Keep the selection when smart selection finds nothing (#2235)

* Keep the selection when smart selection finds nothing

Select Subject and Object Selection run heuristics that often miss on busy
photos. In Replace mode an empty result cleared the selection, so the Select
Subject button looked dead and even destroyed existing work. apply() now
preserves the selection and reports changed:false in every mode.

The UI also answers visibly instead of staying silent: empty smart-selection
results set an info status suggesting what to try next, and a click with
Object Selection falls back to a Quick Selection dab at the brush size
instead of doing nothing.

* Translate the smart-selection status messages; drop needless borrows (clippy)

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

---------

Co-authored-by: Brandon Thomas <echelon@gmail.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/smartselect_cmds.rs

@@ -60,8 +60,12 @@ pub(crate) fn with_doc_sampler<R>(doc: &Document, layer: Option<LayerId>, all_la
 }
 
 /// Stores `region` combined with the current selection by `m` as one history step.
+/// Finding nothing never destroys work: the selection (and history) is left alone and the
+/// caller gets `changed: false`, whatever the mode. (Select Subject and Object Selection run
+/// heuristics that often find nothing on busy photos; clearing the selection then looks like
+/// a dead button.)
 fn apply(s: &mut Session, label: &str, region: Option<Region>, m: SelectionMode) -> Result<Value> {
-    if region.is_none() && matches!(m, SelectionMode::Add | SelectionMode::Subtract) {
+    if region.is_none() {
         // Nothing found: leave the selection (and history) alone.
         let selected = s.active().ok_or(EngineError::NoDocument)?.doc.selection.is_some();
         return Ok(json!({ "selected": selected, "changed": false }));
@@ -388,6 +392,27 @@ mod tests {
         assert!(cov(&s, 10, 10) >= 0.5 && cov(&s, 100, 50) < 0.5);
     }
 
+    #[test]
+    fn empty_result_keeps_the_selection_in_every_mode() {
+        // Finding nothing must never wipe the selection, whatever the mode: Select Subject
+        // and Object Selection run heuristics that often miss on busy photos, and a missed
+        // Quick Selection dab must not destroy the work either.
+        for m in ["add", "subtract", "replace"] {
+            let mut s = two_regions(8);
+            s.execute("select.all", json!({})).unwrap();
+            let r = s.execute("select.quick", json!({"points": [[-5000, -5000]], "size": 8, "mode": m})).unwrap();
+            assert_eq!(r["changed"], false, "mode {m}");
+            assert_eq!(r["selected"], true, "mode {m}");
+            assert!(cov(&s, 10, 50) >= 0.99, "mode {m}: Select All survived an empty result");
+        }
+        // Select Subject on a flat field finds nothing and keeps the selection too.
+        let mut s = session_with(140, 100, 8, |_, _| [0.5, 0.5, 0.5]);
+        s.execute("select.all", json!({})).unwrap();
+        let r = s.execute("select.subject", json!({})).unwrap();
+        assert_eq!(r["changed"], false);
+        assert!(cov(&s, 10, 10) >= 0.99);
+    }
+
     #[test]
     fn object_selection_disc() {
         for depth in [8, 16, 32] {

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

@@ -2356,3 +2356,7 @@ fontWeight	Italic	Kurzíva
 	XOR	XOR
 	Color Burn (Paint.NET)	Ztmavit barvy (Paint.NET)
 	Color Dodge (Paint.NET)	Zesvětlit barvy (Paint.NET)
+	No subject found — try Object Selection or the Lasso	Nebyl nalezen žádný objekt — zkuste Výběr objektu nebo Laso
+	Quick Selection found nothing there	Rychlý výběr zde nic nenašel
+	Object Selection found nothing there — try a tighter rectangle	Výběr objektu zde nic nenašel — zkuste těsnější obdélník
+	No subject found — try a rectangle around the object	Nebyl nalezen žádný objekt — zkuste obdélník kolem objektu

