search_impl will only align cursor center when it isn't in view

Author: cossonleo

helix-term/src/commands.rs

@@ -1170,7 +1170,14 @@ fn split_selection_on_newline(cx: &mut Context) {
     doc.set_selection(view.id, selection);
 }
 
-fn search_impl(doc: &mut Document, view: &mut View, contents: &str, regex: &Regex, extend: bool) {
+fn search_impl(
+    doc: &mut Document,
+    view: &mut View,
+    contents: &str,
+    regex: &Regex,
+    extend: bool,
+    scrolloff: usize,
+) {
     let text = doc.text().slice(..);
     let selection = doc.selection(view.id);
 
@@ -1205,7 +1212,11 @@ fn search_impl(doc: &mut Document, view: &mut View, contents: &str, regex: &Rege
         };
 
         doc.set_selection(view.id, selection);
-        align_view(doc, view, Align::Center);
+        if view.is_cursor_in_view(doc, 0) {
+            view.ensure_cursor_in_view(doc, scrolloff);
+        } else {
+            align_view(doc, view, Align::Center)
+        }
     };
 }
 
@@ -1221,6 +1232,8 @@ fn search_completions(cx: &mut Context, reg: Option<char>) -> Vec<String> {
 // TODO: use one function for search vs extend
 fn search(cx: &mut Context) {
     let reg = cx.register.unwrap_or('/');
+    let scrolloff = cx.editor.config.scrolloff;
+
     let (_, doc) = current!(cx.editor);
 
     // TODO: could probably share with select_on_matches?
@@ -1245,14 +1258,15 @@ fn search(cx: &mut Context) {
             if event != PromptEvent::Update {
                 return;
             }
-            search_impl(doc, view, &contents, &regex, false);
+            search_impl(doc, view, &contents, &regex, false, scrolloff);
         },
     );
 
     cx.push_layer(Box::new(prompt));
 }
 
 fn search_next_impl(cx: &mut Context, extend: bool) {
+    let scrolloff = cx.editor.config.scrolloff;
     let (view, doc) = current!(cx.editor);
     let registers = &cx.editor.registers;
     if let Some(query) = registers.read('/') {
@@ -1267,7 +1281,7 @@ fn search_next_impl(cx: &mut Context, extend: bool) {
             .case_insensitive(case_insensitive)
             .build()
         {
-            search_impl(doc, view, &contents, &regex, extend);
+            search_impl(doc, view, &contents, &regex, extend, scrolloff);
         } else {
             // get around warning `mutable_borrow_reservation_conflict`
             // which will be a hard error in the future

helix-view/src/view.rs

@@ -121,6 +121,35 @@ impl View {
         }
     }
 
+    pub fn is_cursor_in_view(&mut self, doc: &Document, scrolloff: usize) -> bool {
+        let cursor = doc
+            .selection(self.id)
+            .primary()
+            .cursor(doc.text().slice(..));
+
+        let Position { col, row: line } =
+            visual_coords_at_pos(doc.text().slice(..), cursor, doc.tab_width());
+
+        let inner_area = self.inner_area();
+        let last_line = (self.offset.row + inner_area.height as usize).saturating_sub(1);
+
+        // - 1 so we have at least one gap in the middle.
+        // a height of 6 with padding of 3 on each side will keep shifting the view back and forth
+        // as we type
+        let scrolloff = scrolloff.min(inner_area.height.saturating_sub(1) as usize / 2);
+
+        let last_col = self.offset.col + inner_area.width.saturating_sub(1) as usize;
+
+        if (line > last_line.saturating_sub(scrolloff)) || (line < self.offset.row + scrolloff) {
+            return false;
+        }
+
+        if (col > last_col.saturating_sub(scrolloff)) || (col < self.offset.col + scrolloff) {
+            return false;
+        }
+        true
+    }
+
     /// Calculates the last visible line on screen
     #[inline]
     pub fn last_line(&self, doc: &Document) -> usize {