Refactor fast scroll

Completely write my own fast scroller thumb and also redo how the fast scroller is configured in SongsFragment.

app/src/main/java/org/oxycblt/auxio/coil/CoilUtils.kt

@@ -12,6 +12,7 @@ import coil.request.ImageRequest
 import org.oxycblt.auxio.R
 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.Song
 import org.oxycblt.auxio.settings.SettingsManager
@@ -53,8 +54,12 @@ fun ImageView.bindGenreImage(genre: Genre) {
 /**
  * Custom extension function similar to the stock coil load extensions, but handles whether
  * to show images and custom fetchers.
+ * @param T Any datatype that inherits [BaseModel]
+ * @param data The data itself
+ * @param error Drawable resource to use when loading failed/should not occur.
+ * @param fetcher Required fetcher that uses [T] as its datatype
  */
-inline fun <reified T : Any> ImageView.load(
+inline fun <reified T : BaseModel> ImageView.load(
     data: T,
     @DrawableRes error: Int,
     fetcher: Fetcher<T>,
@@ -63,7 +68,6 @@ inline fun <reified T : Any> ImageView.load(
 
     if (!settingsManager.showCovers) {
         setImageResource(error)
-
         return
     }
 

app/src/main/java/org/oxycblt/auxio/playback/PlaybackViewModel.kt

@@ -40,8 +40,8 @@ class PlaybackViewModel : ViewModel(), PlaybackStateManager.Callback {
     private val mPosition = MutableLiveData(0L)
 
     // Queue
-    private val mQueue = MutableLiveData(mutableListOf<Song>())
+    private val mQueue = MutableLiveData(listOf<Song>())
-    private val mUserQueue = MutableLiveData(mutableListOf<Song>())
+    private val mUserQueue = MutableLiveData(listOf<Song>())
     private val mIndex = MutableLiveData(0)
     private val mMode = MutableLiveData(PlaybackMode.ALL_SONGS)
 
@@ -64,9 +64,9 @@ class PlaybackViewModel : ViewModel(), PlaybackStateManager.Callback {
     val position: LiveData<Long> get() = mPosition
 
     /** The current queue determined by [mode] and [parent] */
-    val queue: LiveData<MutableList<Song>> get() = mQueue
+    val queue: LiveData<List<Song>> get() = mQueue
     /** The queue created by the user. */
-    val userQueue: LiveData<MutableList<Song>> get() = mUserQueue
+    val userQueue: LiveData<List<Song>> get() = mUserQueue
     /** The current [PlaybackMode] that also determines the queue */
     val mode: LiveData<PlaybackMode> get() = mMode
     /** Whether playback is originating from the user-generated queue or not  */
@@ -451,11 +451,11 @@ class PlaybackViewModel : ViewModel(), PlaybackStateManager.Callback {
         }
     }
 
-    override fun onQueueUpdate(queue: MutableList<Song>) {
+    override fun onQueueUpdate(queue: List<Song>) {
         mQueue.value = queue
     }
 
-    override fun onUserQueueUpdate(userQueue: MutableList<Song>) {
+    override fun onUserQueueUpdate(userQueue: List<Song>) {
         mUserQueue.value = userQueue
     }
 

app/src/main/java/org/oxycblt/auxio/playback/state/PlaybackStateManager.kt

@@ -101,9 +101,9 @@ class PlaybackStateManager private constructor() {
     /** The current playback progress */
     val position: Long get() = mPosition
     /** The current queue determined by [parent] and [mode] */
-    val queue: MutableList<Song> get() = mQueue
+    val queue: List<Song> get() = mQueue
     /** The queue created by the user. */
-    val userQueue: MutableList<Song> get() = mUserQueue
+    val userQueue: List<Song> get() = mUserQueue
     /** The current index of the queue */
     val index: Int get() = mIndex
     /** The current [PlaybackMode] */
@@ -116,7 +116,7 @@ class PlaybackStateManager private constructor() {
     val loopMode: LoopMode get() = mLoopMode
     /** Whether this instance has already been restored */
     val isRestored: Boolean get() = mIsRestored
-    /** Whether this instance has started playing or not */
+    /** Whether playback has begun in this instance during **PlaybackService's Lifecycle.** */
     val hasPlayed: Boolean get() = mHasPlayed
 
