ScriptCore: Properly use nullable

ScriptCore/Editor/DictionaryEditor.cs

@@ -87,15 +87,15 @@ public class DictionaryEditor
 
                 if (isEntryOpen)
                 {
-                    object newKey = EntityEditor.ShowFieldEditor(entry.Key, entry.Key?.GetType() ?? keyType, "Key");
+                    object? newKey = EntityEditor.ShowFieldEditor(entry.Key, entry.Key?.GetType() ?? keyType, "Key");
 
-                    if (newKey != EntityEditor.DidNotChange)
+                    if (newKey != EntityEditor.DidNotChange && newKey != null)
                     {
                         keysToDelete.Add(entry.Key!);
                         newEntries.Add(new DictionaryEntry(newKey, entry.Value));
                     }
 
-                    object newValue = EntityEditor.ShowFieldEditor(entry.Value, entry.Value?.GetType() ?? valueType, "Value");
+                    object? newValue = EntityEditor.ShowFieldEditor(entry.Value, entry.Value?.GetType() ?? valueType, "Value");
 
                     if (newValue != EntityEditor.DidNotChange)
                     {
@@ -129,9 +129,9 @@ public class DictionaryEditor
 
                 if (isEntryOpen)
                 {
-                    object newKey = EntityEditor.ShowFieldEditor(_newDictionaryValue.Key, keyType, "Key");
+                    object? newKey = EntityEditor.ShowFieldEditor(_newDictionaryValue.Key, keyType, "Key");
 
-                    if (newKey != EntityEditor.DidNotChange)
+                    if (newKey != EntityEditor.DidNotChange && newKey != null)
                     {
                         newEntries.Add(new DictionaryEntry(newKey, _newDictionaryValue.Value));
                         _dictionaryForNewValue = null;
@@ -139,7 +139,7 @@ public class DictionaryEditor
                         _keyLastCreated = newKey;
                     }
 
-                    object newValue = EntityEditor.ShowFieldEditor(_newDictionaryValue.Value, _newDictionaryValue.Value?.GetType() ?? valueType, "Value");
+                    object? newValue = EntityEditor.ShowFieldEditor(_newDictionaryValue.Value, _newDictionaryValue.Value?.GetType() ?? valueType, "Value");
 
                     if (newValue != EntityEditor.DidNotChange)
                     {

ScriptCore/Editor/EntityEditor.cs

@@ -23,7 +23,7 @@ internal class EntityEditor
 {
     public static readonly DidNotChange DidNotChange = new DidNotChange();
     
-    private delegate object? ShowCustomEditorMethod(object reference, Type fieldType, string fieldName);
+    private delegate object? ShowCustomEditorMethod(object? reference, Type fieldType, string fieldName);
 
     private static Dictionary<Type, ShowCustomEditorMethod> _customEditors = new();
 
@@ -51,7 +51,7 @@ internal class EntityEditor
         }
     }
     
-    private static bool TryShowCustomEditor(object reference, Type fieldType, string fieldName, out object? editedValue)
+    private static bool TryShowCustomEditor(object? reference, Type fieldType, string fieldName, out object? editedValue)
     {
         editedValue = DidNotChange;
 
@@ -332,11 +332,11 @@ internal class EntityEditor
         return newValue;
     }
 
-    private static object ShowEnumEditor(object reference, Type fieldType, string fieldName)
+    private static object ShowEnumEditor(object? reference, Type fieldType, string fieldName)
     {
         object newValue = DidNotChange;
 
-        if (ImGui.BeginCombo(fieldName, reference.ToString()))
+        if (ImGui.BeginCombo(fieldName, reference?.ToString()))
         {
             foreach (object enumValue in Enum.GetValues(fieldType))
             {
@@ -352,13 +352,13 @@ internal class EntityEditor
         return newValue;
     }
 
-    public static object ShowFieldEditor(object reference, Type fieldType, string fieldName, IEnumerable<Attribute>? attributes = null)
+    public static object? ShowFieldEditor(object? reference, Type fieldType, string fieldName, IEnumerable<Attribute>? attributes = null)
     {
-        ReadonlyAttribute readonlyAttribute = GetAttribute<ReadonlyAttribute>(attributes);
+        ReadonlyAttribute? readonlyAttribute = GetAttribute<ReadonlyAttribute>(attributes);
         
         ImGui.BeginDisabled(readonlyAttribute != null);
 
