Music.UID] of Auxio format whose [UUID] was derived from the SHA-256 hash of the
- *   metadata given.
- */
-@VisibleForTesting
-fun createHashedUid(mode: MusicMode, updates: MessageDigest.() -> Unit): Music.UID {
-    val digest =
-        MessageDigest.getInstance("SHA-256").run {
-            updates()
-            digest()
-        }
-    // Convert the digest to a UUID. This does cleave off some of the hash, but this
-    // is considered okay.
-    val uuid =
-        UUID(
-            digest[0]
-                .toLong()
-                .shl(56)
-                .or(digest[1].toLong().and(0xFF).shl(48))
-                .or(digest[2].toLong().and(0xFF).shl(40))
-                .or(digest[3].toLong().and(0xFF).shl(32))
-                .or(digest[4].toLong().and(0xFF).shl(24))
-                .or(digest[5].toLong().and(0xFF).shl(16))
-                .or(digest[6].toLong().and(0xFF).shl(8))
-                .or(digest[7].toLong().and(0xFF)),
-            digest[8]
-                .toLong()
-                .shl(56)
-                .or(digest[9].toLong().and(0xFF).shl(48))
-                .or(digest[10].toLong().and(0xFF).shl(40))
-                .or(digest[11].toLong().and(0xFF).shl(32))
-                .or(digest[12].toLong().and(0xFF).shl(24))
-                .or(digest[13].toLong().and(0xFF).shl(16))
-                .or(digest[14].toLong().and(0xFF).shl(8))
-                .or(digest[15].toLong().and(0xFF)))
-    return Music.UID.auxio(mode, uuid)
-}
-
-/**
- * Update a [MessageDigest] with a lowercase [String].
- *
- * @param string The [String] to hash. If null, it will not be hashed.
- */
-@VisibleForTesting
-fun MessageDigest.update(string: String?) {
-    if (string != null) {
-        update(string.lowercase().toByteArray())
-    } else {
-        update(0)
-    }
-}
-
-/**
- * Update a [MessageDigest] with the string representation of a [Date].
- *
- * @param date The [Date] to hash. If null, nothing will be done.
- */
-@VisibleForTesting
-fun MessageDigest.update(date: Date?) {
-    if (date != null) {
-        update(date.toString().toByteArray())
-    } else {
-        update(0)
-    }
-}
-
-/**
- * Update a [MessageDigest] with the lowercase versions of all of the input [String]s.
- *
- * @param strings The [String]s to hash. If a [String] is null, it will not be hashed.
- */
-@VisibleForTesting
-fun MessageDigest.update(strings: List<String?>) {
-    strings.forEach(::update)
-}
-
-/**
- * Update a [MessageDigest] with the little-endian bytes of a [Int].
- *
- * @param n The [Int] to write. If null, nothing will be done.
- */
-@VisibleForTesting
-fun MessageDigest.update(n: Int?) {
-    if (n != null) {
-        update(byteArrayOf(n.toByte(), n.shr(8).toByte(), n.shr(16).toByte(), n.shr(24).toByte()))
-    } else {
-        update(0)
-    }
-}
--- a/app/src/main/java/org/oxycblt/auxio/music/dialog/PlaylistNamingDialog.kt
+++ b/app/src/main/java/org/oxycblt/auxio/music/dialog/PlaylistNamingDialog.kt
@ -1,6 +1,6 @@
 /*
 * Copyright (c) 2023 Auxio Project
- * PlaylistNamingDialog.kt is part of Auxio.
+ * NewPlaylistDialog.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
@ -27,7 +27,7 @@ import androidx.navigation.fragment.findNavController
 import androidx.navigation.fragment.navArgs
 import dagger.hilt.android.AndroidEntryPoint
 import org.oxycblt.auxio.R
-import org.oxycblt.auxio.databinding.DialogPlaylistNamingBinding
+import org.oxycblt.auxio.databinding.DialogPlaylistNameBinding
 import org.oxycblt.auxio.ui.ViewBindingDialogFragment
 import org.oxycblt.auxio.util.collectImmediately

