home: clean up fast scroller

Clean up the fast scroller implementation to remove dead code and
be more coherent in general.

app/build.gradle

@@ -106,7 +106,6 @@ dependencies {
 spotless {
     kotlin {
         target "src/**/*.kt"
-
         ktfmt('0.30').dropboxStyle()
         licenseHeaderFile("NOTICE")
     }

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

@@ -40,8 +40,11 @@ import org.oxycblt.auxio.util.systemBarInsetsCompat
 /**
  * The single [AppCompatActivity] for Auxio.
  *
- * TODO: Add a new view for crashes with a stack trace TODO: Custom language support TODO: Rework
+ * TODO: Add a new view for crashes with a stack trace
- * menus [perhaps add multi-select]
+ *
+ * TODO: Custom language support
+ *
+ * TODO: Rework menus [perhaps add multi-select]
  */
 class MainActivity : AppCompatActivity() {
     private val playbackModel: PlaybackViewModel by viewModels()

app/src/main/java/org/oxycblt/auxio/home/HomeFragment.kt

@@ -55,7 +55,9 @@ import org.oxycblt.auxio.util.logTraceOrThrow
  * respective item.
  * @author OxygenCobalt
  *
- * TODO: Make tabs invisible when there is only one TODO: Add duration and song count sorts
+ * TODO: Make tabs invisible when there is only one
+ *
+ * TODO: Add duration and song count sorts
  */
 class HomeFragment : Fragment() {
     private val playbackModel: PlaybackViewModel by activityViewModels()

app/src/main/java/org/oxycblt/auxio/home/fastscroll/FastScrollPopupDrawable.kt

@@ -1,168 +0,0 @@
-/*
- * Copyright (c) 2021 Auxio Project
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
- 
-package org.oxycblt.auxio.home.fastscroll
-
-import android.content.Context
-import android.graphics.Canvas
-import android.graphics.ColorFilter
-import android.graphics.Matrix
-import android.graphics.Outline
-import android.graphics.Paint
-import android.graphics.Path
-import android.graphics.PixelFormat
-import android.graphics.Rect
-import android.graphics.drawable.Drawable
-import android.os.Build
-import android.view.View
-import androidx.core.graphics.drawable.DrawableCompat
-import kotlin.math.sqrt
-import org.oxycblt.auxio.R
-import org.oxycblt.auxio.util.getAttrColorSafe
-import org.oxycblt.auxio.util.getDimenOffsetSafe
-
-/**
- * The custom drawable used as FastScrollRecyclerView's popup background. This is an adaptation from
- * AndroidFastScroll's MD2 theme.
- *
- * Attributions as per the Apache 2.0 license: ORIGINAL AUTHOR: Hai Zhang
- * [https://github.com/zhanghai] PROJECT: Android Fast Scroll
- * [https://github.com/zhanghai/AndroidFastScroll] MODIFIER: OxygenCobalt [https://github.com/]
- *
- * !!! MODIFICATIONS !!!:
- * - Use modified Auxio resources instead of AFS resources
- * - Variable names are no longer prefixed with m
- * - Made path management compat-friendly
- * - Converted to kotlin
- *
- * @author Hai Zhang, OxygenCobalt
- */
-class FastScrollPopupDrawable(context: Context) : Drawable() {
-    private val paint: Paint =
-        Paint().apply {
-            isAntiAlias = true
-            color = context.getAttrColorSafe(R.attr.colorSecondary)
-            style = Paint.Style.FILL
-        }
-
-    private val path = Path()
-    private val matrix = Matrix()
-
-    private val paddingStart = context.getDimenOffsetSafe(R.dimen.spacing_medium)
-    private val paddingEnd = context.getDimenOffsetSafe(R.dimen.popup_padding_end)
-
-    override fun draw(canvas: Canvas) {
-        canvas.drawPath(path, paint)
-    }
-
-    override fun onBoundsChange(bounds: Rect) {
-        updatePath()
-    }
-
-    override fun onLayoutDirectionChanged(layoutDirection: Int): Boolean {
-        updatePath()
-        return true
-    }
-
-    @Suppress("DEPRECATION")
-    override fun getOutline(outline: Outline) {
-        when {
-            Build.VERSION.SDK_INT >= Build.VERSION_CODES.R -> outline.setPath(path)
-
-            // Paths don't need to be convex on android Q, but the API was mislabeled and so
-            // we still have to use this method.
-            Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q -> outline.setConvexPath(path)
-            else ->
-                if (!path.isConvex) {
-                    // The outline path must be convex before Q, but we may run into floating point
-                    // errors caused by calculations involving sqrt(2) or OEM implementation
-                    // differences,
-                    // so in this case we just omit the shadow instead of crashing.
-                    super.getOutline(outline)
-                }
-        }
-    }
-
-    override fun getPadding(padding: Rect): Boolean {
-        if (isRtl) {
-            padding[paddingEnd, 0, paddingStart] = 0
-        } else {
-            padding[paddingStart, 0, paddingEnd] = 0
-        }
-
-        return true
-    }
-
-    override fun isAutoMirrored(): Boolean = true
-    override fun getOpacity(): Int = PixelFormat.TRANSLUCENT
-    override fun setAlpha(alpha: Int) {}
-    override fun setColorFilter(colorFilter: ColorFilter?) {}
-
-    private fun updatePath() {
-        path.reset()
-
-        var width = bounds.width().toFloat()
-        val height = bounds.height().toFloat()
-        val r = height / 2
-        val sqrt2 = sqrt(2.0).toFloat()
-
-        // Ensure we are convex
-        width = (r + sqrt2 * r).coerceAtLeast(width)
-        pathArcTo(path, r, r, r, 90f, 180f)
-
-        val o1X = width - sqrt2 * r
-        pathArcTo(path, o1X, r, r, -90f, 45f)
-
-        val r2 = r / 5
-        val o2X = width - sqrt2 * r2
-        pathArcTo(path, o2X, r, r2, -45f, 90f)
-        pathArcTo(path, o1X, r, r, 45f, 45f)
-
-        path.close()
-
-        if (isRtl) {
-            matrix.setScale(-1f, 1f, width / 2, 0f)
-        } else {
-            matrix.reset()
-        }
-
-        matrix.postTranslate(bounds.left.toFloat(), bounds.top.toFloat())
-
-        path.transform(matrix)
-    }
-
-    private fun pathArcTo(
-        path: Path,
-        centerX: Float,
-        centerY: Float,
-        radius: Float,
-        startAngle: Float,
-        sweepAngle: Float
-    ) {
-        path.arcTo(
-            centerX - radius,
-            centerY - radius,
-            centerX + radius,
-            centerY + radius,
-            startAngle,
-            sweepAngle,
-            false)
-    }
-
-    private val isRtl: Boolean
-        get() = DrawableCompat.getLayoutDirection(this) == View.LAYOUT_DIRECTION_RTL
-}

