configurable buffers and gutters

Assets/Scenes/RecycleView.unity

@@ -316,6 +316,7 @@ GameObject:
   - component: {fileID: 1889780345}
   - component: {fileID: 1889780344}
   - component: {fileID: 1889780343}
+  - component: {fileID: 1889780346}
   m_Layer: 0
   m_Name: Main Camera
   m_TagString: MainCamera
@@ -397,6 +398,50 @@ Transform:
   m_Children: []
   m_Father: {fileID: 0}
   m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
+--- !u!114 &1889780346
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 1889780342}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: a79441f348de89743a2939f4d699eac1, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  m_RenderShadows: 1
+  m_RequiresDepthTextureOption: 2
+  m_RequiresOpaqueTextureOption: 2
+  m_CameraType: 0
+  m_Cameras: []
+  m_RendererIndex: -1
+  m_VolumeLayerMask:
+    serializedVersion: 2
+    m_Bits: 1
+  m_VolumeTrigger: {fileID: 0}
+  m_VolumeFrameworkUpdateModeOption: 2
+  m_RenderPostProcessing: 0
+  m_Antialiasing: 0
+  m_AntialiasingQuality: 2
+  m_StopNaN: 0
+  m_Dithering: 0
+  m_ClearDepth: 1
+  m_AllowXRRendering: 1
+  m_AllowHDROutput: 1
+  m_UseScreenCoordOverride: 0
+  m_ScreenSizeOverride: {x: 0, y: 0, z: 0, w: 0}
+  m_ScreenCoordScaleBias: {x: 0, y: 0, z: 0, w: 0}
+  m_RequiresDepthTexture: 0
+  m_RequiresColorTexture: 0
+  m_Version: 2
+  m_TaaSettings:
+    m_Quality: 3
+    m_FrameInfluence: 0.1
+    m_JitterScale: 1
+    m_MipBias: 0
+    m_VarianceClampScale: 0.9
+    m_ContrastAdaptiveSharpening: 0
 --- !u!1660057539 &9223372036854775807
 SceneRoots:
   m_ObjectHideFlags: 0

Assets/Scripts/UI/Elements/Layout/DynamicLayout.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
@@ -5,55 +6,15 @@ using UnityEngine.UIElements;
 
 namespace KitsuneCafe.UI
 {
-  public record LayoutItem(float Position, float Size)
+
+  public class DynamicLayout : ILayout
   {
-    public float Min => Position;
-    public float Max => Position + Size;
-  }
-
-  public class DynamicLayout : ILayout, IEnumerable<LayoutItem>
-  {
-
-    public struct LayoutEnumerator : IEnumerator<LayoutItem>
-    {
-      public readonly int Start;
-      public int Index;
-      private readonly DynamicLayout layout;
-
-      public LayoutEnumerator(int index, DynamicLayout layout)
-      {
-        Start = index;
-        Index = index;
-        this.layout = layout;
-      }
-
-      public LayoutEnumerator(DynamicLayout layout) : this(0, layout) { }
-
-      public readonly LayoutItem Current => new(
-        layout.positions[Index - 1],
-        layout.sizes[Index - 1]
-      );
-
-      readonly object IEnumerator.Current => Current;
-
-      public readonly void Dispose() { }
-
-      public bool MoveNext()
-      {
-        Index += 1;
-        return Index < layout.positions.Count;
-      }
-
-      public void Reset()
-      {
-        Index = Start;
-      }
-    }
-
     public float DefaultItemSize { get; set; }
     public float GutterSize { get; set; }
     public FlowDirection Direction { get; set; }
     public float ContentSize { get; private set; }
+    public int Count { get; set; }
+    public int Buffer { get; set; }
 
     private readonly List<float> positions = new();
     private readonly List<float> sizes = new();
@@ -105,6 +66,7 @@ namespace KitsuneCafe.UI
         sizes.RemoveRange(itemCount, sizes.Count - itemCount);
       }
 
+      Count = itemCount;
       ContentSize = LastPositionOrDefault();
     }
 
@@ -112,7 +74,7 @@ namespace KitsuneCafe.UI
     {
       var position = initialPosition;
 
-      for (int i = startingIndex; i < positions.Count; i++)
+      for (int i = startingIndex; i < Count; i++)
       {
         positions[i] = position;
         position += GetItemSize(i) + GutterSize;
@@ -134,13 +96,13 @@ namespace KitsuneCafe.UI
       CalculatePositions(index, position);
     }
 
-    public int GetFirstVisibleIndex(float scrollOffset)
+    public int GetFirstVisibleIndex(float offset)
     {
-      if (scrollOffset <= 0) { return 0; }
+      if (offset <= 0) { return 0; }
 