     private val settingsManager = SettingsManager.getInstance()
@@ -788,8 +788,8 @@ class PlaybackStateManager private constructor() {
         fun onSongUpdate(song: Song?) {}
         fun onParentUpdate(parent: Parent?) {}
         fun onPositionUpdate(position: Long) {}
-        fun onQueueUpdate(queue: MutableList<Song>) {}
+        fun onQueueUpdate(queue: List<Song>) {}
-        fun onUserQueueUpdate(userQueue: MutableList<Song>) {}
+        fun onUserQueueUpdate(userQueue: List<Song>) {}
         fun onModeUpdate(mode: PlaybackMode) {}
         fun onIndexUpdate(index: Int) {}
         fun onPlayingUpdate(isPlaying: Boolean) {}

app/src/main/java/org/oxycblt/auxio/playback/system/PlaybackService.kt

@@ -252,7 +252,11 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateManager.Ca
     }
 
     override fun onLoopUpdate(loopMode: LoopMode) {
-        player.setLoopMode(loopMode)
+        player.repeatMode = if (loopMode == LoopMode.NONE) {
+            Player.REPEAT_MODE_OFF
+        } else {
+            Player.REPEAT_MODE_ALL
+        }
 
         if (!settingsManager.useAltNotifAction) {
             notification.setLoop(this, loopMode)
@@ -344,27 +348,6 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateManager.Ca
         onLoopUpdate(playbackManager.loopMode)
         onSongUpdate(playbackManager.song)
         onSeek(playbackManager.position)
-
-        /*
-        Old Manual restore code, restore this if the above causes bugs
-        notification.setParent(this, playbackManager.parent)
-        notification.setPlaying(this, playbackManager.isPlaying)
-
-        if (settingsManager.useAltNotifAction) {
-            notification.setShuffle(this, playbackManager.isShuffling)
-        } else {
-            notification.setLoop(this, playbackManager.loopMode)
-        }
-
-        player.setLoopMode(playbackManager.loopMode)
-
-        playbackManager.song?.let { song ->
-            notification.setMetadata(this, song, settingsManager.colorizeNotif) {}
-
-            player.setMediaItem(MediaItem.fromUri(song.id.toURI()))
-            player.seekTo(playbackManager.position)
-            player.prepare()
-        }*/
     }
 
     /**
@@ -406,17 +389,6 @@ class PlaybackService : Service(), Player.EventListener, PlaybackStateManager.Ca
         }
     }
 
-    /**
-     * Shortcut to transform a [LoopMode] into a player repeat mode
-     */
-    private fun Player.setLoopMode(mode: LoopMode) {
-        repeatMode = if (mode == LoopMode.NONE) {
-            Player.REPEAT_MODE_OFF
-        } else {
-            Player.REPEAT_MODE_ALL
-        }
-    }
-
     /**
      * Bring the service into the foreground and show the notification, or refresh the notification.
      */

