Highlight all search matches in document

References:
#4798

helix-term/src/commands.rs

@@ -1719,6 +1719,11 @@ fn search_impl(
     let text = doc.text().slice(..);
     let selection = doc.selection(view.id);
 
+    // Update search_matches, but only if search criteria has changed since
+    // last call to search_impl. If 'n' is being used to traverse matches,
+    // update will be skipped.
+    view.update_search_matches(contents, regex);
+
     // Get the right side of the primary block cursor for forward search, or the
     // grapheme before the start of the selection for reverse search.
     let start = match direction {
@@ -2324,6 +2329,12 @@ fn collapse_selection(cx: &mut Context) {
         Range::new(pos, pos)
     });
     doc.set_selection(view.id, selection);
+
+    // clear highlights on search matches
+    // but set search_matches.old to "" so that if 'n' is pressed
+    // to continue to traverse matches, highlights resume
+    view.search_matches.clear();
+    view.search_matches.old = Regex::new("").unwrap();
 }
 
 fn flip_selections(cx: &mut Context) {

helix-term/src/ui/editor.rs

@@ -145,6 +145,13 @@ impl EditorView {
             highlights = Box::new(syntax::merge(highlights, overlay_highlights));
         }
 
+        if !view.search_matches.matches.is_empty() {
+            highlights = match view.get_search_matches(theme) {
+                Some(match_highlights) => Box::new(syntax::merge(highlights, match_highlights)),
+                None => highlights,
+            };
+        }
+
         for diagnostic in Self::doc_diagnostics_highlights(doc, theme) {
             // Most of the `diagnostic` Vecs are empty most of the time. Skipping
             // a merge for any empty Vec saves a significant amount of work.
@@ -1207,6 +1214,9 @@ impl Component for EditorView {
                 let (view, doc) = current!(cx.editor);
                 view.ensure_cursor_in_view(doc, config.scrolloff);
 
+                // document has been alterred, clear search_matches
+                view.search_matches.clear();
+
                 // Store a history state if not in insert mode. Otherwise wait till we exit insert
                 // to include any edits to the paste in the history state.
                 if mode != Mode::Insert {
@@ -1356,6 +1366,14 @@ impl Component for EditorView {
             Self::render_bufferline(cx.editor, area.with_height(1), surface);
         }
 
+        {
+            let (view, doc) = current!(cx.editor);
+            if !doc.changes().is_empty() || doc.has_changed() {
+                // document has been alterred, clear search_matches
+                view.search_matches.clear();
+            }
+        }
+
         for (view, is_focused) in cx.editor.tree.views() {
             let doc = cx.editor.document(view.doc).unwrap();
             self.render_view(cx.editor, doc, view, area, surface, is_focused);

helix-view/src/document.rs

@@ -979,12 +979,24 @@ impl Document {
         self.earlier_later_impl(view, uk, false)
     }
 
+    pub fn has_changed(&self) -> bool {
+        if self.changes.is_empty() {
+            return false;
+        }
+
+        let new_changeset = ChangeSet::new(self.text());
+        self.changes != new_changeset
+    }
+
     /// Commit pending changes to history
     pub fn append_changes_to_history(&mut self, view: &mut View) {
         if self.changes.is_empty() {
             return;
         }
 
+        // doc has changed, so clear search_matches highlights
+        view.search_matches.clear();
+
         let new_changeset = ChangeSet::new(self.text());
         let changes = std::mem::replace(&mut self.changes, new_changeset);
         // Instead of doing this messy merge we could always commit, and based on transaction

helix-view/src/view.rs

@@ -4,11 +4,10 @@ use crate::{
     graphics::Rect,
     Align, Document, DocumentId, Theme, ViewId,
 };
-
 use helix_core::{
-    char_idx_at_visual_offset, doc_formatter::TextFormat, text_annotations::TextAnnotations,
-    visual_offset_from_anchor, visual_offset_from_block, Position, RopeSlice, Selection,
-    Transaction,
+    char_idx_at_visual_offset, doc_formatter::TextFormat, regex::Regex,
+    text_annotations::TextAnnotations, visual_offset_from_anchor, visual_offset_from_block,
+    Position, RopeSlice, Selection, Transaction,
 };
 
 use std::{
@@ -102,6 +101,28 @@ pub struct ViewPosition {
     pub vertical_offset: usize,
 }
 
+#[derive(Clone)]
+pub struct SearchMatches {
+    pub matches: Vec<(usize, usize)>,
+    pub new: Regex,
+    pub old: Regex,
+}
+
+impl SearchMatches {
+    pub fn clear(&mut self) {
+        self.matches.clear();
+    }
+
+    pub fn has_changed(&self, regex: &Regex) -> bool {
+        regex.as_str() != self.old.as_str()
+    }
+
+    pub fn update(&mut self, regex: &Regex) {
+        self.old = self.new.clone();
+        self.new = regex.clone();
+    }
+}
+
 #[derive(Clone)]
 pub struct View {
     pub id: ViewId,
@@ -125,6 +146,7 @@ pub struct View {
     /// mapping keeps track of the last applied history revision so that only new changes
     /// are applied.
     doc_revisions: HashMap<DocumentId, usize>,
+    pub search_matches: SearchMatches,
 }
 
 impl fmt::Debug for View {
@@ -154,6 +176,11 @@ impl View {
             object_selections: Vec::new(),
             gutters,
             doc_revisions: HashMap::new(),
+            search_matches: SearchMatches {
+                matches: Vec::new(),
+                new: Regex::new("").unwrap(),
+                old: Regex::new("").unwrap(),
+            },
         }
     }
 
@@ -576,6 +603,47 @@ impl View {
             self.apply(&transaction, doc);
         }
     }
+
+    pub fn get_backup_theme(&self, theme: &Theme) -> usize {
+        theme
+            .find_scope_index("ui.selection")
+            .expect("could not find `ui.selection` scope in the theme!")
+    }
+
+    pub fn get_search_matches(
+        &self,
+        theme: &Theme,
+    ) -> Option<Vec<(usize, std::ops::Range<usize>)>> {
+        // let selection_scope = match theme.find_scope_index("ui.selection.primary") {
+        let selection_scope = match theme.find_scope_index("ui.cursor.match") {
+            Some(theme) => theme,
+            None => self.get_backup_theme(theme),
+        };
+
+        let mut ret = Vec::new();
+        for (start, end) in &self.search_matches.matches {
+            ret.push((selection_scope, *start..*end));
+        }
+
+        if ret.is_empty() {
+            None
+        } else {
+            Some(ret)
+        }
+    }
+
+    pub fn update_search_matches(&mut self, contents: &str, regex: &Regex) {
+        // this is expensive. only update search matches if search criteria has changed
+        if self.search_matches.has_changed(regex) {
+            self.search_matches.update(regex);
+            self.search_matches.clear();
+            for one_match in self.search_matches.new.find_iter(contents) {
+                self.search_matches
+                    .matches
+                    .push((one_match.start(), one_match.end()));
+            }
+        }
+    }
 }
 
 #[cfg(test)]