Update scrolling

Remove the viscous interpolator and replace it with a variant of the default smooth scroller, dont like it as much but its less buggy.

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

@@ -7,6 +7,7 @@ import android.view.ViewGroup
 import androidx.appcompat.widget.PopupMenu
 import androidx.navigation.fragment.findNavController
 import androidx.navigation.fragment.navArgs
+import androidx.recyclerview.widget.GridLayoutManager
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.databinding.FragmentDetailBinding
 import org.oxycblt.auxio.detail.adapters.AlbumDetailAdapter
@@ -16,8 +17,9 @@ import org.oxycblt.auxio.music.BaseModel
 import org.oxycblt.auxio.music.MusicStore
 import org.oxycblt.auxio.music.Song
 import org.oxycblt.auxio.playback.state.PlaybackMode
-import org.oxycblt.auxio.recycler.LinearCenterScroller
+import org.oxycblt.auxio.recycler.CenterSmoothScroller
 import org.oxycblt.auxio.ui.createToast
+import org.oxycblt.auxio.ui.isLandscape
 import org.oxycblt.auxio.ui.setupAlbumSongActions
 
 /**
@@ -89,6 +91,16 @@ class AlbumDetailFragment : DetailFragment() {
         binding.detailRecycler.apply {
             adapter = detailAdapter
             setHasFixedSize(true)
+
+            if (isLandscape(resources)) {
+                layoutManager = GridLayoutManager(requireContext(), 2).also {
+                    it.spanSizeLookup = object : GridLayoutManager.SpanSizeLookup() {
+                        override fun getSpanSize(position: Int): Int {
+                            return if (position == 0) 2 else 1
+                        }
+                    }
+                }
+            }
         }
 
         // If this fragment was created in order to nav to an item, then snap scroll to that item.
@@ -152,13 +164,12 @@ class AlbumDetailFragment : DetailFragment() {
         // Calculate where the item for the currently played song is, and scroll to there
         val pos = detailModel.albumSortMode.value!!.getSortedSongList(
             detailModel.currentAlbum.value!!.songs
-        ).indexOf(playbackModel.song.value)
+        ).indexOf(playbackModel.song.value).inc()
 
-        if (pos != -1) {
+        if (pos != 0) {
-            // TODO: Re-add snap scrolling.
             binding.detailRecycler.post {
                 binding.detailRecycler.layoutManager?.startSmoothScroll(
-                    LinearCenterScroller(pos)
+                    CenterSmoothScroller(requireContext(), pos)
                 )
             }
 

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

@@ -7,12 +7,14 @@ import android.view.ViewGroup
 import androidx.appcompat.widget.PopupMenu
 import androidx.navigation.fragment.findNavController
 import androidx.navigation.fragment.navArgs
+import androidx.recyclerview.widget.GridLayoutManager
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.detail.adapters.ArtistDetailAdapter
 import org.oxycblt.auxio.logD
 import org.oxycblt.auxio.music.Artist
 import org.oxycblt.auxio.music.BaseModel
 import org.oxycblt.auxio.music.MusicStore
+import org.oxycblt.auxio.ui.isLandscape
 import org.oxycblt.auxio.ui.setupAlbumActions
 
 /**
@@ -87,6 +89,16 @@ class ArtistDetailFragment : DetailFragment() {
         binding.detailRecycler.apply {
             adapter = detailAdapter
             setHasFixedSize(true)
+
+            if (isLandscape(resources)) {
+                layoutManager = GridLayoutManager(requireContext(), 2).also {
+                    it.spanSizeLookup = object : GridLayoutManager.SpanSizeLookup() {
+                        override fun getSpanSize(position: Int): Int {
+                            return if (position == 0) 2 else 1
+                        }
+                    }
+                }
+            }
         }
 
         // --- VIEWMODEL SETUP ---

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

@@ -0,0 +1,20 @@
+package org.oxycblt.auxio.recycler
+
+import android.content.Context
+import androidx.recyclerview.widget.LinearSmoothScroller
+
+class CenterSmoothScroller(context: Context, target: Int) : LinearSmoothScroller(context) {
+    init {
+        targetPosition = target
+    }
+
+    override fun calculateDtToFit(
+        viewStart: Int,
+        viewEnd: Int,
+        boxStart: Int,
+        boxEnd: Int,
+        snapPreference: Int
+    ): Int {
+        return (boxStart + (boxEnd - boxStart) / 2) - (viewStart + (viewEnd - viewStart) / 2)
+    }
+}

