refactor: split complex functions for Sonar S3776

Extract helpers from backstage options (general, calculation and iteration
sections), code_editor python (string scanning), xtask i18n literals
(escape and string readers) and calc recalc loops_among (SCC search).
No behaviour change.

crates/calc/src/recalc.rs

@@ -927,6 +927,64 @@ impl Host for PassHost<'_> {
     }
 }
 
+/// Strongly connected components of a graph given as adjacency lists (Tarjan, iterative): each
+/// node's component index, and the number of nodes in each component.
+fn components(edges: &[Vec<usize>]) -> (Vec<usize>, Vec<usize>) {
+    let n = edges.len();
+    let (mut low, mut num) = (vec![0usize; n], vec![usize::MAX; n]);
+    let (mut on_stack, mut stack, mut comp) = (vec![false; n], Vec::new(), vec![usize::MAX; n]);
+    let (mut next, mut comps) = (0usize, 0usize);
+    for root in 0..n {
+        if num[root] != usize::MAX {
+            continue;
+        }
+        let mut call: Vec<(usize, usize)> = vec![(root, 0)];
+        num[root] = next;
+        low[root] = next;
+        next += 1;
+        stack.push(root);
+        on_stack[root] = true;
+        while let Some(top) = call.last_mut() {
+            let v = top.0;
+            if let Some(&w) = edges.get(v).and_then(|e| e.get(top.1)) {
+                top.1 += 1;
+                if num[w] == usize::MAX {
+                    num[w] = next;
+                    low[w] = next;
+                    next += 1;
+                    stack.push(w);
+                    on_stack[w] = true;
+                    call.push((w, 0));
+                } else if on_stack[w] {
+                    low[v] = low[v].min(num[w]);
+                }
+                continue;
+            }
+            call.pop();
+            if let Some(&(u, _)) = call.last() {
+                low[u] = low[u].min(low[v]);
+            }
+            if low[v] == num[v] {
+                while let Some(w) = stack.pop() {
+                    on_stack[w] = false;
+                    comp[w] = comps;
+                    if w == v {
+                        break;
+                    }
+                }
+                comps += 1;
+            }
+        }
+    }
+    let mut size = vec![0usize; comps];
+    for &c in &comp {
+        if let Some(s) = size.get_mut(c) {
+            *s += 1;
+        }
+    }
+    (comp, size)
+}
+
 impl Calc {
     pub fn new() -> Self {
         Self::default()
@@ -981,59 +1039,8 @@ impl Calc {
                 e
             })
             .collect();
-        // Tarjan's strongly connected components, iterative.
-        let n = circ.len();
-        let (mut low, mut num) = (vec![0usize; n], vec![usize::MAX; n]);
-        let (mut on_stack, mut stack, mut comp) = (vec![false; n], Vec::new(), vec![usize::MAX; n]);
-        let (mut next, mut comps) = (0usize, 0usize);
-        for root in 0..n {
-            if num[root] != usize::MAX {
-                continue;
-            }
-            let mut call: Vec<(usize, usize)> = vec![(root, 0)];
-            num[root] = next;
-            low[root] = next;
-            next += 1;
-            stack.push(root);
-            on_stack[root] = true;
-            while let Some(top) = call.last_mut() {
-                let v = top.0;
-                if let Some(&w) = edges.get(v).and_then(|e| e.get(top.1)) {
-                    top.1 += 1;
-                    if num[w] == usize::MAX {
-                        num[w] = next;
-                        low[w] = next;
-                        next += 1;
-                        stack.push(w);
-                        on_stack[w] = true;
-                        call.push((w, 0));
-                    } else if on_stack[w] {
-                        low[v] = low[v].min(num[w]);
-                    }
-                    continue;
-                }
-                call.pop();
-                if let Some(&(u, _)) = call.last() {
-                    low[u] = low[u].min(low[v]);
-                }
-                if low[v] == num[v] {
-                    while let Some(w) = stack.pop() {
-                        on_stack[w] = false;
-                        comp[w] = comps;
-                        if w == v {
-                            break;
-                        }
-                    }
-                    comps += 1;
-                }
-            }
-        }
-        let mut size = vec![0usize; comps];
-        for &c in &comp {
-            if let Some(s) = size.get_mut(c) {
-                *s += 1;
-            }
-        }
+        // Loop members: nodes in a component of more than one, or with an edge to themselves.
+        let (comp, size) = components(&edges);
         let on_loop = |i: usize| comp.get(i).and_then(|c| size.get(*c)).is_some_and(|s| *s > 1) || edges.get(i).is_some_and(|e| e.contains(&i));
         // A formula with dynamic references (INDIRECT, OFFSET) may close a loop the graph can't see.
         let mut out: Vec<Key> =

