Update ViewHolder structure

Move all shared viewholders to /recycler/, and change structure of shared viewholders to prohibit direct instantiation.

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

@@ -67,6 +67,8 @@ class AlbumDetailFragment : Fragment() {
         // If the album was shown directly from LibraryFragment, Then enable the ability to
         // navigate upwards to the parent artist
         if (args.enableParentNav) {
+            detailModel.doneWithNavToParent()
+
             detailModel.navToParent.observe(viewLifecycleOwner) {
                 if (it) {
                     findNavController().navigate(

app/src/main/java/org/oxycblt/auxio/detail/adapters/DetailAlbumAdapter.kt

@@ -5,9 +5,9 @@ import android.view.ViewGroup
 import androidx.recyclerview.widget.ListAdapter
 import org.oxycblt.auxio.databinding.ItemArtistAlbumBinding
 import org.oxycblt.auxio.music.Album
-import org.oxycblt.auxio.recycler.BaseViewHolder
 import org.oxycblt.auxio.recycler.ClickListener
 import org.oxycblt.auxio.recycler.DiffCallback
+import org.oxycblt.auxio.recycler.viewholders.BaseViewHolder
 
 class DetailAlbumAdapter(
     private val listener: ClickListener<Album>
@@ -23,7 +23,7 @@ class DetailAlbumAdapter(
         holder.bind(getItem(position))
     }
 
-    // Generic ViewHolder for an album
+    // Generic ViewHolder for a detail album
     inner class ViewHolder(
         private val binding: ItemArtistAlbumBinding
     ) : BaseViewHolder<Album>(binding, listener) {

app/src/main/java/org/oxycblt/auxio/detail/adapters/DetailArtistAdapter.kt

@@ -5,9 +5,9 @@ import android.view.ViewGroup
 import androidx.recyclerview.widget.ListAdapter
 import org.oxycblt.auxio.databinding.ItemGenreArtistBinding
 import org.oxycblt.auxio.music.Artist
-import org.oxycblt.auxio.recycler.BaseViewHolder
 import org.oxycblt.auxio.recycler.ClickListener
 import org.oxycblt.auxio.recycler.DiffCallback
+import org.oxycblt.auxio.recycler.viewholders.BaseViewHolder
 
 class DetailArtistAdapter(
     private val listener: ClickListener<Artist>

app/src/main/java/org/oxycblt/auxio/detail/adapters/DetailSongAdapter.kt

@@ -5,9 +5,9 @@ import android.view.ViewGroup
 import androidx.recyclerview.widget.ListAdapter
 import org.oxycblt.auxio.databinding.ItemAlbumSongBinding
 import org.oxycblt.auxio.music.Song
-import org.oxycblt.auxio.recycler.BaseViewHolder
 import org.oxycblt.auxio.recycler.ClickListener
 import org.oxycblt.auxio.recycler.DiffCallback
+import org.oxycblt.auxio.recycler.viewholders.BaseViewHolder
 
 class DetailSongAdapter(
     private val listener: ClickListener<Song>

app/src/main/java/org/oxycblt/auxio/library/LibraryViewModel.kt

@@ -23,7 +23,7 @@ class LibraryViewModel : ViewModel() {
     val searchHasFocus: Boolean get() = mSearchHasFocus
 
     // TODO: Move these to prefs when they're added
-    private val mShowMode = MutableLiveData(SHOW_ARTISTS)
+    private val mShowMode = MutableLiveData(SHOW_ALBUMS)
     val showMode: LiveData<Int> get() = mShowMode
 
     private val mSortMode = MutableLiveData(SortMode.ALPHA_DOWN)

app/src/main/java/org/oxycblt/auxio/library/recycler/LibraryAdapter.kt

@@ -1,21 +1,21 @@
 package org.oxycblt.auxio.library.recycler
 
-import android.view.LayoutInflater
 import android.view.ViewGroup
 import androidx.recyclerview.widget.RecyclerView
-import org.oxycblt.auxio.databinding.ItemAlbumBinding
-import org.oxycblt.auxio.databinding.ItemArtistBinding
-import org.oxycblt.auxio.databinding.ItemGenreBinding
 import org.oxycblt.auxio.music.Album
 import org.oxycblt.auxio.music.Artist
 import org.oxycblt.auxio.music.BaseModel
 import org.oxycblt.auxio.music.Genre
 import org.oxycblt.auxio.recycler.ClickListener
+import org.oxycblt.auxio.recycler.viewholders.AlbumViewHolder
+import org.oxycblt.auxio.recycler.viewholders.ArtistViewHolder
+import org.oxycblt.auxio.recycler.viewholders.GenreViewHolder
 import org.oxycblt.auxio.theme.SHOW_ALBUMS
 import org.oxycblt.auxio.theme.SHOW_ARTISTS
 import org.oxycblt.auxio.theme.SHOW_GENRES
 
