Fix #746: document tabs that don't fit are reached from a » list

With more documents open than the tab strip holds, the tabs past its
right edge were cut off with no way to reach them. As in Illustrator, a
» button at the strip's right end now lists every open document (the
active one checked) and picks one, and the strip always shows the active
tab, starting later when it has to.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

crates/ui-egui/src/chrome.rs

@@ -323,26 +323,55 @@ fn tab_title(d: &vectorcraft_engine::DocState, zoom: f64, outline: bool) -> Stri
 /// Linux and the web).
 const CLOSE_BEFORE_TITLE: bool = cfg!(target_os = "macos");
 
+/// The first of tabs `widths` wide that the strip shows in `room`: the first one, or a later one so
+/// that the `active` tab fits.
+fn first_tab_shown(widths: &[f32], active: Option<usize>, room: f32) -> usize {
+    let Some(a) = active else { return 0 };
+    let mut first = 0;
+    while first < a && widths.get(first..=a).map_or(0.0, |w| w.iter().sum::<f32>()) > room {
+        first += 1;
+    }
+    first
+}
+
 /// Document tab strip: "Name* @ 66.67% (RGB/Preview)". User Interface › Large Tabs makes the tabs
-/// taller, with larger titles.
+/// taller, with larger titles. Tabs that don't fit are reached from a » button at the strip's
+/// right end, which lists every open document, and the active tab is always in view (#746).
 pub fn doc_tabs(app: &mut VectorcraftApp, ui: &mut Ui) {
+    /// The width of the » button.
+    const MORE: f32 = 30.0;
     let t = Tokens::get(ui.ctx());
     let (height, title_size) = if app.session.prefs.large_tabs { (44.0, 14.0) } else { (35.0, 12.5) };
     let (strip, _) = ui.allocate_exact_size(vec2(ui.available_width(), height), Sense::hover());
     ui.painter().rect_filled(strip, 0.0, t.tab_strip);
     ui.painter().line_segment([strip.left_bottom(), strip.right_bottom()], Stroke::new(1.0, t.border));
+    // On the Home screen no tab is the current one.
+    let active = app.session.active_index().filter(|_| app.ui.home.is_none());
+    let tabs: Vec<(String, std::sync::Arc<egui::Galley>)> = app
+        .session
+        .documents()
+        .iter()
+        .enumerate()
+        .map(|(i, d)| {
+            let zoom = app.views.get(i).map(|v| v.zoom).unwrap_or(1.0);
+            let title = tab_title(d, zoom, app.ui.view.outline);
+            let color = if Some(i) == active { t.text_strong } else { t.text_dim };
+            (title.clone(), ui.painter().layout_no_wrap(title, theme::semibold(title_size), color))
+        })
+        .collect();
+    let widths: Vec<f32> = tabs.iter().map(|(_, g)| g.size().x + 50.0).collect();
+    let overflow = widths.iter().sum::<f32>() > strip.width();
+    let room = strip.width() - if overflow { MORE } else { 0.0 };
+    let first = if overflow { first_tab_shown(&widths, active, room) } else { 0 };
     let mut x = strip.left();
     let mut activate = None;
     let mut close = None;
-    let active = app.session.active_index();
-    for (i, d) in app.session.documents().iter().enumerate() {
-        let zoom = app.views.get(i).map(|v| v.zoom).unwrap_or(1.0);
-        let title = tab_title(d, zoom, app.ui.view.outline);
-        // On the Home screen no tab is the current one.
-        let is_active = Some(i) == active && app.ui.home.is_none();
-        let galley = ui.painter().layout_no_wrap(title, theme::semibold(title_size), if is_active { t.text_strong } else { t.text_dim });
-        let w = galley.size().x + 50.0;
-        let r = egui::Rect::from_min_size(egui::pos2(x, strip.top()), vec2(w, strip.height() - 1.0));
+    for (i, ((_, galley), w)) in tabs.iter().zip(&widths).enumerate().skip(first) {
+        if x + w > strip.left() + room && Some(i) != active {
+            break;
+        }
+        let is_active = Some(i) == active;
+        let r = egui::Rect::from_min_size(egui::pos2(x, strip.top()), vec2(*w, strip.height() - 1.0));
         let resp = ui.interact(r, ui.id().with(("tab", i)), Sense::click());
         if is_active {
             ui.painter().rect_filled(r, 0.0, t.panel);
@@ -356,7 +385,7 @@ pub fn doc_tabs(app: &mut VectorcraftApp, ui: &mut Ui) {
         let xr = egui::Rect::from_center_size(egui::pos2(x_center, r.center().y), vec2(12.0, 12.0));
         let xresp = ui.interact(xr.expand(3.0), ui.id().with(("tabx", i)), Sense::click());
         icons::paint(ui, "x", xr, if xresp.hovered() { t.text_strong } else { t.text });
-        ui.painter().galley(egui::pos2(title_left, r.center().y - galley.size().y / 2.0), galley, t.text);
+        ui.painter().galley(egui::pos2(title_left, r.center().y - galley.size().y / 2.0), galley.clone(), t.text);
         if xresp.clicked() {
             close = Some(i);
         } else if resp.clicked() {
@@ -364,6 +393,22 @@ pub fn doc_tabs(app: &mut VectorcraftApp, ui: &mut Ui) {
         }
         x += w;
     }
+    // The » button: every open document, the active one checked.
+    if overflow {
+        let more = egui::Rect::from_min_max(egui::pos2(strip.right() - MORE, strip.top()), egui::pos2(strip.right(), strip.bottom() - 1.0));
+        let resp = ui.interact(more, ui.id().with("tabs-more"), Sense::click());
+        ui.painter().rect_filled(more, 0.0, if resp.hovered() { t.hover.gamma_multiply(0.4) } else { t.tab_strip });
+        icons::paint(ui, "chevrons-right", egui::Rect::from_center_size(more.center(), vec2(14.0, 14.0)), t.text);
+        let resp = resp.on_hover_text(tl!("Show all open documents"));
+        egui::Popup::menu(&resp).show(|ui| {
+            for (i, (title, _)) in tabs.iter().enumerate() {
+                if widgets::menu_item_name(ui, title, true, Some(i) == active) {
+                    activate = Some(i);
+                    ui.close();
+                }
+            }
+        });
+    }
     if let Some(i) = close {
         if let Err(e) = crate::unsaved::close(app, i) {
             app.status(e);
@@ -764,6 +809,16 @@ pub fn hint_bar(app: &mut VectorcraftApp, ui: &mut Ui) {
 
