Store references to items in DetailViewModel

Store references to the artist & album inside DetailViewModel to prevent an artist/album search on every re-creation.

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

@@ -0,0 +1,4 @@
+package org.oxycblt.auxio
+
+// RecyclerView click listener
+class ClickListener<T>(val onClick: (T) -> Unit)

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

@@ -23,6 +23,3 @@ class MainActivity : AppCompatActivity() {
         setContentView(R.layout.activity_main)
     }
 }
-
-// RecyclerView click listener
-class ClickListener<T>(val onClick: (T) -> Unit)

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

@@ -28,17 +28,22 @@ class AlbumDetailFragment : Fragment() {
     ): View? {
         val binding = FragmentAlbumDetailBinding.inflate(inflater)
 
-        // I honestly don't want to turn of the any data classes into parcelables due to how
-        // many lists they store, so just pick up the artist id and find it from musicModel.
-        val musicModel: MusicViewModel by activityViewModels()
-        val album = musicModel.albums.value?.find { it.id == args.albumId }!!
+        // If DetailViewModel isn't already storing the album, get it from MusicViewModel
+        // using the ID given by the navigation arguments.
+        if (detailModel.currentAlbum == null) {
+            val musicModel: MusicViewModel by activityViewModels()
+
+            detailModel.currentAlbum = musicModel.albums.value!!.find {
+                it.id == args.albumId
+            }!!
+        }
 
         binding.lifecycleOwner = this
         binding.detailModel = detailModel
-        binding.album = album
+        binding.album = detailModel.currentAlbum
 
         binding.songRecycler.adapter = DetailSongAdapter(
-            album.songs,
+            detailModel.currentAlbum!!.songs,
             ClickListener {
                 Log.d(this::class.simpleName, it.name)
             }
@@ -46,16 +51,17 @@ class AlbumDetailFragment : Fragment() {
         binding.songRecycler.applyDivider()
         binding.songRecycler.setHasFixedSize(true)
 
-        // If the album was shown directly from LibraryFragment, then enable the ability
-        // to navigate to the artist from the album. Don't do this if the album was shown
-        // from ArtistDetailFragment, as you can just navigate up to see the parent artist.
-        if (args.isFromLibrary) {
+        // If the album was shown directly from LibraryFragment [No parent artist stored],
+        // then enable the ability to navigate upwards to the album's parent artist.
+        if (detailModel.currentArtist == null) {
             detailModel.doneWithNavToParent()
 
             detailModel.navToParentArtist.observe(viewLifecycleOwner) {
                 if (it) {
                     findNavController().navigate(
-                        AlbumDetailFragmentDirections.actionShowParentArtist(album.artist.id)
+                        AlbumDetailFragmentDirections.actionShowParentArtist(
+                            detailModel.currentAlbum!!.artist.id
+                        )
                     )
 
                     detailModel.doneWithNavToParent()
@@ -69,4 +75,4 @@ class AlbumDetailFragment : Fragment() {
 
         return binding.root
     }
-}
+}

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

@@ -28,20 +28,26 @@ class ArtistDetailFragment : Fragment() {
     ): View? {
         val binding = FragmentArtistDetailBinding.inflate(inflater)
 
-        // I honestly don't want to turn of the any data classes into parcelables due to how
-        // many lists they store, so just pick up the artist id and find it from musicModel.
-        val musicModel: MusicViewModel by activityViewModels()
-        val artist = musicModel.artists.value?.find { it.id == args.artistId }!!
+        // If DetailViewModel isn't already storing the artist, get it from MusicViewModel
+        // using the ID given by the navigation arguments
+        if (detailModel.currentArtist == null) {
+            val musicModel: MusicViewModel by activityViewModels()
+            detailModel.currentArtist = musicModel.artists.value!!.find {
+                it.id == args.artistId
+            }!!
+        }
 