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

@@ -2395,3 +2395,7 @@ fontWeight	Italic	Kursiv
 	XOR	XOR
 	Color Burn (Paint.NET)	Farbig nachbelichten (Paint.NET)
 	Color Dodge (Paint.NET)	Farbig abwedeln (Paint.NET)
+	No subject found — try Object Selection or the Lasso	Kein Motiv gefunden — versuchen Sie das Objektauswahlwerkzeug oder das Lasso
+	Quick Selection found nothing there	Die Schnellauswahl hat dort nichts gefunden
+	Object Selection found nothing there — try a tighter rectangle	Die Objektauswahl hat dort nichts gefunden — versuchen Sie ein engeres Rechteck
+	No subject found — try a rectangle around the object	Kein Motiv gefunden — versuchen Sie ein Rechteck um das Objekt

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

@@ -3467,3 +3467,7 @@ fontWeight	Thin	Πολύ λεπτά
 	XOR	XOR
 	Color Burn (Paint.NET)	Κάψιμο χρώματος (Paint.NET)
 	Color Dodge (Paint.NET)	Φωτισμός χρώματος (Paint.NET)
+	No subject found — try Object Selection or the Lasso	Δεν βρέθηκε θέμα — δοκιμάστε την Επιλογή αντικειμένου ή το Λάσο
+	Quick Selection found nothing there	Η Γρήγορη επιλογή δεν βρήκε τίποτα εκεί
+	Object Selection found nothing there — try a tighter rectangle	Η Επιλογή αντικειμένου δεν βρήκε τίποτα εκεί — δοκιμάστε ένα πιο στενό ορθογώνιο
+	No subject found — try a rectangle around the object	Δεν βρέθηκε θέμα — δοκιμάστε ένα ορθογώνιο γύρω από το αντικείμενο

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

@@ -2424,3 +2424,7 @@ fontWeight	Italic	Cursiva
 	XOR	XOR
 	Color Burn (Paint.NET)	Sobreexponer color (Paint.NET)
 	Color Dodge (Paint.NET)	Aclarar color (Paint.NET)
+	No subject found — try Object Selection or the Lasso	No se encontró ningún sujeto — pruebe Selección de objeto o el Lazo
+	Quick Selection found nothing there	Selección rápida no encontró nada ahí
+	Object Selection found nothing there — try a tighter rectangle	Selección de objeto no encontró nada ahí — pruebe un rectángulo más ajustado
+	No subject found — try a rectangle around the object	No se encontró ningún sujeto — pruebe un rectángulo alrededor del objeto

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

@@ -2777,3 +2777,7 @@ fontWeight	Italic	Italique
 	XOR	XOR
 	Color Burn (Paint.NET)	Densité couleur + (Paint.NET)
 	Color Dodge (Paint.NET)	Densité couleur − (Paint.NET)
+	No subject found — try Object Selection or the Lasso	Aucun sujet trouvé — essayez la Sélection d'objet ou le Lasso
+	Quick Selection found nothing there	La Sélection rapide n'a rien trouvé à cet endroit
+	Object Selection found nothing there — try a tighter rectangle	La Sélection d'objet n'a rien trouvé à cet endroit — essayez un rectangle plus serré
+	No subject found — try a rectangle around the object	Aucun sujet trouvé — essayez un rectangle autour de l'objet

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

@@ -2764,3 +2764,7 @@ fontWeight	Italic	Miring
 	XOR	XOR
 	Color Burn (Paint.NET)	Color Burn (Paint.NET)
 	Color Dodge (Paint.NET)	Color Dodge (Paint.NET)
+	No subject found — try Object Selection or the Lasso	Subjek tidak ditemukan — coba Seleksi Objek atau Laso
+	Quick Selection found nothing there	Seleksi Cepat tidak menemukan apa pun di sana
+	Object Selection found nothing there — try a tighter rectangle	Seleksi Objek tidak menemukan apa pun di sana — coba persegi panjang yang lebih rapat
+	No subject found — try a rectangle around the object	Subjek tidak ditemukan — coba persegi panjang di sekitar objek