crates/engine/src/cmd/formulas.rs

@@ -96,75 +96,73 @@ pub fn specs() -> Vec<CommandSpec> {
     ]
 }
 
-fn auto_sum(s: &mut Session, p: &Json) -> Result<Json> {
-    let func = str_param(p, "function").unwrap_or("SUM").to_ascii_uppercase();
-    let d = s.doc()?;
-    let sh = d.wb.active().ok_or(EngineError::NoDocument)?;
-    let sel = match str_param(p, "range") {
-        Some(_) => target_range(s, p)?,
-        None => d.selection.current(),
-    };
-    if !sel.is_single() {
-        // A selection: totals go in its empty last row or column, as Excel's do, and otherwise
-        // past it: to the right of a single row, below each column of anything taller. Columns
-        // past the sheet's data get no total (a whole-row selection doesn't write 16,384
-        // formulas), nor do rows past it, and all totals are one edit (one undo step).
-        let Some(used) = sh.cells.used_range() else { return ok() };
-        let empty = |row: u32, col: u32| sh.value(CellRef::new(row, col)).is_empty();
-        let sum = |from: CellRef, to: CellRef| format!("={func}({})", RangeRef::new(from, to).a1());
-        let last_col = used.end.col.min(sel.end.col);
-        let mut writes: Vec<(CellRef, String)> = Vec::new();
-        if sel.start.row == sel.end.row {
-            // One row: its total goes in its last cell when that is empty, else just after it.
-            let row = sel.start.row;
-            let end_col = if sel.is_full_rows() { last_col } else { sel.end.col };
-            let (data_end, out) = if end_col > sel.start.col && empty(row, end_col) { (end_col - 1, end_col) } else { (end_col, end_col + 1) };
-            if out >= gridcraft_core::MAX_COLS {
-                return Err(EngineError::Other("There's no room to the right of the selection for the total.".into()));
-            }
-            writes.push((CellRef::new(row, out), sum(CellRef::new(row, sel.start.col), CellRef::new(row, data_end))));
-        } else {
-            // An empty last column takes each row's total; rows past the data get none.
-            let rows_end = sel.end.row.min(used.end.row);
-            let right_blank = !sel.is_full_rows() && sel.end.col > sel.start.col && (sel.start.row..=rows_end).all(|r| empty(r, sel.end.col));
-            let data_end_col = if right_blank { sel.end.col - 1 } else { last_col };
-            let last_row_blank = (sel.start.col..=last_col).all(|c| empty(sel.end.row, c));
-            let (data_end_row, out_row) = if last_row_blank { (sel.end.row.saturating_sub(1), sel.end.row) } else { (sel.end.row, sel.end.row + 1) };
-            // Each column's total, below it: unless only the last column is there to take totals.
-            if last_row_blank || !right_blank {
-                if out_row >= gridcraft_core::MAX_ROWS {
-                    return Err(EngineError::Other("There's no room below the selection for the totals.".into()));
-                }
-                for c in sel.start.col..=data_end_col.min(last_col) {
-                    writes.push((CellRef::new(out_row, c), sum(CellRef::new(sel.start.row, c), CellRef::new(data_end_row, c))));
-                }
-            }
-            if right_blank {
-                for r in sel.start.row..=data_end_row.min(rows_end) {
-                    writes.push((CellRef::new(r, sel.end.col), sum(CellRef::new(r, sel.start.col), CellRef::new(r, data_end_col))));
-                }
-                // Both empty: the corner takes the total of the whole block.
-                if last_row_blank {
-                    writes.push((
-                        CellRef::new(sel.end.row, sel.end.col),
-                        sum(CellRef::new(sel.start.row, sel.start.col), CellRef::new(data_end_row, data_end_col)),
-                    ));
-                }
-            }
-        }
-        let sheet = d.wb.active_sheet;
-        edit(s, |cx| {
-            for (c, f) in &writes {
-                let cell = super::edit::input_to_cell(f, sheet, *c, &mut cx.wb)?.unwrap_or_default();
-                cx.sheet_mut(sheet)?.set_cell(*c, cell);
-                cx.touch(sheet, *c);
-            }
-            Ok(())
-        })?;
-        return ok();
+/// Whether a cell on the active sheet is empty.
+fn blank(sh: &gridcraft_model::sheet::Sheet, row: u32, col: u32) -> bool {
+    sh.value(CellRef::new(row, col)).is_empty()
+}
+
+fn sum_formula(func: &str, from: CellRef, to: CellRef) -> String {
+    format!("={func}({})", RangeRef::new(from, to).a1())
+}
+
+/// Totals for a multi-cell selection as `(cell, formula)` writes. `None` when the sheet has no data.
+fn selection_totals(sh: &gridcraft_model::sheet::Sheet, sel: RangeRef, func: &str) -> Result<Option<Vec<(CellRef, String)>>> {
+    // A selection: totals go in its empty last row or column, as Excel's do, and otherwise
+    // past it: to the right of a single row, below each column of anything taller. Columns
+    // past the sheet's data get no total (a whole-row selection doesn't write 16,384
