From 80db641b6f0353ae14d3c01567551b86cc0c95f5 Mon Sep 17 00:00:00 2001
From: Kah Wei <msntkw@msn.com>
Date: Fri, 11 Nov 2022 00:49:20 +0800
Subject: [PATCH] Added ListElementChangeCommand

---
 SHADE_Managed/src/Editor/UndoRedoStack.cxx | 49 ++++++++++++++++++++++
 SHADE_Managed/src/Editor/UndoRedoStack.hxx | 19 ++++++++-
 2 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/SHADE_Managed/src/Editor/UndoRedoStack.cxx b/SHADE_Managed/src/Editor/UndoRedoStack.cxx
index ae0a1dee..3feb43ed 100644
--- a/SHADE_Managed/src/Editor/UndoRedoStack.cxx
+++ b/SHADE_Managed/src/Editor/UndoRedoStack.cxx
@@ -117,4 +117,53 @@ namespace SHADE
         return false;
     }
 
+    generic<typename T>
+    ListElementChangeCommand<T>::ListElementChangeCommand(System::Collections::Generic::List<T>^ list, int index, T newData, T oldData)
+    : list    { list    }
+    , index   { index   }
+    , newData { newData }
+    , oldData { oldData }
+    {}
+    
+    generic<typename T>
+    bool ListElementChangeCommand<T>::Execute()
+    {
+        if (list && index < System::Linq::Enumerable::Count(list))
+        {
+            list[index] = newData;
+            return true;
+        }
+
+        return false;
+    }
+    
+    generic<typename T>
+    bool ListElementChangeCommand<T>::Unexceute()
+    {
+        if (list && index < System::Linq::Enumerable::Count(list))
+        {
+            list[index] = oldData;
+            return true;
+        }
+
+        return false;
+    }
+    
+    generic<typename T>
+    bool ListElementChangeCommand<T>::Merge(ICommand^ command)
+    {
+        ListElementChangeCommand<T>^ otherCommand = safe_cast<ListElementChangeCommand<T>^>(command);
+        if (otherCommand == nullptr)
+        {
+            Debug::LogWarning("[Field Change Command] Attempted to merge two incompatible commands!");
+            return false;
+        }
+
+        if (command && list == otherCommand->list && index == otherCommand->index)
+        {
+            newData = otherCommand->newData;
+            return true;
+        }
+    }
+
 }
diff --git a/SHADE_Managed/src/Editor/UndoRedoStack.hxx b/SHADE_Managed/src/Editor/UndoRedoStack.hxx
index 69f462e3..dd78ecd9 100644
--- a/SHADE_Managed/src/Editor/UndoRedoStack.hxx
+++ b/SHADE_Managed/src/Editor/UndoRedoStack.hxx
@@ -38,7 +38,7 @@ namespace SHADE
         /// <returns>Whether the merge was successful or not.</returns>
         bool Merge(ICommand^ command);
     };
-
+    
     private ref class FieldChangeCommand sealed : public ICommand
     {
       public:
@@ -55,6 +55,23 @@ namespace SHADE
         System::Object^ oldData;
     };
 
+    generic<typename T>
+    private ref class ListElementChangeCommand sealed : public ICommand
+    {
+      public:
+        ListElementChangeCommand(System::Collections::Generic::List<T>^ list, int index, T newData, T oldData);
+
+        bool Execute() override;
+        bool Unexceute() override;
+        bool Merge(ICommand^ command) override;
+
+      private:
+        System::Collections::Generic::List<T>^ list;
+        int index;
+        T newData;
+        T oldData;
+    };
+
     /// <summary>
     /// Class that is able to store a stack of actions that can be done and redone.
     /// </summary>