app/src/main/java/org/oxycblt/auxio/home/fastscroll/FastScrollPopupView.kt

@@ -0,0 +1,173 @@
+/*
+ * Copyright (c) 2022 Auxio Project
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
+package org.oxycblt.auxio.home.fastscroll
+
+import android.content.Context
+import android.graphics.Canvas
+import android.graphics.ColorFilter
+import android.graphics.Matrix
+import android.graphics.Outline
+import android.graphics.Paint
+import android.graphics.Path
+import android.graphics.PixelFormat
+import android.graphics.Rect
+import android.graphics.drawable.Drawable
+import android.os.Build
+import android.text.TextUtils
+import android.util.AttributeSet
+import android.view.Gravity
+import androidx.core.widget.TextViewCompat
+import com.google.android.material.textview.MaterialTextView
+import org.oxycblt.auxio.R
+import org.oxycblt.auxio.util.getAttrColorSafe
+import org.oxycblt.auxio.util.getDimenOffsetSafe
+import org.oxycblt.auxio.util.getDimenSizeSafe
+import org.oxycblt.auxio.util.isRtl
+
+class FastScrollPopupView
+@JvmOverloads
+constructor(context: Context, attrs: AttributeSet? = null, defStyleRes: Int = 0) :
+    MaterialTextView(context, attrs, defStyleRes) {
+    init {
+        minimumWidth = context.getDimenSizeSafe(R.dimen.fast_scroll_popup_min_width)
+        minimumHeight = context.getDimenSizeSafe(R.dimen.fast_scroll_popup_min_height)
+
+        TextViewCompat.setTextAppearance(this, R.style.TextAppearance_Auxio_HeadlineLarge)
+        setTextColor(context.getAttrColorSafe(R.attr.colorOnSecondary))
+        ellipsize = TextUtils.TruncateAt.MIDDLE
+        gravity = Gravity.CENTER
+        includeFontPadding = false
+
+        alpha = 0f
+        elevation = context.getDimenSizeSafe(R.dimen.elevation_normal).toFloat()
+        background = FastScrollPopupDrawable(context)
+    }
+
+    private class FastScrollPopupDrawable(context: Context) : Drawable() {
+        private val paint: Paint =
+            Paint().apply {
+                isAntiAlias = true
+                color = context.getAttrColorSafe(R.attr.colorSecondary)
+                style = Paint.Style.FILL
+            }
+
+        private val path = Path()
+        private val matrix = Matrix()
+
+        private val paddingStart =
+            context.getDimenOffsetSafe(R.dimen.fast_scroll_popup_padding_start)
+        private val paddingEnd = context.getDimenOffsetSafe(R.dimen.fast_scroll_popup_padding_end)
+
+        override fun draw(canvas: Canvas) {
+            canvas.drawPath(path, paint)
+        }
+
+        override fun onBoundsChange(bounds: Rect) {
+            updatePath()
+        }
+
+        override fun onLayoutDirectionChanged(layoutDirection: Int): Boolean {
+            updatePath()
+            return true
+        }
+
+        @Suppress("DEPRECATION")
+        override fun getOutline(outline: Outline) {
+            when {
+                Build.VERSION.SDK_INT >= Build.VERSION_CODES.R -> outline.setPath(path)
+
+                // Paths don't need to be convex on android Q, but the API was mislabeled and so
+                // we still have to use this method.
+                Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q -> outline.setConvexPath(path)
+                else ->
+                    if (!path.isConvex) {
+                        // The outline path must be convex before Q, but we may run into floating
+                        // point errors caused by calculations involving sqrt(2) or OEM differences,
+                        // so in this case we just omit the shadow instead of crashing.
+                        super.getOutline(outline)
+                    }
+            }
+        }
+
+        override fun getPadding(padding: Rect): Boolean {
+            if (isRtl) {
+                padding[paddingEnd, 0, paddingStart] = 0
+            } else {
+                padding[paddingStart, 0, paddingEnd] = 0
+            }
+
+            return true
+        }
+
+        override fun isAutoMirrored(): Boolean = true
+        override fun getOpacity(): Int = PixelFormat.TRANSLUCENT
+        override fun setAlpha(alpha: Int) {}
+        override fun setColorFilter(colorFilter: ColorFilter?) {}
+
+        private fun updatePath() {
+            val r = bounds.height().toFloat() / 2
+            val w = (r + SQRT2 * r).coerceAtLeast(bounds.width().toFloat())
+
+            path.apply {
+                reset()
+
+                // Draw the left pill shape
+                val o1X = w - SQRT2 * r
+                arcToSafe(r, r, r, 90f, 180f)
+                arcToSafe(o1X, r, r, -90f, 45f)
+
+                // Draw the right arrow shape
+                val point = r / 5
+                val o2X = w - SQRT2 * point
+                arcToSafe(o2X, r, point, -45f, 90f)
+                arcToSafe(o1X, r, r, 45f, 45f)
+
+                close()
+            }
+
+            matrix.apply {
+                reset()
+                if (isRtl) setScale(-1f, 1f, w / 2, 0f)
+                postTranslate(bounds.left.toFloat(), bounds.top.toFloat())
+            }
+
+            path.transform(matrix)
+        }
+
+        private fun Path.arcToSafe(
+            centerX: Float,
+            centerY: Float,
+            radius: Float,
+            startAngle: Float,
+            sweepAngle: Float
+        ) {
+            path.arcTo(
+                centerX - radius,
+                centerY - radius,
+                centerX + radius,
+                centerY + radius,
+                startAngle,
+                sweepAngle,
+                false)
+        }
+    }
+
+    companion object {
+        private const val SQRT2 = 1.4142135623730950488f
+    }
+}