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

@@ -0,0 +1,112 @@
+package org.oxycblt.auxio.songs
+
+import android.content.Context
+import android.graphics.drawable.GradientDrawable
+import android.os.Build
+import android.util.AttributeSet
+import android.view.MotionEvent
+import android.view.ViewGroup
+import android.widget.TextView
+import androidx.constraintlayout.widget.ConstraintLayout
+import androidx.core.view.children
+import androidx.core.view.isVisible
+import androidx.core.widget.TextViewCompat
+import androidx.dynamicanimation.animation.DynamicAnimation
+import androidx.dynamicanimation.animation.SpringAnimation
+import androidx.dynamicanimation.animation.SpringForce
+import com.reddit.indicatorfastscroll.FastScrollItemIndicator
+import com.reddit.indicatorfastscroll.FastScrollerView
+import org.oxycblt.auxio.R
+import org.oxycblt.auxio.ui.Accent
+import org.oxycblt.auxio.ui.addIndicatorCallback
+import org.oxycblt.auxio.ui.inflater
+
+/**
+ * A slimmed-down variant of [com.reddit.indicatorfastscroll.FastScrollerThumbView] designed
+ * specifically for Auxio. Also fixes a memory leak that occurs from a bug fix they
+ * added.
+ * @author OxygenCobalt
+ */
+class CobaltScrollThumb @JvmOverloads constructor(
+    context: Context,
+    attrs: AttributeSet? = null,
+    defStyleAttr: Int = -1
+) : ConstraintLayout(context, attrs, defStyleAttr) {
+    private val thumbView: ViewGroup
+    private val textView: TextView
+    private val thumbAnim: SpringAnimation
+
+    init {
+        context.inflater.inflate(R.layout.fast_scroller_thumb_view, this, true)
+
+        val accent = Accent.get().getStateList(context)
+
+        thumbView = findViewById<ViewGroup>(R.id.fast_scroller_thumb).apply {
+            textView = findViewById(R.id.fast_scroller_thumb_text)
+
+            backgroundTintList = accent
+
+            // Workaround for API 21 tint bug
+            if (Build.VERSION.SDK_INT == Build.VERSION_CODES.LOLLIPOP) {
+                (background as GradientDrawable).apply {
+                    mutate()
+                    color = accent
+                }
+            }
+        }
+
+        textView.apply {
+            isVisible = true
+            TextViewCompat.setTextAppearance(this, R.style.TextAppearance_ThumbIndicator)
+        }
+
+        thumbAnim = SpringAnimation(thumbView, DynamicAnimation.TRANSLATION_Y).apply {
+            spring = SpringForce().also {
+                it.dampingRatio = SpringForce.DAMPING_RATIO_NO_BOUNCY
+            }
+        }
+
+        isActivated = false
+    }
+
+    /**
+     * Set up this view with a [FastScrollerView]. Should only be called once.
+     */
+    fun setup(scrollView: FastScrollerView) {
+        scrollView.addIndicatorCallback { indicator, centerY, _ ->
+            thumbAnim.animateToFinalPosition(centerY.toFloat() - (thumbView.measuredHeight / 2))
+
+            if (indicator is FastScrollItemIndicator.Text) {
+                textView.text = indicator.text
+            }
+        }
+
+        @Suppress("ClickableViewAccessibility")
+        scrollView.setOnTouchListener { v, event ->
+            scrollView.onTouchEvent(event)
+            scrollView.performClick()
+
+            val action = event.actionMasked
+
+            // If we arent deselecting the scroll view, determine if we are selecting an item.
+            isActivated = if (
+                action != MotionEvent.ACTION_UP && action != MotionEvent.ACTION_CANCEL
+            ) isPointerOnItem(scrollView, event.y.toInt()) else false
+
+            true
+        }
+    }
+
+    /**
+     * Hack that determines whether the pointer is currently on the [scrollView] or not.
+     */
+    private fun isPointerOnItem(scrollView: FastScrollerView, touchY: Int): Boolean {
+        scrollView.children.forEach { child ->
+            if (touchY in (child.top until child.bottom)) {
+                return true
+            }
+        }
+
+        return false
+    }
+}

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

@@ -10,6 +10,7 @@ import androidx.fragment.app.Fragment
 import androidx.fragment.app.activityViewModels
 import androidx.recyclerview.widget.GridLayoutManager
 import androidx.recyclerview.widget.LinearLayoutManager
+import androidx.recyclerview.widget.RecyclerView
 import com.reddit.indicatorfastscroll.FastScrollItemIndicator
 import com.reddit.indicatorfastscroll.FastScrollerView
 import org.oxycblt.auxio.R
@@ -18,6 +19,7 @@ import org.oxycblt.auxio.logD
 import org.oxycblt.auxio.music.MusicStore
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.ui.Accent
+import org.oxycblt.auxio.ui.addIndicatorCallback
 import org.oxycblt.auxio.ui.canScroll
 import org.oxycblt.auxio.ui.getSpans
 import org.oxycblt.auxio.ui.newMenu
@@ -57,9 +59,7 @@ class SongsFragment : Fragment() {
                 if (it.itemId == R.id.action_shuffle) {
                     playbackModel.shuffleAll()
                     true
-                }
+                } else false
-
-                false
             }
         }
 
