Make layout/master placeholder formatting reach slides

Fixes #1487

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

crates/engine/src/cmd/text/formatting.rs

@@ -31,8 +31,10 @@ pub(crate) fn format_run(s: &mut Session, f: &(dyn Fn(&mut RunProps) + Send + Sy
         return Err(bad("format", SELECT_TEXT_OR_SHAPE));
     }
     let cells = st.selection.cells;
+    let on_master = editing_master(st);
     edit_shapes(s, &json!({"ids": ids}), "format", |sh| {
         let id = sh.id;
+        let inherited = on_master && sh.ph.is_some();
         match &mut sh.kind {
             ShapeKind::Table(t) => {
                 // Only the selected cells, when a range of them is selected.
@@ -48,6 +50,13 @@ pub(crate) fn format_run(s: &mut Session, f: &(dyn Fn(&mut RunProps) + Send + Sy
             _ => {
                 let body = sh.text.get_or_insert_with(TextBody::default);
                 ed::format_all(body, f);
+                if inherited {
+                    for l in 0..LIST_LEVELS {
+                        let mut lvl = body.list_style.level(l).cloned().unwrap_or_default();
+                        f(&mut lvl.run);
+                        body.list_style.set(l, lvl);
+                    }
+                }
             }
         }
         Ok(())
@@ -58,6 +67,15 @@ pub(crate) fn format_run(s: &mut Session, f: &(dyn Fn(&mut RunProps) + Send + Sy
     ok()
 }
 
+/// List-style levels (`lvl1pPr`–`lvl9pPr`) a placeholder passes on to the slides that use it.
+const LIST_LEVELS: u8 = 9;
+
+/// Formatting a placeholder on a layout or master (Slide Master view) also sets its list style,
+/// which is what the placeholders on slides inherit; its own runs may be few or none.
+fn editing_master(st: &DocState) -> bool {
+    matches!(st.selection.target, crate::Target::Layout { .. } | crate::Target::Master { .. })
+}
+
 /// What `format_run` formats while editing: the selection, or for a bare caret the word it's in
 /// (without its trailing space). Empty when the caret is at a word boundary. Insert Hyperlink
 /// edits this same span, so the dialog reads it too.
@@ -128,8 +146,10 @@ pub(crate) fn format_para(s: &mut Session, f: &(dyn Fn(&mut deckcraft_model::tex
         return Err(bad("format", SELECT_TEXT_OR_SHAPE));
     }
     let cells = st.selection.cells;
+    let on_master = editing_master(st);
     edit_shapes(s, &json!({"ids": ids}), "format", |sh| {
         let id = sh.id;
+        let inherited = on_master && sh.ph.is_some();
         match &mut sh.kind {
             ShapeKind::Table(t) => {
                 let range = crate::cmd::table::selected_range(cells, id, t);
@@ -147,6 +167,18 @@ pub(crate) fn format_para(s: &mut Session, f: &(dyn Fn(&mut deckcraft_model::tex
                     body.paragraphs.push(Default::default());
                 }
                 body.paragraphs.iter_mut().for_each(f);
+                if inherited {
+                    for l in 0..LIST_LEVELS {
+                        let mut lvl = body.list_style.level(l).cloned().unwrap_or_default();
+                        let mut p = deckcraft_model::text::Paragraph { level: l, props: lvl.para, ..Default::default() };
+                        f(&mut p);
+                        // A level change (indent/outdent) means nothing for a list-style level.
+                        if p.level == l {
+                            lvl.para = p.props;
+                            body.list_style.set(l, lvl);
+                        }
+                    }
+                }
             }
         }
         Ok(())

crates/engine/src/tests.rs

@@ -5956,3 +5956,29 @@ fn invalid_slide_index_never_falls_back_to_the_selection_in_export_commands() {
     }
     let _ = std::fs::remove_dir_all(&dir);
 }
+
+#[test]
+fn master_layout_placeholder_format_inherits() {
+    let mut s = Session::new();
+    sample::open_sample(&mut s).unwrap();
+    let title_of = |shapes: &[model::Shape]| shapes.iter().find(|sh| sh.ph.as_ref().is_some_and(|p| p.kind.is_title())).map(|sh| sh.id.0).unwrap();
+    let existing = title_of(&s.doc().unwrap().doc.slides[0].shapes);
+    s.execute("view.slideMaster", &json!({"master": 0, "layout": 0})).unwrap();
+    let layout_title = title_of(&s.doc().unwrap().doc.masters[0].layouts[0].shapes);
+    s.execute("edit.select", &json!({"ids": [layout_title]})).unwrap();
+    s.execute("format.font", &json!({"family": "Montserrat"})).unwrap();
+    s.execute("format.align", &json!({"align": "right"})).unwrap();
+    let st = s.execute("format.state", &json!({})).unwrap();
+    assert_eq!(st["fontRef"], "Montserrat", "layout placeholder: {st}");
+    s.execute("view.closeMaster", &json!({})).unwrap();
+    s.execute("slide.new", &json!({"layout": "title"})).unwrap();
+    let slide = s.doc().unwrap().selection.slide;
+    let fresh = title_of(&s.doc().unwrap().doc.slides[slide].shapes);
+    for (index, id) in [(slide, fresh), (0, existing)] {
+        s.execute("slide.go", &json!({"index": index})).unwrap();
+        s.execute("edit.select", &json!({"ids": [id]})).unwrap();
+        let st = s.execute("format.state", &json!({})).unwrap();
+        assert_eq!(st["fontRef"], "Montserrat", "slide placeholder {id}: {st}");
+        assert_eq!(st["align"], "r", "slide placeholder {id}: {st}");
+    }
+}