+    // formulas), nor do rows past it, and all totals are one edit (one undo step).
+    let Some(used) = sh.cells.used_range() else { return Ok(None) };
+    if sel.start.row == sel.end.row { single_row_totals(sh, sel, used, func).map(Some) } else { block_totals(sh, sel, used, func).map(Some) }
+}
+
+/// One row: its total goes in its last cell when that is empty, else just after it.
+fn single_row_totals(sh: &gridcraft_model::sheet::Sheet, sel: RangeRef, used: RangeRef, func: &str) -> Result<Vec<(CellRef, String)>> {
+    let row = sel.start.row;
+    let last_col = used.end.col.min(sel.end.col);
+    let end_col = if sel.is_full_rows() { last_col } else { sel.end.col };
+    let (data_end, out) = if end_col > sel.start.col && blank(sh, row, end_col) { (end_col - 1, end_col) } else { (end_col, end_col + 1) };
+    if out >= gridcraft_core::MAX_COLS {
+        return Err(EngineError::Other("There's no room to the right of the selection for the total.".into()));
     }
-    // Single cell: guess the range above, else to the left.
-    let at = sel.start;
+    Ok(vec![(CellRef::new(row, out), sum_formula(func, CellRef::new(row, sel.start.col), CellRef::new(row, data_end)))])
+}
+
+/// A block of rows: each column's total below it, and each row's total in an empty last column.
+fn block_totals(sh: &gridcraft_model::sheet::Sheet, sel: RangeRef, used: RangeRef, func: &str) -> Result<Vec<(CellRef, String)>> {
+    let mut writes: Vec<(CellRef, String)> = Vec::new();
+    let last_col = used.end.col.min(sel.end.col);
+    // An empty last column takes each row's total; rows past the data get none.
+    let rows_end = sel.end.row.min(used.end.row);
+    let right_blank = !sel.is_full_rows() && sel.end.col > sel.start.col && (sel.start.row..=rows_end).all(|r| blank(sh, r, sel.end.col));
+    let data_end_col = if right_blank { sel.end.col - 1 } else { last_col };
+    let last_row_blank = (sel.start.col..=last_col).all(|c| blank(sh, sel.end.row, c));
+    let (data_end_row, out_row) = if last_row_blank { (sel.end.row.saturating_sub(1), sel.end.row) } else { (sel.end.row, sel.end.row + 1) };
+    // Each column's total, below it: unless only the last column is there to take totals.
+    if last_row_blank || !right_blank {
+        if out_row >= gridcraft_core::MAX_ROWS {
+            return Err(EngineError::Other("There's no room below the selection for the totals.".into()));
+        }
+        for c in sel.start.col..=data_end_col.min(last_col) {
+            writes.push((CellRef::new(out_row, c), sum_formula(func, CellRef::new(sel.start.row, c), CellRef::new(data_end_row, c))));
+        }
+    }
+    if right_blank {
+        for r in sel.start.row..=data_end_row.min(rows_end) {
+            writes.push((CellRef::new(r, sel.end.col), sum_formula(func, CellRef::new(r, sel.start.col), CellRef::new(r, data_end_col))));
+        }
+        // Both empty: the corner takes the total of the whole block.
+        if last_row_blank {
+            writes.push((
+                CellRef::new(sel.end.row, sel.end.col),
+                sum_formula(func, CellRef::new(sel.start.row, sel.start.col), CellRef::new(data_end_row, data_end_col)),
+            ));
+        }
+    }
+    Ok(writes)
+}
+
+/// The range a single cell's AutoSum guesses: the numbers above it, else the numbers to its left.
+fn guessed_range(sh: &gridcraft_model::sheet::Sheet, at: CellRef) -> Option<RangeRef> {
     let numeric = |c: CellRef| sh.value(c).is_number();
     let mut range = None;
     if at.row > 0 && (numeric(CellRef::new(at.row - 1, at.col)) || at.col == 0 || !numeric(CellRef::new(at.row, at.col - 1))) {
@@ -186,7 +184,33 @@ fn auto_sum(s: &mut Session, p: &Json) -> Result<Json> {
         }
         range = Some(RangeRef::new(CellRef::new(at.row, left), CellRef::new(at.row, at.col - 1)));
     }
-    let text = match range {
+    range
+}
+
+fn auto_sum(s: &mut Session, p: &Json) -> Result<Json> {
+    let func = str_param(p, "function").unwrap_or("SUM").to_ascii_uppercase();
+    let d = s.doc()?;
+    let sh = d.wb.active().ok_or(EngineError::NoDocument)?;
+    let sel = match str_param(p, "range") {
+        Some(_) => target_range(s, p)?,
+        None => d.selection.current(),
+    };
+    if !sel.is_single() {
+        let Some(writes) = selection_totals(sh, sel, &func)? else { return ok() };
+        let sheet = d.wb.active_sheet;
+        edit(s, |cx| {
+            for (c, f) in &writes {
+                let cell = super::edit::input_to_cell(f, sheet, *c, &mut cx.wb)?.unwrap_or_default();
+                cx.sheet_mut(sheet)?.set_cell(*c, cell);
+                cx.touch(sheet, *c);
+            }
+            Ok(())
+        })?;
+        return ok();
+    }
+    // Single cell: guess the range above, else to the left.
+    let at = sel.start;
+    let text = match guessed_range(sh, at) {
         Some(r) => format!("={func}({})", r.a1()),
         None => {
             s.ui_requests.push(crate::UiRequest::EditCell(Some(format!("={func}()"))));