-// A Great Value androidx ListAdapter that can display three types of ViewHolders.
+// A ListAdapter that can contain three different types of ViewHolders depending
+// the showmode given. It cannot display multiple types of viewholders *at once*.
 class LibraryAdapter(
     private val showMode: Int,
     val listener: ClickListener<BaseModel>
@@ -39,36 +39,21 @@ class LibraryAdapter(
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
         // Return a different View Holder depending on the show type
         return when (showMode) {
-            SHOW_GENRES -> GenreViewHolder(
-                listener,
-                ItemGenreBinding.inflate(LayoutInflater.from(parent.context))
-            )
-
-            SHOW_ARTISTS -> ArtistViewHolder(
-                listener,
-                ItemArtistBinding.inflate(LayoutInflater.from(parent.context))
-            )
-
-            SHOW_ALBUMS -> AlbumViewHolder(
-                listener,
-                ItemAlbumBinding.inflate(LayoutInflater.from(parent.context))
-            )
-
-            else -> ArtistViewHolder(
-                listener,
-                ItemArtistBinding.inflate(LayoutInflater.from(parent.context))
-            )
+            SHOW_GENRES -> GenreViewHolder.from(parent.context, listener)
+            SHOW_ARTISTS -> ArtistViewHolder.from(parent.context, listener)
+            SHOW_ALBUMS -> AlbumViewHolder.from(parent.context, listener)
+            else -> ArtistViewHolder.from(parent.context, listener)
         }
     }
 
     override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
         when (showMode) {
-            SHOW_GENRES -> holder as GenreViewHolder
-            SHOW_ARTISTS -> holder as ArtistViewHolder
-            SHOW_ALBUMS -> holder as AlbumViewHolder
+            SHOW_GENRES -> (holder as GenreViewHolder).bind(data[position] as Genre)
+            SHOW_ARTISTS -> (holder as ArtistViewHolder).bind(data[position] as Artist)
+            SHOW_ALBUMS -> (holder as AlbumViewHolder).bind(data[position] as Album)
 
             else -> return
-        }.bind(data[position])
+        }
     }
 
     // Update the data, as its an internal value.

app/src/main/java/org/oxycblt/auxio/library/recycler/SearchAdapter.kt

@@ -1,14 +1,8 @@
 package org.oxycblt.auxio.library.recycler
 
-import android.view.LayoutInflater
 import android.view.ViewGroup
 import androidx.recyclerview.widget.ListAdapter
 import androidx.recyclerview.widget.RecyclerView
-import org.oxycblt.auxio.databinding.ItemAlbumBinding
-import org.oxycblt.auxio.databinding.ItemArtistBinding
-import org.oxycblt.auxio.databinding.ItemGenreBinding
-import org.oxycblt.auxio.databinding.ItemHeaderBinding
-import org.oxycblt.auxio.databinding.ItemSongBinding
 import org.oxycblt.auxio.music.Album
 import org.oxycblt.auxio.music.Artist
 import org.oxycblt.auxio.music.BaseModel
@@ -17,62 +11,34 @@ import org.oxycblt.auxio.music.Header
 import org.oxycblt.auxio.music.Song
 import org.oxycblt.auxio.recycler.ClickListener
 import org.oxycblt.auxio.recycler.DiffCallback
+import org.oxycblt.auxio.recycler.viewholders.AlbumViewHolder
+import org.oxycblt.auxio.recycler.viewholders.ArtistViewHolder
+import org.oxycblt.auxio.recycler.viewholders.GenreViewHolder
+import org.oxycblt.auxio.recycler.viewholders.HeaderViewHolder
+import org.oxycblt.auxio.recycler.viewholders.SongViewHolder
 
 class SearchAdapter(
     private val listener: ClickListener<BaseModel>
 ) : ListAdapter<BaseModel, RecyclerView.ViewHolder>(DiffCallback<BaseModel>()) {
     override fun getItemViewType(position: Int): Int {
         return when (getItem(position)) {
-            is Genre -> ITEM_TYPE_GENRE
-            is Artist -> ITEM_TYPE_ARTIST
-            is Album -> ITEM_TYPE_ALBUM
-            is Song -> ITEM_TYPE_SONG
-            is Header -> ITEM_TYPE_HEADER
+            is Genre -> GenreViewHolder.ITEM_TYPE
+            is Artist -> ArtistViewHolder.ITEM_TYPE
+            is Album -> AlbumViewHolder.ITEM_TYPE
+            is Song -> SongViewHolder.ITEM_TYPE
+            is Header -> HeaderViewHolder.ITEM_TYPE
         }
     }
 
