Merge pull request #4144 from Taha-Mahmoodi/feat/port-double-click-breaks-thread

Type: a double-click on a threaded port breaks the thread there

crates/engine/src/cmd/threads.rs

@@ -50,6 +50,15 @@ pub fn specs() -> Vec<CommandSpec> {
             has_thread_selection,
             remove
         ),
+        cmd!(
+            "text.thread.break",
+            "Break Thread",
+            [],
+            None,
+            "{id, port: \"in\"|\"out\"} break the thread of area type or type on a path `id` before it (its in port) or after it (its out port), as a double-click on that port does: the story flows into the frames before the break, and the frames after it are left empty (still threaded with each other when two or more)",
+            has_doc,
+            break_thread
+        ),
         cmd!(query "text.thread.info", "Threads", [], None, "{} → [[id…]] every thread in order", has_doc, |s, _| {
             Ok(json!(s.doc()?.doc.text_threads.iter().map(|t| t.iter().map(|i| i.0).collect::<Vec<_>>()).collect::<Vec<_>>()))
         }),
@@ -648,6 +657,56 @@ fn remove(s: &mut Session, _: &Value) -> Result<Value> {
     ok()
 }
 
+/// `text.thread.break`: a double-click on a threaded port. The thread is split there; the whole
+/// story moves into the frames before the split, and the frames after it are emptied, staying
+/// threaded with each other when two or more remain.
+fn break_thread(s: &mut Session, p: &Value) -> Result<Value> {
+    const C: &str = "text.thread.break";
+    let id = checked_id(s, p.get("id").unwrap_or(&Value::Null), C)?;
+    let before = match p.get("port").and_then(Value::as_str) {
+        Some("in") => true,
+        Some("out") => false,
+        _ => return Err(bad(C, "`port` must be \"in\" or \"out\"")),
+    };
+    let d = &s.doc()?.doc;
+    let thread = d.text_threads.iter().find(|t| t.contains(&id)).cloned().unwrap_or_default();
+    let at = thread.iter().position(|x| *x == id).map(|i| if before { i } else { i + 1 });
+    let Some(at) = at.filter(|at| *at > 0 && *at < thread.len()) else {
+        return Err(bad(C, if before { "no frame comes before `id` in a thread" } else { "no frame comes after `id` in a thread" }));
+    };
+    let (head, tail) = (thread[..at].to_vec(), thread[at..].to_vec());
+    s.edit("Break Thread", |d, _| {
+        let sources: Vec<TextObject> = thread.iter().filter_map(|id| text_of(d, *id).cloned()).collect();
+        let mut story: Vec<TextRun> = sources.iter().flat_map(|t| t.runs.iter().cloned()).collect();
+        let paras = vectorcraft_text::thread::story_paras(&sources.iter().collect::<Vec<_>>(), &[]);
+        let end_style = story.last().map(|r| r.style.clone()).unwrap_or_default();
+        let last_para = paras.last().cloned().unwrap_or_default();
+        // Every frame but the first holds nothing, for the re-flow to share the story out among
+        // the first part's frames once.
+        for id in head.iter().skip(1).chain(&tail) {
+            if let Some(NodeKind::Text(t)) = d.node_mut(*id).map(|n| &mut n.kind) {
+                t.runs = vec![TextRun { text: String::new(), style: end_style.clone(), inline: None }];
+                t.set_all_paras(last_para.clone());
+                t.first_para_continues = false;
+                refresh_bounds(t);
+            }
+        }
+        if let Some(NodeKind::Text(t)) = head.first().and_then(|id| d.node_mut(*id)).map(|n| &mut n.kind) {
+            vectorcraft_text::edit::normalize(&mut story);
+            t.runs = story;
+            t.set_paragraph_styles(paras);
+            t.first_para_continues = false;
+            refresh_bounds(t);
+        }
+        if let Some(i) = d.text_threads.iter().position(|t| *t == thread) {
+            d.text_threads.splice(i..=i, [head, tail]);
+        }
+        d.text_threads.retain(|t| t.len() >= 2);
+        Ok(())
+    })?;
+    ok()
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -1056,6 +1115,68 @@ mod tests {
         (s, [a, b, c])
     }
 
