fix: center LSP definition destinations in the viewport

src/editor.rs

@@ -8,6 +8,7 @@ use crate::plugin::{
 };
 use serde::Serialize;
 use std::borrow::Cow;
+use std::cell::Cell;
 use std::collections::{BTreeMap, HashMap, HashSet, VecDeque};
 use std::fmt;
 use std::fs::{self, OpenOptions};
@@ -1337,6 +1338,7 @@ struct ViewState {
     search_match: Option<SearchMatch>,
     command_line: String,
     caret_reveal_revision: u64,
+    lsp_center: Cell<Option<(u64, u64, Cursor)>>,
     insert_start: Option<Snapshot>,
     pending_edit: Option<EditRecipe>,
     visual_motions: Option<Vec<Motion>>,
@@ -1354,6 +1356,7 @@ impl ViewState {
             search_match: None,
             command_line: String::new(),
             caret_reveal_revision: 0,
+            lsp_center: Cell::new(None),
             insert_start: None,
             pending_edit: None,
             visual_motions: None,
@@ -3527,6 +3530,7 @@ impl Editor {
         target_range: Option<Utf16Range>,
     ) -> Result<(), String> {
         self.pending_lsp_navigation = None;
+        self.active.view.lsp_center.set(None);
         if path.as_os_str().is_empty() || path.to_string_lossy().chars().any(char::is_control) {
             return Err("Navigation path must be nonempty and contain no controls".into());
         }
@@ -3808,6 +3812,7 @@ impl Editor {
         diff.normalize_focus();
         diff.reveal_source_row(focus, row);
         self.place_navigation(position);
+        self.request_lsp_center();
         self.record_jump(source);
         Ok(())
     }
@@ -3829,6 +3834,7 @@ impl Editor {
             self.switch_buffer(id);
         }
         self.place_navigation(position);
+        self.request_lsp_center();
         self.record_jump(source);
     }
 
@@ -3933,7 +3939,26 @@ impl Editor {
         self.active.view.caret_reveal_revision
     }
 
+    fn request_lsp_center(&self) {
+        self.active.view.lsp_center.set(Some((
+            self.text_revision(),
+            self.caret_reveal_revision(),
+            self.cursor(),
+        )));
+    }
+
+    /// Consume only when the destination has a usable text viewport.
+    pub(crate) fn take_lsp_center(&self) -> bool {
+        self.active.view.lsp_center.take()
+            == Some((
+                self.text_revision(),
+                self.caret_reveal_revision(),
+                self.cursor(),
+            ))
+    }
+
     fn reveal_caret(&mut self) {
+        self.active.view.lsp_center.set(None);
         self.active.view.caret_reveal_revision =
             self.active.view.caret_reveal_revision.wrapping_add(1);
     }
@@ -5613,6 +5638,7 @@ impl Editor {
 
     pub fn handle(&mut self, input: Input) -> Option<Invocation> {
         self.pending_lsp_navigation = None;
+        self.active.view.lsp_center.set(None);
         // Normalize genuine terminal aliases before list and editing dispatch.
         let input = match input {
             Input::Ctrl(ch) => control_key(ch),