-        binding.lifecycleOwner = this
-        binding.artist = artist
-
-        binding.albumRecycler.adapter = DetailAlbumAdapter(
-            artist.albums,
+        val artistAdapter = DetailAlbumAdapter(
+            detailModel.currentArtist!!.albums,
             ClickListener {
                 navToAlbum(it)
             }
         )
+
+        binding.lifecycleOwner = this
+        binding.artist = detailModel.currentArtist!!
+
+        binding.albumRecycler.adapter = artistAdapter
         binding.albumRecycler.applyDivider()
         binding.albumRecycler.setHasFixedSize(true)
 
@@ -56,14 +62,22 @@ class ArtistDetailFragment : Fragment() {
         detailModel.isAlreadyNavigating = false
     }
 
+    override fun onDestroy() {
+        super.onDestroy()
+
+        // Reset the stored artist so that the next instance of ArtistDetailFragment
+        // will not read it.
+        detailModel.currentArtist = null
+    }
+
     private fun navToAlbum(album: Album) {
         // Don't navigate if an item already has been selected.
         if (!detailModel.isAlreadyNavigating) {
             detailModel.isAlreadyNavigating = true
 
             findNavController().navigate(
-                ArtistDetailFragmentDirections.actionShowAlbum(album.id, false)
+                ArtistDetailFragmentDirections.actionShowAlbum(album.id)
             )
         }
     }
-}
+}

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

@@ -3,6 +3,8 @@ package org.oxycblt.auxio.detail
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
+import org.oxycblt.auxio.music.models.Album
+import org.oxycblt.auxio.music.models.Artist
 
 class DetailViewModel : ViewModel() {
     var isAlreadyNavigating = false
@@ -10,6 +12,9 @@ class DetailViewModel : ViewModel() {
     private val mNavToParentArtist = MutableLiveData<Boolean>()
     val navToParentArtist: LiveData<Boolean> get() = mNavToParentArtist
 
+    var currentArtist: Artist? = null
+    var currentAlbum: Album? = null
+
     fun navToParent() {
         mNavToParentArtist.value = true
     }
@@ -17,4 +22,4 @@ class DetailViewModel : ViewModel() {
     fun doneWithNavToParent() {
         mNavToParentArtist.value = false
     }
-}
+}

app/src/main/java/org/oxycblt/auxio/music/models/Artist.kt

@@ -19,8 +19,7 @@ data class Artist(
     }
 
     fun finalizeGenre() {
-        // If the artist has more than one genre, pick the most "prominent" one.
-        // [Really just eliminate duplicates created from my hacky way of getting genres loaded but shhhh]
+        // If the artist has more than one genre, pick the most "Prominent" one.
         genre = if (genres.size > 1) {
             val groupGenres = genres.groupBy { it.name }
 

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

@@ -1,4 +1,5 @@
-<?xml version="1.0" encoding="utf-8"?><!--
+<?xml version="1.0" encoding="utf-8"?>
+<!--
 Divider used by recyclerview header items
 https://stackoverflow.com/a/61157571/14143986
 -->
@@ -12,4 +13,11 @@ https://stackoverflow.com/a/61157571/14143986
                 android:color="@color/divider_color" />
         </shape>
     </item>
+
+    <item>
+        <ripple
+            android:color="@color/selection_color"
+            android:radius="@dimen/divider_ripple_size">
+        </ripple>
+    </item>
 </layer-list>

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

@@ -26,8 +26,7 @@
             android:background="?android:attr/windowBackground"
             android:elevation="@dimen/elevation_normal"
             app:titleTextAppearance="@style/TextAppearance.Toolbar.Bold"
-            app:title="@string/title_library_fragment"
-            tools:titleTextColor="@color/blue" />
+            app:title="@string/title_library_fragment" />
 
         <androidx.core.widget.NestedScrollView
             android:layout_width="match_parent"
@@ -36,8 +35,7 @@
             <androidx.constraintlayout.widget.ConstraintLayout
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"
-                android:animateLayoutChanges="true"
-                android:orientation="vertical">
+                android:animateLayoutChanges="true">
 