+    fn continues(s: &Session, id: u64) -> bool {
+        text_of(&s.doc().unwrap().doc, NodeId(id)).is_some_and(|t| t.first_para_continues)
+    }
+
+    /// A double-click on a threaded port breaks the thread there: the story flows into the frames
+    /// before the break and the frames after it are left empty, still threaded with each other
+    /// when two or more. One undo step restores the thread and its text.
+    #[test]
+    fn break_splits_the_thread_and_the_story_flows_into_the_first_part() {
+        let story = TEXT.repeat(12);
+        let (mut s, [a, b, c]) = three_frames(&story, 40.0);
+        let d = new_id(s.execute("text.create", &json!({"x": 200, "y": 100, "text": "", "area": {"width": 150, "height": 100}})).unwrap());
+        s.execute("text.thread.add", &json!({"from": c, "to": d})).unwrap();
+        let all = [a, b, c, d];
+        let shown: Vec<String> = all.iter().map(|id| text(&s, *id)).collect();
+        assert!(shown.iter().all(|t| !t.is_empty()), "each frame shows part of the story");
+        let joined = |s: &Session, ids: &[u64]| ids.iter().map(|id| text(s, *id)).collect::<String>();
+        // (frame, port, threads after, the frames that hold the story, the frames left empty)
+        let cases = [
+            (a, "out", vec![vec![b, c, d]], vec![a], vec![b, c, d]),
+            (b, "in", vec![vec![b, c, d]], vec![a], vec![b, c, d]),
+            (b, "out", vec![vec![a, b], vec![c, d]], vec![a, b], vec![c, d]),
+            (d, "in", vec![vec![a, b, c]], vec![a, b, c], vec![d]),
+            (c, "out", vec![vec![a, b, c]], vec![a, b, c], vec![d]),
+        ];
+        for (id, port, after, full, empty) in cases {
+            let case = format!("{port} port of {id}");
+            s.execute("text.thread.break", &json!({"id": id, "port": port})).unwrap();
+            assert_eq!(threads(&s), after, "{case}");
+            assert_eq!(joined(&s, &full), story, "{case}: the story flows into the first part");
+            assert!(empty.iter().all(|id| text(&s, *id).is_empty()), "{case}: the frames after the break are empty");
+            assert!(!continues(&s, empty[0]), "{case}: the first frame after the break starts a paragraph");
+            assert!(!continues(&s, a), "{case}: the first frame starts the story");
+            s.execute("edit.undo", &json!({})).unwrap();
+            assert_eq!(threads(&s), [all.to_vec()], "{case}: undo");
+            assert_eq!(all.iter().map(|id| text(&s, *id)).collect::<Vec<_>>(), shown, "{case}: undo");
+        }
+    }
+
+    #[test]
+    fn break_refuses_a_port_with_no_thread_and_bad_params() {
+        let (mut s, [a, b, c]) = three_frames(&TEXT.repeat(4), 200.0);
+        let lone = new_id(s.execute("text.create", &json!({"x": 400, "y": 10, "text": "Alone.", "area": {"width": 100, "height": 100}})).unwrap());
+        let ids = [a, b, c, lone];
+        let shown: Vec<String> = ids.iter().map(|id| text(&s, *id)).collect();
+        let before = threads(&s);
+        for params in [
+            json!({"id": a, "port": "in"}),
+            json!({"id": c, "port": "out"}),
+            json!({"id": lone, "port": "out"}),
+            json!({"id": lone, "port": "in"}),
+            json!({"id": a, "port": "up"}),
+            json!({"id": a}),
+            json!({"port": "out"}),
+            json!({"id": 9999, "port": "out"}),
+        ] {
+            assert!(s.execute("text.thread.break", &params).is_err(), "{params}");
+        }
+        assert_eq!(threads(&s), before);
+        assert_eq!(ids.iter().map(|id| text(&s, *id)).collect::<Vec<_>>(), shown);
+    }
+
     /// Whether the document holds area type or type on a path `id`.
     fn is_frame(s: &Session, id: u64) -> bool {
         text_of(&s.doc().unwrap().doc, NodeId(id)).is_some()

