Reworked Undo-Redo system to be more flexible and stable

SHADE_Managed/src/Editor/Editor.cxx

@@ -149,7 +149,7 @@ namespace SHADE
         }
         SHEditorUI::PopID();
     }
-    void Editor::renderFieldInInspector(Reflection::FieldInfo^ field, Object^ object)
+    void Editor::renderFieldInInspector(Reflection::FieldInfo^ field, System::Object^ object)
     {
         bool isHovered = false;
 
@@ -343,12 +343,7 @@ namespace SHADE
     void Editor::registerUndoAction(System::Object^ object, System::Reflection::FieldInfo^ field, System::Object^ newData, System::Object^ oldData)
     {
         // Create command and add it into the undo stack
-        UndoRedoStack::Command cmd;
+        actionStack.Add(gcnew FieldChangeCommand(object, field, newData, oldData));
-        cmd.Field = field;
-        cmd.Object = object;
-        cmd.NewData = newData;
-        cmd.OldData = oldData;
-        actionStack.Add(cmd);
 
         // Inform the C++ Undo-Redo stack
         SHCommandManager::RegisterCommand(std::reinterpret_pointer_cast<SHBaseCommand>(std::make_shared<SHCLICommand>()));

SHADE_Managed/src/Editor/Editor.h++

@@ -30,7 +30,8 @@ namespace SHADE
                 rangeAttrib = hasAttribute<RangeAttribute^>(fieldInfo);
             }
 
-            ManagedType val = safe_cast<ManagedType>(fieldInfo->GetValue(object));
+            ManagedType oldVal = safe_cast<ManagedType>(fieldInfo->GetValue(object));
+            ManagedType val = oldVal;
             if (renderFieldInInspector<NativeType, ManagedType>
             (
                 Convert::ToNative(fieldInfo->Name),
@@ -41,7 +42,7 @@ namespace SHADE
             ))
             {
                 fieldInfo->SetValue(object, val);
-                // TODO: Register undo
+                registerUndoAction(object, fieldInfo, fieldInfo->GetValue(object), oldVal);
             }
             
             return true;
@@ -90,15 +91,12 @@ namespace SHADE
         {
             if constexpr (IsPrimitiveTypeMatches_V<NativeType>)
             {
-                //field->SetValue(object, val);
                 managedVal = val;
-                //registerUndoAction(object, field, val, oldVal);
             }
             else
             {
 
                 managedVal = Convert::ToCLI(val);
-                //registerUndoAction(object, field, Convert::ToCLI(val), Convert::ToCLI(oldVal));
             }
 
             return true;

SHADE_Managed/src/Editor/Editor.hxx

@@ -89,7 +89,7 @@ namespace SHADE
         /// <param name="object">
         /// The object that contains the data of the field to render.
         /// </param>
-        static void renderFieldInInspector(System::Reflection::FieldInfo^ field, Object^ object);
+        static void renderFieldInInspector(System::Reflection::FieldInfo^ field, System::Object^ object);
         /// <summary>
         /// Renders a context menu when right clicked for the scripts
         /// </summary>

SHADE_Managed/src/Editor/UndoRedoStack.cxx

@@ -19,6 +19,8 @@ of DigiPen Institute of Technology is prohibited.
 // External Dependencies
 #include "Editor/SHEditorUI.h"
 // Project Headers
+#include "Utility/Debug.hxx"
+#include "Utility/Convert.hxx"
 
 namespace SHADE
 {
@@ -32,7 +34,7 @@ namespace SHADE
         return latestActionIndex >= 0 && latestActionIndex < commandStack->Count - 1;
     }
 
-    void UndoRedoStack::Add(Command command)
+    void UndoRedoStack::Add(ICommand^ command)
     {
         // Erase any other actions ahead of the current action
         if (latestActionIndex >= 0 && latestActionIndex < commandStack->Count - 1)
@@ -52,8 +54,8 @@ namespace SHADE
         if (!UndoActionPresent)
             return;
 
-        Command cmd = commandStack[latestActionIndex];
+        ICommand^ cmd = commandStack[latestActionIndex];
-        cmd.Field->SetValue(cmd.Object, cmd.OldData);
+        cmd->Unexceute();
         --latestActionIndex;
     }
 
@@ -62,8 +64,57 @@ namespace SHADE
         if (!RedoActionPresent)
             return;
 
