View: Hide White Space between pages in Print Layout (#645) (#684)

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

ROADMAP.md

@@ -130,6 +130,7 @@ Ranked, to beta (detail and remaining milestones in [docs/roadmap.md](docs/roadm
 ## Progress log
 
 | Date | What landed |
+| 2026-10-11 | Hide White Space (#645): `view.hideWhiteSpace` (View › Show checkbox, or double-click the gap between pages) collapses margins, headers and footers between pages to a thin line in Print Layout; screen only, page count unchanged |
 | 2026-10-11 | Fonts: Palatino Linotype and Book Antiqua fall back to Palatino (macOS) or TeX Gyre Pagella / P052 / URW Palladio (Linux) before generic serif (#670) |
 |---|---|
 | 2026-10-11 | Security review fixes: `ui.render`/`ui.screenshot` without a `path` (and the MCP bridge's `render_page`/`screenshot`) return the PNG in the reply instead of writing a fixed name into the shared temporary folder; exported HTML/Markdown write `href` only for web, mail, bookmark and relative links, never `javascript:` and other schemes (one allow-list in `wordcraft_doc::link`) |

crates/engine/src/cmd/view.rs

@@ -27,6 +27,10 @@ pub fn specs() -> Vec<CommandSpec> {
         // The body as an outline of its headings, with the Outlining tab (`outline.*`).
         CommandSpec::new("view.outline", "Outline", "View › Views", |s, _| mode(s, ViewMode::Outline, false)).key("Mod+Alt+O").pure(),
         CommandSpec::new("view.readMode", "Read Mode", "View › Views", |s, _| mode(s, ViewMode::Print, true)).pure(),
+        // Print Layout: hide the white space (margins, headers, footers) between pages. Screen only.
+        CommandSpec::new("view.hideWhiteSpace", "Hide White Space", "View › Show", |s, v| toggle(s, v, |x| &mut x.hide_white_space))
+            .params(r#"{"value"?: bool}"#)
+            .pure(),
         CommandSpec::new("view.focus", "Focus", "View › Immersive", |s, v| toggle(s, v, |x| &mut x.focus_mode)).pure(),
         CommandSpec::new("view.ruler", "Ruler", "View › Show", |s, v| toggle(s, v, |x| &mut x.ruler)).pure(),
         // The drawing grid over the page (screen only; never printed or exported).

crates/engine/src/session.rs

@@ -95,6 +95,11 @@ pub struct ViewState {
     /// Show field codes instead of their results (`view.fieldCodes`, Alt+F9).
     #[serde(default)]
     pub field_codes: bool,
+    /// Print Layout › Hide White Space: pages run together, the top and bottom margins (with
+    /// headers and footers) between pages collapse to a thin line. On screen only; the layout
+    /// and page count are unchanged.
+    #[serde(default)]
+    pub hide_white_space: bool,
     /// Outline view: collapsed headings, Show Level, first lines, text formatting.
     #[serde(default)]
     pub outline: crate::cmd::outline::OutlineState,
@@ -136,6 +141,7 @@ impl Default for ViewState {
             hide_ink: false,
             draw: Default::default(),
             field_codes: false,
+            hide_white_space: false,
             outline: Default::default(),
             design_mode: false,
         }

crates/engine/src/tests.rs

@@ -3588,6 +3588,17 @@ fn note_options_per_section_and_convert_notes() {
     assert!(s.run("references.convertNotes", &json!({"to": "sideways"})).is_err());
 }
 
+#[test]
+fn hide_white_space_toggles_view_state_only() {
+    let mut s = s();
+    let before = s.doc.body.len();
+    assert!(!s.view.hide_white_space);
+    assert_eq!(run(&mut s, "view.hideWhiteSpace", json!({}))["value"], true);
+    assert!(s.view.hide_white_space);
+    assert_eq!(run(&mut s, "view.hideWhiteSpace", json!({"value": false}))["value"], false);
+    assert_eq!(s.doc.body.len(), before, "a view option never edits the document");
+}
+
 /// The first SmartArt (or other graphic) in the body, selected.
 fn select_graphic(s: &mut Session) {
     let (path, off) = (0..s.doc.body.len() as u32)