-        object? newValue = DidNotChange;
+        object? newValue;
         
         if (TryShowCustomEditor(reference, fieldType, fieldName, out newValue))
         {
@@ -396,7 +396,7 @@ internal class EntityEditor
             }
             else if (fieldType == typeof(bool2))
             {
-                bool2 value = (bool2)reference;
+                bool2 value = (bool2)reference!;
                     
                 ImGui.TextUnformatted(fieldName);
 
@@ -496,14 +496,14 @@ internal class EntityEditor
         return newValue;
     }
 
-    private static object ShowComponentDropTarget(string fieldName, Type fieldType, object currentValue)
+    private static object? ShowComponentDropTarget(string fieldName, Type fieldType, object? currentValue)
     {
-        object newValue = DidNotChange;
+        object? newValue = DidNotChange;
         
         ImGui.Text($"{fieldName}: ");
         ImGui.SameLine();
 
-        Component component = currentValue as Component;
+        Component? component = currentValue as Component;
 
         string entityName = "None";
 
@@ -512,7 +512,7 @@ internal class EntityEditor
             entityName = component.Entity.Name;
         }
         
-        Type actualType = component?.GetType();
+        Type? actualType = component?.GetType();
 
         entityName += $" ({(actualType ?? fieldType).Name})";
         
@@ -570,23 +570,23 @@ internal class EntityEditor
         return newValue;
     }
 
-    private static object ShowEntityDropTarget(string fieldName, Type fieldType, object currentValue)
+    private static object? ShowEntityDropTarget(string fieldName, Type fieldType, object? currentValue)
     {
-        object newValue = DidNotChange;
+        object? newValue = DidNotChange;
 
         ImGui.Text($"{fieldName}: ");
         ImGui.SameLine();
 
         string entityName = "None";
         
-        Entity entity = currentValue as Entity;
+        Entity? entity = currentValue as Entity;
 
         if (entity != null)
         {
             entityName = entity.Name;
         }
 
-        Type actualType = entity?.GetType();
+        Type? actualType = entity?.GetType();
 
         entityName += $" ({(actualType ?? fieldType).Name})";
 
@@ -620,7 +620,7 @@ internal class EntityEditor
                     }
                     else
                     {
-                        Entity scriptInstance = Entity.GetScriptReference(draggedId, typeof(Entity));
+                        Entity? scriptInstance = Entity.GetScriptReference(draggedId, typeof(Entity));
 
                         allowDrop = fieldType.IsInstanceOfType(scriptInstance);
                     }
@@ -661,11 +661,11 @@ internal class EntityEditor
         return newValue;
     }
 
-    private static object ShowStringEditor(object reference, Type fieldType, string fieldName, IEnumerable<Attribute> attributes)
+    private static object ShowStringEditor(object? reference, Type fieldType, string fieldName, IEnumerable<Attribute>? attributes)
     {
         object newValue = DidNotChange;
 
-        TextFieldAttribute textField = GetAttribute<TextFieldAttribute>(attributes);
+        TextFieldAttribute? textField = GetAttribute<TextFieldAttribute>(attributes);
 
         string value = reference as string ?? $"{float.MinValue}";
 
@@ -684,7 +684,7 @@ internal class EntityEditor
         return newValue;
     }
 
-    public static void ShowEditor(Type type, object reference)
+    public static void ShowEditor(Type type, object? reference)
     {
         int i = 0;
 
@@ -700,7 +700,7 @@ internal class EntityEditor
 
                 IEnumerable<Attribute> attributes = field.GetCustomAttributes();
 
-                object newValue = ShowFieldEditor(value, value?.GetType() ?? field.FieldType, field.Name, attributes);
+                object? newValue = ShowFieldEditor(value, value?.GetType() ?? field.FieldType, field.Name, attributes);
 
                 if (newValue != DidNotChange)
                 {
@@ -748,12 +748,14 @@ internal class EntityEditor
         public int Element;
     }
 
-    private static object ShowListEditor(Type fieldType, object fieldValue, string fieldName)
+    private static object? ShowListEditor(Type fieldType, object? fieldValue, string fieldName)
     {
         Type elementType = fieldType.GenericTypeArguments[0];
 
-        void AddElement(IList list, ref object newList)
+        void AddElement(IList? list, out object? newList)
         {
+            newList = DidNotChange;
+
             if (list == null)
             {
                 newList = Activator.CreateInstance(fieldType);
@@ -762,36 +764,50 @@ internal class EntityEditor
                 Debug.Assert(list != null);
             }
 