-      for (int i = 0; i < positions.Count; i++)
+      for (int i = 0; i < Count; i++)
       {
-        if (positions[i] >= scrollOffset)
+        if (positions[i] >= offset)
         {
           return i;
         }
@@ -149,28 +111,29 @@ namespace KitsuneCafe.UI
       return positions.Count - 1;
     }
 
-    public IEnumerable<LayoutItem> Enumerate(int startIndex = 0)
+    public Range GetVisibleRange(float offset, float size)
     {
-      var len = positions.Count;
+      var halfBuffer = Mathf.CeilToInt(Buffer / 2);
-      for (int i = startIndex; i < len; i++)
+
+      var first = Math.Max(
+        GetFirstVisibleIndex(offset) - halfBuffer,
+        0
+      );
+
+      var count = 1;
+      var position = GetItemPosition(first);
+      var width = position + size;
+
+      for (int i = first; i < Count; i++)
       {
-        yield return new LayoutItem(positions[i], sizes[i]);
+        var item = GetItemPosition(i);
-      }
+        if (item > width) { break; }
+        count += 1;
       }
 
-    public IEnumerator<LayoutItem> GetEnumerator()
+      count += halfBuffer;
-    {
-      return new LayoutEnumerator(this);
-    }
 
-    public IEnumerator<LayoutItem> GetEnumerator(int startIndex)
+      return new Range(first, Math.Min(Count, first + count));
-    {
-      return new LayoutEnumerator(startIndex, this);
-    }
-
-    IEnumerator IEnumerable.GetEnumerator()
-    {
-      return GetEnumerator();
     }
   }
 }

Assets/Scripts/UI/Elements/Layout/FixedLayout.cs

@@ -1,3 +1,5 @@
+using System;
+using UnityEngine;
 using UnityEngine.UIElements;
 
 namespace KitsuneCafe.UI
@@ -10,6 +12,8 @@ namespace KitsuneCafe.UI
 
     public float ItemSize { get; set; }
     public float GutterSize { get; set; }
+    public int Count { get; set; }
+    public int Buffer { get; set; }
 
     public FixedLayout(FlowDirection direction, float itemSize, float gutterSize)
     {
@@ -32,7 +36,18 @@ namespace KitsuneCafe.UI
 
     public void Update(int itemCount, VisualElement _container)
     {
+      Count = itemCount;
       ContentSize = itemCount * (ItemSize + GutterSize);
     }
+
+    public Range GetVisibleRange(float offset, float containerSize)
+    {
+      var size = ItemSize + GutterSize;
+      var first = Mathf.FloorToInt(offset / (ItemSize + GutterSize));
+      var count = Mathf.CeilToInt(containerSize / size) + Buffer;
+      var last = Math.Min(Count, first + count);
+
+      return new Range(first, last);
+    }
   }
 }

Assets/Scripts/UI/Elements/Layout/ILayout.cs

@@ -1,3 +1,5 @@
+using System;
+using System.Collections.Generic;
 using UnityEngine.UIElements;
 
 namespace KitsuneCafe.UI
@@ -6,9 +8,11 @@ namespace KitsuneCafe.UI
   {
     FlowDirection Direction { get; }
     float ContentSize { get; }
+    int Buffer { get; }
 
     float GetItemPosition(int index);
     float GetItemSize(int index);
+    Range GetVisibleRange(float offset, float size);
     void Update(int itemCount, VisualElement container);
   }
 }

Assets/Scripts/UI/Elements/RecycleView/RecycleView.cs

@@ -112,6 +112,53 @@ namespace KitsuneCafe.UI
       }
     }
 
+    private int bufferCount = 8;
+
+    [UxmlAttribute, CreateProperty, Delayed]
+    public int BufferCount
+    {
+      get => bufferCount;
+      set
+      {
+        if (bufferCount != value)
+        {
+          bufferCount = value;
+          if (virtualizationController.Layout is FixedLayout fixedLayout)
+          {
+            fixedLayout.Buffer = value;
+          }
+          else if (virtualizationController.Layout is DynamicLayout dynamicLayout)
+          {
+            dynamicLayout.Buffer = value;
+          }
+        }
+      }
+    }
+
+    private float gutter = 0;
+
+    [UxmlAttribute, CreateProperty, Delayed]
+    public float Gutter
+    {
+      get => gutter;
+      set
+      {
+        if (gutter != value)
+        {
+          gutter = value;
+          if (virtualizationController.Layout is FixedLayout fixedLayout)
+          {
+            fixedLayout.GutterSize = value;
+          }
+          else if (virtualizationController.Layout is DynamicLayout dynamicLayout)
+          {
+            dynamicLayout.GutterSize = value;
+          }
+        }
+      }
+    }
+
+
     [CreateProperty]
     public ICollectionDataSource DataSource
     {
@@ -152,8 +199,8 @@ namespace KitsuneCafe.UI
     {
       return isDynamicSize switch
       {
-        true => new DynamicLayout(Direction, itemSize),
+        true => new DynamicLayout(Direction, itemSize) { Buffer = bufferCount, GutterSize = gutter },
-        false => new FixedLayout(Direction, itemSize)
+        false => new FixedLayout(Direction, itemSize) { Buffer = bufferCount, GutterSize = gutter }
       };
     }
 