crates/ui-egui/src/canvas.rs

@@ -181,6 +181,62 @@ pub struct Geometry {
     pub scale: f32,
     /// Pages per row.
     pub cols: usize,
+    /// Per page, the vertical range (pixels from the page rect's top) that is on screen. The
+    /// whole page, except with Hide White Space, which cuts the margins between pages.
+    pub bands: Vec<(f32, f32)>,
+}
+
+/// Room kept above the first line and below the last line of a page when white space is hidden (points).
+const WHITE_SPACE_PAD: f32 = 6.0;
+/// The line drawn between two pages when white space is hidden (pixels).
+const SEAM: f32 = 1.0;
+
+/// Hide White Space: stack single-column pages (`rects`, full pages) so that only each page's
+/// text area (`bodies`: top and bottom of the body in points, plus a little room) shows, with a
+/// [`SEAM`] between pages. The first page keeps its top and the last its bottom. Rects keep the
+/// full page size, so page coordinates still map as `(p - rect.min) / scale`; neighbouring rects
+/// overlap in the hidden margins. Returns the moved rects, the visible band of each, and the
+/// content height.
+fn collapse_white_space(rects: &[Rect], bodies: &[(f32, f32)], scale: f32, avail_h: f32) -> (Vec<Rect>, Vec<(f32, f32)>, f32) {
+    let n = rects.len();
+    let scale = if scale.is_finite() { scale.clamp(0.01, 10.0) } else { PX_PER_PT };
+    let avail_h = if avail_h.is_finite() { avail_h } else { 0.0 };
+    let mut out = Vec::with_capacity(n);
+    let mut bands = Vec::with_capacity(n);
+    let Some(first) = rects.first() else { return (out, bands, avail_h) };
+    let mut cursor = first.min.y;
+    for (i, r) in rects.iter().enumerate() {
+        let h = if r.height().is_finite() { r.height().max(0.0) } else { 0.0 };
+        let (bt, bb) = bodies.get(i).copied().unwrap_or((0.0, h));
+        let fin = |v: f32, d: f32| if v.is_finite() { v } else { d };
+        let top = if i == 0 { 0.0 } else { (fin(bt, 0.0) * scale - WHITE_SPACE_PAD * scale).clamp(0.0, h) };
+        let bot = if i + 1 == n { h } else { (fin(bb, 0.0) * scale + WHITE_SPACE_PAD * scale).clamp(top, h) };
+        let y = cursor - top;
+        out.push(Rect::from_min_size(pos2(r.min.x, y), r.size()));
+        bands.push((top, bot));
+        cursor = y + bot + SEAM;
+    }
+    (out, bands, (cursor - SEAM + GAP).max(avail_h))
+}
+
+/// True when any page is cut to a band (white space is hidden).
+fn white_space_hidden(rects: &[Rect], bands: &[(f32, f32)]) -> bool {
+    rects.iter().zip(bands).any(|(r, b)| b.0 > 0.5 || b.1 < r.height() - 0.5)
+}
+
+/// True when a double-click at `p` is on the space between two pages (or on the seam when white
+/// space is hidden): Word's way to toggle Hide White Space.
+fn on_page_gap(rects: &[Rect], bands: &[(f32, f32)], p: Pos2) -> bool {
+    let hidden = white_space_hidden(rects, bands);
+    rects.windows(2).enumerate().any(|(i, w)| {
+        let (a, b) = (w[0], w[1]);
+        let in_x = p.x >= a.min.x.min(b.min.x) && p.x <= a.max.x.max(b.max.x);
+        let (y0, y1) = match bands.get(i) {
+            Some(&(_, bot)) if hidden => (a.min.y + bot - 3.0, a.min.y + bot + SEAM + 3.0),
+            _ => (a.max.y, b.min.y),
+        };
+        in_x && p.y >= y0 && p.y <= y1
+    })
 }
 
 /// Width of the markup area beside each page for comment balloons (points), or 0.
@@ -281,8 +337,16 @@ pub fn geometry(app: &WordApp, l: &DocLayout, avail: egui::Vec2) -> Geometry {
     };
     let cols = if v.read_mode { 2 } else { columns_for(avail.x, maxw * scale, l.pages.len(), min_cols, auto) };
     let sizes: Vec<(f32, f32)> = l.pages.iter().map(|p| (p.w, p.h)).collect();
-    let (rects, size) = place_pages(&sizes, markup, scale, cols, avail);
-    Geometry { rects, size, scale, cols }
+    let (mut rects, mut size) = place_pages(&sizes, markup, scale, cols, avail);
+    let mut bands: Vec<(f32, f32)> = rects.iter().map(|r| (0.0, r.height())).collect();
+    let editing_part = matches!(app.session.sel.focus.story, StoryRef::Part(_));
+    if v.hide_white_space && v.mode == wordcraft_layout::ViewMode::Print && !v.read_mode && cols == 1 && !editing_part && rects.len() > 1 {
+        let bodies: Vec<(f32, f32)> = l.pages.iter().map(|p| (p.body.y, p.body.bottom())).collect();
+        let (r, b, h) = collapse_white_space(&rects, &bodies, scale, avail.y);
+        (rects, bands) = (r, b);
+        size.y = h;
+    }
+    Geometry { rects, size, scale, cols, bands }
 }
 