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
         return when (viewType) {
-            ITEM_TYPE_GENRE -> GenreViewHolder(
-                listener,
-                ItemGenreBinding.inflate(
-                    LayoutInflater.from(parent.context)
-                )
-            )
+            GenreViewHolder.ITEM_TYPE -> GenreViewHolder.from(parent.context, listener)
+            ArtistViewHolder.ITEM_TYPE -> ArtistViewHolder.from(parent.context, listener)
+            AlbumViewHolder.ITEM_TYPE -> AlbumViewHolder.from(parent.context, listener)
+            SongViewHolder.ITEM_TYPE -> SongViewHolder.from(parent.context, listener)
+            HeaderViewHolder.ITEM_TYPE -> HeaderViewHolder.from(parent.context)
 
-            ITEM_TYPE_ARTIST -> ArtistViewHolder(
-                listener,
-                ItemArtistBinding.inflate(
-                    LayoutInflater.from(parent.context)
-                )
-            )
-
-            ITEM_TYPE_ALBUM -> AlbumViewHolder(
-                listener,
-                ItemAlbumBinding.inflate(
-                    LayoutInflater.from(parent.context)
-                )
-            )
-
-            ITEM_TYPE_SONG -> SongViewHolder(
-                listener,
-                ItemSongBinding.inflate(
-                    LayoutInflater.from(parent.context)
-                )
-            )
-
-            ITEM_TYPE_HEADER -> HeaderViewHolder(
-                ItemHeaderBinding.inflate(
-                    LayoutInflater.from(parent.context)
-                )
-            )
-
-            else -> ArtistViewHolder(
-                listener,
-                ItemArtistBinding.inflate(
-                    LayoutInflater.from(parent.context)
-                )
-            )
+            else -> HeaderViewHolder.from(parent.context)
         }
     }
 
@@ -85,6 +51,6 @@ class SearchAdapter(
             is HeaderViewHolder -> holder
 
             else -> return
-        }.onBind(getItem(position))
+        }.bind(getItem(position))
     }
 }

app/src/main/java/org/oxycblt/auxio/library/recycler/ViewHolders.kt

@@ -1,75 +0,0 @@
-package org.oxycblt.auxio.library.recycler
-
-import org.oxycblt.auxio.databinding.ItemAlbumBinding
-import org.oxycblt.auxio.databinding.ItemArtistBinding
-import org.oxycblt.auxio.databinding.ItemGenreBinding
-import org.oxycblt.auxio.databinding.ItemHeaderBinding
-import org.oxycblt.auxio.databinding.ItemSongBinding
-import org.oxycblt.auxio.music.Album
-import org.oxycblt.auxio.music.Artist
-import org.oxycblt.auxio.music.BaseModel
-import org.oxycblt.auxio.music.Genre
-import org.oxycblt.auxio.music.Header
-import org.oxycblt.auxio.music.Song
-import org.oxycblt.auxio.recycler.BaseViewHolder
-import org.oxycblt.auxio.recycler.ClickListener
-
-const val ITEM_TYPE_GENRE = 10
-const val ITEM_TYPE_ARTIST = 11
-const val ITEM_TYPE_ALBUM = 12
-const val ITEM_TYPE_SONG = 13
-const val ITEM_TYPE_HEADER = 14
-
-class GenreViewHolder(
-    listener: ClickListener<BaseModel>,
-    private val binding: ItemGenreBinding
-) : BaseViewHolder<BaseModel>(binding, listener) {
-
-    override fun onBind(model: BaseModel) {
-        binding.genre = model as Genre
-        binding.genreName.requestLayout()
-    }
-}
-
-class ArtistViewHolder(
-    listener: ClickListener<BaseModel>,
-    private val binding: ItemArtistBinding
-) : BaseViewHolder<BaseModel>(binding, listener) {
-
-    override fun onBind(model: BaseModel) {
-        binding.artist = model as Artist
-        binding.artistName.requestLayout()
-    }
-}
-
-class AlbumViewHolder(
-    listener: ClickListener<BaseModel>,
-    private val binding: ItemAlbumBinding
-) : BaseViewHolder<BaseModel>(binding, listener) {
-
-    override fun onBind(model: BaseModel) {
-        binding.album = model as Album
-        binding.albumName.requestLayout()
-    }
-}
-
-class SongViewHolder(
-    listener: ClickListener<BaseModel>,
-    private val binding: ItemSongBinding
-) : BaseViewHolder<BaseModel>(binding, listener) {
-
-    override fun onBind(model: BaseModel) {
-        binding.song = model as Song
-
-        binding.songName.requestLayout()
-        binding.songInfo.requestLayout()
-    }
-}
-
-class HeaderViewHolder(
-    private val binding: ItemHeaderBinding
-) : BaseViewHolder<BaseModel>(binding, null) {
-    override fun onBind(model: BaseModel) {
-        binding.header = model as Header
-    }
-}