Assets/Scripts/UI/Elements/RecycleView/RecycleVirtualizationController.cs

@@ -71,9 +71,6 @@ namespace KitsuneCafe.UI
     private readonly BiDictionary<int, VisualElement> visibleItems = new();
     private float parentSize = 0;
     private float lastKnownScrollOffset = 0;
-
-    private readonly int itemCountBuffer = 2;
-
     private readonly Subject<UpdateRequest> requestSubject = new();
     private IDisposable subscriptions;
 
@@ -102,16 +99,6 @@ namespace KitsuneCafe.UI
         });
 
       subscriptions = Disposable.Combine(full, partial);
-      // subscriptions = Observable.Merge(full, partial)
-      // // var updateSubscription = requestSubject.ThrottleLastFrame(1)
-      //   .Subscribe(request =>
-      //   {
-      //     if (request is PartialUpdate req)
-      //     {
-      //       UpdateFromIndex(req.Index);
-      //     }
-      //     else { UpdateVisibleItems(); }
-      //   });
 
       Layout.Update(DataSource.Length, Container);
       ScheduleUpdate();
@@ -238,33 +225,6 @@ namespace KitsuneCafe.UI
       }
     }
 
-    private Range GetDynamicItems(DynamicLayout layout, float scrollOffset)
-    {
-      var first = layout.GetFirstVisibleIndex(scrollOffset);
-      var count = 1;
-      var position = layout.GetItemPosition(first);
-      var width = position + parentSize;
-
-      foreach (var item in layout.Enumerate(first))
-      {
-        if (item.Position > width) { break; }
-        count += 1;
-        position = item.Position;
-      }
-
-      return new Range(first, Math.Min(DataSource.Length, first + count));
-    }
-
-    private Range GetFixedItems(FixedLayout layout, float scrollOffset)
-    {
-      var size = layout.ItemSize + layout.GutterSize;
-      var first = Mathf.FloorToInt(scrollOffset / (layout.ItemSize + layout.GutterSize));
-      var count = Mathf.CeilToInt(parentSize / size) + itemCountBuffer;
-      var last = Math.Min(DataSource.Length, first + count);
-
-      return new Range(first, last);
-    }
-
     private void UpdateVisibleItems()
     {
       if (DataSource == null || DataSource.Length == 0 || Mathf.Approximately(parentSize, 0))
@@ -272,15 +232,9 @@ namespace KitsuneCafe.UI
         return;
       }
 
-
       var scrollOffset = lastKnownScrollOffset;
 
-      var range = Layout switch
+      var range = layout.GetVisibleRange(scrollOffset, parentSize);
-      {
-        FixedLayout fl => GetFixedItems(fl, scrollOffset),
-        DynamicLayout dl => GetDynamicItems(dl, scrollOffset),
-        _ => throw new NotImplementedException(),
-      };
 
       var firstIndex = range.Start.Value;
       var lastIndex = range.End.Value;

Assets/UI/Test/Resources/UserProfileList.uxml

@@ -1,3 +1,3 @@
 <ui:UXML xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ui="UnityEngine.UIElements" xmlns:uie="UnityEditor.UIElements" noNamespaceSchemaLocation="../../../../UIElementsSchema/UIElements.xsd" editor-extension-mode="False">
-    <KitsuneCafe.UI.RecycleView name="recycle-view" direction="Horizontal" a="Stupid" is-dynamic-size="true" default-item-size="50" fixed-item-size="22" item-size="22" style="flex-grow: 1; flex-direction: row;" />
+    <KitsuneCafe.UI.RecycleView name="recycle-view" direction="Horizontal" a="Stupid" is-dynamic-size="true" default-item-size="50" fixed-item-size="22" gutter="0" style="flex-grow: 1; flex-direction: row;" />
 </ui:UXML>