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

@@ -2426,3 +2426,7 @@ fontWeight	Italic	Corsivo
 	XOR	XOR
 	Color Burn (Paint.NET)	Colore brucia (Paint.NET)
 	Color Dodge (Paint.NET)	Colore scherma (Paint.NET)
+	No subject found — try Object Selection or the Lasso	Nessun soggetto trovato — prova Selezione oggetto o il Lazo
+	Quick Selection found nothing there	Selezione rapida non ha trovato nulla lì
+	Object Selection found nothing there — try a tighter rectangle	Selezione oggetto non ha trovato nulla lì — prova un rettangolo più stretto
+	No subject found — try a rectangle around the object	Nessun soggetto trovato — prova un rettangolo attorno all'oggetto

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

@@ -3380,3 +3380,7 @@ fontWeight	Italic	斜体
 	XOR	XOR
 	Color Burn (Paint.NET)	焼き込みカラー (Paint.NET)
 	Color Dodge (Paint.NET)	覆い焼きカラー (Paint.NET)
+	No subject found — try Object Selection or the Lasso	被写体が見つかりません — オブジェクト選択ツールまたはなげなわツールを試してください
+	Quick Selection found nothing there	クイック選択ではそこに何も見つかりませんでした
+	Object Selection found nothing there — try a tighter rectangle	オブジェクト選択ではそこに何も見つかりませんでした — より狭い長方形で試してください
+	No subject found — try a rectangle around the object	被写体が見つかりません — オブジェクトを囲む長方形を試してください

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

@@ -2935,3 +2935,7 @@ fontWeight	Italic	기울임
 	XOR	XOR
 	Color Burn (Paint.NET)	색상 번 (Paint.NET)
 	Color Dodge (Paint.NET)	색상 닷지 (Paint.NET)
+	No subject found — try Object Selection or the Lasso	피사체를 찾을 수 없습니다 — 개체 선택 또는 올가미를 사용해 보세요
+	Quick Selection found nothing there	빠른 선택으로 해당 위치에서 아무것도 찾지 못했습니다
+	Object Selection found nothing there — try a tighter rectangle	개체 선택으로 해당 위치에서 아무것도 찾지 못했습니다 — 더 좁은 사각형을 사용해 보세요
+	No subject found — try a rectangle around the object	피사체를 찾을 수 없습니다 — 개체 주위에 사각형을 그려 보세요

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

@@ -3539,3 +3539,7 @@ cameraRaw	Whites	Witten
 	Color Dodge (Paint.NET)	Kleur tegenhouden (Paint.NET)
 	Pro Medium	Pro Medium
 	Studio Light	Studio Light
+	No subject found — try Object Selection or the Lasso	Geen onderwerp gevonden — probeer Objectselectie of de Lasso
+	Quick Selection found nothing there	Snelle selectie heeft daar niets gevonden
+	Object Selection found nothing there — try a tighter rectangle	Objectselectie heeft daar niets gevonden — probeer een krappere rechthoek
+	No subject found — try a rectangle around the object	Geen onderwerp gevonden — probeer een rechthoek rond het object

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

@@ -3379,3 +3379,7 @@ cameraRaw	Roughness	Chropowatość
 	XOR	XOR
 	Color Burn (Paint.NET)	Wypalanie koloru (Paint.NET)
 	Color Dodge (Paint.NET)	Rozjaśnianie koloru (Paint.NET)
+	No subject found — try Object Selection or the Lasso	Nie znaleziono obiektu — spróbuj Zaznaczania obiektu lub Lassa
+	Quick Selection found nothing there	Szybkie zaznaczanie nic tam nie znalazło
+	Object Selection found nothing there — try a tighter rectangle	Zaznaczanie obiektu nic tam nie znalazło — spróbuj ciaśniejszego prostokąta
+	No subject found — try a rectangle around the object	Nie znaleziono obiektu — spróbuj prostokąta wokół obiektu

