fix mono_isolate nullptr

com.unity.uiwidgets/Editor/UIWidgetsPanelEditor.cs

 using UnityEditor.UI;
 
 namespace Unity.UIWidgets.Editor {
-    // [CustomEditor(typeof(UIWidgetsPanel.UIWidgetRawImage), true)]
-    // [CanEditMultipleObjects]
-    // public class UIWidgetsPanelEditor : RawImageEditor {
-    //     public override void OnInspectorGUI() {
-    //         base.OnInspectorGUI();
-    //         var pixelRatioProperty = serializedObject.FindProperty("devicePixelRatioOverride");
-    //         var antiAliasingProperty = serializedObject.FindProperty("hardwareAntiAliasing");
-    //         EditorGUILayout.PropertyField(pixelRatioProperty);
-    //         EditorGUILayout.PropertyField(antiAliasingProperty);
-    //         serializedObject.ApplyModifiedProperties(); 
-    //     }
-    // }
+    [CustomEditor(typeof(UIWidgetsPanel), true)]
+    [CanEditMultipleObjects]
+    public class UIWidgetsPanelEditor : RawImageEditor {
+        
+        public override void OnInspectorGUI() {
+            base.OnInspectorGUI();
+            var pixelRatioProperty = serializedObject.FindProperty("devicePixelRatioOverride");
+            var antiAliasingProperty = serializedObject.FindProperty("hardwareAntiAliasing");
+            
+            EditorGUILayout.PropertyField(serializedObject.FindProperty("fonts"), true);
+
+            EditorGUILayout.PropertyField(pixelRatioProperty);
+            EditorGUILayout.PropertyField(antiAliasingProperty);
+            serializedObject.ApplyModifiedProperties(); 
+        }
+    }
 }

com.unity.uiwidgets/Runtime/engine2/UIWidgetsPanel.cs

 using NativeBindings = Unity.UIWidgets.ui.NativeBindings;
 
 namespace Unity.UIWidgets.engine2 {
-    public partial class UIWidgetsPanel : MonoBehaviour{
+    public partial class UIWidgetsPanel : RawImage{
-        public class TextFont {
+        public struct TextFont {
-        public List<TextFont> fonts;
+        public TextFont[] fonts;
-        public class UIWidgetRawImage : RawImage {
-            public void SetPanel(UIWidgetsPanel panel) {
-                _uiWidgetsPanel = panel;
-            }
-            
-            UIWidgetsPanel _uiWidgetsPanel;
+        public float devicePixelRatioOverride;
-            protected override void OnRectTransformDimensionsChange() {
-                _uiWidgetsPanel.OnRectTransformDimensionsChange();
-            }
-        }
-        
-        RawImage _rawImage;
-        RectTransform rectTransform {
-            get { return _rawImage.rectTransform; }
-        }
+        public float hardwareAntiAliasing;
+        // RectTransform rectTransform {
+        //     get { return rectTransform; }
+        // }
-        Canvas canvas {
-            get { return _rawImage.canvas; }
-        }
+        // Canvas canvas {
+        //     get { return canvas; }
+        // }
-        Texture texture {
-            set { _rawImage.texture = value; }
-        }
+        // Texture texture {
+        //     set { texture = value; }
+        // }
         
         public static UIWidgetsPanel current {
             get { return Window.instance._panel; }
         }
 
         protected void OnEnable() {
-            _rawImage = gameObject.GetComponent<RawImage>();
-            if (_rawImage == null) {
-                _rawImage = gameObject.AddComponent<UIWidgetRawImage>();
-                ((UIWidgetRawImage)_rawImage).SetPanel(this);
-            }
-
+            base.OnEnable();
             _recreateRenderTexture(_currentWidth, _currentHeight, _currentDevicePixelRatio);
 
             _handle = GCHandle.Alloc(this);
             }
         }
 
-        protected void OnRectTransformDimensionsChange() {
+        protected override void OnRectTransformDimensionsChange() {
             if (_ptr != IntPtr.Zero) {
                 if (_recreateRenderTexture(_currentWidth, _currentHeight, _currentDevicePixelRatio)) {
                     UIWidgetsPanel_onRenderTexture(_ptr,
             }
         }
 
-        protected void OnDisable() {
+        protected override void OnDisable() {
             Input_OnDisable();
 
             UIWidgetsPanel_onDisable(_ptr);
             _handle.Free();
             _handle = default;
-            _destroyRenderTexture();
-            Destroy(_rawImage);
+            // _destroyRenderTexture();
+            // Destroy(_rawImage);
+            base.OnDisable();
         }
 
         bool _recreateRenderTexture(int width, int height, float devicePixelRatio) {

engine/src/lib/ui/ui_mono_state.cc

 UIWIDGETS_API(void)
 UIMonoState_postTaskForTime(MonoMicrotaskQueue::CallbackFunc callback,
                             Mono_Handle handle, int64_t target_time_nanos) {
+  auto const weak_mono_state = MonoState::Current()->GetWeakPtr();
+
-      [callback, handle]() -> void { callback(handle); },
+      [callback, handle, weak_mono_state]() -> void {
+        if (auto mono_state = weak_mono_state.lock()) {
+          MonoState::Scope mono_scope(mono_state.get());
+
+          callback(handle);
+        }
+      },
       fml::TimePoint::FromEpochDelta(
           fml::TimeDelta::FromNanoseconds(target_time_nanos)));
 }