crates/tools/src/select.rs

@@ -23,7 +23,10 @@
 //! kind, shape and size at the click on empty canvas, and a drag draws a rectangle for the new
 //! frame (`text.thread.add`), which comes after the clicked one in its thread. A click on the in
 //! port does the same with the new frame put before it: the story then starts there and flows on
-//! into the clicked one. Escape drops the loaded text.
+//! into the clicked one. Escape drops the loaded text. A double-click on a port where the frame is
+//! threaded splits the thread at that port (`text.thread.break`), as the archived help section on
+//! threading describes
+//! (<https://web.archive.org/web/20220127090642/https://helpx.adobe.com/illustrator/using/creating-text.html>).
 //! With Smart Guides and Invoke Distance Guides on, Alt/Option held over another object shows how
 //! far the selection is from it, and over an empty part of an artboard how far it is from the
 //! artboard's edges ([`crate::guides::distance_guides`]).
@@ -498,6 +501,14 @@ impl SelectionTool {
     fn loaded(&mut self, cx: &ToolContext, ev: &PointerEvent, from: NodeId, before: bool, press: Option<(Point, Point)>) -> Option<Vec<Action>> {
         let p = ev.pos;
         match (ev.kind, press) {
+            // The second press of a double-click on the port that loaded the text: the text is
+            // put down, and the double-click breaks the thread there.
+            (PointerKind::Down, _)
+                if crate::text::port_at(cx, p) == Some((from, if before { crate::text::Port::In } else { crate::text::Port::Out })) =>
+            {
+                self.state = State::Idle;
+                return Some(vec![]);
+            }
             (PointerKind::Down, _) if !cx.doc.node(from).is_some_and(is_threadable) => {
                 self.state = State::Idle;
                 return None;
@@ -678,6 +689,16 @@ impl Tool for SelectionTool {
         match (ev.kind, self.state.clone()) {
             (PointerKind::DoubleClick, _) => {
                 self.state = State::Idle;
+                // A threaded port: the thread breaks there. Any other port takes the double-click
+                // too, so it neither edits the type nor isolates.
+                if let Some((id, port)) = crate::text::port_at(cx, p) {
+                    let (input, output) = crate::text::port_states(cx.doc, id, false);
+                    let (state, name) = if port == crate::text::Port::In { (input, "in") } else { (output, "out") };
+                    if state == crate::text::PortState::Threaded {
+                        return vec![Action::Exec("text.thread.break".into(), json!({ "id": id.0, "port": name }))];
+                    }
+                    return vec![];
+                }
                 if let Some(a) = corners::double_click(cx, p, false).or_else(|| pie::double_click(cx, p)).or_else(|| typewidget::double_click(cx, p))
                 {
                     return vec![a];
@@ -2720,6 +2741,35 @@ mod tests {
         assert_eq!(t.pointer(&cx, &ev(PointerKind::Down, corner.x, corner.y)), vec![Action::Begin("Resize Type Area".into())]);
     }
 
+    /// A double-click on a threaded port breaks the thread there, its in port before the frame
+    /// and its out port after it; it doesn't thread the loaded text into a new frame. A
+    /// double-click on a port with no thread does nothing (it doesn't switch to the Type tool).
+    #[test]
+    fn a_double_click_on_a_threaded_port_breaks_the_thread() {
+        let (mut d, id, input, output) = fitting_area_type();
+        let rect = d.children(Some(d.layers[0].id)).unwrap()[0].id;
+        let mut s = Selection::default();
+        s.set([id]);
+        let p = paint();
+        let double_click = |d: &vectorcraft_doc::Document, at: Point| {
+            let cx = cx(d, &s, &p);
+            let mut t = SelectionTool::default();
+            let kinds = [PointerKind::Down, PointerKind::Up, PointerKind::Down, PointerKind::Up, PointerKind::DoubleClick];
+            let out: Vec<Action> = kinds.into_iter().flat_map(|k| t.pointer(&cx, &ev(k, at.x, at.y))).collect();
+            assert_ne!(t.cursor(&cx, Point::new(30.0, 420.0), Mods::default()), Cursor::LoadedText, "no text stays loaded");
+            out
+        };
+        let breaks = |port: &str| vec![Action::Exec("text.thread.break".into(), json!({"id": id.0, "port": port}))];
+        d.text_threads = vec![vec![id, rect]];
+        assert_eq!(double_click(&d, output), breaks("out"));
+        assert_eq!(double_click(&d, input), vec![], "no frame before it");
+        d.text_threads = vec![vec![rect, id]];
+        assert_eq!(double_click(&d, input), breaks("in"));
+        assert_eq!(double_click(&d, output), vec![], "no frame after it");
+        d.text_threads.clear();
+        assert_eq!(double_click(&d, output), vec![]);
+    }
+
     /// The memo answers for the revision, the selected objects and Use Preview Bounds it measured
     /// for, and measures again when any of them changes.
     #[test]

crates/ui-egui/src/canvas.rs

@@ -10787,6 +10787,36 @@ mod tests {
         assert!(thread_overlays(&app, zoom).is_empty());
     }
 
