riversong code showcase

Source/Riversong/Game/UI/Framework/UIRoot.cs

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+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using Cysharp.Threading.Tasks;
+using UnityEngine;
+using UnityEngine.UIElements;
+
+namespace DanieleMarotta.RiversongCodeShowcase
+{
+    [RequireComponent(typeof(UIDocument))]
+    public class UIRoot : MonoBehaviour, IUIRoot
+    {
+        private UIDocument _document;
+
+        private Dictionary<Type, UIView> _views = new();
+
+        public VisualElement RootVisualElement { get; private set; }
+
+        public event Action<ClickEvent> ElementClicked;
+
+        private void Awake()
+        {
+            _document = GetComponent<UIDocument>();
+        }
+
+        public async UniTask Initialize(UIService uiService)
+        {
+            RootVisualElement = _document.rootVisualElement;
+
+            await DiscoverViewsAsync(uiService);
+
+            InitializeDragging();
+
+            RootVisualElement.RegisterCallback<ClickEvent>(OnClick);
+        }
+
+        public void Dispose()
+        {
+            foreach (var view in _views.Values) view.Dispose();
+
+            RootVisualElement.UnregisterCallback<ClickEvent>(OnClick);
+        }
+
+        private void OnClick(ClickEvent evt)
+        {
+            ElementClicked?.Invoke(evt);
+        }
+
+        private async UniTask DiscoverViewsAsync(UIService uiService)
+        {
+            var assemblies = AppDomain.CurrentDomain.GetAssemblies();
+
+            foreach (var assembly in assemblies)
+            foreach (var type in assembly.GetTypes())
+            {
+                var viewAttribute = type.GetCustomAttribute<UIViewAttribute>();
+                if (viewAttribute == null) continue;
+
+                var element = RootVisualElement.Q(className: viewAttribute.UssClassName);
+                var view = await uiService.CreateView(type, element);
+
+                _views.Add(type, view);
+            }
+        }
+
+        private void InitializeDragging()
+        {
+            var targets = RootVisualElement.Query<VisualElement>(className: "drag-target").ToList();
+            foreach (var target in targets) MakeDraggable(target);
+        }
+
+        public void MakeDraggable(VisualElement target)
+        {
+            var handle = target.Q<VisualElement>(className: "drag-handle") ?? target;
+            handle.AddManipulator(new DraggableManipulator(target));
+        }
+
+        public T GetView<T>() where T : UIView
+        {
+            return _views.TryGetValue(typeof(T), out var view) ? (T)view : null;
+        }
+    }
+}