Hacky undo/redo integration.

2 files changed, 12 insertions, 1 deletions

diff --git a/helix-core/src/state.rs b/helix-core/src/state.rs
index 9d51c8c5..ed0df9cf 100644
--- a/helix-core/src/state.rs
+++ b/helix-core/src/state.rs
@@ -1,6 +1,6 @@
 use crate::graphemes::{nth_next_grapheme_boundary, nth_prev_grapheme_boundary, RopeGraphemes};
 use crate::syntax::LOADER;
-use crate::{Position, Range, Rope, RopeSlice, Selection, Syntax};
+use crate::{ChangeSet, Position, Range, Rope, RopeSlice, Selection, Syntax};
 use anyhow::Error;
 
 use std::path::PathBuf;
@@ -25,6 +25,8 @@ pub struct State {
 
     //
     pub syntax: Option<Syntax>,
+    pub changes: Option<ChangeSet>,
+    pub old_state: Option<(Rope, Selection)>,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq)]
@@ -50,6 +52,8 @@ impl State {
             mode: Mode::Normal,
             restore_cursor: false,
             syntax: None,
+            changes: None,
+            old_state: None,
         }
     }
 
diff --git a/helix-core/src/transaction.rs b/helix-core/src/transaction.rs
index d6b151ba..7871052a 100644
--- a/helix-core/src/transaction.rs
+++ b/helix-core/src/transaction.rs
@@ -369,6 +369,13 @@ impl Transaction {
                 return false;
             }
 
+            // Compose this transaction with the previous one
+            let old_changes = state.changes.take();
+            state.changes = Some(old_changes.map_or_else(
+                || self.changes.clone(),
+                |changes| changes.compose(self.changes.clone()).unwrap(),
+            ));
+
             if let Some(syntax) = &mut state.syntax {
                 // TODO: no unwrap
                 syntax.update(&old_doc, &state.doc, &self.changes).unwrap();