+    /// A double-click with the Selection tool on the out port of a threaded frame breaks the
+    /// thread there: no new frame is threaded on, and the story flows back into the first frame.
+    #[test]
+    fn a_double_click_on_a_threaded_out_port_breaks_the_thread() {
+        use vectorcraft_tools::text::{Port, port_centre};
+        let mut app = VectorcraftApp::new(Session::new(), Default::default());
+        app.run("file.new", json!({"width": 600, "height": 400})).unwrap();
+        let text = "Words that fill more than the frame holds. ".repeat(10);
+        let a =
+            app.run("text.create", json!({"x": 20, "y": 20, "text": text, "area": {"width": 150, "height": 60}})).unwrap()["id"].as_u64().unwrap();
+        app.run("text.thread.add", json!({"from": a, "at": [300, 200]})).unwrap();
+        app.run("select.set", json!({"ids": [a]})).unwrap();
+        app.select_tool("selection");
+        let doc = |app: &VectorcraftApp| app.session.active().unwrap().doc.clone();
+        let before = doc(&app);
+        let NodeKind::Text(t) = &before.node(vectorcraft_doc::NodeId(a)).unwrap().kind else { panic!("not text") };
+        let view = app.view_info();
+        let at = port_centre(t, Port::Out, 1.0 / view.zoom).unwrap();
+        let count = doc(&app).layers[0].children().map_or(0, |c| c.len());
+        for kind in [PointerKind::Down, PointerKind::Up, PointerKind::Down, PointerKind::Up, PointerKind::DoubleClick] {
+            crate::canvas::dispatch(&mut app, &PointerEvent::new(kind, at.x, at.y), view);
+        }
+        let d = doc(&app);
+        assert!(d.text_threads.is_empty(), "the thread is broken");
+        assert_eq!(d.layers[0].children().map_or(0, |c| c.len()), count, "no new frame");
+        let NodeKind::Text(t) = &d.node(vectorcraft_doc::NodeId(a)).unwrap().kind else { panic!("not text") };
+        assert_eq!(t.plain_text(), text, "the story flows into the first frame");
+        assert_eq!(app.session.tool_id(), "selection");
+    }
+
     /// With more than `PORTS_MAX` type objects selected the tools draw no ports, and Show Text
     /// Threads draws only its lines, no port boxes.
     #[test]

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

@@ -2545,6 +2545,7 @@ font-technology	Variable	Променливи
 	Remove Plug-in	Премахване на добавка
 	Remove Selected Assets	Премахване на избраните активи
 	Remove Threading	Премахване на свързването
+	Break Thread	Прекъсване на свързването
 	Remove “{keyword}”	Премахване на „{keyword}“
 	Rename	Преименуване
 	Rename Asset	Преименуване на актива

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

@@ -374,6 +374,7 @@
 	Create	Vytvořit
 	Release Selection	Uvolnit výběr
 	Remove Threading	Odstranit zřetězení
+	Break Thread	Přerušit zřetězení
 	Fit Headline	Přizpůsobit titulek
 	Find Font…	Najít písmo…
 	Change Case	Změnit velikost písmen

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

@@ -336,6 +336,7 @@
 	Create	Opret
 	Release Selection	Frigør markering
 	Remove Threading	Fjern sammenkædning
+	Break Thread	Bryd sammenkædning
 	Fit Headline	Tilpas overskrift
 	Find Font…	Find skrifttype…
 	Change Case	Ændr store/små bogstaver

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

@@ -2566,6 +2566,7 @@ mark-style	Japanese	Japanisch
 	Remove Plug-in	Plug-in entfernen
 	Remove Selected Assets	Ausgewählte Assets entfernen
 	Remove Threading	Verkettung entfernen
+	Break Thread	Verkettung trennen
 	Remove “{keyword}”	„{keyword}“ entfernen
 	Rename	Umbenennen
 	Rename Asset	Asset umbenennen

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

@@ -3144,6 +3144,7 @@ theme	Appearance	Εμφάνιση
 	Remove Plug-in	Αφαίρεση προσθέτου
 	Remove Selected Assets	Αφαίρεση επιλεγμένων στοιχείων
 	Remove Threading	Αφαίρεση σύνδεσης κειμένου
+	Break Thread	Διακοπή σύνδεσης κειμένου
 	Remove “{keyword}”	Αφαίρεση «{keyword}»
 	Rename Asset	Μετονομασία στοιχείου
 	Rename Character Style	Μετονομασία στυλ χαρακτήρων

