Unity Project

reference
https://cardgames.io/yahtzee/

Library/PackageCache/com.unity.timeline@1.2.15/Editor/treeview/PickerUtils.cs

@@ -0,0 +1,41 @@
+using System.Collections.Generic;
+using System.Linq;
+using UnityEngine;
+
+namespace UnityEditor.Timeline
+{
+    static class PickerUtils
+    {
+        public static List<object> pickedElements { get; private set; }
+
+        public static void DoPick(WindowState state, Vector2 mousePosition)
+        {
+            if (state.GetWindow().sequenceContentRect.Contains(mousePosition))
+            {
+                pickedElements = state.spacePartitioner.GetItemsAtPosition<object>(mousePosition).ToList();
+            }
+            else
+            {
+                if (pickedElements != null)
+                    pickedElements.Clear();
+                else
+                    pickedElements = new List<object>();
+            }
+        }
+
+        public static T PickedLayerableOfType<T>() where T : class, ILayerable
+        {
+            return pickedElements.OfType<ILayerable>().OrderBy(x => x.zOrder).LastOrDefault() as T;
+        }
+
+        public static InlineCurveResizeHandle PickedInlineCurveResizer()
+        {
+            return pickedElements.FirstOrDefault(e => e is InlineCurveResizeHandle) as InlineCurveResizeHandle;
+        }
+
+        public static TimelineTrackBaseGUI PickedTrackBaseGUI()
+        {
+            return pickedElements.FirstOrDefault(e => e is TimelineTrackBaseGUI) as TimelineTrackBaseGUI;
+        }
+    }
+}