From 5a549f7436b788b47b26a84975ce574de1412edf Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Wed, 22 Dec 2021 17:59:19 -0500
Subject: [PATCH] prepare for undo

---
 src/gui/gui.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/gui/gui.h b/src/gui/gui.h
index 03ab2ca1c..e04c1210c 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -63,6 +63,19 @@ struct SelectionPoint {
     xCoarse(0), xFine(0), y(0) {}
 };
 
+enum ActionType {
+  GUI_ACTION_PATTERN
+};
+
+struct UndoData {
+  int data;
+};
+
+struct UndoStep {
+  ActionType type;
+  std::vector<UndoData> data;
+};
+
 class FurnaceGUI {
   DivEngine* e;