                 <ImageView
                     android:id="@+id/cover"
@@ -56,11 +54,11 @@
                     style="@style/DetailHeader"
                     android:layout_width="0dp"
                     android:layout_height="wrap_content"
+                    android:layout_marginStart="@dimen/margin_medium"
                     android:layout_marginTop="@dimen/margin_medium"
                     android:layout_marginEnd="@dimen/margin_medium"
-                    android:layout_marginStart="@dimen/margin_medium"
-                    android:text="@{album.name}"
                     android:maxLines="1"
+                    android:text="@{album.name}"
                     app:autoSizeMaxTextSize="@dimen/detail_header_size_max"
                     app:autoSizeMinTextSize="@dimen/generic_size_min"
                     app:autoSizeStepGranularity="@dimen/generic_size_increment"
@@ -73,15 +71,15 @@
 
                 <TextView
                     android:id="@+id/artist_name"
-                    android:clickable="true"
-                    android:focusable="true"
                     android:layout_width="0dp"
                     android:layout_height="wrap_content"
+                    android:layout_marginStart="@dimen/margin_medium"
+                    android:clickable="true"
+                    android:focusable="true"
+                    android:onClick="@{() -> detailModel.navToParent()}"
+                    android:text="@{album.artist.name}"
                     android:textAppearance="?android:attr/textAppearanceListItem"
                     android:textColor="?android:attr/textColorSecondary"
-                    android:onClick="@{() -> detailModel.navToParent()}"
-                    android:layout_marginStart="@dimen/margin_medium"
-                    android:text="@{album.artist.name}"
                     app:layout_constraintStart_toStartOf="parent"
                     app:layout_constraintTop_toBottomOf="@+id/album_name"
                     tools:text="Artist Name" />
@@ -90,30 +88,29 @@
                     android:id="@+id/album_year"
                     android:layout_width="0dp"
                     android:layout_height="wrap_content"
-                    android:textAppearance="?android:attr/textAppearanceListItem"
-                    android:textColor="?android:attr/textColorSecondary"
                     android:layout_marginStart="@dimen/margin_medium"
                     android:text="@{album.year != 0 ? String.valueOf(album.year) : @string/placeholder_no_date}"
+                    android:textAppearance="?android:attr/textAppearanceListItem"
+                    android:textColor="?android:attr/textColorSecondary"
                     app:layout_constraintStart_toStartOf="parent"
                     app:layout_constraintTop_toBottomOf="@+id/artist_name"
                     tools:text="2020" />
 
                 <TextView
-                    android:id="@+id/header"
+                    android:id="@+id/header_title"
                     android:layout_width="match_parent"
                     android:layout_height="match_parent"
+                    android:layout_marginTop="@dimen/padding_medium"
+                    android:background="@drawable/header_dividers"
+                    android:fontFamily="@font/inter_bold"
+                    android:paddingStart="@dimen/padding_medium"
+                    android:paddingTop="@dimen/padding_small"
+                    android:paddingEnd="@dimen/padding_small"
+                    android:paddingBottom="@dimen/padding_small"
                     android:text="@string/label_songs"
                     android:textAppearance="@style/TextAppearance.MaterialComponents.Overline"
                     android:textSize="16sp"
-                    android:fontFamily="@font/inter_bold"
-                    android:layout_marginTop="@dimen/padding_medium"
-                    android:paddingStart="@dimen/padding_medium"
-                    android:paddingEnd="@dimen/padding_small"
-                    android:paddingTop="@dimen/padding_small"
-                    android:paddingBottom="@dimen/padding_small"
-                    android:background="@drawable/header_dividers"
-                    app:layout_constraintTop_toBottomOf="@+id/album_year"
-                    tools:layout_editor_absoluteX="60dp" />
+                    app:layout_constraintTop_toBottomOf="@+id/album_year" />
 
                 <androidx.recyclerview.widget.RecyclerView
                     android:id="@+id/song_recycler"
@@ -124,7 +121,7 @@
                     android:overScrollMode="never"
                     app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
                     app:layout_constraintBottom_toBottomOf="parent"
-                    app:layout_constraintTop_toBottomOf="@+id/header"
+                    app:layout_constraintTop_toBottomOf="@+id/header_title"
                     tools:itemCount="4"
                     tools:listitem="@layout/item_album_song" />
 