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

@@ -131,7 +131,7 @@ fun TextView.bindArtistCounts(artist: Artist) {
 
 // Get a bunch of miscellaneous album information [Year, Songs, Duration] and combine them
 @BindingAdapter("albumDetails")
-fun TextView.bindAlbumDetails(album: Album) {
+fun TextView.bindAllAlbumDetails(album: Album) {
     text = context.getString(
         R.string.format_double_info,
         album.year.toYear(context),
@@ -143,6 +143,18 @@ fun TextView.bindAlbumDetails(album: Album) {
     )
 }
 
+@BindingAdapter("albumInfo")
+fun TextView.bindAlbumInfo(album: Album) {
+    text = context.getString(
+        R.string.format_info,
+        album.artist.name,
+        context.resources.getQuantityString(
+            R.plurals.format_song_count,
+            album.numSongs, album.numSongs
+        )
+    )
+}
+
 @BindingAdapter("albumYear")
 fun TextView.bindAlbumDate(album: Album) {
     text = album.year.toYear(context)

app/src/main/java/org/oxycblt/auxio/recycler/RecyclerUtils.kt

@@ -4,7 +4,7 @@ import androidx.recyclerview.widget.DiffUtil
 import org.oxycblt.auxio.music.BaseModel
 
 // RecyclerView click listener
-class ClickListener<T>(val onClick: (T) -> Unit)
+class ClickListener<T : BaseModel>(val onClick: (T) -> Unit)
 
 // Base Diff callback
 class DiffCallback<T : BaseModel> : DiffUtil.ItemCallback<T>() {

app/src/main/java/org/oxycblt/auxio/recycler/viewholders/BaseViewHolder.kt

@@ -1,10 +1,12 @@
-package org.oxycblt.auxio.recycler
+package org.oxycblt.auxio.recycler.viewholders
 
 import androidx.databinding.ViewDataBinding
 import androidx.recyclerview.widget.RecyclerView
 import org.oxycblt.auxio.music.BaseModel
+import org.oxycblt.auxio.recycler.ClickListener
 
 // ViewHolder abstraction that automates some of the things that are common for all ViewHolders.
+// TODO: Implement some kind of abstraction for BaseViewHolder.from()
 abstract class BaseViewHolder<T : BaseModel>(
     private val baseBinding: ViewDataBinding,
     protected val listener: ClickListener<T>?

