feat: scroll viewports with mouse wheel without moving the caret

src/editor.rs

@@ -889,6 +889,7 @@ pub struct Editor {
     next_buffer_id: usize,
     jumps: VecDeque<JumpLocation>,
     jump_index: usize,
+    caret_reveal_revision: u64,
     command_line: String,
     clipboard: Vec<String>,
     clipboard_mode: ClipboardMode,
@@ -931,6 +932,7 @@ impl Editor {
             next_buffer_id: 2,
             jumps: VecDeque::new(),
             jump_index: 0,
+            caret_reveal_revision: 0,
             command_line: String::new(),
             clipboard: Vec::new(),
             clipboard_mode: ClipboardMode::System,
@@ -1329,6 +1331,7 @@ impl Editor {
     }
 
     fn place_navigation(&mut self, position: TextPosition) {
+        self.reveal_caret();
         self.park_source();
         self.active.mode = Mode::Normal;
         let row = position.row.min(self.active.lines.len() - 1);
@@ -1422,6 +1425,14 @@ impl Editor {
     pub fn cursor(&self) -> Cursor {
         self.active.targets[self.active.primary].active
     }
+    /// Navigation requests caret following even when its logical position stays unchanged.
+    pub(crate) fn caret_reveal_revision(&self) -> u64 {
+        self.caret_reveal_revision
+    }
+
+    fn reveal_caret(&mut self) {
+        self.caret_reveal_revision = self.caret_reveal_revision.wrapping_add(1);
+    }
     pub fn mode(&self) -> Mode {
         self.active.mode
     }
@@ -2580,6 +2591,7 @@ impl Editor {
     }
 
     fn seek_search(&mut self, forward: bool, count: usize) {
+        self.reveal_caret();
         let source = self.jump_location();
         self.active.search_match = None;
         if self.active.search_query.is_empty() {
@@ -2671,6 +2683,7 @@ impl Editor {
     }
 
     fn traverse_jumps(&mut self, forward: bool, count: usize) {
+        self.reveal_caret();
         let departure = self.jump_location();
         let mut destination = departure;
         let mut index = self.jump_index;
@@ -2752,6 +2765,7 @@ impl Editor {
 
     fn switch_buffer(&mut self, id: usize) {
         if id == self.active.id {
+            self.reveal_caret();
             self.park_source();
             self.show_buffer();
         } else if let Some(buffer) = self.parked.remove(&id) {
@@ -3981,6 +3995,7 @@ impl Editor {
     }
 
     fn move_targets(&mut self, action: Action, count: usize) {
+        self.reveal_caret();
         for index in 0..self.active.targets.len() {
             let mut cursor = self.active.targets[index].active;
             match action {