-            object newElement = ActivatorExtension.CreateInstanceSafe(elementType);
+            object? newElement = ActivatorExtension.CreateInstanceSafe(elementType);
-            list.Add(newElement);
+            list?.Add(newElement);
         }
 
-        void RemoveElement(IList list, ref object newList)
+        void RemoveElement(IList? list, out object? newList)
+        {
+            newList = DidNotChange;
+
+            if (list == null)
+                return;
+
+            if (list.Count == 0)
+            {
+                newList = null;
+            }
+            else
             {
                 list.RemoveAt(list.Count - 1);
             }
+        }
 
-        return ShowGenericListEditor(fieldType, elementType, (IEnumerable)fieldValue, fieldName, 
+        return ShowGenericListEditor(fieldType, elementType, (IEnumerable?)fieldValue, fieldName, 
             AddElement, RemoveElement);
     }
 
-    private static object ShowArrayEditor(Type fieldType, object fieldValue, string fieldName)
+    private static object? ShowArrayEditor(Type fieldType, object? fieldValue, string fieldName)
     {
         Debug.Assert(fieldType.IsArray);
 
-        Type elementType = fieldType.GetElementType();
+        Type? elementType = fieldType.GetElementType();
 
         Debug.Assert(elementType != null);
 
-        Array myArray = fieldValue as Array;
+        Array? myArray = fieldValue as Array;
         
         if (myArray?.Rank > 1)
         {
             throw new NotImplementedException("Multidimensional arrays are not yet supported.");
         }
 
-        void AddElement(IList list, ref object newList)
+        void AddElement(IList? list, out object? newList)
         {
+            newList = DidNotChange;
+
             int newIndex = 0;
 
             if (list == null)
@@ -812,25 +828,37 @@ internal class EntityEditor
             ((IList)newList)[newIndex] = newElement;
         }
 
-        void RemoveElement(IList list, ref object newList)
+        void RemoveElement(IList? list, out object? newList)
+        {
+            newList = DidNotChange;
+
+            if (list == null)
+                return;
+
+            if (list.Count == 0)
+            {
+                newList = null;
+            }
+            else
             {
                 Array newArray = Array.CreateInstance(elementType, list.Count - 1);
                 Array.Copy((Array)list, newArray, newArray.Length);
 
                 newList = newArray;
             }
+        }
 
-        return ShowGenericListEditor(fieldType, elementType, (IEnumerable)fieldValue, fieldName, 
+        return ShowGenericListEditor(fieldType, elementType!, (IEnumerable?)fieldValue, fieldName, 
             AddElement, RemoveElement);
     }
 
-    public delegate void ModifyList(IList currentList, ref object oldList);
+    public delegate void ModifyList(IList? currentList, out object? oldList);
 
-    private static object ShowGenericListEditor(Type listType, Type elementType, IEnumerable list, string fieldName, 
+    private static object? ShowGenericListEditor(Type listType, Type elementType, IEnumerable? list, string fieldName, 
         ModifyList addElement, ModifyList removeElement)
     {
-        object newList = DidNotChange;
+        object? newList = DidNotChange;
-        IList myList = list as IList;
+        IList? myList = list as IList;
 
         // The buttons should always be visible -> save whether the node is open
         // If we have no instance, the user shouldn't be able to open the list
@@ -847,7 +875,7 @@ internal class EntityEditor
 
         if (ImGui.SmallButton("+"))
         {
-            addElement(myList, ref newList);
+            addElement(myList, out newList);
         }
 
         ImGuiExtension.AttachTooltip("Add a new Element at the end of the list.");
@@ -858,7 +886,7 @@ internal class EntityEditor
 
         if (ImGui.SmallButton("-"))
         {
-            removeElement(myList, ref newList);
+            removeElement(myList, out newList);
         }
 
         ImGuiExtension.AttachTooltip("Remove the last Element from the list.");
@@ -869,7 +897,7 @@ internal class EntityEditor
         {
             Debug.Assert(myList != null, "Opened tree node even though it should have been a leaf!");
 
-            /// Returns true if something was dropped into the droptarget
+            // Returns true if something was dropped into the droptarget
             bool DropTarget(int insertIndex, string tooltip)
             {
                 bool dropped = false;
@@ -887,7 +915,7 @@ internal class EntityEditor
                             ref ListPayload payload = ref Unsafe.AsRef<ListPayload>((void*)payloadPtr.Data);
 
