redo

Undo / Redo are currently bound to Pageup/down. This is ideally temporary, I just need to figure out ctrl+r for redo. "u" is also bound to undo as it should be

src/app/app.rs

@@ -419,13 +419,23 @@ impl App {
             },
             Mode::Normal => match event::read()? {
                 event::Event::Key(key_event) => match key_event.code {
-                    event::KeyCode::F(_) => {},
+                    event::KeyCode::F(n) => {},
                     event::KeyCode::Char(c) => Mode::process_key(self, c),
+                    // Pretend that the arrow keys are vim movement keys
                     event::KeyCode::Left => Mode::process_key(self, 'h'),
                     event::KeyCode::Right => Mode::process_key(self, 'l'),
                     event::KeyCode::Up => Mode::process_key(self, 'k'),
                     event::KeyCode::Down => Mode::process_key(self, 'j'),
-                    event::KeyCode::Modifier(modifier_key_code) => todo!(),
+                    // Getting ctrl to work isn't going will right now. Use page keys for the time being.
+                    event::KeyCode::PageUp => self.grid.redo(),
+                    event::KeyCode::PageDown => self.grid.undo(),
+                    event::KeyCode::Modifier(modifier_key_code) => {
+                        if let event::ModifierKeyCode::LeftControl | event::ModifierKeyCode::RightControl = modifier_key_code {
+                            // TODO my terminal (alacritty) isn't showing me ctrl presses. I know
+                            // that they work tho, since ctrl+r works here in neovim.
+                            // panic!("heard ctrl");
+                        }
+                    },
                     _ => {}
                 },
                 _ => {}

src/app/logic/calc.rs

@@ -243,7 +243,7 @@ impl Grid {
         self.current_grid = self.current_grid.saturating_sub(1);
     }
     pub fn redo(&mut self) {
-        self.current_grid += 1;
+        self.current_grid = min(self.grid_history.len() - 1, self.current_grid + 1);
     }
 
     pub fn transact_on_grid<F>(&mut self, mut action: F)