app/src/main/java/org/oxycblt/auxio/home/fastscroll/FastScrollRecyclerView.kt

@@ -17,11 +17,9 @@
  
 package org.oxycblt.auxio.home.fastscroll
 
-import android.annotation.SuppressLint
 import android.content.Context
 import android.graphics.Canvas
 import android.graphics.Rect
-import android.text.TextUtils
 import android.util.AttributeSet
 import android.view.Gravity
 import android.view.MotionEvent
@@ -30,12 +28,9 @@ import android.view.ViewConfiguration
 import android.view.ViewGroup
 import android.view.WindowInsets
 import android.widget.FrameLayout
-import android.widget.TextView
 import androidx.annotation.AttrRes
-import androidx.appcompat.widget.AppCompatTextView
 import androidx.core.math.MathUtils
 import androidx.core.view.isInvisible
-import androidx.core.widget.TextViewCompat
 import androidx.recyclerview.widget.GridLayoutManager
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
@@ -43,19 +38,21 @@ import kotlin.math.abs
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.ui.EdgeRecyclerView
 import org.oxycblt.auxio.util.canScroll
-import org.oxycblt.auxio.util.getAttrColorSafe
 import org.oxycblt.auxio.util.getDimenOffsetSafe
 import org.oxycblt.auxio.util.getDimenSizeSafe
 import org.oxycblt.auxio.util.getDrawableSafe
+import org.oxycblt.auxio.util.isRtl
+import org.oxycblt.auxio.util.isUnder
 import org.oxycblt.auxio.util.systemBarInsetsCompat
 
 /**
  * A [RecyclerView] that enables better fast-scrolling. This is fundamentally a implementation of
  * Hai Zhang's AndroidFastScroll but slimmed down for Auxio and with a couple of enhancements.
  *
- * Attributions as per the Apache 2.0 license: ORIGINAL AUTHOR: Hai Zhang
+ * Attributions as per the Apache 2.0 license:
- * [https://github.com/zhanghai] PROJECT: Android Fast Scroll
+ * - ORIGINAL AUTHOR: Hai Zhang [https://github.com/zhanghai]
- * [https://github.com/zhanghai/AndroidFastScroll] MODIFIER: OxygenCobalt [https://github.com/]
+ * - PROJECT: Android Fast Scroll [https://github.com/zhanghai/AndroidFastScroll]
+ * - MODIFIER: OxygenCobalt [https://github.com/oxygencobalt]
  *
  * !!! MODIFICATIONS !!!:
  * - Scroller will no longer show itself on startup or relayouts, which looked unpleasant with
@@ -72,11 +69,90 @@ import org.oxycblt.auxio.util.systemBarInsetsCompat
  * - Added documentation
  *
  * @author Hai Zhang, OxygenCobalt
+ *
+ * TODO: Fix strange touch behavior when the pointer is slightly outside of the view.
+ *
+ * TODO: Really try to make this view less insane.
  */
 class FastScrollRecyclerView
 @JvmOverloads
 constructor(context: Context, attrs: AttributeSet? = null, @AttrRes defStyleAttr: Int = 0) :
     EdgeRecyclerView(context, attrs, defStyleAttr) {
+    private val minTouchTargetSize =
+        context.getDimenSizeSafe(R.dimen.fast_scroll_thumb_touch_target_size)
+    private val touchSlop = ViewConfiguration.get(context).scaledTouchSlop
+
+    // Thumb
+    private val thumbView =
+        View(context).apply {
+            alpha = 0f
+            background = context.getDrawableSafe(R.drawable.ui_scroll_thumb)
+            this@FastScrollRecyclerView.overlay.add(this)
+        }
+
+    private val thumbWidth = thumbView.background.intrinsicWidth
+    private val thumbHeight = thumbView.background.intrinsicHeight
+    private val thumbPadding = Rect(0, 0, 0, 0)
+    private var thumbOffset = 0
+
+    private var showingThumb = false
+    private val hideThumbRunnable = Runnable {
+        if (!dragging) {
+            hideScrollbar()
+        }
+    }
+
+    // Popup
+    private val popupView =
+        FastScrollPopupView(context).apply {
+            layoutParams =
+                FrameLayout.LayoutParams(
+                        ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)
+                    .apply {
+                        gravity = Gravity.CENTER_HORIZONTAL or Gravity.TOP
+                        marginEnd = context.getDimenOffsetSafe(R.dimen.spacing_small)
+                    }
+
+            this@FastScrollRecyclerView.overlay.add(this)
+        }
+
+    private var showingPopup = false
+
+    // Touch events
+    private var downX = 0f
+    private var downY = 0f
+    private var lastY = 0f
+    private var dragStartY = 0f
+    private var dragStartThumbOffset = 0
+
+    private var dragging = false
+        set(value) {
+            if (field == value) {
+                return
+            }
+
+            field = value
+
+            if (value) {
+                parent.requestDisallowInterceptTouchEvent(true)
+            }
+
+            thumbView.isPressed = value
+
+            if (field) {
+                removeCallbacks(hideThumbRunnable)
+                showScrollbar()
+                showPopup()
+            } else {
+                postAutoHideScrollbar()
+                hidePopup()
+            }
+
+            onDragListener?.invoke(value)
+        }
+
+    private val childRect = Rect()
+
     /** Callback to provide a string to be shown on the popup when an item is passed */
     var popupProvider: ((Int) -> String)? = null
 