                             // Make sure the index is still correct
-                            if (payload.Element < myList.Count)
+                            if (payload.Element < myList!.Count)
                             {
                                 object item = myList[payload.Element];
 
@@ -917,7 +945,7 @@ internal class EntityEditor
 
             bool orderChanged = false;
 
-            for (int i = 0, id = 0; i < myList.Count; i++, id++)
+            for (int i = 0, id = 0; i < myList!.Count; i++, id++)
             {
                 ImGui.PushID(id);
 
@@ -957,7 +985,7 @@ internal class EntityEditor
                 
                 ImGui.SameLine();
 
-                object newValue = ShowFieldEditor(element, element?.GetType() ?? elementType, $"Element {i}");
+                object? newValue = ShowFieldEditor(element, element?.GetType() ?? elementType, $"Element {i}");
 
                 // Don't apply changes, when the order changed
                 if (newValue != DidNotChange && !orderChanged)
@@ -981,7 +1009,7 @@ internal class EntityEditor
 
     private static T ReadStaticField<T>(string name)
     {
-        FieldInfo field = typeof(T).GetField(name, BindingFlags.Public | BindingFlags.Static);
+        FieldInfo? field = typeof(T).GetField(name, BindingFlags.Public | BindingFlags.Static);
         
         if (field == null)
         {

ScriptCore/Editor/ShowInEditorAttribute.cs

@@ -18,5 +18,5 @@ public sealed class ShowInEditorAttribute : Attribute
     /// The label with which the field will be shown in the editor.
     /// If not specified, the fields name will be used.
     /// </summary>
-    public string DisplayName { get; set; } = null;
+    public string? DisplayName { get; set; } = null;
 }

ScriptCore/Serialization/DeserializationObject.cs

@@ -277,7 +277,7 @@ public class DeserializationObject
 
             object currentValue = field.GetValue(obj);
 
-            object deserializeValue = DeserializeField(currentValue, field.FieldType, field.Name);
+            object? deserializeValue = DeserializeField(currentValue, field.FieldType, field.Name);
             
             if (deserializeValue != NoValueDeserialized)
             {
@@ -347,7 +347,10 @@ public class DeserializationObject
         }
         if (fieldType.IsValueType)
         {
-            return DeserializeStruct(fieldName, fieldValue);
+            // Null Value doesn't make any sense, because we need a value to deserialize into!
+            Debug.Assert(fieldValue != null);
+
+            return DeserializeStruct(fieldName, fieldValue!);
         }
         if (fieldType.IsClass)
         {

ScriptCore/Serialization/DictionarySerializer.cs

@@ -79,9 +79,9 @@ public static class DictionarySerializer
             return null;
         
         // Get serialization container for the instance
-        DeserializationObject deserializedObject = container.GetDeserializedObject(id);
+        DeserializationObject? deserializedObject = container.GetDeserializedObject(id);
 
-        Type type = deserializedObject.StoredType;
+        Type? type = deserializedObject?.StoredType;
 
         if (type?.IsAssignableTo(fieldType) != true)
             return DeserializationObject.NoValueDeserialized;
@@ -89,7 +89,7 @@ public static class DictionarySerializer
         Type keyType = fieldType.GetGenericArguments()[0];
         Type valueType = fieldType.GetGenericArguments()[1];
 
-        int count = deserializedObject.GetFieldValue<int>("Count", SerializationType.Int32);
+        int count = deserializedObject!.GetFieldValue<int>("Count", SerializationType.Int32);
         
         // Create instance, pass in capacity
         object? instance = ActivatorExtension.CreateInstanceSafe(type, count);
@@ -103,7 +103,7 @@ public static class DictionarySerializer
             deserializedObject.PushScope(i.ToString());
 
             object? key = deserializedObject.DeserializeField(null, keyType, "Key");
-            object value = deserializedObject.DeserializeField(null, valueType, "Value");
+            object? value = deserializedObject.DeserializeField(null, valueType, "Value");
 
             if (key != null)
             {

ScriptCore/Serialization/SerializedObject.cs

@@ -18,7 +18,7 @@ public class SerializedObject
 
     private Stack<string> _structScope = new();
 
-    private string _structScopeName;
+    private string _structScopeName = "";
     
     private delegate void SerializeMethod(SerializedObject container, string fieldName, object? fieldValue, Type fieldType);
 
@@ -86,7 +86,7 @@ public class SerializedObject
         _structScopeName = _structScopeName.Remove(_structScopeName.Length - scopeToRemove.Length - 1);
     }
 
