The OnUndo field is an event handler that is triggered whenever an undo operation is executed within the UndoSystem. This field is of type System.Action<Sandbox.Helpers.UndoSystem.Entry>, allowing you to specify a method that takes an Entry object as a parameter. This can be used to perform additional actions or logging when an undo operation occurs.
To use the OnUndo field, you can assign a method to it that matches the signature of System.Action<Sandbox.Helpers.UndoSystem.Entry>. This method will be called automatically whenever an undo operation is performed.
// Example of subscribing to the OnUndo event
UndoSystem undoSystem = new UndoSystem();
// Define a method that matches the Action<Entry> signature
void OnUndoAction(Sandbox.Helpers.UndoSystem.Entry entry)
{
// Perform custom logic when an undo is executed
// For example, logging the undo action
Log.Info($"Undo performed: {entry.Title}");
}
// Subscribe the method to the OnUndo event
undoSystem.OnUndo += OnUndoAction;
// Now, whenever an undo is executed, OnUndoAction will be called.