 /// While a fit mode (Page Width, One Page, Multiple Pages) sizes the page, keep the session's zoom
@@ -476,6 +540,7 @@ pub fn show(app: &mut WordApp, ui: &mut Ui) {
         for (i, pr) in geo.rects.iter().enumerate() {
             let sr = pr.translate(content_origin.to_vec2());
             let Some(page) = layout.pages.get(i) else { continue };
+            let (band_top, band_bot) = geo.bands.get(i).copied().unwrap_or((0.0, sr.height()));
             let scale_px = (geo.scale * ppp).min(max_tex / page.w.max(1.0)).min(max_tex / page.h.clamp(1.0, 1e6)).max(0.05);
             let key = page_key(app, page, scale_px, dim_body);
             let fresh = app.canvas.textures.get(&i).is_some_and(|(k, _)| *k == key);
@@ -486,9 +551,17 @@ pub fn show(app: &mut WordApp, ui: &mut Ui) {
                 sr
             };
             rects.push(visual_sr);
-            if !sr.intersects(ui.clip_rect().expand(200.0)) {
+            // Hide White Space shows only a band of the page; everything below paints into it.
+            let band =
+                Rect::from_min_max(pos2(visual_sr.min.x - 4.0, visual_sr.min.y + band_top), pos2(visual_sr.max.x + 4.0, visual_sr.min.y + band_bot));
+            if !band.intersects(ui.clip_rect().expand(200.0)) {
                 continue;
             }
+            let painter = if band_top <= 0.0 && band_bot >= sr.height() {
+                painter.clone()
+            } else {
+                painter.with_clip_rect(painter.clip_rect().intersect(band))
+            };
             // Shadow and paper.
             painter.rect_filled(visual_sr.translate(vec2(0.0, 2.0)).expand(1.5), 1.0, t.page_shadow);
             painter.rect_filled(visual_sr, 0.0, if dark_page { Color32::from_gray(dark_paper) } else { Color32::WHITE });
@@ -581,6 +654,14 @@ pub fn show(app: &mut WordApp, ui: &mut Ui) {
                 }
             }
         }
+        // Hide White Space: a thin line where one page ends and the next begins.
+        for (i, pair) in rects.windows(2).enumerate() {
+            let Some(&(_, bot)) = geo.bands.get(i) else { continue };
+            if white_space_hidden(&geo.rects, &geo.bands) {
+                let y = pair[0].min.y + bot;
+                painter.rect_filled(Rect::from_min_max(pos2(pair[0].min.x, y), pos2(pair[0].max.x, y + SEAM)), 0.0, t.border_strong);
+            }
+        }
         if rendered > 0 {
             app.canvas.render_ms = crate::now_ms() - t0;
         }
@@ -749,6 +830,15 @@ pub fn show(app: &mut WordApp, ui: &mut Ui) {
     app.canvas.focused = resp.has_focus();
     // Screen readers: the document under the canvas, with the caret (#488).
     crate::a11y::expose(app, ui.ctx(), resp.id, &layout, &rects, area);
+    // Double-click the space between two pages (or the line between them) to hide or show it.
+    if resp.double_clicked()
+        && app.session.view.mode == wordcraft_layout::ViewMode::Print
+        && !app.session.view.read_mode
+        && let Some(p) = resp.interact_pointer_pos()
+        && on_page_gap(&rects, &geo.bands, p)
+    {
+        let _ = app.run("view.hideWhiteSpace", json!({"value": !app.session.view.hide_white_space}));
+    } else
     // Draw Table / Eraser own the mouse while on (no caret moves); else the usual editing.
     if !crate::table_pen::pointer(app, ui, &resp, &rects, &layout, geo.scale) {
         mouse(app, ui, &resp, &rects, &layout, geo.scale);
@@ -1123,7 +1213,8 @@ pub fn nearest_page(rects: &[Rect], p: Pos2) -> Option<usize> {
     let mut best: Option<(usize, f32)> = None;
     for (i, r) in rects.iter().enumerate() {
         let d = if r.contains(p) {
-            0.0
+            // Pages overlap in the margins Hide White Space cuts: the one whose middle is nearer wins.
+            1e-3 * (p.y - r.center().y).abs() / r.height().max(1.0)
         } else {
             let dx = (r.min.x - p.x).max(p.x - r.max.x).max(0.0);
             let dy = (r.min.y - p.y).max(p.y - r.max.y).max(0.0);
@@ -2223,4 +2314,36 @@ mod tests {
 