crates/ui-egui/src/backstage.rs

@@ -957,6 +957,35 @@ pub fn export_as(app: &mut SheetApp, fmt: &str) -> bool {
 fn options(app: &mut SheetApp, ui: &mut Ui) {
     let lang = app.ui.language;
     section(ui, lang, "Options|General");
+    general_options(app, ui, lang);
+    ui.add_space(6.0);
+    let mut formula_bar = app.session.prefs.formula_bar;
+    if ui.checkbox(&mut formula_bar, lang.tr("Show formula bar")).changed() {
+        app.run_or_alert("view.formulaBar", json!({"on": formula_bar}));
+    }
+    ui.add_space(18.0);
+    section(ui, lang, "Options|Editing");
+    let mut autocomplete = app.ui.autocomplete;
+    if ui.checkbox(&mut autocomplete, lang.tr("Enable AutoComplete for cell values")).changed() {
+        app.run_or_alert("options.autoComplete", json!({"on": autocomplete}));
+    }
+    ui.add_space(18.0);
+    section(ui, lang, "Options|Save");
+    let mut autosave = app.ui.autosave;
+    if ui.checkbox(&mut autosave, lang.tr("Save .xlsx workbooks automatically after every change")).changed() {
+        app.toggle_autosave();
+    }
+    let Some(calc) = app.session.active().map(|d| d.wb.calc.clone()) else { return };
+    ui.add_space(18.0);
+    section(ui, lang, "Formulas");
+    ui.label(lang.tr("Workbook calculation"));
+    calc_options(app, ui, lang, &calc);
+    ui.add_space(6.0);
+    dim(ui, lang.tr("Calculation settings are saved with the workbook."));
+}
+
+/// The display theme and interface language controls of the General section.
+fn general_options(app: &mut SheetApp, ui: &mut Ui, lang: Language) {
     egui::Grid::new("backstage_options_general").num_columns(2).spacing(vec2(18.0, 10.0)).show(ui, |ui| {
         let label = ui.label(lang.tr("Display theme"));
         let mode = app.ui.theme_mode();
@@ -993,27 +1022,10 @@ fn options(app: &mut SheetApp, ui: &mut Ui) {
             .labelled_by(label.id);
         ui.end_row();
     });
-    ui.add_space(6.0);
-    let mut formula_bar = app.session.prefs.formula_bar;
-    if ui.checkbox(&mut formula_bar, lang.tr("Show formula bar")).changed() {
-        app.run_or_alert("view.formulaBar", json!({"on": formula_bar}));
-    }
-    ui.add_space(18.0);
-    section(ui, lang, "Options|Editing");
-    let mut autocomplete = app.ui.autocomplete;
-    if ui.checkbox(&mut autocomplete, lang.tr("Enable AutoComplete for cell values")).changed() {
-        app.run_or_alert("options.autoComplete", json!({"on": autocomplete}));
-    }
-    ui.add_space(18.0);
-    section(ui, lang, "Options|Save");
-    let mut autosave = app.ui.autosave;
-    if ui.checkbox(&mut autosave, lang.tr("Save .xlsx workbooks automatically after every change")).changed() {
-        app.toggle_autosave();
-    }
-    let Some(calc) = app.session.active().map(|d| d.wb.calc.clone()) else { return };
-    ui.add_space(18.0);
-    section(ui, lang, "Formulas");
-    ui.label(lang.tr("Workbook calculation"));
+}
+
+/// The calculation mode, and iterative calculation, of the active workbook.
+fn calc_options(app: &mut SheetApp, ui: &mut Ui, lang: Language, calc: &gridcraft_engine::model::CalcSettings) {
     use gridcraft_engine::model::CalcMode;
     for (mode, id, label) in [
         (CalcMode::Automatic, "automatic", "Automatic"),
@@ -1030,6 +1042,13 @@ fn options(app: &mut SheetApp, ui: &mut Ui) {
         app.run_or_alert("formulas.calculationOptions", json!({"iterative": iterative}));
     }
     // Maximum Iterations and Maximum Change apply only while iteration is on, as in Excel.
+    iteration_options(app, ui, lang, calc, iterative);
+    // TODO: add "Set precision as displayed" here once `formulas.calculationOptions` takes
+    // `precisionAsDisplayed` (PR #1366); the model already stores it.
+}
+
+/// Maximum Iterations and Maximum Change, live only while iterative calculation is on.
+fn iteration_options(app: &mut SheetApp, ui: &mut Ui, lang: Language, calc: &gridcraft_engine::model::CalcSettings, iterative: bool) {
     ui.add_enabled_ui(iterative, |ui| {
         ui.horizontal(|ui| {
             ui.add_space(24.0);
@@ -1070,10 +1089,6 @@ fn options(app: &mut SheetApp, ui: &mut Ui) {
             });
         });
     });
-    // TODO: add "Set precision as displayed" here once `formulas.calculationOptions` takes
-    // `precisionAsDisplayed` (PR #1366); the model already stores it.
-    ui.add_space(6.0);
-    dim(ui, lang.tr("Calculation settings are saved with the workbook."));
 }
 