@@ -86,83 +162,7 @@ constructor(context: Context, attrs: AttributeSet? = null, @AttrRes defStyleAttr
      */
     var onDragListener: ((Boolean) -> Unit)? = null
 
-    private val minTouchTargetSize: Int = context.getDimenSizeSafe(R.dimen.size_btn_small)
-    private val touchSlop: Int = ViewConfiguration.get(context).scaledTouchSlop
-
-    // Views for the track, thumb, and popup. Note that the track view is mostly vestigial
-    // and is only for bounds checking.
-    private val trackView: View
-    private val thumbView: View
-    private val popupView: TextView
-
-    // Touch values
-    private val thumbWidth: Int
-    private val thumbHeight: Int
-    private var thumbOffset = 0
-    private var downX = 0f
-    private var downY = 0f
-    private var lastY = 0f
-    private var dragStartY = 0f
-    private var dragStartThumbOffset = 0
-
-    // State
-    private var dragging = false
-    private var showingScrollbar = false
-    private var showingPopup = false
-
-    private val childRect = Rect()
-
-    private val hideScrollbarRunnable = Runnable {
-        if (!dragging) {
-            hideScrollbar()
-        }
-    }
-
-    private val scrollerPadding = Rect(0, 0, 0, 0)
-
     init {
-        val thumbDrawable = context.getDrawableSafe(R.drawable.ui_scroll_thumb)
-
-        trackView = View(context)
-        thumbView =
-            View(context).apply {
-                alpha = 0f
-                background = thumbDrawable
-            }
-
-        popupView =
-            AppCompatTextView(context).apply {
-                alpha = 0f
-                layoutParams =
-                    FrameLayout.LayoutParams(
-                        ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)
-
-                minimumWidth = context.getDimenSizeSafe(R.dimen.popup_min_width)
-                minimumHeight = context.getDimenSizeSafe(R.dimen.size_btn_large)
-
-                (layoutParams as FrameLayout.LayoutParams).apply {
-                    gravity = Gravity.CENTER_HORIZONTAL or Gravity.TOP
-                    marginEnd = context.getDimenOffsetSafe(R.dimen.spacing_small)
-                }
-
-                TextViewCompat.setTextAppearance(this, R.style.TextAppearance_Auxio_HeadlineLarge)
-                setTextColor(context.getAttrColorSafe(R.attr.colorOnSecondary))
-
-                background = FastScrollPopupDrawable(context)
-                elevation = context.getDimenSizeSafe(R.dimen.elevation_normal).toFloat()
-                ellipsize = TextUtils.TruncateAt.MIDDLE
-                gravity = Gravity.CENTER
-                includeFontPadding = false
-                isSingleLine = true
-            }
-
-        thumbWidth = thumbDrawable.intrinsicWidth
-        thumbHeight = thumbDrawable.intrinsicHeight
-
-        check(thumbWidth >= 0)
-        check(thumbHeight >= 0)
-
-        overlay.add(trackView)
         overlay.add(thumbView)
         overlay.add(popupView)
 
@@ -195,42 +195,33 @@ constructor(context: Context, attrs: AttributeSet? = null, @AttrRes defStyleAttr
     private fun onPreDraw() {
         updateScrollbarState()
 
-        trackView.layoutDirection = layoutDirection
         thumbView.layoutDirection = layoutDirection
         popupView.layoutDirection = layoutDirection
 
-        val trackLeft =
-            if (isRtl) {
-                scrollerPadding.left
-            } else {
-                width - scrollerPadding.right - thumbWidth
-            }
-
-        trackView.layout(
-            trackLeft, scrollerPadding.top, trackLeft + thumbWidth, height - scrollerPadding.bottom)
-
         val thumbLeft =
             if (isRtl) {
-                scrollerPadding.left
+                thumbPadding.left
             } else {
-                width - scrollerPadding.right - thumbWidth
+                width - thumbPadding.right - thumbWidth
             }
 
