From 734f69ad725376d82b7ba436d8ee110180d09d3e Mon Sep 17 00:00:00 2001
From: DuBearte <130190089+DuBearte@users.noreply.github.com>
Date: Wed, 14 Oct 2026 20:20:21 -0400
Subject: [PATCH] Parameters: arrow keys move the cursor while renaming (#1248)

Fixes #1165.
---
 crates/ui-egui/src/params_dialog.rs     | 13 +++++++------
 crates/ui-egui/tests/parameter_enter.rs | 18 ++++++++++++++++++
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/crates/ui-egui/src/params_dialog.rs b/crates/ui-egui/src/params_dialog.rs
index a8abf159..2f2f030e 100644
--- a/crates/ui-egui/src/params_dialog.rs
+++ b/crates/ui-egui/src/params_dialog.rs
@@ -240,17 +240,18 @@ fn table(app: &mut SolveApp, ui: &mut egui::Ui, d: &mut ParamsDialog, rows: &[&R
                             d.error = app.run("parameters.rename", json!({"name": old, "new_name": new})).err();
                         }
                         d.renaming = None;
-                    } else {
+                    } else if !resp.has_focus() {
+                        // Only take focus once: requesting it every frame resets the text box's
+                        // focus lock, so arrow keys would move focus away and end the rename.
                         resp.request_focus();
                     }
                 }
                 _ => {
                     let name = if r.source == "user" { RichText::new(&r.name) } else { RichText::new(&r.name).color(t.text_dim) };
-                    if ui
-                        .add(egui::Label::new(name).sense(egui::Sense::click()))
-                        .on_hover_text(crate::i18n::tr_label("Double-click to rename"))
-                        .double_clicked()
-                    {
+                    let resp =
+                        ui.add(egui::Label::new(name).sense(egui::Sense::click())).on_hover_text(crate::i18n::tr_label("Double-click to rename"));
+                    crate::scenario::publish_handle(&format!("param:name:{}", r.name), resp.rect.center());
+                    if resp.double_clicked() {
                         d.renaming = Some((r.name.clone(), r.name.clone()));
                     }
                 }
diff --git a/crates/ui-egui/tests/parameter_enter.rs b/crates/ui-egui/tests/parameter_enter.rs
index 39dbf8de..92fe227f 100644
--- a/crates/ui-egui/tests/parameter_enter.rs
+++ b/crates/ui-egui/tests/parameter_enter.rs
@@ -106,3 +106,21 @@ fn parameter_enter_comment_uses_selected_unit_and_unrelated_focus_does_not_submi
     assert!(result["parameters"].as_array().unwrap().iter().any(|p| p["name"] == "length" && p["unit"] == "cm" && p["comment"] == "Overall length"));
     assert_eq!(h.app.session.undo.len(), undo + 1);
 }
+#[test]
+fn parameter_rename_arrow_keys_move_cursor_and_keep_editing() {
+    let mut h = open();
+    h.app.session.execute("parameters.add", &json!({"name":"width","expression":"10 mm"})).unwrap();
+    // Let the click that opened the dialog age, or egui counts the double-click as a triple.
+    h.frames(30);
+    h.run(&json!([{"click":{"handle":"param:name:width"},"double":true}])).unwrap();
+    h.frames(2);
+    let renaming = |h: &Harness| h.app.params.as_ref().unwrap().renaming.clone();
+    assert_eq!(renaming(&h), Some(("width".to_string(), "width".to_string())));
+    // Move the cursor to the start and type there; every arrow key keeps the rename open.
+    h.run(&json!([{"key":"ArrowLeft"}, {"key":"ArrowUp"}, {"key":"ArrowDown"}, {"key":"ArrowRight"}, {"key":"Home"}, {"text":"plate_"}])).unwrap();
+    assert_eq!(renaming(&h), Some(("width".to_string(), "plate_width".to_string())));
+    enter(&mut h, false);
+    assert_eq!(renaming(&h), None);
+    let result = h.app.session.execute("parameters.list", &json!({})).unwrap();
+    assert!(result["parameters"].as_array().unwrap().iter().any(|p| p["name"] == "plate_width"));
+}