From 75d4d274f63112a65e4befa19639bc93fc56b0bc Mon Sep 17 00:00:00 2001
From: Jay <jays2kings@gmail.com>
Date: Mon, 18 May 2020 18:02:46 -0400
Subject: [PATCH] Category recycler puts active category center of view if list
 is scrollable

Also removed scrolling logic for opening/closing the sheet
---
 .../tachiyomi/ui/library/LibraryController.kt | 22 +------------------
 .../library/category/CategoryRecyclerView.kt  | 11 ++++++++++
 2 files changed, 12 insertions(+), 21 deletions(-)

diff --git a/app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryController.kt b/app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryController.kt
index 6909a1d87b..76cfaf4dea 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryController.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryController.kt
@@ -749,30 +749,10 @@ class LibraryController(
         val translateY = if (show) full else 0f
         recycler.animate().translationY(translateY).start()
         category_hopper_frame.animate().translationY(translateY).start()
-        if (scroll) {
-            // Smooth scroll the recycler to hide the hidden content blocked by the app bar
-            val vA = ValueAnimator.ofInt(recycler.translationY.roundToInt(), translateY
-                .roundToInt()).apply {
-                var start = 0f
-                var last = recycler.translationY.roundToInt()
-                val distance = abs(recycler.translationY.roundToInt() - translateY.roundToInt())
-                addUpdateListener {
-                    val diff = abs(it.animatedValue as Int - last)
-                    last = it.animatedValue as Int
-                    start += diff.toFloat() / distance * recycler.paddingTop.toFloat()
-                    if (start > 1) {
-                        recycler.scrollBy(0, start.toInt() * if (show) 1 else -1)
-                        start %= 1
-                    }
-                }
-                addListener(EndAnimatorListener {
-                    fast_scroller?.hideScrollbar()
-                })
-            }.start()
-        }
         recycler_cover.animate().translationY(translateY).start()
         recycler_cover.animate().alpha(if (show) 0.75f else 0f).start()
         if (show) {
+            category_recycler.scrollToCategory(activeCategory)
             fast_scroller?.hideScrollbar()
             activity?.appbar?.y = 0f
             elevateFunc(false)
diff --git a/app/src/main/java/eu/kanade/tachiyomi/ui/library/category/CategoryRecyclerView.kt b/app/src/main/java/eu/kanade/tachiyomi/ui/library/category/CategoryRecyclerView.kt
index 3c7822a2de..00d338da05 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/ui/library/category/CategoryRecyclerView.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/ui/library/category/CategoryRecyclerView.kt
@@ -10,6 +10,7 @@ import com.mikepenz.fastadapter.adapters.ItemAdapter
 import com.mikepenz.fastadapter.listeners.OnBindViewHolderListenerImpl
 import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.data.database.models.Category
+import eu.kanade.tachiyomi.util.system.dpToPx
 import eu.kanade.tachiyomi.util.view.marginBottom
 
 class CategoryRecyclerView @JvmOverloads constructor(
@@ -51,6 +52,16 @@ class CategoryRecyclerView @JvmOverloads constructor(
         }
     }
 
+    fun scrollToCategory(order: Int) {
+        val index = itemAdapter.adapterItems.indexOfFirst { it.category.order == order }
+        if (index > -1) {
+            manager.scrollToPositionWithOffset(
+                index,
+                (height - 38.dpToPx) / 2
+            )
+        }
+    }
+
     fun setCategories(selected: Int) {
         selectedCategory = selected
         for (i in 0..manager.itemCount) {