Initial commit

Library/PackageCache/com.unity.2d.path@2.1.0/Editor/Selection/SerializableSelection.cs

@@ -0,0 +1,143 @@
+using UnityEngine;
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace UnityEditor.U2D.Path
+{
+    [Serializable]
+    internal abstract class SerializableSelection<T> : ISelection<T>, ISerializationCallbackReceiver
+    {
+        internal readonly static int kInvalidID = -1;
+        
+        [SerializeField]
+        private T[] m_Keys = new T[0];
+
+        private HashSet<T> m_Selection = new HashSet<T>();
+        private HashSet<T> m_TemporalSelection = new HashSet<T>();
+        private bool m_SelectionInProgress = false;
+
+        public int Count
+        {
+            get { return m_Selection.Count + m_TemporalSelection.Count; }
+        }
+
+        public T activeElement
+        {
+            get { return First(); }
+            set
+            {
+                Clear();
+                Select(value, true);
+            }
+        }
+
+        public T[] elements
+        {
+            get
+            {
+                var set = m_Selection;
+
+                if (m_SelectionInProgress)
+                {
+                    var union = new HashSet<T>(m_Selection);
+                    union.UnionWith(m_TemporalSelection);
+                    set = union; 
+                }
+
+                return new List<T>(set).ToArray();
+            }
+            set
+            {
+                Clear();
+                foreach(var element in value)
+                    Select(element, true);
+            }
+        }
+
+        protected abstract T GetInvalidElement();
+
+        public void Clear()
+        {
+            GetSelection().Clear();
+        }
+
+        public void BeginSelection()
+        {
+            m_SelectionInProgress = true;
+            Clear();
+        }
+
+        public void EndSelection(bool select)
+        {
+            m_SelectionInProgress = false;
+
+            if (select)
+                m_Selection.UnionWith(m_TemporalSelection);
+            else
+                m_Selection.ExceptWith(m_TemporalSelection);
+
+            m_TemporalSelection.Clear();
+        }
+
+        public bool Select(T element, bool select)
+        {
+            var changed = false;
+
+            if(EqualityComparer<T>.Default.Equals(element, GetInvalidElement()))
+                return changed;
+
+            if (select)
+                changed = GetSelection().Add(element);
+            else if (Contains(element))
+                changed = GetSelection().Remove(element);
+
+            return changed;
+        }
+
+        public bool Contains(T element)
+        {
+            return m_Selection.Contains(element) || m_TemporalSelection.Contains(element);
+        }
+
+        private HashSet<T> GetSelection()
+        {
+            if (m_SelectionInProgress)
+                return m_TemporalSelection;
+
+            return m_Selection;
+        }
+
+        private T First()
+        {
+            T element = First(m_Selection);
+
+            if(EqualityComparer<T>.Default.Equals(element, GetInvalidElement()))
+                element = First(m_TemporalSelection);
+
+            return element;
+        }
+
+        private T First(HashSet<T> set)
+        {
+            if(set.Count == 0)
+                return GetInvalidElement();
+            
+            using (var enumerator = set.GetEnumerator())
+            {
+                Debug.Assert(enumerator.MoveNext());
+                return enumerator.Current;
+            }
+        }
+
+        void ISerializationCallbackReceiver.OnBeforeSerialize()
+        {
+            m_Keys = new List<T>(m_Selection).ToArray();
+        }
+
+        void ISerializationCallbackReceiver.OnAfterDeserialize()
+        {
+            elements = m_Keys;
+        }
+    }
+}