import Coffee.Internal

Runtime/Internal/Utilities/UIExtraCallbacks.cs

@@ -0,0 +1,93 @@
+using System;
+using UnityEditor;
+using UnityEngine;
+using UnityEngine.UI;
+
+namespace Coffee.UIParticleInternal
+{
+    /// <summary>
+    /// Provides additional callbacks related to canvas and UI system.
+    /// </summary>
+    internal static class UIExtraCallbacks
+    {
+        private static bool s_IsInitializedAfterCanvasRebuild;
+        private static readonly FastAction s_AfterCanvasRebuildAction = new FastAction();
+        private static readonly FastAction s_LateAfterCanvasRebuildAction = new FastAction();
+        private static readonly FastAction s_BeforeCanvasRebuildAction = new FastAction();
+
+        static UIExtraCallbacks()
+        {
+            Canvas.willRenderCanvases += OnBeforeCanvasRebuild;
+            Logging.LogMulticast(typeof(Canvas), "willRenderCanvases", message: "ctor");
+        }
+
+        /// <summary>
+        /// Event that occurs after canvas rebuilds.
+        /// </summary>
+        public static event Action onLateAfterCanvasRebuild
+        {
+            add => s_LateAfterCanvasRebuildAction.Add(value);
+            remove => s_LateAfterCanvasRebuildAction.Remove(value);
+        }
+
+        /// <summary>
+        /// Event that occurs before canvas rebuilds.
+        /// </summary>
+        public static event Action onBeforeCanvasRebuild
+        {
+            add => s_BeforeCanvasRebuildAction.Add(value);
+            remove => s_BeforeCanvasRebuildAction.Remove(value);
+        }
+
+        /// <summary>
+        /// Event that occurs after canvas rebuilds.
+        /// </summary>
+        public static event Action onAfterCanvasRebuild
+        {
+            add => s_AfterCanvasRebuildAction.Add(value);
+            remove => s_AfterCanvasRebuildAction.Remove(value);
+        }
+
+        /// <summary>
+        /// Initializes the UIExtraCallbacks to ensure proper event handling.
+        /// </summary>
+        private static void InitializeAfterCanvasRebuild()
+        {
+            if (s_IsInitializedAfterCanvasRebuild) return;
+            s_IsInitializedAfterCanvasRebuild = true;
+
+            CanvasUpdateRegistry.IsRebuildingLayout();
+            Canvas.willRenderCanvases += OnAfterCanvasRebuild;
+            Logging.LogMulticast(typeof(Canvas), "willRenderCanvases",
+                message: "InitializeAfterCanvasRebuild");
+        }
+
+#if UNITY_EDITOR
+        [InitializeOnLoadMethod]
+#endif
+        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
+        private static void InitializeOnLoad()
+        {
+            Canvas.willRenderCanvases -= OnAfterCanvasRebuild;
+            s_IsInitializedAfterCanvasRebuild = false;
+        }
+
+        /// <summary>
+        /// Callback method called before canvas rebuilds.
+        /// </summary>
+        private static void OnBeforeCanvasRebuild()
+        {
+            s_BeforeCanvasRebuildAction.Invoke();
+            InitializeAfterCanvasRebuild();
+        }
+
+        /// <summary>
+        /// Callback method called after canvas rebuilds.
+        /// </summary>
+        private static void OnAfterCanvasRebuild()
+        {
+            s_AfterCanvasRebuildAction.Invoke();
+            s_LateAfterCanvasRebuildAction.Invoke();
+        }
+    }
+}