add portal component for uitoolkit

Author: KurtGokhan

Runtime/Frameworks/UIToolkit/Components/PortalComponent.cs

@@ -0,0 +1,159 @@
+using UnityEngine.UIElements;
+
+namespace ReactUnity.UIToolkit
+{
+    public class PortalComponent : UIToolkitComponent<VisualElement>, IShadowComponent
+    {
+        VisualElement DefaultTarget => (Context.Host as UIToolkitComponent<VisualElement>).TargetElement;
+        public IReactComponent ShadowParent { get; private set; }
+
+        VisualElement currentTarget;
+
+        public bool Detached { get; private set; }
+        public VisualElement ReplacedLayout { get; } = new VisualElement();
+
+        public PortalComponent(UIToolkitContext context, string tag = "portal") : base(context, tag)
+        {
+            ShadowParent = Context.Host;
+            currentTarget = DefaultTarget;
+            ReplacedLayout.style.display = DisplayStyle.None;
+            ReplacedLayout.userData = this;
+        }
+
+        void SetTarget(VisualElement target, IReactComponent shadowParent)
+        {
+            VisualElement newTarget;
+
+            if (target != null)
+            {
+                newTarget = target;
+                ShadowParent = shadowParent;
+            }
+            else
+            {
+                newTarget = DefaultTarget;
+                ShadowParent = Context.Host;
+            }
+            if (currentTarget == newTarget) return;
+
+            if (currentTarget != null)
+            {
+                FireEvent("onUnmount", currentTarget);
+                currentTarget = null;
+            }
+
+            currentTarget = newTarget;
+
+            if (currentTarget != null)
+            {
+                FireEvent("onMount", currentTarget);
+            }
+
+            Attach();
+        }
+
+        public override void SetParent(IContainerComponent newParent, IReactComponent relativeTo = null, bool insertAfter = false)
+        {
+            if (Parent is UIToolkitComponent<VisualElement> pp)
+            {
+                pp.Element?.Remove(ReplacedLayout);
+            }
+
+            base.SetParent(newParent, relativeTo, insertAfter);
+
+            if (Parent is UIToolkitComponent<VisualElement> p)
+            {
+                var oldParent = p.Element;
+                if (oldParent != null)
+                {
+                    var layoutIndex = oldParent.IndexOf(Element);
+
+                    if (layoutIndex >= 0)
+                    {
+                        oldParent.RemoveAt(layoutIndex);
+                        oldParent.Insert(layoutIndex, ReplacedLayout);
+                    }
+                }
+            }
+
+            Attach();
+        }
+
+        void Attach()
+        {
+            if (Parent == null || Destroyed)
+            {
+                if (Element?.parent != null)
+                {
+                    Element.RemoveFromHierarchy();
+
+                    ReplacedLayout.RemoveFromHierarchy();
+                    Context.DetachedRoots.Remove(this);
+                }
+                return;
+            }
+
+            if (Element != null && Element.parent != currentTarget)
+            {
+                if (currentTarget != null) currentTarget.Add(Element);
+                else Element.RemoveFromHierarchy();
+
+                if (ShadowParent is UIToolkitComponent<VisualElement> sp)
+                {
+                    sp.Element.Add(Element);
+                    Detached = false;
+                    Context.DetachedRoots.Remove(this);
+                }
+                else
+                {
+                    Detached = true;
+                    Context.DetachedRoots.Add(this);
+                }
+
+                ResolveStyle(true);
+            }
+        }
+
+        (VisualElement, IReactComponent) FindTarget(object value)
+        {
+            if (value == null) return (null, null);
+            if (value is VisualElement t) return (t, null);
+            if (value is UIToolkitComponent<VisualElement> u) return (u.Element, u);
+            return (null, null);
+        }
+
+        public override void SetProperty(string propertyName, object value)
+        {
+            switch (propertyName)
+            {
+                case "target":
+                    var tg = FindTarget(value);
+                    SetTarget(tg.Item1, tg.Item2?.Context == Context ? tg.Item2 : null);
+                    break;
+                default:
+                    base.SetProperty(propertyName, value);
+                    break;
+            }
+        }
+
+        protected override void DestroySelf()
+        {
+            SetTarget(null, null);
+            base.DestroySelf();
+        }
+
+        public override bool Pool()
+        {
+            SetTarget(null, null);
+            if (!base.Pool()) return false;
+            return true;
+        }
+
+        public override bool Revive()
+        {
+            if (!base.Revive()) return false;
+            Element.RemoveFromHierarchy();
+            return true;
+        }
+    }
+}

Runtime/Frameworks/UIToolkit/Components/PortalComponent.cs.meta

@@ -28,6 +28,7 @@ public class UIToolkitContext : ReactContext
         public static Dictionary<string, Func<string, string, UIToolkitContext, IReactComponent>> ComponentCreators
             = new Dictionary<string, Func<string, string, UIToolkitContext, IReactComponent>>()
             {
+                { "portal", (tag, text, context) => new PortalComponent(context, tag) },
                 { "text", (tag, text, context) => new TextComponent<TextElement>(text, context, tag, false) },
                 { "br", (tag, text, context) => new BrComponent(context, tag) },
                 { "richtext", (tag, text, context) => new TextComponent<TextElement>(text, context, tag, false, true) },