From 53dcf2ffc94144c4846c675f02e327f7636d1b24 Mon Sep 17 00:00:00 2001
From: Rushmore75 <oliveratkinsoneng@gmail.com>
Date: Fri, 6 Feb 2026 17:04:12 -0700
Subject: [PATCH] mock up history

---
 src/app/logic/calc.rs | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/app/logic/calc.rs b/src/app/logic/calc.rs
index 4ad249b..3a59a16 100644
--- a/src/app/logic/calc.rs
+++ b/src/app/logic/calc.rs
@@ -236,12 +236,27 @@ impl Grid {
         &mut self.grid_history[self.current_grid]
     }
 
+    fn undo(&mut self) {
+        self.current_grid.saturating_sub(1);
+    }
+    fn redo(&mut self) {
+        self.current_grid += 1;
+    }
+
     fn transact_on_grid<F>(&mut self, mut action: F)
     where
         F: FnMut(&mut CellGrid) -> (),
     {
-        let old = self.get_grid().clone();
-        self.grid_history.push(old);
+        // push on a new reality
+        let new = self.get_grid().clone();
+        self.grid_history.push(new);
+        self.current_grid += 1;
+
+        // delete the other fork of the history
+        for i in self.current_grid+1..self.grid_history.len() {
+            self.grid_history.remove(i);
+        }
+        
         action(&mut self.grid_history[self.current_grid]);
 
         self.dirty = true;