-        val thumbTop = scrollerPadding.top + thumbOffset
+        val thumbTop = thumbPadding.top + thumbOffset
 
         thumbView.layout(thumbLeft, thumbTop, thumbLeft + thumbWidth, thumbTop + thumbHeight)
 
         val firstPos = firstAdapterPos
         val popupText =
             if (firstPos != NO_POSITION) {
-                popupProvider?.invoke(firstPos) ?: ""
+                popupProvider?.invoke(firstPos)?.ifEmpty { null }
             } else {
-                ""
+                null
             }
 
-        popupView.isInvisible = popupText.isEmpty()
+        // Lay out the popup view
 
-        if (popupText.isNotEmpty()) {
+        popupView.isInvisible = popupText == null
+
+        if (popupText != null) {
             val popupLayoutParams = popupView.layoutParams as FrameLayout.LayoutParams
 
             if (popupView.text != popupText) {
@@ -239,8 +230,8 @@ constructor(context: Context, attrs: AttributeSet? = null, @AttrRes defStyleAttr
                 val widthMeasureSpec =
                     ViewGroup.getChildMeasureSpec(
                         MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY),
-                        scrollerPadding.left +
+                        thumbPadding.left +
-                            scrollerPadding.right +
+                            thumbPadding.right +
                             thumbWidth +
                             popupLayoutParams.leftMargin +
                             popupLayoutParams.rightMargin,
@@ -249,8 +240,8 @@ constructor(context: Context, attrs: AttributeSet? = null, @AttrRes defStyleAttr
                 val heightMeasureSpec =
                     ViewGroup.getChildMeasureSpec(
                         MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY),
-                        scrollerPadding.top +
+                        thumbPadding.top +
-                            scrollerPadding.bottom +
+                            thumbPadding.bottom +
                             popupLayoutParams.topMargin +
                             popupLayoutParams.bottomMargin,
                         popupLayoutParams.height)
@@ -262,39 +253,23 @@ constructor(context: Context, attrs: AttributeSet? = null, @AttrRes defStyleAttr
             val popupHeight = popupView.measuredHeight
             val popupLeft =
                 if (layoutDirection == View.LAYOUT_DIRECTION_RTL) {
-                    scrollerPadding.left + thumbWidth + popupLayoutParams.leftMargin
+                    thumbPadding.left + thumbWidth + popupLayoutParams.leftMargin
                 } else {
                     width -
-                        scrollerPadding.right -
+                        thumbPadding.right -
                         thumbWidth -
                         popupLayoutParams.rightMargin -
                         popupWidth
                 }
 
-            // We handle RTL separately, so it's okay if Gravity.RIGHT is used here
+            val popupAnchorY = popupHeight / 2
-            @SuppressLint("RtlHardcoded")
+            val thumbAnchorY = thumbView.paddingTop
-            val popupAnchorY =
-                when (popupLayoutParams.gravity and Gravity.HORIZONTAL_GRAVITY_MASK) {
-                    Gravity.CENTER_HORIZONTAL -> popupHeight / 2
-                    Gravity.RIGHT -> popupHeight
-                    else -> 0
-                }
-
-            val thumbAnchorY =
-                when (popupLayoutParams.gravity and Gravity.VERTICAL_GRAVITY_MASK) {
-                    Gravity.CENTER_VERTICAL -> {
-                        thumbView.paddingTop +
-                            (thumbHeight - thumbView.paddingTop - thumbView.paddingBottom) / 2
-                    }
-                    Gravity.BOTTOM -> thumbHeight - thumbView.paddingBottom
-                    else -> thumbView.paddingTop
-                }
 
             val popupTop =
                 MathUtils.clamp(
                     thumbTop + thumbAnchorY - popupAnchorY,
-                    scrollerPadding.top + popupLayoutParams.topMargin,
+                    thumbPadding.top + popupLayoutParams.topMargin,
-                    height - scrollerPadding.bottom - popupLayoutParams.bottomMargin - popupHeight)
+                    height - thumbPadding.bottom - popupLayoutParams.bottomMargin - popupHeight)
 
             popupView.layout(popupLeft, popupTop, popupLeft + popupWidth, popupTop + popupHeight)
         }
@@ -317,7 +292,7 @@ constructor(context: Context, attrs: AttributeSet? = null, @AttrRes defStyleAttr
     override fun onApplyWindowInsets(insets: WindowInsets): WindowInsets {
         super.onApplyWindowInsets(insets)
         val bars = insets.systemBarInsetsCompat
-        scrollerPadding.bottom = bars.bottom
+        thumbPadding.bottom = bars.bottom
         return insets
     }
 
@@ -345,38 +320,36 @@ constructor(context: Context, attrs: AttributeSet? = null, @AttrRes defStyleAttr
                 downX = eventX
                 downY = eventY
 
-                val scrollX = trackView.scrollX
+                if (eventX >= thumbView.left && eventX < thumbView.right) {
-                val isInScrollbar =
-                    eventX >= thumbView.left - scrollX && eventX < thumbView.right - scrollX
-
-                if (trackView.alpha > 0 && isInScrollbar) {
                     dragStartY = eventY
 