 /// Refuses a typed setting with a message, leaving the workbook as it was. The Enter that

crates/ui-egui/src/code_editor.rs

@@ -78,6 +78,32 @@ pub fn highlight(text: &str, lang: Lang) -> Vec<(Range<usize>, Token)> {
     }
 }
 
+/// End (exclusive, in chars) of the Python string literal opening with quote `c` at char `i`.
+fn python_string_end(chars: &[(usize, char)], i: usize, c: char) -> usize {
+    let triple = chars.get(i + 1).is_some_and(|(_, d)| *d == c) && chars.get(i + 2).is_some_and(|(_, d)| *d == c);
+    let mut j = if triple { i + 3 } else { i + 1 };
+    loop {
+        match chars.get(j) {
+            None => break,
+            Some((_, '\\')) => j += 2,
+            Some((_, '\n')) if !triple => break,
+            Some((_, d)) if *d == c => {
+                if !triple {
+                    j += 1;
+                    break;
+                }
+                if chars.get(j + 1).is_some_and(|(_, d)| *d == c) && chars.get(j + 2).is_some_and(|(_, d)| *d == c) {
+                    j += 3;
+                    break;
+                }
+                j += 1;
+            }
+            Some(_) => j += 1,
+        }
+    }
+    j.min(chars.len())
+}
+
 fn python(text: &str) -> Vec<(Range<usize>, Token)> {
     let chars: Vec<(usize, char)> = text.char_indices().collect();
     let end_of = |i: usize| chars.get(i).map(|(b, _)| *b).unwrap_or(text.len());
@@ -92,28 +118,7 @@ fn python(text: &str) -> Vec<(Range<usize>, Token)> {
             out.push((start..end_of(j), Token::Comment));
             i = j;
         } else if c == '"' || c == '\'' {
-            let triple = chars.get(i + 1).is_some_and(|(_, d)| *d == c) && chars.get(i + 2).is_some_and(|(_, d)| *d == c);
-            let mut j = if triple { i + 3 } else { i + 1 };
-            loop {
-                match chars.get(j) {
-                    None => break,
-                    Some((_, '\\')) => j += 2,
-                    Some((_, '\n')) if !triple => break,
-                    Some((_, d)) if *d == c => {
-                        if !triple {
-                            j += 1;
-                            break;
-                        }
-                        if chars.get(j + 1).is_some_and(|(_, d)| *d == c) && chars.get(j + 2).is_some_and(|(_, d)| *d == c) {
-                            j += 3;
-                            break;
-                        }
-                        j += 1;
-                    }
-                    Some(_) => j += 1,
-                }
-            }
-            let j = j.min(chars.len());
+            let j = python_string_end(&chars, i, c);
             out.push((start..end_of(j), Token::String));
             i = j;
         } else if c.is_ascii_digit() || (c == '.' && chars.get(i + 1).is_some_and(|(_, d)| d.is_ascii_digit())) {