@@ -82,26 +82,18 @@ class SongsFragment : Fragment() {
             }
         }
 
-        setupFastScroller(binding)
+        binding.songFastScroll.setup(binding.songRecycler, binding.songFastScrollThumb)
 
         logD("Fragment created.")
 
         return binding.root
     }
 
-    override fun onDestroyView() {
-        requireView().rootView.clearFocus()
-
-        super.onDestroyView()
-    }
-
     /**
-     * Go through the fast scroller setup process.
+     * Perform the (Frustratingly Long and Complicated) FastScrollerView setup.
-     * @param binding Binding required
      */
-    private fun setupFastScroller(binding: FragmentSongsBinding) {
+    private fun FastScrollerView.setup(recycler: RecyclerView, thumb: CobaltScrollThumb) {
-        binding.songFastScroll.apply {
+        var concatInterval: Int = -1
-            var concatInterval = -1
 
         // API 22 and below don't support the state color, so just use the accent.
         if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.M) {
@@ -109,25 +101,9 @@ class SongsFragment : Fragment() {
         }
 
         setupWithRecyclerView(
-                binding.songRecycler,
+            recycler,
             { pos ->
-                    val item = musicStore.songs[pos]
+                val char = musicStore.songs[pos].name.first
-
-                    // If the item starts with "the"/"a", then actually use the character after that
-                    // as its initial. Yes, this is stupidly western-centric but the code [hopefully]
-                    // shouldn't run with other languages.
-                    val char: Char = if (item.name.length > 5 &&
-                        item.name.startsWith("the ", ignoreCase = true)
-                    ) {
-                        item.name[4].toUpperCase()
-                    } else if (item.name.length > 3 &&
-                        item.name.startsWith("a ", ignoreCase = true)
-                    ) {
-                        item.name[2].toUpperCase()
-                    } else {
-                        // If it doesn't begin with that word, then just use the first character.
-                        item.name[0].toUpperCase()
-                    }
 
                 // Use "#" if the character is a digit, also has the nice side-effect of
                 // truncating extra numbers.
@@ -136,12 +112,11 @@ class SongsFragment : Fragment() {
                 } else {
                     FastScrollItemIndicator.Text(char.toString())
                 }
-                }
+            },
+            null, false
         )
 
         showIndicator = { _, i, total ->
-                var isGood = true
-
             if (concatInterval == -1) {
                 // If the scroller size is too small to contain all the entries, truncate entries
                 // so that the fast scroller entries fit.
@@ -150,46 +125,46 @@ class SongsFragment : Fragment() {
                 if (total > maxEntries.toInt()) {
                     concatInterval = ceil(total / maxEntries).toInt()
 
-                        logD("More entries than screen space, truncating by $concatInterval.")
-
                     check(concatInterval > 1) {
-                            "ConcatInterval was one despite truncation being needed"
+                        "Needed to truncate, but concatInterval was 1 or lower anyway"
                     }
+
+                    logD("More entries than screen space, truncating by $concatInterval.")
                 } else {
                     concatInterval = 1
                 }
             }
 
-                if ((i % concatInterval) != 0) {
+            // Any items that need to be truncated will be hidden
-                    isGood = false
+            (i % concatInterval) == 0
         }
 
