refactor: split complex functions for Sonar S3776

Extract helpers from auto_sum (selection and single-cell guess), update_cursor
(drag, hover, freeze, and header-edge cursors) and read_styles (dxf reader).
No behaviour change.

crates/engine/src/cmd/data.rs

@@ -1454,34 +1454,6 @@ fn show_levels(s: &mut Session, p: &Json) -> Result<Json> {
 
 /// Data ▸ Outline ▸ Settings: whether summary rows sit below their detail and summary columns
 /// right of it. A changed direction moves each collapsed group's mark (+) to its new summary line.
-/// Moves the collapsed marks of a line axis to the summary line on its new side (`on` is the new
-/// setting, `was_before` the old one). A line that nested groups share keeps its mark on the outermost
-/// group whose detail is all hidden, or the outermost when none is.
-fn move_marks(map: &mut std::collections::BTreeMap<u32, LineInfo>, was_before: bool, on: bool) {
-    let mut marked: Vec<outline::OutlineGroup> =
-        outline::groups_with(map, was_before).into_iter().filter(|g| g.has_summary() && map.get(&g.summary()).is_some_and(|e| e.collapsed)).collect();
-    // A mark on a line that nested groups share moves with the outermost of them whose
-    // detail is all hidden, or with the outermost when none is.
-    let mut owner: std::collections::BTreeMap<u32, (bool, u8)> = std::collections::BTreeMap::new();
-    for g in &marked {
-        let key = (!g.collapsed, g.level);
-        let best = owner.entry(g.summary()).or_insert(key);
-        *best = (*best).min(key);
-    }
-    marked.retain(|g| owner.get(&g.summary()) == Some(&(!g.collapsed, g.level)));
-    for g in &marked {
-        if let Some(e) = map.get_mut(&g.summary()) {
-            e.collapsed = false;
-        }
-    }
-    for g in marked {
-        let g = outline::OutlineGroup { summary_before: !on, ..g };
-        if g.has_summary() {
-            map.entry(g.summary()).or_default().collapsed = true;
-        }
-    }
-}
-
 fn outline_settings(s: &mut Session, p: &Json) -> Result<Json> {
     let si = target_sheet(s, p)?;
     edit(s, |cx| {
@@ -1497,7 +1469,31 @@ fn outline_settings(s: &mut Session, p: &Json) -> Result<Json> {
             if was_before != on {
                 continue;
             }
-            move_marks(if rows { &mut sh.rows } else { &mut sh.cols }, was_before, on);
+            let map = if rows { &mut sh.rows } else { &mut sh.cols };
+            let mut marked: Vec<outline::OutlineGroup> = outline::groups_with(map, was_before)
+                .into_iter()
+                .filter(|g| g.has_summary() && map.get(&g.summary()).is_some_and(|e| e.collapsed))
+                .collect();
+            // A mark on a line that nested groups share moves with the outermost of them whose
+            // detail is all hidden, or with the outermost when none is.
+            let mut owner: std::collections::BTreeMap<u32, (bool, u8)> = std::collections::BTreeMap::new();
+            for g in &marked {
+                let key = (!g.collapsed, g.level);
+                let best = owner.entry(g.summary()).or_insert(key);
+                *best = (*best).min(key);
+            }
+            marked.retain(|g| owner.get(&g.summary()) == Some(&(!g.collapsed, g.level)));
+            for g in &marked {
+                if let Some(e) = map.get_mut(&g.summary()) {
+                    e.collapsed = false;
+                }
+            }
+            for g in marked {
+                let g = outline::OutlineGroup { summary_before: !on, ..g };
+                if g.has_summary() {
+                    map.entry(g.summary()).or_default().collapsed = true;
+                }
+            }
         }
         Ok(json!({"summaryBelow": sh.summary_below, "summaryRight": sh.summary_right}))
     })

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/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/ui-egui/src/outline.rs

@@ -165,35 +165,6 @@ impl Dir<'_> {
 }
 
 /// The band's buttons and brackets for this frame.
-/// The bracket for one group's detail, and its tick, on the lane `across`; `button` is the group's
-/// summary button when it is on screen.
-fn group_bracket(out: &mut Layout, dir: &Dir, grp: &OutlineGroup, button: Option<f32>, across: f32, side: f32) {
-    let first = dir.first_visible(grp.start, grp.end);
-    let Some((first_line, (a0, _))) = first else { return };
-    if grp.summary_before {
-        // From the button down (or across) to the last detail line, with the tick there.
-        let a0 = button.map_or(a0, |mid| mid + side / 2.0);
-        let end = dir.start(grp.end) + dir.size(grp.end);
-        let a1 = end.min(dir.hi);
-        if a1 <= a0 {
-            return;
-        }
-        let tick = (end <= dir.hi).then(|| [dir.point(a1 - 0.5, across), dir.point(a1 - 0.5, across + side / 2.0)]);
-        out.brackets.push(Bracket { line: [dir.point(a0, across), dir.point(a1 - 0.5, across)], tick });
-        return;
-    }
-    let a1 = match button {
-        Some(mid) => mid - side / 2.0,
-        None => dir.start(grp.summary()).min(dir.hi),
-    };
-    if a1 <= a0 {
-        return;
-    }
-    let start_shown = first_line == grp.start && (a0 - dir.start(grp.start)).abs() < 0.5;
-    let tick = start_shown.then(|| [dir.point(a0 + 0.5, across), dir.point(a0 + 0.5, across + side / 2.0)]);
-    out.brackets.push(Bracket { line: [dir.point(a0 + 0.5, across), dir.point(a1, across)], tick });
-}
-
 pub fn layout(geo: &Geo, sh: &Sheet) -> Layout {
     let mut out = Layout::default();
     let zoom = (geo.z / DISPLAY_SCALE).max(0.1);
@@ -241,7 +212,30 @@ pub fn layout(geo: &Geo, sh: &Sheet) -> Layout {
                 continue;
             }
             // The bracket, over the part of the detail that is on screen.
-            group_bracket(&mut out, dir, grp, button, across, side);
+            let first = dir.first_visible(grp.start, grp.end);
+            let Some((first_line, (a0, _))) = first else { continue };
+            if grp.summary_before {
+                // From the button down (or across) to the last detail line, with the tick there.
+                let a0 = button.map_or(a0, |mid| mid + side / 2.0);
+                let end = dir.start(grp.end) + dir.size(grp.end);
+                let a1 = end.min(dir.hi);
+                if a1 <= a0 {
+                    continue;
+                }
+                let tick = (end <= dir.hi).then(|| [dir.point(a1 - 0.5, across), dir.point(a1 - 0.5, across + side / 2.0)]);
+                out.brackets.push(Bracket { line: [dir.point(a0, across), dir.point(a1 - 0.5, across)], tick });
+                continue;
+            }
+            let a1 = match button {
+                Some(mid) => mid - side / 2.0,
+                None => dir.start(grp.summary()).min(dir.hi),
+            };
+            if a1 <= a0 {
+                continue;
+            }
+            let start_shown = first_line == grp.start && (a0 - dir.start(grp.start)).abs() < 0.5;
+            let tick = start_shown.then(|| [dir.point(a0 + 0.5, across), dir.point(a0 + 0.5, across + side / 2.0)]);
+            out.brackets.push(Bracket { line: [dir.point(a0 + 0.5, across), dir.point(a1, across)], tick });
         }
     }
     out

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 {