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

@@ -22,8 +22,7 @@
             android:background="?android:attr/windowBackground"
             android:elevation="@dimen/elevation_normal"
             app:titleTextAppearance="@style/TextAppearance.Toolbar.Bold"
-            app:title="@string/title_library_fragment"
-            tools:titleTextColor="@color/blue" />
+            app:title="@string/title_library_fragment" />
 
         <androidx.core.widget.NestedScrollView
             android:layout_width="match_parent"
@@ -91,21 +90,39 @@
                     tools:text="2 Albums, 20 Songs" />
 
                 <TextView
-                    android:id="@+id/header"
+                    android:id="@+id/header_title"
                     android:layout_width="match_parent"
                     android:layout_height="match_parent"
+                    android:layout_marginTop="@dimen/margin_medium"
+                    android:background="@drawable/header_dividers"
+                    android:fontFamily="@font/inter_bold"
+                    android:paddingStart="@dimen/padding_medium"
+                    android:paddingTop="@dimen/padding_small"
+                    android:paddingEnd="@dimen/padding_small"
+                    android:paddingBottom="@dimen/padding_small"
                     android:text="@string/label_albums"
                     android:textAppearance="@style/TextAppearance.MaterialComponents.Overline"
                     android:textSize="16sp"
-                    android:fontFamily="@font/inter_bold"
-                    android:layout_marginTop="@dimen/padding_medium"
-                    android:paddingStart="@dimen/padding_medium"
-                    android:paddingEnd="@dimen/padding_small"
-                    android:paddingTop="@dimen/padding_small"
-                    android:paddingBottom="@dimen/padding_small"
-                    android:background="@drawable/header_dividers"
+                    app:layout_constraintStart_toStartOf="parent"
                     app:layout_constraintTop_toBottomOf="@+id/artist_counts" />
 
+                <!--
+                <ImageButton
+                    android:id="@+id/sort_button"
+                    android:layout_width="wrap_content"
+                    android:layout_height="0dp"
+                    android:layout_marginTop="@dimen/margin_medium"
+                    android:background="@drawable/header_dividers"
+                    android:contentDescription="@string/description_sort_button"
+                    android:paddingStart="@dimen/padding_medium"
+                    android:paddingTop="@dimen/padding_small"
+                    android:paddingEnd="@dimen/margin_medium"
+                    android:paddingBottom="@dimen/padding_small"
+                    app:layout_constraintBottom_toTopOf="@+id/album_recycler"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintTop_toBottomOf="@+id/artist_counts" />
+                    -->
+
                 <androidx.recyclerview.widget.RecyclerView
                     android:id="@+id/album_recycler"
                     android:layout_width="match_parent"
@@ -115,7 +132,7 @@
                     android:overScrollMode="never"
                     app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
                     app:layout_constraintBottom_toBottomOf="parent"
-                    app:layout_constraintTop_toBottomOf="@+id/header"
+                    app:layout_constraintTop_toBottomOf="@+id/header_title"
                     tools:itemCount="4"
                     tools:listitem="@layout/item_album" />
 

app/src/main/res/navigation/nav_main.xml

@@ -58,9 +58,6 @@
         <argument
             android:name="albumId"
             app:argType="long" />
-        <argument
-            android:name="isFromLibrary"
-            app:argType="boolean" />
         <action
             android:id="@+id/action_show_parent_artist"
             app:enterAnim="@anim/fragment_fade_enter"

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

@@ -24,5 +24,7 @@
     <dimen name="generic_size_min">10sp</dimen>'
     <dimen name="generic_size_increment">2sp</dimen>
 
+    <dimen name="divider_ripple_size">18dp</dimen>
+
     <dimen name="elevation_normal">4dp</dimen>
 </resources>

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

@@ -18,6 +18,7 @@
     <string name="description_artist_image">Artist Cover for %s</string>
     <string name="description_track_number">Track %s</string>
     <string name="description_error">Error</string>
+    <string name="description_sort_button">Change Sorting Mode</string>
 
     <string name="placeholder_genre">Unknown Genre</string>
     <string name="placeholder_artist">Unknown Artist</string>