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

@@ -2600,6 +2600,7 @@ font-technology	Variable	Variables
 	Remove Plug-in	Quitar plugin
 	Remove Selected Assets	Quitar recursos seleccionados
 	Remove Threading	Quitar enlace
+	Break Thread	Romper enlace
 	Remove “{keyword}”	Quitar “{keyword}”
 	Rename	Cambiar nombre
 	Rename Asset	Cambiar nombre del recurso

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

@@ -371,6 +371,7 @@
 	Create	Luo
 	Release Selection	Vapauta valinta
 	Remove Threading	Poista ketjutus
+	Break Thread	Katkaise ketjutus
 	Fit Headline	Sovita otsikko
 	Find Font…	Etsi fontti…
 	Change Case	Vaihda kirjainkoko

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

@@ -2597,6 +2597,7 @@ font-technology	Variable	Variables
 	Remove Plug-in	Supprimer le module externe
 	Remove Selected Assets	Supprimer les ressources sélectionnées
 	Remove Threading	Supprimer le chaînage
+	Break Thread	Rompre le chaînage
 	Remove “{keyword}”	Supprimer « {keyword} »
 	Rename	Renommer
 	Rename Asset	Renommer la ressource

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

@@ -3126,6 +3126,7 @@ mark-style	Japanese	Japán
 	Remove Selected Assets	Kijelölt elemek eltávolítása
 	Remove the shortcut	Billentyűparancs eltávolítása
 	Remove Threading	Szövegláncolás megszüntetése
+	Break Thread	Szövegláncolás megszakítása
 	Remove “{keyword}”	Eltávolítás: „{keyword}”
 	Rename	Átnevezés
 	Rename Asset	Elem átnevezése

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

@@ -336,6 +336,7 @@
 	Create	Buat
 	Release Selection	Lepaskan seleksi
 	Remove Threading	Hapus rangkaian
+	Break Thread	Putus rangkaian
 	Fit Headline	Sesuaikan judul
 	Find Font…	Cari font…
 	Change Case	Ubah huruf besar-kecil

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

@@ -2631,6 +2631,7 @@ mark-style	Japanese	Giapponese
 	Remove Plug-in	Rimuovi plug-in
 	Remove Selected Assets	Rimuovi risorse selezionate
 	Remove Threading	Rimuovi concatenamento
+	Break Thread	Interrompi concatenamento
 	Remove “{keyword}”	Rimuovi “{keyword}”
 	Rename	Rinomina
 	Rename Asset	Rinomina risorsa

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

@@ -363,6 +363,7 @@ font-technology	Variable	バリアブル
 	Create	作成
 	Release Selection	選択部分をリリース
 	Remove Threading	スレッドを解除
+	Break Thread	スレッドを切断
 	Fit Headline	ヘッドラインを合わせる
 	Decrease Font Size	フォントサイズを小さく
 	Decrease Font Size by Five Steps	フォントサイズを5段階小さく

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

@@ -294,6 +294,7 @@
 	Create	შექმნა
 	Release Selection	მონიშნულის მოხსნა
 	Remove Threading	დაკავშირების მოხსნა
+	Break Thread	დაკავშირების გაწყვეტა
 	Fit Headline	სათაურის მორგება
 	Find Font…	შრიფტის ძებნა…
 	Change Case	რეგისტრის შეცვლა

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

@@ -359,6 +359,7 @@ font-technology	Variable	가변
 	Create	만들기
 	Release Selection	선택 해제
 	Remove Threading	연결 제거
+	Break Thread	연결 끊기
 	Fit Headline	제목에 맞추기
 	Decrease Font Size	글꼴 크기 줄이기
 	Decrease Font Size by Five Steps	글꼴 크기 5단계 줄이기

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

@@ -350,6 +350,7 @@
 	Create	Maken
 	Release Selection	Selectie vrijgeven
 	Remove Threading	Koppeling opheffen
+	Break Thread	Koppeling verbreken
 	Fit Headline	Kop passend maken
 	Find Font…	Lettertype zoeken…
 	Change Case	Hoofdlettergebruik wijzigen

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

@@ -334,6 +334,7 @@
 	Create	Utwórz
 	Release Selection	Uwolnij zaznaczenie
 	Remove Threading	Usuń wątki
+	Break Thread	Przerwij wątek
 	Fit Headline	Dopasuj nagłówek
 	Find Font…	Znajdź czcionkę…
 	Change Case	Zmień wielkość liter

