Resolve fast-scroll resource issues

Accidentally forgot to move the resources from the fast scroll library, so here it is.

app/build.gradle

@@ -53,6 +53,9 @@ afterEvaluate {
 dependencies {
     implementation fileTree(dir: "libs", include: ["*.jar"])
 
+    // FIXME: A good chunk of the dependencies I use are implicit,
+    //  I may want to explicitly declare them to avoid any annoying build issues in the future.
+
     // Kotlin
     implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
@@ -98,10 +101,11 @@ dependencies {
     implementation 'com.google.android.material:material:1.3.0'
 
     // Dialogs
+    // TODO: Eliminate these, don't want their bloat.
     implementation 'com.afollestad.material-dialogs:core:3.3.0'
     implementation 'com.afollestad.material-dialogs:files:3.3.0'
 
-    // --- DEV ---
+    // --- DEBUG ---
 
     // Lint
     ktlint "com.pinterest:ktlint:0.40.0"

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

@@ -20,8 +20,9 @@ import org.oxycblt.auxio.ui.inflater
 /**
  * The companion thumb for [FastScrollView]. This does not need any setup, instead pass it as an
  * argument to [FastScrollView.setup].
- * This code is fundamentally an adaptation of Reddit's IndicatorFastScroll, targeted towards
+ * This code is fundamentally an adaptation of Reddit's IndicatorFastScroll, albeit specialized
- * Auxio specifically. Check them out here: https://github.com/reddit/IndicatorFastScroll/
+ * towards Auxio. The original library is here: https://github.com/reddit/IndicatorFastScroll/
+ * TODO: Merge this view and FastScrollView? They are effectively reliant on eachother
  * @author OxygenCobalt
  */
 class FastScrollThumb @JvmOverloads constructor(
@@ -70,7 +71,7 @@ class FastScrollThumb @JvmOverloads constructor(
 
     /**
      * Make the thumb jump to a new position and update its text to the given [indicator].
-     * This is not meant for use outside of the main [FastScrollView] code, don't use it.
+     * This is not meant for use outside of the main [FastScrollView] code. Do not use it.
      */
     fun jumpTo(indicator: FastScrollView.Indicator, centerY: Int) {
         binding.thumbText.text = indicator.char.toString()

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

@@ -24,8 +24,8 @@ import kotlin.math.min
 /**
  * A view that allows for quick scrolling through a [RecyclerView] with many items. Unlike other
  * fast-scrollers, this one displays indicators instead of simply a scroll bar.
- * This code is fundamentally an adaptation of Reddit's IndicatorFastScroll, targeted towards
+ * This code is fundamentally an adaptation of Reddit's IndicatorFastScroll, albeit specialized
- * Auxio specifically. Check them out here: https://github.com/reddit/IndicatorFastScroll/
+ * towards Auxio. The original library is here: https://github.com/reddit/IndicatorFastScroll/
  * @author OxygenCobalt
  */
 class FastScrollView @JvmOverloads constructor(
@@ -172,6 +172,7 @@ class FastScrollView @JvmOverloads constructor(
         }
 
         if (touchY in (indicatorText.top until indicatorText.bottom)) {
+            // Try to roughly caculate which indicator the user is currently touching [Since the
             val textHeight = indicatorText.height / indicators.size
             val indicatorIndex = min(
                 (touchY - indicatorText.top) / textHeight, indicators.lastIndex

app/src/main/res/animator/animator_thumb.xml

@@ -0,0 +1,46 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Animator from IndicatorFastScroll (https://github.com/reddit/IndicatorFastScroll) -->
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:state_activated="true">
+        <set>
+            <objectAnimator
+                android:duration="@android:integer/config_shortAnimTime"
+                android:propertyName="scaleX"
+                android:valueTo="1"
+                android:valueType="floatType" />
+
+            <objectAnimator
+                android:duration="@android:integer/config_shortAnimTime"
+                android:propertyName="scaleY"
+                android:valueTo="1"
+                android:valueType="floatType" />
+
+            <objectAnimator
+                android:duration="@android:integer/config_shortAnimTime"
+                android:propertyName="alpha"
+                android:valueTo="1"
+                android:valueType="floatType" />
+        </set>
+    </item>
+    <item>
+        <set>
+            <objectAnimator
+                android:duration="@android:integer/config_shortAnimTime"
+                android:propertyName="scaleX"
+                android:valueTo="0"
+                android:valueType="floatType" />
+
+            <objectAnimator
+                android:duration="@android:integer/config_shortAnimTime"
+                android:propertyName="scaleY"
+                android:valueTo="0"
+                android:valueType="floatType" />
+
+            <objectAnimator
+                android:duration="@android:integer/config_shortAnimTime"
+                android:propertyName="alpha"
+                android:valueTo="0"
+                android:valueType="floatType" />
+        </set>
+    </item>
+</selector>

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

@@ -1,19 +1,20 @@
 <?xml version="1.0" encoding="utf-8"?>
+<!-- Animator from IndicatorFastScroll (https://github.com/reddit/IndicatorFastScroll) -->
 <layout>
     <merge xmlns:android="http://schemas.android.com/apk/res/android"
         xmlns:app="http://schemas.android.com/apk/res-auto"
         xmlns:tools="http://schemas.android.com/tools"
         tools:layout_height="match_parent"
-        tools:layout_width="@dimen/fast_scroller_thumb_size"
+        tools:layout_width="@dimen/size_scroll_thumb"
         tools:parentTag="androidx.constraintlayout.widget.ConstraintLayout">
 
         <FrameLayout
             android:id="@+id/thumb_layout"
             android:layout_width="0dp"
             android:layout_height="0dp"
-            android:background="@drawable/thumb_circle"
+            android:background="@drawable/ui_circular_button"
-            android:elevation="@dimen/fast_scroller_thumb_elevation"
+            android:elevation="@dimen/elevation_small"
-            android:stateListAnimator="@animator/fast_scroll_thumb"
+            android:stateListAnimator="@animator/animator_thumb"
             app:layout_constraintDimensionRatio="W,1:1"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent">

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

@@ -40,6 +40,7 @@
 
     <dimen name="size_play_pause">70dp</dimen>
     <dimen name="size_play_pause_compact">36dp</dimen>
+    <dimen name="size_scroll_thumb">32dp</dimen>
     <dimen name="size_clear">32dp</dimen>
 
     <dimen name="size_app_icon">60dp</dimen>
@@ -55,6 +56,7 @@
     <dimen name="text_size_toolbar_header">20sp</dimen>
 
     <!-- Misc -->
+    <dimen name="elevation_small">2dp</dimen>
     <dimen name="elevation_normal">4dp</dimen>
     <dimen name="offset_thumb">4dp</dimen>
 </resources>