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

@@ -1,164 +0,0 @@
-package org.oxycblt.auxio.recycler
-
-import android.graphics.PointF
-import android.view.View
-import android.view.animation.Interpolator
-import androidx.recyclerview.widget.RecyclerView
-import org.oxycblt.auxio.BuildConfig
-import kotlin.math.exp
-
-/**
- * A custom [RecyclerView.SmoothScroller] partially copied from [androidx.recyclerview.widget.LinearSmoothScroller] that has a scroll effect similar
- * to [androidx.core.widget.NestedScrollView].
- *
- * I don't know what half of this code does but it works and looks better than the default scroller so I use it
- */
-class LinearCenterScroller(target: Int) : RecyclerView.SmoothScroller() {
-    private val viscousInterpolator = ViscousFluidInterpolator()
-    private var targetVec: PointF? = null
-
-    // Temporary variables to keep track of the interim scroll target. These values do not
-    // point to a real item position, rather point to an estimated location pixels.
-    private var interimTargetDx = 0
-    private var interimTargetDy = 0
-
-    init {
-        targetPosition = target
-    }
-
-    // Not used
-    override fun onStart() {}
-
-    override fun onTargetFound(targetView: View, state: RecyclerView.State, action: Action) {
-        val dx = calcDxToMakeVisible(targetView)
-        val dy = calcDyToMakeVisible(targetView)
-
-        action.update(-dx, -dy, DEFAULT_TIME, viscousInterpolator)
-    }
-
-    override fun onSeekTargetStep(dx: Int, dy: Int, state: RecyclerView.State, action: Action) {
-        if (childCount == 0) {
-            stop()
-            return
-        }
-
-        if (BuildConfig.DEBUG && targetVec != null && ((targetVec!!.x * dx < 0 || targetVec!!.y * dy < 0))) {
-            error("Scroll happened in the opposite direction of the target. Some calculations are wrong")
-        }
-
-        interimTargetDx = clampApplyScroll(interimTargetDx, dx)
-        interimTargetDy = clampApplyScroll(interimTargetDy, dy)
-
-        if (interimTargetDx == 0 && interimTargetDy == 0) {
-            updateActionForInterimTarget(action)
-        }
-    }
-
-    override fun onStop() {
-        interimTargetDx = 0
-        interimTargetDy = 0
-        targetVec = null
-    }
-
-    private fun calcDxToMakeVisible(view: View): Int {
-        val manager = layoutManager ?: return 0
-
-        if (!manager.canScrollHorizontally()) return 0
-
-        val params = view.layoutParams as RecyclerView.LayoutParams
-        val top = manager.getDecoratedTop(view) - params.topMargin
-        val bottom = manager.getDecoratedBottom(view) + params.bottomMargin
-        val start = manager.paddingTop
-        val end = manager.height - manager.paddingBottom
-
-        return calculateDeltaToFit(top, bottom, start, end)
-    }
-
-    fun calcDyToMakeVisible(view: View): Int {
-        val manager = layoutManager ?: return 0
-
-        if (!manager.canScrollVertically()) return 0
-
-        val params = view.layoutParams as RecyclerView.LayoutParams
-        val top = manager.getDecoratedTop(view) - params.topMargin
-        val bottom = manager.getDecoratedBottom(view) + params.bottomMargin
-        val start = manager.paddingTop
-        val end = manager.height - manager.paddingBottom
-
-        return calculateDeltaToFit(top, bottom, start, end)
-    }
-
-    private fun calculateDeltaToFit(viewStart: Int, viewEnd: Int, boxStart: Int, boxEnd: Int): Int {
-        // Center the view instead of making it sit at the top or bottom.
-        return (boxStart + (boxEnd - boxStart) / 2) - (viewStart + (viewEnd - viewStart) / 2)
-    }
-
-    private fun clampApplyScroll(argTmpDt: Int, dt: Int): Int {
-        var tmpDt = argTmpDt
-        tmpDt -= dt
-        if (argTmpDt * tmpDt <= 0) { // changed sign, reached 0 or was 0, reset
-            return 0
-        }
-        return tmpDt
-    }
-
-    private fun updateActionForInterimTarget(action: Action) {
-        val scrollVector = computeScrollVectorForPosition(targetPosition)
-        if (scrollVector == null || (scrollVector.x == 0.0f && scrollVector.y == 0.0f)) {
-            val target = targetPosition
-            action.jumpTo(target)
-            stop()
-            return
-        }
-        normalize(scrollVector)
-
-        targetVec = scrollVector
-
-        interimTargetDx = (TARGET_SEEK_SCROLL_DIST * scrollVector.x).toInt()
-        interimTargetDy = (TARGET_SEEK_SCROLL_DIST * scrollVector.y).toInt()
-
-        action.update(
-            (interimTargetDx * TARGET_SEEK_EXTRA_SCROLL_RATIO).toInt(),
-            (interimTargetDy * TARGET_SEEK_EXTRA_SCROLL_RATIO).toInt(),
-            DEFAULT_TIME, viscousInterpolator
-        )
-    }
-
-    /**
-     * A nice-looking interpolator that is similar to the [androidx.core.widget.NestedScrollView] interpolator.
-     */
-    private inner class ViscousFluidInterpolator : Interpolator {
-        private val viscousNormalize = 1.0f / viscousFluid(1.0f)
-        private val viscousOffset = 1.0f - viscousNormalize * viscousFluid(1.0f)
-
-        fun viscousFluid(argX: Float): Float {
-            var x = argX
-
-            x *= VISCOUS_FLUID_SCALE
-
-            if (x < 1.0f) {
-                x -= (1.0f - exp(-x))
-            } else {
-                val start = 0.36787944117f; // 1/e == exp(-1)
-                x = 1.0f - exp(1.0f - x)
-                x = start + x * (1.0f - start)
-            }
-            return x
-        }
-
-        override fun getInterpolation(input: Float): Float {
-            val interpolated = viscousNormalize * viscousFluid(input)
-            if (interpolated > 0) {
-                return interpolated + viscousOffset
-            }
-            return interpolated
-        }
-    }
-
-    companion object {
-        private const val VISCOUS_FLUID_SCALE = 12.0f
-        private const val TARGET_SEEK_SCROLL_DIST = 10000
-        private const val TARGET_SEEK_EXTRA_SCROLL_RATIO = 1.2f
-        private const val DEFAULT_TIME = 500
-    }
-}