Make the Merge & Center ribbon label part of its split button

Fixes #2920

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

crates/ui-egui/src/ribbon/home.rs

@@ -5,7 +5,7 @@ use super::controls::{
 use super::galleries::{cell_style_gallery, table_gallery};
 use super::{
     HAlign, Icon, Key, Modifiers, Rect, SheetApp, Style, Tokens, Ui, VAlign, big_button, color_palette, icon_button, json, keytip_table,
-    small_button, split_button, theme, toggle_button, vec2,
+    small_button, small_split_button, split_button, theme, toggle_button, vec2,
 };
 
 /// The Accounting Number Format dropdown: label and the code Excel applies for that symbol.
@@ -292,12 +292,11 @@ pub(super) fn home(app: &mut SheetApp, ui: &mut Ui) {
             if __k.clicked() {
                 act(app, "home.increaseIndent", json!({}));
             }
-            let (m, ma) = split_button(ui, Icon::Merge, None, "Merge & Center");
+            let (m, ma) = small_split_button(ui, Icon::Merge, "Merge & Center", "Merge & Center");
             control_keytip(app, ui, &ma, "home.mergeCenter");
-            if m {
+            if m.clicked() {
                 act(app, "home.mergeCenter", json!({}));
             }
-            ui.label(egui::RichText::new(app.ui.language.tr("Merge & Center")).font(theme::ui_font(12.5)));
             egui::Popup::menu(&ma).show(|ui| {
                 menu_items(
                     app,

crates/ui-egui/tests/it/main.rs

@@ -63,6 +63,7 @@ mod keytips_generated;
 mod macro_editor;
 mod macros_ui;
 mod menu_hover;
+mod merge_center_label;
 mod merged_cells;
 mod more_colors;
 mod native_print;

crates/ui-egui/tests/it/merge_center_label.rs

@@ -0,0 +1,51 @@
+//! Home › Merge & Center is a split button: clicking its text label runs `home.mergeCenter`, like
+//! its icon does.
+
+use egui::{Event, Shape, vec2};
+use gridcraft_engine::Session;
+use gridcraft_ui_egui::SheetApp;
+use gridcraft_ui_egui::i18n::Language;
+use serde_json::json;
+
+#[test]
+fn clicking_the_label_merges_and_centers() {
+    for language in [Language::En, Language::De] {
+        click_label(language);
+    }
+}
+
+fn click_label(language: Language) {
+    let label = language.tr("Merge & Center");
+    let mut s = Session::new();
+    s.new_workbook();
+    s.execute("selection.set", json!({"range": "A1:B1"})).unwrap();
+    let mut h = crate::common::builder().with_size(vec2(1400.0, 800.0)).build_ui_state(
+        |ui, app: &mut SheetApp| {
+            app.logic(ui.ctx());
+            app.ui(ui);
+        },
+        {
+            let mut app = crate::common::app(s);
+            app.ui.language = language;
+            app
+        },
+    );
+    h.run_steps(4);
+    let at = h
+        .output()
+        .shapes
+        .iter()
+        .find_map(|s| match &s.shape {
+            Shape::Text(t) if t.galley.job.text == label => Some(t.pos + t.galley.size() / 2.0),
+            _ => None,
+        })
+        .unwrap_or_else(|| panic!("the Home tab shows {label}"));
+    h.input_mut().events.push(Event::PointerMoved(at));
+    h.run_steps(2);
+    for pressed in [true, false] {
+        h.input_mut().events.push(Event::PointerButton { pos: at, button: egui::PointerButton::Primary, pressed, modifiers: egui::Modifiers::NONE });
+        h.run_steps(2);
+    }
+    h.run_steps(2);
+    assert!(h.state().session.journal.iter().any(|(id, _)| id == "home.mergeCenter"), "{label}");
+}