@ -37,13 +37,13 @@ import org.oxycblt.auxio.util.collectImmediately
 * @author Alexander Capehart (OxygenCobalt)
 */
@AndroidEntryPoint
-class PlaylistNamingDialog : ViewBindingDialogFragment<DialogPlaylistNamingBinding>() {
+class NewPlaylistDialog : ViewBindingDialogFragment<DialogPlaylistNameBinding>() {
    // activityViewModels is intentional here as the ViewModel will do work that we
    // do not want to cancel after this dialog closes.
    private val dialogModel: PlaylistDialogViewModel by activityViewModels()
    // Information about what playlist to name for is initially within the navigation arguments
    // as UIDs, as that is the only safe way to parcel playlist information.
-    private val args: PlaylistNamingDialogArgs by navArgs()
+    private val args: NewPlaylistDialogArgs by navArgs()
    private var initializedInput = false

    override fun onConfigDialog(builder: AlertDialog.Builder) {
@ -54,12 +54,9 @@ class PlaylistNamingDialog : ViewBindingDialogFragment<DialogPlaylistNamingBindi
    }

    override fun onCreateBinding(inflater: LayoutInflater) =
-        DialogPlaylistNamingBinding.inflate(inflater)
+        DialogPlaylistNameBinding.inflate(inflater)

-    override fun onBindingCreated(
-        binding: DialogPlaylistNamingBinding,
-        savedInstanceState: Bundle?
-    ) {
+    override fun onBindingCreated(binding: DialogPlaylistNameBinding, savedInstanceState: Bundle?) {
        super.onBindingCreated(binding, savedInstanceState)

        binding.playlistName.addTextChangedListener {
@ -82,6 +79,6 @@ class PlaylistNamingDialog : ViewBindingDialogFragment<DialogPlaylistNamingBindi
        }
        // Disable the OK button if the name is invalid (empty or whitespace)
        (dialog as AlertDialog).getButton(AlertDialog.BUTTON_POSITIVE)?.isEnabled =
-            pendingName.name.isNotBlank()
+            pendingName.valid
    }
 }
--- a/app/src/main/java/org/oxycblt/auxio/music/dialog/PlaylistDialogViewModel.kt
+++ b/app/src/main/java/org/oxycblt/auxio/music/dialog/PlaylistDialogViewModel.kt
@ -31,6 +31,7 @@ import org.oxycblt.auxio.music.Song

 /**
 * A [ViewModel] managing the state of the playlist editing dialogs.
+ *
 * @author Alexander Capehart
 */
@HiltViewModel
@ -44,15 +45,25 @@ class PlaylistDialogViewModel @Inject constructor(private val musicRepository: M
    }

    override fun onMusicChanges(changes: MusicRepository.Changes) {
-        if (!changes.deviceLibrary) return
-        val deviceLibrary = musicRepository.deviceLibrary ?: return
-        // Update the pending name to reflect new information in the music library.
-        _currentPendingName.value =
-            _currentPendingName.value?.let { pendingName ->
-                PendingName(
-                    pendingName.name,
-                    pendingName.songs.mapNotNull { deviceLibrary.findSong(it.uid) })
+        val pendingName = _currentPendingName.value ?: return
+
+        val deviceLibrary = musicRepository.deviceLibrary
+        val newSongs =
+            if (changes.deviceLibrary && deviceLibrary != null) {
+                pendingName.songs.mapNotNull { deviceLibrary.findSong(it.uid) }
+            } else {
+                pendingName.songs
            }
+
+        val userLibrary = musicRepository.userLibrary
+        val newValid =
+            if (changes.userLibrary && userLibrary != null) {
+                validateName(pendingName.name)
+            } else {
+                pendingName.valid
+            }
+
+        _currentPendingName.value = PendingName(pendingName.name, newSongs, newValid)
    }

    override fun onCleared() {
@ -61,17 +72,22 @@ class PlaylistDialogViewModel @Inject constructor(private val musicRepository: M