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

@@ -2149,6 +2149,7 @@
 	Remove Plug-in	Remover Plug-in
 	Remove Selected Assets	Remover Ativos Selecionados
 	Remove Threading	Remover Encadeamento
+	Break Thread	Quebrar Encadeamento
 	Remove blank lines between paragraphs	Remover linhas em branco entre parágrafos
 	Remove “{keyword}”	Remover “{keyword}”
 	Rename	Renomear

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

@@ -2627,6 +2627,7 @@ mark-style	Japanese	Японский
 	Remove Plug-in	Убрать модуль
 	Remove Selected Assets	Убрать выбранные ресурсы
 	Remove Threading	Убрать связывание
+	Break Thread	Разорвать связывание
 	Remove “{keyword}”	Убрать «{keyword}»
 	Rename	Переименовать
 	Rename Asset	Переименовать ресурс

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

@@ -2545,6 +2545,7 @@ font-technology	Variable	Variabla
 	Remove Plug-in	Ta bort plugin
 	Remove Selected Assets	Ta bort markerade resurser
 	Remove Threading	Ta bort textlänkning
+	Break Thread	Bryt textlänkning
 	Remove “{keyword}”	Ta bort ”{keyword}”
 	Rename	Byt namn
 	Rename Asset	Byt namn på resurs

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

@@ -2419,6 +2419,7 @@ font-technology	Variable	Değişken
 	Remove Plug-in	Eklentiyi Kaldır
 	Remove Selected Assets	Seçilen Varlıkları Kaldır
 	Remove Threading	Diş Açmayı Kaldır
+	Break Thread	Metin Bağını Kopar
 	Remove “{keyword}”	“{keyword}”yi kaldırın
 	Rename	Yeniden adlandır
 	Rename Asset	Varlığı Yeniden Adlandır

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

@@ -2623,6 +2623,7 @@ mark-style	Japanese	Японський
 	Remove Plug-in	Забрати модуль
 	Remove Selected Assets	Забрати вибрані ресурси
 	Remove Threading	Прибрати зв’язування
+	Break Thread	Розірвати зв’язування
 	Remove “{keyword}”	Прибрати "{keyword}"
 	Rename	Перейменувати
 	Rename Asset	Перейменувати ресурс

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

@@ -2892,6 +2892,7 @@ mark-style	Japanese	Kiểu Nhật
 	Remove Plug-in	Gỡ plug-in
 	Remove Selected Assets	Gỡ các asset đã chọn
 	Remove Threading	Gỡ liên kết chuỗi văn bản
+	Break Thread	Ngắt chuỗi văn bản
 	Remove “{keyword}”	Gỡ “{keyword}”
 	Rename	Đổi tên
 	Rename Asset	Đổi tên asset

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

@@ -2500,6 +2500,7 @@ font-script	Japanese	汉字
 	Remove Plug-in	移除插件
 	Remove Selected Assets	移除所选资源
 	Remove Threading	移除线程
+	Break Thread	断开串接
 	Remove “{keyword}”	移除“{keyword}”
 	Rename	重命名
 	Rename Asset	重命名资源

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

@@ -3404,6 +3404,7 @@ font-script	Japanese	漢字
 	Remove Plug-in	移除增效模組
 	Remove Selected Assets	移除所選資產
 	Remove Threading	移除串連
+	Break Thread	中斷串連
 	Remove “{keyword}”	移除「{keyword}」
 	Rename	重新命名
 	Rename Asset	重新命名資產

docs/mcp.md

@@ -4279,6 +4279,13 @@ that doesn't exist, a `from` that is point type, a `to` that is an open path, `f
 or already in a thread (`from` may be threaded already: the frame goes in beside it), coordinates that aren't finite
 numbers and a `before` that isn't true or false.
 
+A double-click on a port where the frame is threaded breaks the thread there (one undo step, `text.thread.break`):
+
+`text.thread.break {id, port: "in" | "out"}` splits the thread of area type or type on a path `id` before it (`in`) or
+after it (`out`). The whole story flows into the frames before the break; the frames after it are left empty, still
+threaded with each other when two or more remain, and the first of them starts a paragraph. It refuses an `id` that
+doesn't exist, a `port` other than `in` or `out`, and a side where no frame of a thread comes before or after `id`.
+
 In every thread, a paragraph that continues from one frame into the next has its first line, first-line indent and
 bullet or number in the frame where it starts. In the next frame its first line starts where its wrapped lines start,
 and it has no bullet or number. In a frame that is no longer threaded (after `text.thread.releaseSelection` or