 #[cfg(test)]
 mod tests {
+
+    /// With more tabs than fit, the strip starts late enough to show the active one (#746).
+    #[test]
+    fn the_active_tab_stays_in_view() {
+        let widths = [100.0; 10];
+        assert_eq!(super::first_tab_shown(&widths, Some(2), 350.0), 0, "it fits from the start");
+        assert_eq!(super::first_tab_shown(&widths, Some(9), 350.0), 7, "the last three tabs shown");
+        assert_eq!(super::first_tab_shown(&widths, None, 350.0), 0);
+        assert_eq!(super::first_tab_shown(&widths, Some(4), 50.0), 4, "a tab wider than the room still shows");
+    }
     use serde_json::json;
     use vectorcraft_engine::Session;
 

crates/ui-egui/src/i18n/es.tsv

@@ -2648,6 +2648,7 @@
 	Swatch Tiles	Mosaicos de muestras
 	Swatches	Muestras
 	Switch workspace	Cambiar espacio de trabajo
+	Show all open documents	Mostrar todos los documentos abiertos
 	Symbol Instance	Instancia de símbolo
 	Symbol Libraries	Bibliotecas de símbolos
 	Symbol Libraries (on the roadmap)	Bibliotecas de símbolos (en la hoja de ruta)

crates/ui-egui/src/i18n/fr.tsv

@@ -2645,6 +2645,7 @@
 	Swatch Tiles	Carreaux de nuances
 	Swatches	Nuancier
 	Switch workspace	Changer d’espace de travail
+	Show all open documents	Afficher tous les documents ouverts
 	Symbol Instance	Occurrence de symbole
 	Symbol Libraries	Bibliothèques de symboles
 	Symbol Libraries (on the roadmap)	Bibliothèques de symboles (prévu dans la feuille de route)

crates/ui-egui/src/i18n/it.tsv

@@ -2648,6 +2648,7 @@
 	Swatch Tiles	Riquadri campioni
 	Swatches	Campioni
 	Switch workspace	Cambia area di lavoro
+	Show all open documents	Mostra tutti i documenti aperti
 	Symbol Instance	Istanza di simbolo
 	Symbol Libraries	Librerie simboli
 	Symbol Libraries (on the roadmap)	Librerie simboli (in programma)

crates/ui-egui/src/i18n/ja.tsv

@@ -2422,6 +2422,7 @@
 	Swatch Options…	スウォッチオプション…
 	Swatch Tiles	スウォッチタイル
 	Switch workspace	ワークスペースを切り替え
+	Show all open documents	開いているすべてのドキュメントを表示
 	Symbol Libraries (on the roadmap)	シンボルライブラリ (今後対応予定)
 	Symbol Screener Tool	シンボルスクリーナーツール
 	Symbol Scruncher Tool	シンボルスクランチャーツール

crates/ui-egui/src/i18n/ru.tsv

@@ -2644,6 +2644,7 @@
 	Swatch Tiles	Плитки образцов
 	Swatches	Образцы
 	Switch workspace	Переключить рабочую среду
+	Show all open documents	Показать все открытые документы
 	Symbol Instance	Экземпляр символа
 	Symbol Libraries	Библиотеки символов
 	Symbol Libraries (on the roadmap)	Библиотеки символов (в плане развития)

crates/ui-egui/src/i18n/zh-hans.tsv

@@ -2565,6 +2565,7 @@
 	Swatch Tiles	色板拼贴
 	Swatches	色板
 	Switch workspace	切换工作区
+	Show all open documents	显示所有打开的文档
 	Symbol Instance	符号实例
 	Symbol Libraries	符号库
 	Symbol Libraries (on the roadmap)	符号库 (已列入路线图)

crates/ui-egui/src/i18n/zh-hant.tsv

@@ -2651,6 +2651,7 @@
 	Swatch Tiles	色票拼貼
 	Swatches	色票
 	Switch workspace	切換工作區
+	Show all open documents	顯示所有開啟的文件
 	Symbol Instance	符號範例
 	Symbol Libraries	符號資料庫
 	Symbol Libraries (on the roadmap)	符號資料庫 (已列入路線圖)