    /**
     * Update the current [PendingName] based on the given [PendingName.Args].
+     *
     * @param args The [PendingName.Args] to update with.
     */
    fun setPendingName(args: PendingName.Args) {
        val deviceLibrary = musicRepository.deviceLibrary ?: return
        val name =
-            PendingName(args.preferredName, args.songUids.mapNotNull(deviceLibrary::findSong))
+            PendingName(
+                args.preferredName,
+                args.songUids.mapNotNull(deviceLibrary::findSong),
+                validateName(args.preferredName))
        _currentPendingName.value = name
    }

    /**
     * Update the current [PendingName] based on new user input.
+     *
     * @param name The new user-inputted name, directly from the UI.
     */
    fun updatePendingName(name: String?) {
@ -79,25 +95,31 @@ class PlaylistDialogViewModel @Inject constructor(private val musicRepository: M
        // music items.
        val normalized = (name ?: return).trim()
        _currentPendingName.value =
-            _currentPendingName.value?.run { PendingName(normalized, songs) }
+            _currentPendingName.value?.run { PendingName(normalized, songs, validateName(name)) }
    }

-    /**
-     * Confirm the current [PendingName] operation and write it to the database.
-     */
+    /** Confirm the current [PendingName] operation and write it to the database. */
    fun confirmPendingName() {
        val pendingName = _currentPendingName.value ?: return
        musicRepository.createPlaylist(pendingName.name, pendingName.songs)
        _currentPendingName.value = null
    }
+
+    private fun validateName(name: String) =
+        name.isNotBlank() && musicRepository.userLibrary?.findPlaylist(name) == null
 }

 /**
- * Represents a name operation
+ * Represents the current state of a name operation.
+ *
+ * @param name The name of the playlist.
+ * @param songs Any songs that will be in the playlist when added.
+ * @param valid Whether the current configuration is valid.
 */
-data class PendingName(val name: String, val songs: List<Song>) {
+data class PendingName(val name: String, val songs: List<Song>, val valid: Boolean) {
    /**
     * A [Parcelable] version of [PendingName], to be used as a dialog argument.
+     *
     * @param preferredName The name to be used initially by the dialog.
     * @param songUids The [Music.UID] of any pending [Song]s that will be put in the playlist.
     */
--- a/app/src/main/java/org/oxycblt/auxio/music/user/PlaylistImpl.kt
+++ b/app/src/main/java/org/oxycblt/auxio/music/user/PlaylistImpl.kt
@ -22,11 +22,12 @@ import java.util.*
 import org.oxycblt.auxio.music.*
 import org.oxycblt.auxio.music.device.DeviceLibrary
 import org.oxycblt.auxio.music.info.Name
+import org.oxycblt.auxio.util.update

 class PlaylistImpl
 private constructor(
    override val uid: Music.UID,
-    override val name: Name,
+    override val name: Name.Known,
    override val songs: List<Song>
 ) : Playlist {
    override val durationMs = songs.sumOf { it.durationMs }
@ -62,7 +63,7 @@ private constructor(
         */
        fun from(name: String, songs: List<Song>, musicSettings: MusicSettings) =
            PlaylistImpl(
-                Music.UID.auxio(MusicMode.PLAYLISTS, UUID.randomUUID()),
+                Music.UID.auxio(MusicMode.PLAYLISTS) { update(name) },
                Name.Known.from(name, null, musicSettings),
                songs)

--- a/app/src/main/java/org/oxycblt/auxio/music/user/UserLibrary.kt
+++ b/app/src/main/java/org/oxycblt/auxio/music/user/UserLibrary.kt
@ -44,6 +44,14 @@ interface UserLibrary {
     */
    fun findPlaylist(uid: Music.UID): Playlist?

+    /**
+     * Finds a playlist by it's [name]. Since all [Playlist] names must be unique, this will always
+     * return at most 1 value.
+     *
+     * @param name The name [String] to search for.
+     */
+    fun findPlaylist(name: String): Playlist?
+
    /** Constructs a [UserLibrary] implementation in an asynchronous manner. */
    interface Factory {
        /**
@ -104,6 +112,8 @@ private class UserLibraryImpl(

    override fun findPlaylist(uid: Music.UID) = playlistMap[uid]