app/src/main/java/org/oxycblt/auxio/recycler/viewholders/ModelHolders.kt

@@ -0,0 +1,127 @@
+package org.oxycblt.auxio.recycler.viewholders
+
+import android.content.Context
+import android.view.LayoutInflater
+import org.oxycblt.auxio.databinding.ItemAlbumBinding
+import org.oxycblt.auxio.databinding.ItemArtistBinding
+import org.oxycblt.auxio.databinding.ItemGenreBinding
+import org.oxycblt.auxio.databinding.ItemHeaderBinding
+import org.oxycblt.auxio.databinding.ItemSongBinding
+import org.oxycblt.auxio.music.Album
+import org.oxycblt.auxio.music.Artist
+import org.oxycblt.auxio.music.BaseModel
+import org.oxycblt.auxio.music.Genre
+import org.oxycblt.auxio.music.Header
+import org.oxycblt.auxio.music.Song
+import org.oxycblt.auxio.recycler.ClickListener
+
+// Basic ViewHolders for each music model.
+// FIXME: Mode these type signaturs to something sensible.
+
+class GenreViewHolder private constructor(
+    listener: ClickListener<BaseModel>,
+    private val binding: ItemGenreBinding
+) : BaseViewHolder<BaseModel>(binding, listener) {
+
+    override fun onBind(model: BaseModel) {
+        binding.genre = model as Genre
+        binding.genreName.requestLayout()
+    }
+
+    companion object {
+        const val ITEM_TYPE = 10
+
+        fun from(context: Context, listener: ClickListener<BaseModel>): GenreViewHolder {
+            return GenreViewHolder(
+                ClickListener { listener.onClick(it) },
+                ItemGenreBinding.inflate(LayoutInflater.from(context))
+            )
+        }
+    }
+}
+
+class ArtistViewHolder private constructor(
+    listener: ClickListener<BaseModel>,
+    private val binding: ItemArtistBinding
+) : BaseViewHolder<BaseModel>(binding, listener) {
+
+    override fun onBind(model: BaseModel) {
+        binding.artist = model as Artist
+        binding.artistName.requestLayout()
+    }
+
+    companion object {
+        const val ITEM_TYPE = 11
+
+        fun from(context: Context, listener: ClickListener<BaseModel>): ArtistViewHolder {
+            return ArtistViewHolder(
+                ClickListener { listener.onClick(it) },
+                ItemArtistBinding.inflate(LayoutInflater.from(context))
+            )
+        }
+    }
+}
+
+class AlbumViewHolder private constructor(
+    listener: ClickListener<BaseModel>,
+    private val binding: ItemAlbumBinding
+) : BaseViewHolder<BaseModel>(binding, listener) {
+
+    override fun onBind(model: BaseModel) {
+        binding.album = model as Album
+        binding.albumName.requestLayout()
+    }
+
+    companion object {
+        const val ITEM_TYPE = 12
+
+        fun from(context: Context, listener: ClickListener<BaseModel>): AlbumViewHolder {
+            return AlbumViewHolder(
+                listener,
+                ItemAlbumBinding.inflate(LayoutInflater.from(context))
+            )
+        }
+    }
+}
+
+class SongViewHolder private constructor(
+    listener: ClickListener<BaseModel>,
+    private val binding: ItemSongBinding
+) : BaseViewHolder<BaseModel>(binding, listener) {
+
+    override fun onBind(model: BaseModel) {
+        binding.song = model as Song
+
+        binding.songName.requestLayout()
+        binding.songInfo.requestLayout()
+    }
+
+    companion object {
+        const val ITEM_TYPE = 13
+
+        fun from(context: Context, listener: ClickListener<BaseModel>): SongViewHolder {
+            return SongViewHolder(
+                listener,
+                ItemSongBinding.inflate(LayoutInflater.from(context))
+            )
+        }
+    }
+}
+
+class HeaderViewHolder(
+    private val binding: ItemHeaderBinding
+) : BaseViewHolder<BaseModel>(binding, null) {
+    override fun onBind(model: BaseModel) {
+        binding.header = model as Header
+    }
+
+    companion object {
+        const val ITEM_TYPE = 14
+
+        fun from(context: Context): HeaderViewHolder {
+            return HeaderViewHolder(
+                ItemHeaderBinding.inflate(LayoutInflater.from(context))
+            )
+        }
+    }
+}

app/src/main/java/org/oxycblt/auxio/songs/SongAdapter.kt

@@ -5,8 +5,8 @@ import android.view.ViewGroup
 import androidx.recyclerview.widget.RecyclerView
 import org.oxycblt.auxio.databinding.ItemSongBinding
 import org.oxycblt.auxio.music.Song
-import org.oxycblt.auxio.recycler.BaseViewHolder
 import org.oxycblt.auxio.recycler.ClickListener
+import org.oxycblt.auxio.recycler.viewholders.BaseViewHolder
 
 class SongAdapter(
     private val data: List<Song>,

app/src/main/java/org/oxycblt/auxio/theme/PrefConstants.kt

@@ -1,6 +1,7 @@
 package org.oxycblt.auxio.theme
 
 // Preference Constants
+// TODO: Move these to dedicated enum class.
 const val SHOW_ARTISTS = 0
 const val SHOW_ALBUMS = 1
 const val SHOW_GENRES = 2

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

@@ -39,7 +39,7 @@
             android:textColor="?android:attr/textColorPrimary"
             android:ellipsize="end"
             android:maxLines="1"
-            app:layout_constraintBottom_toTopOf="@+id/album_song_count"
+            app:layout_constraintBottom_toTopOf="@+id/album_info"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toEndOf="@+id/album_cover"
             app:layout_constraintTop_toTopOf="parent"
@@ -47,14 +47,14 @@
             tools:text="Album Name" />
 
         <TextView
-            android:id="@+id/album_song_count"
+            android:id="@+id/album_info"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginStart="@dimen/margin_medium"
             android:textAppearance="?android:attr/textAppearanceListItemSecondary"
             android:textColor="?android:attr/textColorSecondary"
             android:maxLines="1"
-            app:albumSongCount="@{album}"
+            app:albumInfo="@{album}"
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintStart_toEndOf="@+id/album_cover"
             app:layout_constraintTop_toBottomOf="@+id/album_name"