-                isGood
+        addIndicatorCallback { _, _, pos ->
-            }
+            recycler.apply {
-
-            useDefaultScroller = false
-
-            addIndicatorCallback { pos ->
-                binding.songRecycler.apply {
                 (layoutManager as LinearLayoutManager).scrollToPositionWithOffset(pos, 0)
 
                 stopScroll()
             }
         }
+
+        thumb.setup(this)
     }
 
-        binding.songFastScrollThumb.setupWithFastScroller(binding.songFastScroll)
+    /**
+     * Dumb shortcut for getting the first letter in a string, while regarding certain
+     * semantics when it comes to articles.
+     */
+    private val String.first: Char get() {
+        // If the name actually starts with "The" or "A", get the character *after* that word.
+        // Yes, this is stupidly english centric but it wont run with other languages.
+        if (length > 5 && startsWith("the ", true)) {
+            return get(4).toUpperCase()
         }
 
-    private fun FastScrollerView.addIndicatorCallback(callback: (pos: Int) -> Unit) {
+        if (length > 3 && startsWith("a ", true)) {
-        itemIndicatorSelectedCallbacks.add(
+            return get(2).toUpperCase()
-            object : FastScrollerView.ItemIndicatorSelectedCallback {
-                override fun onItemIndicatorSelected(
-                    indicator: FastScrollItemIndicator,
-                    indicatorCenterY: Int,
-                    itemPosition: Int
-                ) = callback(itemPosition)
         }
-        )
+
+        return get(0).toUpperCase()
     }
 }

app/src/main/java/org/oxycblt/auxio/ui/InterfaceUtils.kt

@@ -23,6 +23,8 @@ import androidx.core.content.ContextCompat
 import androidx.fragment.app.Fragment
 import androidx.recyclerview.widget.RecyclerView
 import com.google.android.material.button.MaterialButton
+import com.reddit.indicatorfastscroll.FastScrollItemIndicator
+import com.reddit.indicatorfastscroll.FastScrollerView
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.logE
 
@@ -121,6 +123,22 @@ fun String.createToast(context: Context) {
     Toast.makeText(context.applicationContext, this, Toast.LENGTH_SHORT).show()
 }
 
+/**
+ * Shortcut that allows me to add a indicator callback to [FastScrollerView] without
+ * the nightmarish boilerplate that entails.
+ */
+fun FastScrollerView.addIndicatorCallback(
+    callback: (indicator: FastScrollItemIndicator, centerY: Int, pos: Int) -> Unit
+) {
+    itemIndicatorSelectedCallbacks += object : FastScrollerView.ItemIndicatorSelectedCallback {
+        override fun onItemIndicatorSelected(
+            indicator: FastScrollItemIndicator,
+            indicatorCenterY: Int,
+            itemPosition: Int
+        ) = callback(indicator, indicatorCenterY, itemPosition)
+    }
+}
+
 // --- CONFIGURATION ---
 
 /**

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

@@ -39,7 +39,7 @@
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintTop_toBottomOf="@+id/song_toolbar" />
 
-        <org.oxycblt.auxio.recycler.NoLeakThumbView
+        <org.oxycblt.auxio.songs.CobaltScrollThumb
             android:id="@+id/song_fast_scroll_thumb"
             android:layout_width="@dimen/width_thumb_view"
             android:layout_height="0dp"

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

@@ -100,8 +100,8 @@
 
     <!-- Fast scroll theme -->
     <style name="FastScrollTheme" parent="Widget.IndicatorFastScroll.FastScroller">
-        <item name="android:textColor">@color/color_scroll_tints</item>
         <item name="android:textAppearance">@style/TextAppearance.FastScroll</item>
+        <item name="android:textColor">@color/color_scroll_tints</item>
     </style>
 
     <!-- Fast scroll text appearance -->
@@ -112,6 +112,7 @@
     <!-- Fast scroll thumb appearance -->
     <style name="TextAppearance.ThumbIndicator" parent="TextAppearance.FastScroll">
         <item name="android:textSize">@dimen/text_size_thumb</item>
+        <item name="android:textColor">?android:attr/windowBackground</item>
     </style>
 
     <!-- Style for the general item background -->

build.gradle

@@ -1,6 +1,6 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 buildscript {
-    ext.kotlin_version = '1.4.30'
+    ext.kotlin_version = '1.4.31'
 
     repositories {
         google()