-                    if (isInViewTouchTarget(thumbView, eventX, eventY)) {
+                    if (thumbView.isUnder(eventX, eventY, minTouchTargetSize)) {
                         dragStartThumbOffset = thumbOffset
                     } else {
                         dragStartThumbOffset =
-                            (eventY - scrollerPadding.top - thumbHeight / 2f).toInt()
+                            (eventY - thumbPadding.top - thumbHeight / 2f).toInt()
                         scrollToThumbOffset(dragStartThumbOffset)
                     }
 
-                    setDragging(true)
+                    dragging = true
                 }
             }
             MotionEvent.ACTION_MOVE -> {
                 if (!dragging &&
-                    isInViewTouchTarget(trackView, downX, downY) &&
+                    thumbView.isUnder(downX, thumbView.top.toFloat(), minTouchTargetSize) &&
                     abs(eventY - downY) > touchSlop) {
-                    if (isInViewTouchTarget(thumbView, downX, downY)) {
+
+                    if (thumbView.isUnder(downX, downY, minTouchTargetSize)) {
                         dragStartY = lastY
                         dragStartThumbOffset = thumbOffset
                     } else {
                         dragStartY = eventY
                         dragStartThumbOffset =
-                            (eventY - scrollerPadding.top - thumbHeight / 2f).toInt()
+                            (eventY - thumbPadding.top - thumbHeight / 2f).toInt()
                         scrollToThumbOffset(dragStartThumbOffset)
                     }
-                    setDragging(true)
+
+                    dragging = true
                 }
 
                 if (dragging) {
@@ -384,49 +357,13 @@ constructor(context: Context, attrs: AttributeSet? = null, @AttrRes defStyleAttr
                     scrollToThumbOffset(thumbOffset)
                 }
             }
-            MotionEvent.ACTION_UP, MotionEvent.ACTION_CANCEL -> setDragging(false)
+            MotionEvent.ACTION_UP, MotionEvent.ACTION_CANCEL -> dragging = false
         }
 
         lastY = eventY
         return dragging
     }
 
-    private fun isInViewTouchTarget(view: View, x: Float, y: Float): Boolean {
-        return isInTouchTarget(x, view.left - scrollX, view.right - scrollX, width) &&
-            isInTouchTarget(y, view.top - scrollY, view.bottom - scrollY, height)
-    }
-
-    private fun isInTouchTarget(
-        position: Float,
-        viewStart: Int,
-        viewEnd: Int,
-        parentEnd: Int
-    ): Boolean {
-        val viewSize = viewEnd - viewStart
-
-        if (viewSize >= minTouchTargetSize) {
-            return position >= viewStart && position < viewEnd
-        }
-
-        var touchTargetStart = viewStart - (minTouchTargetSize - viewSize) / 2
-
-        if (touchTargetStart < 0) {
-            touchTargetStart = 0
-        }
-
-        var touchTargetEnd = touchTargetStart + minTouchTargetSize
-        if (touchTargetEnd > parentEnd) {
-            touchTargetEnd = parentEnd
-            touchTargetStart = touchTargetEnd - minTouchTargetSize
-
-            if (touchTargetStart < 0) {
-                touchTargetStart = 0
-            }
-        }
-
-        return position >= touchTargetStart && position < touchTargetEnd
-    }
-
     private fun scrollToThumbOffset(thumbOffset: Int) {
         val clampedThumbOffset = MathUtils.clamp(thumbOffset, 0, thumbOffsetRange)
 
@@ -464,54 +401,28 @@ constructor(context: Context, attrs: AttributeSet? = null, @AttrRes defStyleAttr
         }
     }
 
-    private fun setDragging(isDragging: Boolean) {
-        if (dragging == isDragging) {
-            return
-        }
-
-        dragging = isDragging
-
-        if (dragging) {
-            parent.requestDisallowInterceptTouchEvent(true)
-        }
-
-        trackView.isPressed = dragging
-        thumbView.isPressed = dragging
-
-        if (dragging) {
-            removeCallbacks(hideScrollbarRunnable)
-            showScrollbar()
-            showPopup()
-        } else {
-            postAutoHideScrollbar()
-            hidePopup()
-        }
-
-        onDragListener?.invoke(isDragging)
-    }
-
     // --- SCROLLBAR APPEARANCE ---
 
     private fun postAutoHideScrollbar() {
-        removeCallbacks(hideScrollbarRunnable)
+        removeCallbacks(hideThumbRunnable)
-        postDelayed(hideScrollbarRunnable, AUTO_HIDE_SCROLLBAR_DELAY_MILLIS.toLong())
+        postDelayed(hideThumbRunnable, AUTO_HIDE_SCROLLBAR_DELAY_MILLIS.toLong())
     }
 
     private fun showScrollbar() {
-        if (showingScrollbar) {
+        if (showingThumb) {
             return
         }
 
-        showingScrollbar = true
+        showingThumb = true
         animateView(thumbView, 1f)
     }
 
     private fun hideScrollbar() {
-        if (!showingScrollbar) {
+        if (!showingThumb) {
             return
         }
 
-        showingScrollbar = false
+        showingThumb = false
         animateView(thumbView, 0f)
     }
 
@@ -539,12 +450,9 @@ constructor(context: Context, attrs: AttributeSet? = null, @AttrRes defStyleAttr
 