crates/ui-egui/src/grid.rs

@@ -2046,38 +2046,46 @@ fn update_cursor(app: &mut SheetApp, ui: &egui::Ui, resp: &egui::Response, geo:
     }
     // A held drag owns the cursor even outside the grid; a press below egui's threshold still
     // has Drag::None and uses hover. A click can briefly leave a drag state after release.
-    if resp.dragged() && pointer.primary_down() {
-        let cursor = match app.grid.drag {
-            Drag::None => None,
-            Drag::Select => Some(CursorIcon::Cell),
-            Drag::Rows(_) | Drag::Cols(_) => Some(CursorIcon::Default),
-            Drag::Fill { .. } => Some(CursorIcon::Crosshair),
-            Drag::Move { .. } | Drag::MoveCols { .. } | Drag::Object { resize: false, .. } => Some(CursorIcon::Move),
-            Drag::ResizeCol { .. } => Some(CursorIcon::ResizeColumn),
-            Drag::ResizeRow { .. } => Some(CursorIcon::ResizeRow),
-            Drag::Freeze { cols, .. } => Some(if cols { CursorIcon::ResizeHorizontal } else { CursorIcon::ResizeVertical }),
-            Drag::Object { resize: true, .. } => Some(CursorIcon::ResizeNwSe),
-        };
-        if let Some(cursor) = cursor {
-            ctx.set_cursor_icon(cursor);
-            return;
-        }
+    if resp.dragged()
+        && pointer.primary_down()
+        && let Some(cursor) = drag_cursor(&app.grid.drag)
+    {
+        ctx.set_cursor_icon(cursor);
+        return;
     }
     if !resp.hovered() {
         return;
     }
     let Some(p) = pos else { return };
+    hover_cursor(app, ctx, resp, &pointer, geo, sh, p);
+}
+
+/// The cursor a held drag shows, or `None` when the drag leaves it to hover.
+fn drag_cursor(drag: &Drag) -> Option<CursorIcon> {
+    match drag {
+        Drag::None => None,
+        Drag::Select => Some(CursorIcon::Cell),
+        Drag::Rows(_) | Drag::Cols(_) => Some(CursorIcon::Default),
+        Drag::Fill { .. } => Some(CursorIcon::Crosshair),
+        Drag::Move { .. } | Drag::MoveCols { .. } | Drag::Object { resize: false, .. } => Some(CursorIcon::Move),
+        Drag::ResizeCol { .. } => Some(CursorIcon::ResizeColumn),
+        Drag::ResizeRow { .. } => Some(CursorIcon::ResizeRow),
+        Drag::Freeze { cols, .. } => Some(if *cols { CursorIcon::ResizeHorizontal } else { CursorIcon::ResizeVertical }),
+        Drag::Object { resize: true, .. } => Some(CursorIcon::ResizeNwSe),
+    }
+}
+
+/// The cursor over the grid when no drag owns it: freeze bars, header edges, the fill handle, cells.
+fn hover_cursor(app: &SheetApp, ctx: &egui::Context, resp: &egui::Response, pointer: &egui::PointerState, geo: &Geo, sh: &Sheet, p: Pos2) {
+    let (freeze_cols, freeze_rows) = freeze_handles(geo);
     if freeze_cols.contains(p) || freeze_rows.contains(p) {
-        let cols = freeze_cols.contains(p);
-        ctx.set_cursor_icon(if cols { CursorIcon::ResizeHorizontal } else { CursorIcon::ResizeVertical });
-        if app.grid.drag == Drag::None && !pointer.any_down() {
-            let tip = if cols { "Drag to freeze columns" } else { "Drag to freeze rows" };
-            resp.clone().on_hover_text_at_pointer(crate::i18n::current(ctx).tr(tip));
-        }
+        freeze_cursor(app, ctx, resp, pointer, freeze_cols.contains(p));
         return;
     }
+    let in_cells = geo.in_cells(p);
     let in_col_header = p.y < geo.cells.top() && p.y >= geo.head_top() && p.x >= geo.cells.left();
     let in_row_header = p.x < geo.cells.left() && p.x >= geo.head_left() && p.y >= geo.cells.top();
+    let near_col_edge = in_col_header && col_edge(geo, sh, p.x).is_some();
     let sel = app.session.active().map(|d| d.selection.clone()).unwrap_or_default();
     let cur_rect = geo.range_rect(sh, sel.current());
     let handle = Rect::from_center_size(cur_rect.right_bottom(), vec2(9.0, 9.0));
@@ -2089,16 +2097,8 @@ fn update_cursor(app: &mut SheetApp, ui: &egui::Ui, resp: &egui::Response, geo:
     let near_corner = selected_object.is_some_and(|(_, _, rect)| (p - rect.right_bottom()).length() < OBJECT_RESIZE_RADIUS);
     if app.grid.drag == Drag::None && near_corner {
         ctx.set_cursor_icon(CursorIcon::ResizeNwSe);
-    } else if (in_col_header && col_edge(geo, sh, p.x).is_some()) || (in_row_header && row_edge(geo, sh, p.y).is_some()) {
-        let near_col_edge = in_col_header && col_edge(geo, sh, p.x).is_some();
-        // Just past a hidden column or row, Excel shows a split cursor: dragging or
-        // double-clicking there unhides it.
-        let hidden = app.grid.drag == Drag::None
-            && if near_col_edge { hidden_col_edge(geo, sh, p.x).is_some() } else { hidden_row_edge(geo, sh, p.y).is_some() };
-        match pointer.hover_pos() {
-            Some(at) if hidden => paint_split_cursor(ctx, at, near_col_edge),
-            _ => ctx.set_cursor_icon(if near_col_edge { CursorIcon::ResizeColumn } else { CursorIcon::ResizeRow }),
-        }
+    } else if near_col_edge || (in_row_header && row_edge(geo, sh, p.y).is_some()) {
+        header_edge_cursor(app, ctx, pointer, geo, sh, p, near_col_edge);
     } else if on_handle && app.editor.is_none() {
         ctx.set_cursor_icon(CursorIcon::Crosshair);
         if app.grid.drag == Drag::None && !pointer.any_down() {
@@ -2115,6 +2115,26 @@ fn update_cursor(app: &mut SheetApp, ui: &egui::Ui, resp: &egui::Response, geo:
     }
 }
 
