Track document changes in the jumplist

Previously, the jumplist was not updated by changes to the document.
This meant that the jumplist entries were prone to being incorrect
after some edits and that usages of the jumplist were prone to panics
if, for example, some edits truncated the document.

This change applies `Transaction`s (document edits) to the selections
stored in any jumplists.

helix-term/src/commands.rs

@@ -2346,7 +2346,7 @@ fn jumplist_picker(cx: &mut Context) {
                 view.jumps
                     .get()
                     .iter()
-                    .map(|(doc_id, selection)| new_meta(view, *doc_id, selection.clone()))
+                    .map(|(doc_id, selection)| new_meta(view, *doc_id, selection.borrow().clone()))
             })
             .collect(),
         (),
@@ -2644,9 +2644,8 @@ fn try_restore_indent(doc: &mut Document, view_id: ViewId) {
 }
 
 // Store a jump on the jumplist.
-fn push_jump(view: &mut View, doc: &Document) {
-    let jump = (doc.id(), doc.selection(view.id).clone());
-    view.jumps.push(jump);
+fn push_jump(view: &mut View, doc: &mut Document) {
+    view.jumps.push(doc, doc.selection(view.id).clone());
 }
 
 fn goto_line(cx: &mut Context) {
@@ -4048,7 +4047,7 @@ fn jump_forward(cx: &mut Context) {
 
     if let Some((id, selection)) = view.jumps.forward(count) {
         view.doc = *id;
-        let selection = selection.clone();
+        let selection = selection.borrow().clone();
         let (view, doc) = current!(cx.editor); // refetch doc
         doc.set_selection(view.id, selection);
 
@@ -4062,7 +4061,7 @@ fn jump_backward(cx: &mut Context) {
 
     if let Some((id, selection)) = view.jumps.backward(view.id, doc, count) {
         view.doc = *id;
-        let selection = selection.clone();
+        let selection = selection.borrow().clone();
         let (view, doc) = current!(cx.editor); // refetch doc
         doc.set_selection(view.id, selection);
 

helix-term/src/ui/mod.rs

@@ -69,7 +69,6 @@ pub fn regex_prompt(
     fun: impl Fn(&mut View, &mut Document, Regex, PromptEvent) + 'static,
 ) {
     let (view, doc) = current!(cx.editor);
-    let doc_id = view.doc;
     let snapshot = doc.selection(view.id).clone();
     let offset_snapshot = view.offset;
     let config = cx.editor.config();
@@ -109,8 +108,7 @@ pub fn regex_prompt(
                             doc.set_selection(view.id, snapshot.clone());
 
                             if event == PromptEvent::Validate {
-                                // Equivalent to push_jump to store selection just before jump
-                                view.jumps.push((doc_id, snapshot.clone()));
+                                view.jumps.push(doc, snapshot.clone());
                             }
 
                             fun(view, doc, regex, event);

helix-view/src/document.rs

@@ -5,11 +5,12 @@ use helix_core::auto_pairs::AutoPairs;
 use helix_core::Range;
 use serde::de::{self, Deserialize, Deserializer};
 use serde::Serialize;
-use std::cell::Cell;
+use std::cell::{Cell, RefCell};
 use std::collections::HashMap;
 use std::fmt::Display;
 use std::future::Future;
 use std::path::{Path, PathBuf};
+use std::rc::Rc;
 use std::str::FromStr;
 use std::sync::Arc;
 
@@ -86,6 +87,7 @@ pub struct Document {
     pub(crate) id: DocumentId,
     text: Rope,
     selections: HashMap<ViewId, Selection>,
+    jump_selections: Vec<Rc<RefCell<Selection>>>,
 
     path: Option<PathBuf>,
     encoding: &'static encoding::Encoding,
@@ -347,6 +349,7 @@ impl Document {
             encoding,
             text,
             selections: HashMap::default(),
+            jump_selections: vec![Rc::new(RefCell::new(Selection::point(0)))],
             indent_style: DEFAULT_INDENT,
             line_ending: DEFAULT_LINE_ENDING,
             mode: Mode::Normal,
@@ -744,6 +747,14 @@ impl Document {
             }
 
             self.modified_since_accessed = true;
+
+            for selection in &self.jump_selections {
+                let mut selection = selection.borrow_mut();
+                *selection = selection
+                    .clone()
+                    .map(transaction.changes())
+                    .ensure_invariants(self.text.slice(..));
+            }
         }
 
         if !transaction.changes().is_empty() {
@@ -1075,6 +1086,11 @@ impl Document {
             None => global_config,
         }
     }
+
+    #[inline]
+    pub fn push_jump_selection(&mut self, selection: Rc<RefCell<Selection>>) {
+        self.jump_selections.push(selection)
+    }
 }
 
 impl Default for Document {

helix-view/src/editor.rs

@@ -905,8 +905,7 @@ impl Editor {
                         view.remove_document(&id);
                     }
                 } else {
-                    let jump = (view.doc, doc.selection(view.id).clone());
-                    view.jumps.push(jump);
+                    view.jumps.push(doc, doc.selection(view.id).clone());
                     // Set last accessed doc if it is a different document
                     if doc.id != id {
                         view.add_to_history(view.doc);

helix-view/src/view.rs

@@ -5,9 +5,9 @@ use crate::{
 };
 use helix_core::{pos_at_visual_coords, visual_coords_at_pos, Position, RopeSlice, Selection};
 
-use std::fmt;
+use std::{cell::RefCell, fmt, rc::Rc};
 
-type Jump = (DocumentId, Selection);
+type Jump = (DocumentId, Rc<RefCell<Selection>>);
 
 #[derive(Debug, Clone)]
 pub struct JumpList {
@@ -23,7 +23,11 @@ impl JumpList {
         }
     }
 
-    pub fn push(&mut self, jump: Jump) {
+    pub fn push(&mut self, doc: &mut Document, selection: Selection) {
+        let selection = Rc::new(RefCell::new(selection));
+        let jump = (doc.id, selection.clone());
+        doc.push_jump_selection(selection);
+
         self.jumps.truncate(self.current);
         // don't push duplicates
         if self.jumps.last() != Some(&jump) {
@@ -45,8 +49,7 @@ impl JumpList {
     pub fn backward(&mut self, view_id: ViewId, doc: &mut Document, count: usize) -> Option<&Jump> {
         if let Some(current) = self.current.checked_sub(count) {
             if self.current == self.jumps.len() {
-                let jump = (doc.id(), doc.selection(view_id).clone());
-                self.push(jump);
+                self.push(doc, doc.selection(view_id).clone());
             }
             self.current = current;
             self.jumps.get(self.current)
@@ -126,7 +129,7 @@ impl View {
             doc,
             offset: Position::new(0, 0),
             area: Rect::default(), // will get calculated upon inserting into tree
-            jumps: JumpList::new((doc, Selection::point(0))), // TODO: use actual sel
+            jumps: JumpList::new((doc, Rc::new(RefCell::new(Selection::point(0))))),
             docs_access_history: Vec::new(),
             last_modified_docs: [None, None],
             object_selections: Vec::new(),