crates/ui-egui/src/i18n/pt-br.tsv

@@ -2785,3 +2785,7 @@ fontWeight	Italic	Itálico
 	XOR	XOR
 	Color Burn (Paint.NET)	Superexposição de cores (Paint.NET)
 	Color Dodge (Paint.NET)	Subexposição de cores (Paint.NET)
+	No subject found — try Object Selection or the Lasso	Nenhum assunto encontrado — tente Seleção de objeto ou o Laço
+	Quick Selection found nothing there	A Seleção rápida não encontrou nada ali
+	Object Selection found nothing there — try a tighter rectangle	A Seleção de objeto não encontrou nada ali — tente um retângulo mais justo
+	No subject found — try a rectangle around the object	Nenhum assunto encontrado — tente um retângulo ao redor do objeto

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

@@ -2631,3 +2631,7 @@ fontWeight	Italic	Курсив
 	XOR	XOR
 	Color Burn (Paint.NET)	Затемнение основы (Paint.NET)
 	Color Dodge (Paint.NET)	Осветление основы (Paint.NET)
+	No subject found — try Object Selection or the Lasso	Объект не найден — попробуйте «Выделение объектов» или «Лассо»
+	Quick Selection found nothing there	Быстрое выделение ничего здесь не нашло
+	Object Selection found nothing there — try a tighter rectangle	Выделение объектов ничего здесь не нашло — попробуйте более узкий прямоугольник
+	No subject found — try a rectangle around the object	Объект не найден — попробуйте прямоугольник вокруг объекта

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

@@ -3466,3 +3466,7 @@ cameraRaw	Masking	Маскування
 	Color Dodge (Paint.NET)	Освітлення основи (Paint.NET)
 	Pro Medium	Pro Medium
 	Studio Light	Studio Light
+	No subject found — try Object Selection or the Lasso	Об'єкт не знайдено — спробуйте «Виділення об'єктів» або «Ласо»
+	Quick Selection found nothing there	Швидке виділення нічого тут не знайшло
+	Object Selection found nothing there — try a tighter rectangle	Виділення об'єктів нічого тут не знайшло — спробуйте вужчий прямокутник
+	No subject found — try a rectangle around the object	Об'єкт не знайдено — спробуйте прямокутник навколо об'єкта

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

@@ -2364,3 +2364,7 @@ fontWeight	Italic	斜体
 	XOR	XOR
 	Color Burn (Paint.NET)	颜色加深 (Paint.NET)
 	Color Dodge (Paint.NET)	颜色减淡 (Paint.NET)
+	No subject found — try Object Selection or the Lasso	未找到主体 — 请尝试对象选择工具或套索工具
+	Quick Selection found nothing there	快速选择在该处未找到任何内容
+	Object Selection found nothing there — try a tighter rectangle	对象选择在该处未找到任何内容 — 请尝试更紧凑的矩形
+	No subject found — try a rectangle around the object	未找到主体 — 请尝试在对象周围绘制矩形

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

@@ -2333,3 +2333,7 @@ fontWeight	Italic	斜體
 	XOR	XOR
 	Color Burn (Paint.NET)	加深顏色 (Paint.NET)
 	Color Dodge (Paint.NET)	加亮顏色 (Paint.NET)
+	No subject found — try Object Selection or the Lasso	找不到主體 — 請嘗試物件選取工具或套索工具
+	Quick Selection found nothing there	快速選取在該處找不到任何內容
+	Object Selection found nothing there — try a tighter rectangle	物件選取在該處找不到任何內容 — 請嘗試更緊密的矩形
+	No subject found — try a rectangle around the object	找不到主體 — 請嘗試在物件周圍繪製矩形

crates/ui-egui/src/panels.rs

@@ -1009,7 +1009,8 @@ pub fn options_bar(app: &mut PhotocraftApp, ui: &mut egui::Ui) {
                         widgets::checkbox(ui, &mut app.ui.tool_options.sample_all_layers, tl!("Sample All Layers"));
                         widgets::vline(ui, 22.0);
                         if widgets::secondary_button(ui, tl!("Select Subject"), 0.0).clicked() {
-                            let _ = app.run("select.subject", json!({}));
+                            let r = app.run("select.subject", json!({}));
+                            crate::retouch_ui::report_smart_result(app, r, tl!("No subject found — try Object Selection or the Lasso"));
                         }
                         if widgets::secondary_button(ui, tl!("Select and Mask…"), 0.0).clicked() {
                             let _ = crate::menus::invoke(app, ui.ctx(), "select.selectAndMask", json!({}));

