Fix viewport width when hovering collection

Co-authored-by: Metalit <48568911+Metalit@users.noreply.github.com>

PlaylistManager/AffinityPatches/AnnotatedBeatmapLevelCollectionsGridViewAnimatorPatches.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Reflection;
 using System.Reflection.Emit;
 using HarmonyLib;
 using SiraUtil.Affinity;
@@ -92,5 +93,21 @@ private IEnumerable<CodeInstruction> OpenCollectionWithOneRow(IEnumerable<CodeIn
                 .SetOpcodeAndAdvance(OpCodes.Ldc_I4_0)
                 .InstructionEnumeration();
         }
+
+        [AffinityPatch(typeof(AnnotatedBeatmapLevelCollectionsGridViewAnimator), nameof(AnnotatedBeatmapLevelCollectionsGridViewAnimator.AnimateOpen))]
+        [AffinityTranspiler]
+        private IEnumerable<CodeInstruction> FixViewportWidth(IEnumerable<CodeInstruction> instructions)
+        {
+            return new CodeMatcher(instructions)
+                .PrintInstructions()
+                .MatchStartForward(
+                    new CodeMatch(OpCodes.Ldloc_S),
+                    new CodeMatch(i => i.opcode == OpCodes.Call && (ConstructorInfo)i.operand == AccessTools.Constructor(typeof(Vector2))))
+                .ThrowIfInvalid()
+                .SetInstruction(new CodeInstruction(OpCodes.Ldarg_0))
+                .Insert(Transpilers.EmitDelegate<Func<AnnotatedBeatmapLevelCollectionsGridViewAnimator, float>>(animator =>
+                    ((animator._columnCount - animator._visibleColumnCount) * 2 + animator._visibleColumnCount) * animator._columnWidth))
+                .InstructionEnumeration();
+        }
     }
 }