-    public void AddField(string fieldName, SerializationType serializationType, object value, string? fullTypeName = null)
+    public void AddField(string fieldName, SerializationType serializationType, object? value, string? fullTypeName = null)
     {
         string completeFieldName = $"{_structScopeName}{fieldName}";
 
@@ -107,14 +107,14 @@ public class SerializedObject
             if (!EntitySerializer.SerializeField(field))
                 continue;
 
-            object fieldValue = field.GetValue(obj);
+            object? fieldValue = field.GetValue(obj);
             Type fieldType = fieldValue?.GetType() ?? field.FieldType;
 
             SerializeField(field.Name, fieldValue, fieldType);
         }
     }
 
-    private bool TryCustomSerializer(string fieldName, object fieldValue, Type fieldType)
+    private bool TryCustomSerializer(string fieldName, object? fieldValue, Type fieldType)
     {
         try
         {
@@ -142,11 +142,12 @@ public class SerializedObject
         return false;
     }
 
-    public void SerializeField(string fieldName, object fieldValue, Type fieldType)
+    public void SerializeField(string fieldName, object? fieldValue, Type fieldType)
     {
         if (fieldType.IsPrimitive || fieldType == typeof(decimal))
         {
-            SerializePrimitive(fieldName, fieldValue, fieldType);
+            // Primitives can't be null
+            SerializePrimitive(fieldName, fieldValue!, fieldType);
         }
         else if (fieldType == typeof(string))
         {
@@ -158,14 +159,14 @@ public class SerializedObject
         }
         else if (fieldType.IsArray)
         {
-            Array myArray = fieldValue as Array;
+            Array? myArray = fieldValue as Array;
         
             if (myArray?.Rank > 1)
             {
                 throw new NotImplementedException("Serializing multidimensional arrays is not yet supported.");
             }
 
-            SerializeList(fieldName, fieldValue, fieldType, fieldType.GetElementType());
+            SerializeList(fieldName, fieldValue, fieldType, fieldType.GetElementType()!);
         }
         else if (fieldType.IsGenericType)
         {
@@ -191,7 +192,8 @@ public class SerializedObject
             if (TryCustomSerializer(fieldName, fieldValue, fieldType))
                 return;
 
-            SerializeStruct(fieldName, fieldValue, fieldType);
+            // Value Types cant be null
+            SerializeStruct(fieldName, fieldValue!, fieldType);
         }
         else if (fieldType.IsClass)
         {
@@ -206,7 +208,7 @@ public class SerializedObject
         }
     }
 
-    public void SerializeList(string fieldName, object listObject, Type fieldType, Type elementType)
+    public void SerializeList(string fieldName, object? listObject, Type fieldType, Type elementType)
     {
         if (listObject == null)
         {
@@ -274,9 +276,9 @@ public class SerializedObject
         AddField(fieldName, type, fieldValue);
     }
 
-    public void SerializeEnum(string fieldName, object fieldValue, Type fieldType)
+    public void SerializeEnum(string fieldName, object? fieldValue, Type fieldType)
     {
-        AddField(fieldName, SerializationType.Enum, fieldValue.ToString());
+        AddField(fieldName, SerializationType.Enum, fieldValue?.ToString());
     }
 
     public void SerializeStruct(string fieldName, object fieldValue, Type fieldType)
@@ -288,15 +290,15 @@ public class SerializedObject
         PopScope();
     }
 
-    public void SerializeClass(string fieldName, object fieldValue, Type fieldType)
+    public void SerializeClass(string fieldName, object? fieldValue, Type fieldType)
     {
         if (typeof(Entity).IsAssignableFrom(fieldType))
         {
-            AddField(fieldName, SerializationType.EntityReference, ((Entity)fieldValue)?.UUID ?? UUID.Zero, fieldValue?.GetType().FullName);
+            AddField(fieldName, SerializationType.EntityReference, ((Entity?)fieldValue)?.UUID ?? UUID.Zero, fieldValue?.GetType().FullName);
         }
         else if (fieldType.IsSubclassOf(typeof(Component)))
         {
-            AddField(fieldName, SerializationType.ComponentReference, ((Component)fieldValue)?.UUID ?? UUID.Zero, fieldValue?.GetType().FullName);
+            AddField(fieldName, SerializationType.ComponentReference, ((Component?)fieldValue)?.UUID ?? UUID.Zero, fieldValue?.GetType().FullName);
         }
         else
         {