     // --- LAYOUT STATE ---
 
-    private val isRtl: Boolean
-        get() = layoutDirection == LAYOUT_DIRECTION_RTL
-
     private val thumbOffsetRange: Int
         get() {
-            return height - scrollerPadding.top - scrollerPadding.bottom - thumbHeight
+            return height - thumbPadding.top - thumbPadding.bottom - thumbHeight
         }
 
     private val scrollRange: Int

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

@@ -44,7 +44,7 @@ import org.oxycblt.auxio.util.systemBarInsetsCompat
 class PlaybackFragment : Fragment() {
     private val playbackModel: PlaybackViewModel by activityViewModels()
     private val detailModel: DetailViewModel by activityViewModels()
-    private var mLastBinding: FragmentPlaybackBinding? = null
+    private var lastBinding: FragmentPlaybackBinding? = null
 
     override fun onCreateView(
         inflater: LayoutInflater,
@@ -55,7 +55,7 @@ class PlaybackFragment : Fragment() {
         val queueItem: MenuItem
 
         // See onDestroyView for why we do this
-        mLastBinding = binding
+        lastBinding = binding
 
         // --- UI SETUP ---
 
@@ -157,8 +157,8 @@ class PlaybackFragment : Fragment() {
 
         // playbackSong will leak if we don't disable marquee, keep the binding around
         // so that we can turn it off when we destroy the view.
-        mLastBinding?.playbackSong?.isSelected = false
+        lastBinding?.playbackSong?.isSelected = false
-        mLastBinding = null
+        lastBinding = null
     }
 
     private fun navigateUp() {

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

@@ -47,6 +47,7 @@ import org.oxycblt.auxio.util.disableDropShadowCompat
 import org.oxycblt.auxio.util.getAttrColorSafe
 import org.oxycblt.auxio.util.getDimenSafe
 import org.oxycblt.auxio.util.getDrawableSafe
+import org.oxycblt.auxio.util.isUnder
 import org.oxycblt.auxio.util.logD
 import org.oxycblt.auxio.util.pxOfDp
 import org.oxycblt.auxio.util.replaceSystemBarInsetsCompat
@@ -458,27 +459,25 @@ constructor(context: Context, attrs: AttributeSet? = null, defStyle: Int = 0) :
             return super.onInterceptTouchEvent(ev)
         }
 
-        val adx = abs(ev.x - initMotionX)
-        val ady = abs(ev.y - initMotionY)
-        val dragSlop = dragHelper.touchSlop
-
         when (ev.actionMasked) {
             MotionEvent.ACTION_DOWN -> {
                 initMotionX = ev.x
                 initMotionY = ev.y
 
-                if (!playbackContainerView.isUnder(ev.x.toInt(), ev.y.toInt())) {
+                if (!playbackContainerView.isUnder(ev.x, ev.y)) {
                     // Pointer is not on our view, do not intercept this event
                     dragHelper.cancel()
                     return false
                 }
             }
             MotionEvent.ACTION_MOVE -> {
-                val pointerUnder = playbackContainerView.isUnder(ev.x.toInt(), ev.y.toInt())
+                val adx = abs(ev.x - initMotionX)
-                val motionUnder =
+                val ady = abs(ev.y - initMotionY)
-                    playbackContainerView.isUnder(initMotionX.toInt(), initMotionY.toInt())
 
-                if (!(pointerUnder || motionUnder) || ady > dragSlop && adx > ady) {
+                val pointerUnder = playbackContainerView.isUnder(ev.x, ev.y)
+                val motionUnder = playbackContainerView.isUnder(initMotionX, initMotionY)
+
+                if (!(pointerUnder || motionUnder) || ady > dragHelper.touchSlop && adx > ady) {
                     // Pointer has moved beyond our control, do not intercept this event
                     dragHelper.cancel()
                     return false
@@ -502,22 +501,6 @@ constructor(context: Context, attrs: AttributeSet? = null, defStyle: Int = 0) :
         }
     }
 
-    private fun View.isUnder(x: Int, y: Int): Boolean {
-        val viewLocation = IntArray(2)
-        getLocationOnScreen(viewLocation)
-
-        val parentLocation = IntArray(2)
-        (parent as View).getLocationOnScreen(parentLocation)
-
-        val screenX = parentLocation[0] + x
-        val screenY = parentLocation[1] + y
-
-        val inX = screenX >= viewLocation[0] && screenX < viewLocation[0] + width
-        val inY = screenY >= viewLocation[1] && screenY < viewLocation[1] + height
-
-        return inX && inY
-    }
-
     private val ViewDragHelper.isDragging: Boolean
         get() {
             // We can't grab the drag state outside of a callback, but that's stupid and I don't

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

@@ -441,6 +441,7 @@ class PlaybackService :
                 // Technically the MediaSession seems to handle bluetooth events on their
                 // own, but keep this around as a fallback in the case that the former fails
                 // for whatever reason.
+                // TODO: Remove this since the headset hook KeyEvent should be fine enough.
                 AudioManager.ACTION_SCO_AUDIO_STATE_UPDATED -> {
                     when (intent.getIntExtra(AudioManager.EXTRA_SCO_AUDIO_STATE, -1)) {
                         AudioManager.SCO_AUDIO_STATE_DISCONNECTED -> pauseFromPlug()
@@ -459,7 +460,7 @@ class PlaybackService :
                     initialHeadsetPlugEventHandled = true
                 }
 
-                // I have never seen this ever happen but it might be useful
+                // I have never seen this happen but it might be useful
                 AudioManager.ACTION_AUDIO_BECOMING_NOISY -> pauseFromPlug()
 
