library: add fast-scroller

Add a fast-scroller to the library view. This makes long lists of
items such as albums easier to scroll through, but also requires
pre-sorting of artists to make sure that unintended behavior does
not occur. A future commit may improve the sort options here so that
this does not need to occur.

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

@@ -17,6 +17,7 @@ import org.oxycblt.auxio.music.Artist
 import org.oxycblt.auxio.music.Genre
 import org.oxycblt.auxio.music.Parent
 import org.oxycblt.auxio.music.Song
+import org.oxycblt.auxio.recycler.sliceArticle
 import org.oxycblt.auxio.ui.getSpans
 import org.oxycblt.auxio.ui.newMenu
 
@@ -67,6 +68,13 @@ class LibraryFragment : Fragment() {
             }
         }
 
+        binding.libraryFastScroll.setup(binding.libraryRecycler) { pos ->
+            val item = libraryModel.libraryData.value!![pos]
+            val char = item.displayName.sliceArticle().first().uppercaseChar()
+
+            if (char.isDigit()) '#' else char
+        }
+
         // --- VIEWMODEL SETUP ---
 
         libraryModel.libraryData.observe(viewLifecycleOwner) { data ->

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

@@ -11,6 +11,7 @@ import androidx.core.database.getStringOrNull
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.database.BlacklistDatabase
 import org.oxycblt.auxio.logD
+import org.oxycblt.auxio.recycler.SortMode
 
 /**
  * Class that loads/constructs [Genre]s, [Artist]s, [Album]s, and [Song] objects from the filesystem
@@ -227,6 +228,9 @@ class MusicLoader(private val context: Context) {
             )
         }
 
+        // Make the artist view line up with the rest of the lists by sorting it.
+        artists = SortMode.ALPHA_DOWN.getSortedArtistList(artists).toMutableList()
+
         logD("Albums successfully linked into ${artists.size} artists")
     }
 

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

@@ -31,7 +31,6 @@ import kotlin.math.roundToInt
  * fast-scrollers, this one displays indicators and a thumb instead of simply a scroll bar.
  * This code is fundamentally an adaptation of Reddit's IndicatorFastScroll, albeit specialized
  * towards Auxio. The original library is here: https://github.com/reddit/IndicatorFastScroll/
- * TODO: Make this update with data.
  * @author OxygenCobalt
  */
 class FastScrollView @JvmOverloads constructor(

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

@@ -4,7 +4,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     tools:context=".library.LibraryFragment">
 
-    <LinearLayout
+    <androidx.constraintlayout.widget.ConstraintLayout
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:animateLayoutChanges="true"
@@ -13,6 +13,9 @@
         <androidx.appcompat.widget.Toolbar
             android:id="@+id/library_toolbar"
             style="@style/Toolbar.Style"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toTopOf="parent"
             app:menu="@menu/menu_library"
             app:title="@string/label_library" />
 
@@ -22,7 +25,17 @@
             android:layout_height="0dp"
             android:layout_weight="1"
             app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintTop_toBottomOf="@+id/library_toolbar"
             tools:listitem="@layout/item_artist" />
 
-    </LinearLayout>
+        <org.oxycblt.auxio.songs.FastScrollView
+            android:id="@+id/library_fast_scroll"
+            android:layout_width="wrap_content"
+            android:layout_height="0dp"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintTop_toBottomOf="@+id/library_toolbar" />
+
+    </androidx.constraintlayout.widget.ConstraintLayout>
 </layout>