+/// The resize cursor for dragging a freeze bar.
+fn freeze_cursor(app: &SheetApp, ctx: &egui::Context, resp: &egui::Response, pointer: &egui::PointerState, cols: bool) {
+    ctx.set_cursor_icon(if cols { CursorIcon::ResizeHorizontal } else { CursorIcon::ResizeVertical });
+    if app.grid.drag == Drag::None && !pointer.any_down() {
+        let tip = if cols { "Drag to freeze columns" } else { "Drag to freeze rows" };
+        resp.clone().on_hover_text_at_pointer(crate::i18n::current(ctx).tr(tip));
+    }
+}
+
+/// The resize cursor over a column or row header edge. Just past a hidden column or row, Excel
+/// shows a split cursor: dragging or double-clicking there unhides it.
+fn header_edge_cursor(app: &SheetApp, ctx: &egui::Context, pointer: &egui::PointerState, geo: &Geo, sh: &Sheet, p: Pos2, near_col_edge: bool) {
+    let hidden =
+        app.grid.drag == Drag::None && if near_col_edge { hidden_col_edge(geo, sh, p.x).is_some() } else { hidden_row_edge(geo, sh, p.y).is_some() };
+    match pointer.hover_pos() {
+        Some(at) if hidden => paint_split_cursor(ctx, at, near_col_edge),
+        _ => ctx.set_cursor_icon(if near_col_edge { CursorIcon::ResizeColumn } else { CursorIcon::ResizeRow }),
+    }
+}
+
 fn interact(app: &mut SheetApp, ui: &mut egui::Ui, resp: &egui::Response, geo: &Geo, sh: &Sheet, wb: &Workbook) {
     // Text selection and editing must not also move the object or edit worksheet cells.
     if app.text_box_editor.is_some() || app.grid.hf_edit.is_some() {

crates/xlsx/src/styles.rs

@@ -359,59 +359,55 @@ pub fn read_styles(root: &El, checkboxes: &[bool], minor_font: &str) -> StylesIn
             }
         }
     }
-    let dxfs = root
-        .child("dxfs")
-        .map(|d| {
-            d.kids("dxf")
-                .map(|x| {
-                    let mut s = Style::default();
-                    if let Some(e) = x.child("font") {
-                        let f = read_font(e, &palette);
-                        // Differential fonts rarely name a face; unless stated, keep the default face and size.
-                        let has_size = e.child("sz").and_then(|n| n.attr_f64("val")).is_some();
-                        let has_name = e.child("name").and_then(|n| n.attr("val")).is_some();
-                        let name = if has_name { f.name.clone() } else { s.font.name.clone() };
-                        let size = if has_size { f.size } else { s.font.size };
-                        let def = Font::default();
-                        let st = &mut s.dxf_stated;
-                        st.bold = e.child("b").is_some() && !f.bold;
-                        st.italic = e.child("i").is_some() && !f.italic;
-                        st.strike = e.child("strike").is_some() && !f.strike;
-                        st.underline = e.child("u").is_some() && f.underline == Underline::None;
-                        st.size = has_size && size == def.size;
-                        st.name = has_name && name == def.name;
-                        st.scheme = e.child_val("scheme").map(str::to_string);
-                        // A differential font's scheme is in `dxf_stated`.
-                        s.font = Font { name, size, minor: s.font.minor, ..f };
-                    }
-                    if let Some(n) = x.child("numFmt") {
-                        if let Some(code) = n.attr("formatCode") {
-                            s.num_fmt = NumFmt::new(code);
-                        } else if let Some(id) = n.attr_u32("numFmtId") {
-                            s.num_fmt = num_fmt_code(id, &fmts);
-                        }
-                    }
-                    if let Some(f) = x.child("fill") {
-                        s.fill = read_fill(f, &palette, true);
-                    }
-                    if let Some(b) = x.child("border") {
-                        s.borders = read_border(b, &palette);
-                    }
-                    if let Some(a) = x.child("alignment") {
-                        s.align = read_alignment(a);
-                    }
-                    if let Some(p) = x.child("protection") {
-                        s.protection = read_protection(p);
-                        s.dxf_stated.protection = s.protection == Protection::default();
-                    }
-                    s
-                })
-                .collect()
-        })
-        .unwrap_or_default();
+    let dxfs = root.child("dxfs").map(|d| d.kids("dxf").map(|x| read_dxf(x, &palette, &fmts)).collect()).unwrap_or_default();
     StylesIn { xfs, dxfs, palette, named, num_fmts: fmts }
 }
 