+    override fun findPlaylist(name: String) = playlistMap.values.find { it.name.raw == name }
+
    @Synchronized
    override fun createPlaylist(name: String, songs: List<Song>) {
        val playlistImpl = PlaylistImpl.from(name, songs, musicSettings)
--- a/app/src/main/java/org/oxycblt/auxio/util/LangUtil.kt
+++ b/app/src/main/java/org/oxycblt/auxio/util/LangUtil.kt
@ -18,9 +18,11 @@
 
 package org.oxycblt.auxio.util

+import java.security.MessageDigest
 import java.util.UUID
 import kotlin.reflect.KClass
 import org.oxycblt.auxio.BuildConfig
+import org.oxycblt.auxio.music.info.Date

 /**
 * Sanitizes a value that is unlikely to be null. On debug builds, this aliases to [requireNotNull],
@ -89,3 +91,51 @@ fun String.toUuidOrNull(): UUID? =
    } catch (e: IllegalArgumentException) {
        null
    }
+
+/**
+ * Update a [MessageDigest] with a lowercase [String].
+ *
+ * @param string The [String] to hash. If null, it will not be hashed.
+ */
+fun MessageDigest.update(string: String?) {
+    if (string != null) {
+        update(string.lowercase().toByteArray())
+    } else {
+        update(0)
+    }
+}
+
+/**
+ * Update a [MessageDigest] with the string representation of a [Date].
+ *
+ * @param date The [Date] to hash. If null, nothing will be done.
+ */
+fun MessageDigest.update(date: Date?) {
+    if (date != null) {
+        update(date.toString().toByteArray())
+    } else {
+        update(0)
+    }
+}
+
+/**
+ * Update a [MessageDigest] with the lowercase versions of all of the input [String]s.
+ *
+ * @param strings The [String]s to hash. If a [String] is null, it will not be hashed.
+ */
+fun MessageDigest.update(strings: List<String?>) {
+    strings.forEach(::update)
+}
+
+/**
+ * Update a [MessageDigest] with the little-endian bytes of a [Int].
+ *
+ * @param n The [Int] to write. If null, nothing will be done.
+ */
+fun MessageDigest.update(n: Int?) {
+    if (n != null) {
+        update(byteArrayOf(n.toByte(), n.shr(8).toByte(), n.shr(16).toByte(), n.shr(24).toByte()))
+    } else {
+        update(0)
+    }
+}
--- a/app/src/main/res/layout/dialog_playlist_naming.xml
+++ b/app/src/main/res/layout/dialog_playlist_naming.xml
--- a/app/src/main/res/navigation/nav_main.xml
+++ b/app/src/main/res/navigation/nav_main.xml
@ -18,8 +18,8 @@
            android:id="@+id/action_show_details"
            app:destination="@id/song_detail_dialog" />
        <action
-            android:id="@+id/action_name_playlist"
-            app:destination="@id/playlist_naming_dialog" />
+            android:id="@+id/action_new_playlist"
+            app:destination="@id/new_playlist_dialog" />
        <action
            android:id="@+id/action_pick_navigation_artist"
            app:destination="@id/artist_navigation_picker_dialog" />
@ -42,10 +42,10 @@
    </dialog>

    <dialog
-        android:id="@+id/playlist_naming_dialog"
-        android:name="org.oxycblt.auxio.music.dialog.PlaylistNamingDialog"
-        android:label="playlist_naming_dialog"
-        tools:layout="@layout/dialog_song_detail">
+        android:id="@+id/new_playlist_dialog"
+        android:name="org.oxycblt.auxio.music.dialog.NewPlaylistDialog"
+        android:label="new_playlist_dialog"
+        tools:layout="@layout/dialog_playlist_name">
        <argument
            android:name="pendingName"
            app:argType="org.oxycblt.auxio.music.dialog.PendingName$Args" />
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@ -376,6 +376,8 @@

    <!-- As in "Disc 1", "Disc 2", etc. in a set -->
    <string name="fmt_disc_no">Disc %d</string>
+    <!-- As in "Playlist 1", "Playlist 2", etc. -->
+    <string name="fmt_def_playlist">Playlist %d</string>

    <!-- Use your native country's abbreviation for decibel units. -->
    <string name="fmt_db_pos">+%.1f dB</string>