                 // --- AUXIO EVENTS ---
@@ -484,9 +485,7 @@ class PlaybackService :
          * that friendly
          * 2. There is a bug where playback will always start when this service starts, mostly due
          * to AudioManager.ACTION_HEADSET_PLUG always firing on startup. This is fixed, but I fear
-         * that it may not work on OEM skins that for whatever reason don't make this action fire.
+         * that it may not work on OEM skins that for whatever reason don't make this action fire.\
-         * TODO: Figure out how players like Retro are able to get autoplay working with bluetooth
-         * headsets
          */
         private fun maybeResumeFromPlug() {
             if (playbackManager.song != null &&
@@ -497,12 +496,7 @@ class PlaybackService :
             }
         }
 
-        /**
+        /** Pause from a headset plug. */
-         * Pause from a headset plug.
-         *
-         * TODO: Find a way to centralize this stuff into a single BroadcastReceiver instead of the
-         * weird disjointed arrangement between MediaSession and this.
-         */
         private fun pauseFromPlug() {
             if (playbackManager.song != null) {
                 logD("Device disconnected, pausing")

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

@@ -56,8 +56,11 @@ fun Fragment.newMenu(anchor: View, data: Item, flag: Int = ActionMenu.FLAG_NONE)
  * @throws IllegalStateException When there is no menu for this specific datatype/flag
  * @author OxygenCobalt
  *
- * TODO: Stop scrolling when a menu is open TODO: Prevent duplicate menus from showing up TODO:
+ * TODO: Stop scrolling when a menu is open
- * Maybe replace this with a bottom sheet?
+ *
+ * TODO: Prevent duplicate menus from showing up
+ *
+ * TODO: Maybe replace this with a bottom sheet?
  */
 class ActionMenu(
     activity: AppCompatActivity,

app/src/main/java/org/oxycblt/auxio/util/ViewUtil.kt

@@ -20,7 +20,9 @@ package org.oxycblt.auxio.util
 import android.content.res.ColorStateList
 import android.graphics.Insets
 import android.graphics.Rect
+import android.graphics.drawable.Drawable
 import android.os.Build
+import android.util.Log
 import android.view.View
 import android.view.WindowInsets
 import androidx.annotation.ColorRes
@@ -73,6 +75,50 @@ fun View.disableDropShadowCompat() {
     }
 }
 
+fun View.isUnder(x: Float, y: Float, minTouchTargetSize: Int = 0): Boolean {
+    return isUnderImpl(x, left, right, (parent as View).width, minTouchTargetSize) &&
+        isUnderImpl(y, top, bottom, (parent as View).height, minTouchTargetSize)
+}
+
+private fun isUnderImpl(
+    position: Float,
+    viewStart: Int,
+    viewEnd: Int,
+    parentEnd: Int,
+    minTouchTargetSize: Int
+): Boolean {
+    val viewSize = viewEnd - viewStart
+
+    if (viewSize >= minTouchTargetSize) {
+        return position >= viewStart && position < viewEnd
+    }
+
+    Log.d("Auxio.ViewUtil", "isInTouchTarget: $minTouchTargetSize")
+
+    var touchTargetStart = viewStart - (minTouchTargetSize - viewSize) / 2
+
+    if (touchTargetStart < 0) {
+        touchTargetStart = 0
+    }
+
+    var touchTargetEnd = touchTargetStart + minTouchTargetSize
+    if (touchTargetEnd > parentEnd) {
+        touchTargetEnd = parentEnd
+        touchTargetStart = touchTargetEnd - minTouchTargetSize
+
+        if (touchTargetStart < 0) {
+            touchTargetStart = 0
+        }
+    }
+
+    return position >= touchTargetStart && position < touchTargetEnd
+}
+
+val View.isRtl: Boolean
+    get() = layoutDirection == View.LAYOUT_DIRECTION_RTL
+val Drawable.isRtl: Boolean
+    get() = layoutDirection == View.LAYOUT_DIRECTION_RTL
+
 /**
  * Resolve system bar insets in a version-aware manner. This can be used to apply padding to a view
  * that properly follows all the frustrating changes that were made between 8-11.

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

@@ -30,8 +30,11 @@
     <dimen name="elevation_small">2dp</dimen>
     <dimen name="elevation_normal">4dp</dimen>
 
-    <dimen name="popup_min_width">78dp</dimen>
+    <dimen name="fast_scroll_popup_min_width">80dp</dimen>
-    <dimen name="popup_padding_end">28dp</dimen>
+    <dimen name="fast_scroll_popup_min_height">64dp</dimen>
+    <dimen name="fast_scroll_popup_padding_start">@dimen/spacing_medium</dimen>
+    <dimen name="fast_scroll_popup_padding_end">28dp</dimen>
+    <dimen name="fast_scroll_thumb_touch_target_size">16dp</dimen>
 
     <dimen name="slider_thumb_radius">6dp</dimen>
     <dimen name="slider_halo_radius">12dp</dimen>

prebuild.py

@@ -19,7 +19,7 @@ import re
 
 # WARNING: THE EXOPLAYER VERSION MUST BE KEPT IN LOCK-STEP WITH THE FLAC EXTENSION AND 
 # THE GRADLE DEPENDENCY. IF NOT, VERY UNFRIENDLY BUILD FAILURES AND CRASHES MAY ENSUE.
-EXO_VERSION = "2.17.0"
+EXO_VERSION = "2.17.1"
 FLAC_VERSION = "1.3.2"
 
 FATAL="\033[1;31m"