crates/ui-egui/src/retouch_ui.rs

@@ -103,8 +103,9 @@ pub fn finish_stroke(app: &mut PhotocraftApp, tool: Tool, points: &[[f64; 3]], m
             let size = app.session.tools.brush.size;
             let mode = if mods.alt { "subtract" } else { "add" };
             let xy: Vec<[f64; 2]> = points.iter().map(|q| [q[0], q[1]]).collect();
-            let _ = app
-                .run("select.quick", json!({"points": xy, "size": size, "mode": mode, "enhanceEdge": o.enhance_edge, "sampleAllLayers": o.sample_all_layers}));
+            let (sample_all, enhance) = (o.sample_all_layers, o.enhance_edge);
+            let r = app.run("select.quick", json!({"points": xy, "size": size, "mode": mode, "enhanceEdge": enhance, "sampleAllLayers": sample_all}));
+            report_smart_result(app, r, tl!("Quick Selection found nothing there"));
             return true;
         }
         _ => return false,
@@ -203,11 +204,19 @@ pub fn finish_content_aware_move(app: &mut PhotocraftApp, start: [f64; 2], end:
     }
 }
 
-/// Object Selection: the dragged rectangle.
+/// Object Selection: the dragged rectangle. A click (or a sub-2 px nudge) cannot be a
+/// rectangle: like Photoshop's click-to-select, it falls back to a Quick Selection dab at
+/// the brush size instead of looking dead (⌥ subtracts, otherwise it adds). Larger drags
+/// run the rectangle GrabCut (⌥ subtracts, ⇧ adds, otherwise replaces).
 pub fn finish_object_selection(app: &mut PhotocraftApp, start: [f64; 2], end: [f64; 2], mods: egui::Modifiers) {
     let (x, y) = (start[0].min(end[0]), start[1].min(end[1]));
     let (w, h) = ((end[0] - start[0]).abs(), (end[1] - start[1]).abs());
+    let sample_all = app.ui.tool_options.sample_all_layers;
     if w < 2.0 || h < 2.0 {
+        let size = app.session.tools.brush.size;
+        let mode = if mods.alt { "subtract" } else { "add" };
+        let r = app.run("select.quick", json!({"points": [[end[0], end[1]]], "size": size, "mode": mode, "sampleAllLayers": sample_all}));
+        report_smart_result(app, r, tl!("Quick Selection found nothing there"));
         return;
     }
     let mode = if mods.alt {
@@ -217,10 +226,19 @@ pub fn finish_object_selection(app: &mut PhotocraftApp, start: [f64; 2], end: [f
     } else {
         "replace"
     };
-    let _ = app.run(
-        "select.object",
-        json!({"rect": [x.round(), y.round(), w.round(), h.round()], "mode": mode, "sampleAllLayers": app.ui.tool_options.sample_all_layers}),
-    );
+    let r = app.run("select.object", json!({"rect": [x.round(), y.round(), w.round(), h.round()], "mode": mode, "sampleAllLayers": sample_all}));
+    report_smart_result(app, r, tl!("Object Selection found nothing there — try a tighter rectangle"));
+}
+
+/// Reports a smart-selection command result in the status bar. Engine errors are already
+/// reported by [`PhotocraftApp::run`], but an empty result (`changed: false`) is a silent
+/// success that looks like a dead button (Select Subject finding nothing on a busy photo,
+/// Object Selection missing its rectangle). `empty_msg` says what to try next.
+pub fn report_smart_result(app: &mut PhotocraftApp, res: Result<Value, String>, empty_msg: &str) {
+    if matches!(res, Ok(ref v) if v.get("changed").and_then(Value::as_bool) == Some(false)) {
+        app.ui.status = empty_msg.into();
+        app.ui.status_error = false;
+    }
 }
 