+/// One differential format (`dxf`): the style it sets over a cell's own.
+fn read_dxf(x: &El, palette: &[u32], fmts: &HashMap<u32, String>) -> Style {
+    let mut s = Style::default();
+    if let Some(e) = x.child("font") {
+        let f = read_font(e, palette);
+        // Differential fonts rarely name a face; unless stated, keep the default face and size.
+        let has_size = e.child("sz").and_then(|n| n.attr_f64("val")).is_some();
+        let has_name = e.child("name").and_then(|n| n.attr("val")).is_some();
+        let name = if has_name { f.name.clone() } else { s.font.name.clone() };
+        let size = if has_size { f.size } else { s.font.size };
+        let def = Font::default();
+        let st = &mut s.dxf_stated;
+        st.bold = e.child("b").is_some() && !f.bold;
+        st.italic = e.child("i").is_some() && !f.italic;
+        st.strike = e.child("strike").is_some() && !f.strike;
+        st.underline = e.child("u").is_some() && f.underline == Underline::None;
+        st.size = has_size && size == def.size;
+        st.name = has_name && name == def.name;
+        st.scheme = e.child_val("scheme").map(str::to_string);
+        // A differential font's scheme is in `dxf_stated`.
+        s.font = Font { name, size, minor: s.font.minor, ..f };
+    }
+    if let Some(n) = x.child("numFmt") {
+        if let Some(code) = n.attr("formatCode") {
+            s.num_fmt = NumFmt::new(code);
+        } else if let Some(id) = n.attr_u32("numFmtId") {
+            s.num_fmt = num_fmt_code(id, fmts);
+        }
+    }
+    if let Some(f) = x.child("fill") {
+        s.fill = read_fill(f, palette, true);
+    }
+    if let Some(b) = x.child("border") {
+        s.borders = read_border(b, palette);
+    }
+    if let Some(a) = x.child("alignment") {
+        s.align = read_alignment(a);
+    }
+    if let Some(p) = x.child("protection") {
+        s.protection = read_protection(p);
+        s.dxf_stated.protection = s.protection == Protection::default();
+    }
+    s
+}
+
 // ---------------------------------------------------------------- writing
 
 pub fn color_attrs(c: &Color) -> String {

xtask/src/i18n_report.rs

@@ -116,6 +116,55 @@ pub fn catalog_keys(source: &str) -> BTreeSet<String> {
     keys
 }
 
+/// The character a `\u{...}` escape stands for, if it names a valid code point.
+fn unicode_escape(chars: &mut std::iter::Peekable<std::str::CharIndices<'_>>) -> Option<char> {
+    let mut hex = String::new();
+    for (_, c) in chars.by_ref() {
+        match c {
+            '}' => break,
+            '{' => {}
+            c => hex.push(c),
+        }
+    }
+    u32::from_str_radix(&hex, 16).ok().and_then(char::from_u32)
+}
+
+/// The value of a string literal whose opening quote was just read, and the byte offset past
+/// its closing quote (`len`, the source's length, when it is never closed).
+fn string_literal(chars: &mut std::iter::Peekable<std::str::CharIndices<'_>>, len: usize) -> (String, usize) {
+    let mut value = String::new();
+    let mut end = len;
+    while let Some((j, c)) = chars.next() {
+        match c {
+            '"' => {
+                end = j + 1;
+                break;
+            }
+            '\\' => match chars.next().map(|(_, c)| c) {
+                Some('n') => value.push('\n'),
+                Some('t') => value.push('\t'),
+                Some('r') => value.push('\r'),
+                Some('0') => value.push('\0'),
+                Some(c @ ('\\' | '"' | '\'')) => value.push(c),
+                Some('u') => {
+                    if let Some(c) = unicode_escape(chars) {
+                        value.push(c);
+                    }
+                }
+                // A line continuation skips the newline and the next line's indentation.
+                Some('\n') => {
+                    while chars.peek().is_some_and(|(_, c)| c.is_whitespace()) {
+                        chars.next();
+                    }
+                }
+                _ => {}
+            },
+            c => value.push(c),
+        }
+    }
+    (value, end)
+}
+
 /// Every string literal outside `//` comments: its decoded value, and the byte range from its
 /// opening quote to just past its closing one.
 fn literals(source: &str) -> Vec<(String, usize, usize)> {
@@ -133,44 +182,7 @@ fn literals(source: &str) -> Vec<(String, usize, usize)> {
         if c != '"' {
             continue;
         }
-        let mut value = String::new();
-        let mut end = source.len();
-        while let Some((j, c)) = chars.next() {
-            match c {
-                '"' => {
-                    end = j + 1;
-                    break;
-                }
-                '\\' => match chars.next().map(|(_, c)| c) {
-                    Some('n') => value.push('\n'),
-                    Some('t') => value.push('\t'),
-                    Some('r') => value.push('\r'),
-                    Some('0') => value.push('\0'),
-                    Some(c @ ('\\' | '"' | '\'')) => value.push(c),
-                    Some('u') => {
-                        let mut hex = String::new();
-                        for (_, c) in chars.by_ref() {
-                            match c {
-                                '}' => break,
-                                '{' => {}
-                                c => hex.push(c),
-                            }
-                        }
-                        if let Some(c) = u32::from_str_radix(&hex, 16).ok().and_then(char::from_u32) {
-                            value.push(c);
-                        }
-                    }
-                    // A line continuation skips the newline and the next line's indentation.
-                    Some('\n') => {
-                        while chars.peek().is_some_and(|(_, c)| c.is_whitespace()) {
-                            chars.next();
-                        }
-                    }
-                    _ => {}
-                },
-                c => value.push(c),
-            }
-        }
+        let (value, end) = string_literal(&mut chars, source.len());
         out.push((value, i, end));
     }
     out