-        Command cmd = commandStack[latestActionIndex];
+        ICommand^ cmd = commandStack[latestActionIndex];
-        cmd.Field->SetValue(cmd.Object, cmd.NewData);
+        cmd->Execute();
         ++latestActionIndex;
     }
+
+    FieldChangeCommand::FieldChangeCommand(System::Object^ obj, System::Reflection::FieldInfo^ field, System::Object^ newData, System::Object^ oldData)
+    : objectToChange { obj }
+    , field { field }
+    , newData { newData }
+    , oldData { oldData }
+    {}
+
+    bool FieldChangeCommand::Execute()
+    {
+        if (field && objectToChange)
+        {
+            field->SetValue(objectToChange, newData);
+            return true;
+        }
+
+        return false;
+    }
+
+    bool FieldChangeCommand::Unexceute()
+    {
+        if (field && objectToChange)
+        {
+            field->SetValue(objectToChange, oldData);
+            return true;
+        }
+
+        return false;
+    }
+
+    bool FieldChangeCommand::Merge(ICommand^ command)
+    {
+        FieldChangeCommand^ otherCommand = safe_cast<FieldChangeCommand^>(command);
+        if (otherCommand == nullptr)
+        {
+            Debug::LogWarning("[Field Change Command] Attempted to merge two incompatible commands!");
+            return false;
+        }
+
+        // Only merge if they are workng on the same object and field
+        if (field == otherCommand->field && objectToChange == otherCommand->objectToChange)
+        {
+            newData = otherCommand->newData;
+            return true;
+        }
+
+        return false;
+    }
+
 }

SHADE_Managed/src/Editor/UndoRedoStack.hxx

@@ -15,27 +15,52 @@ of DigiPen Institute of Technology is prohibited.
 
 namespace SHADE
 {
+    /// <summary>
+    /// Interface for command that fits into the UndoRedoStack which can perform 
+    /// undo-able and redo-able operations.
+    /// </summary>
+    private interface class ICommand
+    {
+        /// <summary>
+        /// Executes an action. This is called when a "Redo" is performed.
+        /// </summary>
+        /// <returns>Whether the action was successful or not.</returns>
+        bool Execute();
+        /// <summary>
+        /// Undoes an action. This is called when an "Undo" is performed.
+        /// </summary>
+        /// <returns>Whether the action was successful or not.</returns>
+        bool Unexceute();
+        /// <summary>
+        /// Merges this command with another command.
+        /// </summary>
+        /// <param name="command"></param>
+        /// <returns>Whether the merge was successful or not.</returns>
+        bool Merge(ICommand^ command);
+    };
+
+    private ref class FieldChangeCommand sealed : public ICommand
+    {
+      public:
+        FieldChangeCommand(System::Object^ obj, System::Reflection::FieldInfo^ field, System::Object^ newData, System::Object^ oldData);
+
+        bool Execute() override;
+        bool Unexceute() override;
+        bool Merge(ICommand^ command) override;
+
+      private:
+        System::Object^ objectToChange;
+        System::Reflection::FieldInfo^ field;
+        System::Object^ newData;
+        System::Object^ oldData;
+    };
+
     /// <summary>
     /// Class that is able to store a stack of actions that can be done and redone.
     /// </summary>
     private ref class UndoRedoStack sealed
     {
       public:
-        /*-----------------------------------------------------------------------------*/
-        /* Type Definitions                                                            */
-        /*-----------------------------------------------------------------------------*/
-        /// <summary>
-        /// Command for the stack that represents a data modification.
-        /// </summary>
-        value struct Command
-        {
-          public:
-            System::Object^ Object;
-            System::Reflection::FieldInfo^ Field;
-            System::Object^ NewData;
-            System::Object^ OldData;
-		};
-
 		/*-----------------------------------------------------------------------------*/
 		/* Properties                                                                  */
 		/*-----------------------------------------------------------------------------*/
@@ -55,7 +80,7 @@ namespace SHADE
 		/// Adds a command onto the stack.
 		/// </summary>
 		/// <param name="command"></param>
-		void Add(Command command);
+		void Add(ICommand^ command);
         /// <summary>
         /// Undos the last added command if it exists.
         /// </summary>
@@ -70,6 +95,6 @@ namespace SHADE
         /* Data Members                                                                */
         /*-----------------------------------------------------------------------------*/
         int latestActionIndex                                     = -1;
-		System::Collections::Generic::List<Command>^ commandStack = gcnew System::Collections::Generic::List<Command>();
+		System::Collections::Generic::List<ICommand^>^ commandStack = gcnew System::Collections::Generic::List<ICommand^>();
     };
 }