 /// ⌥-click with Clone Stamp / Healing Brush sets the source.
@@ -356,7 +374,8 @@ pub fn options_bar(app: &mut PhotocraftApp, ui: &mut egui::Ui, tool: Tool) -> bo
             opt(ui, &crate::i18n::fmt(tl!("{key} to subtract"), &[("key", &crate::shortcuts::pretty("Alt"))]));
             crate::widgets::vline(ui, 22.0);
             if crate::widgets::secondary_button(ui, tl!("Select Subject"), 0.0).clicked() {
-                let _ = app.run("select.subject", json!({}));
+                let r = app.run("select.subject", json!({}));
+                report_smart_result(app, r, tl!("No subject found — try Object Selection or the Lasso"));
             }
         }
         Tool::ObjectSelection => {
@@ -364,7 +383,8 @@ pub fn options_bar(app: &mut PhotocraftApp, ui: &mut egui::Ui, tool: Tool) -> bo
             opt(ui, tl!("Drag a rectangle around the object"));
             crate::widgets::vline(ui, 22.0);
             if crate::widgets::secondary_button(ui, tl!("Select Subject"), 0.0).clicked() {
-                let _ = app.run("select.subject", json!({}));
+                let r = app.run("select.subject", json!({}));
+                report_smart_result(app, r, tl!("No subject found — try a rectangle around the object"));
             }
         }
         Tool::RedEye => {
@@ -511,6 +531,44 @@ mod tests {
         }
     }
 
+    #[test]
+    fn object_selection_click_falls_back_to_quick_selection() {
+        // A click cannot be a rectangle: it selects at the cursor instead of looking dead.
+        let mut app = app();
+        app.ui.tool = Tool::ObjectSelection;
+        let m = egui::Modifiers::NONE;
+        tool_event(&mut app, ToolEvent::Down { x: 50.0, y: 30.0, pressure: 1.0 }, m);
+        tool_event(&mut app, ToolEvent::Up { x: 50.0, y: 30.0 }, m);
+        assert!(!app.ui.status_error, "{}", app.ui.status);
+        assert_eq!(app.session.journal.last().map(|(id, _)| id.as_str()), Some("select.quick"));
+    }
+
+    #[test]
+    fn object_selection_rect_runs_object_selection_and_reports() {
+        let mut app = app();
+        app.run("paint.pencil", json!({"points": [[20, 10], [20, 50]], "size": 8, "color": "#ff0000"})).unwrap();
+        app.ui.tool = Tool::ObjectSelection;
+        let m = egui::Modifiers::NONE;
+        tool_event(&mut app, ToolEvent::Down { x: 5.0, y: 5.0, pressure: 1.0 }, m);
+        tool_event(&mut app, ToolEvent::Move { x: 60.0, y: 55.0, pressure: 1.0 }, m);
+        tool_event(&mut app, ToolEvent::Up { x: 60.0, y: 55.0 }, m);
+        assert!(!app.ui.status_error, "{}", app.ui.status);
+        assert_eq!(app.session.journal.last().map(|(id, _)| id.as_str()), Some("select.object"));
+    }
+
+    #[test]
+    fn empty_smart_result_is_reported_without_error() {
+        // An empty smart selection (Select Subject missing on a busy photo) is an info, not
+        // an error and not silence: the button must visibly answer.
+        let mut app = app();
+        report_smart_result(&mut app, Ok(json!({"selected": false, "changed": false})), "nothing there");
+        assert_eq!(app.ui.status.as_str(), "nothing there");
+        assert!(!app.ui.status_error);
+        app.ui.status.clear();
+        report_smart_result(&mut app, Ok(json!({"selected": true, "changed": true})), "nothing there");
+        assert!(app.ui.status.is_empty());
+    }
+
     #[test]
     fn mixer_brush_is_selectable_and_paints_only_inside_the_selection_via_control() {
         use crate::control::{ControlRequest, Outcome, handle};