         assert_eq!(visual, layout);
     }
+
+    #[test]
+    fn hiding_white_space_stacks_page_bands_and_keeps_hit_testing() {
+        let scale = 1.0;
+        let sizes = [(612.0, 792.0); 3];
+        let (rects, _) = place_pages(&sizes, 0.0, scale, 1, vec2(800.0, 600.0));
+        // Body from 72 to 720 pt on every page.
+        let bodies = [(72.0, 720.0); 3];
+        let (moved, bands, h) = collapse_white_space(&rects, &bodies, scale, 600.0);
+        assert_eq!(bands[0].0, 0.0, "first page keeps its top");
+        assert_eq!(bands[2].1, 792.0, "last page keeps its bottom");
+        assert_eq!(bands[1], (66.0, 726.0));
+        // Bands abut with one seam, so the content is much shorter than three full pages.
+        assert_eq!(moved[1].min.y + bands[1].0, moved[0].min.y + bands[0].1 + SEAM);
+        assert!(h < rects[2].bottom() - 2.0 * 66.0 * 2.0);
+        // A point inside page 2's band maps to that page and the right page coordinates.
+        let p = pos2(moved[1].center().x, moved[1].min.y + 300.0);
+        assert_eq!(page_at_index(&moved, p), Some(1));
+        // Just above the seam is page 1's text area, just below is page 2's, though the rects overlap.
+        let seam = moved[0].min.y + bands[0].1;
+        assert_eq!(nearest_page(&moved, pos2(moved[0].center().x, seam - 2.0)), Some(0));
+        assert_eq!(nearest_page(&moved, pos2(moved[0].center().x, seam + SEAM + 2.0)), Some(1));
+        assert!(on_page_gap(&moved, &bands, pos2(moved[0].center().x, seam + 0.5)));
+        assert!(!on_page_gap(&moved, &bands, pos2(moved[0].center().x, seam - 40.0)));
+        // Hostile numbers never panic.
+        let _ = collapse_white_space(&rects, &[(f32::NAN, f32::INFINITY), (-1e9, 1e9)], f32::NAN, f32::NAN);
+        let _ = collapse_white_space(&[], &[], 1.0, 1.0);
+    }
+
+    fn page_at_index(rects: &[Rect], p: Pos2) -> Option<usize> {
+        nearest_page(rects, p)
+    }
 }

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

@@ -1698,6 +1698,7 @@
 	Continuous numbering	Numeración continua
 	Apply	Aplicar
 	Convert Notes	Convertir notas
+	Hide White Space	Ocultar espacio en blanco
 	All pages	Todas las páginas
 	Current page	Página actual
 	Selected pages	Páginas seleccionadas

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

@@ -1659,6 +1659,7 @@
 	Continuous numbering	Pidev nummerdus
 	Apply	Rakenda
 	Convert Notes	Teisenda märkused
+	Hide White Space	Peida tühi ala lehtede vahel
 	All pages	Kõik leheküljed
 	Current page	Praegune lehekülg
 	Selected pages	Valitud leheküljed

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

@@ -1682,6 +1682,7 @@
 	Continuous numbering	通し番号
 	Apply	適用
 	Convert Notes	注の変換
+	Hide White Space	余白を非表示
 	All pages	すべてのページ
 	Current page	現在のページ
 	Selected pages	選択したページ

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

@@ -1694,6 +1694,7 @@
 	Continuous numbering	Numeração contínua
 	Apply	Aplicar
 	Convert Notes	Converter notas
+	Hide White Space	Ocultar espaço em branco
 	All pages	Todas as páginas
 	Current page	Página atual
 	Selected pages	Páginas selecionadas

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

@@ -2127,6 +2127,7 @@ preview	Title	Пример
 	Continuous numbering	Сквозная нумерация
 	Apply	Применить
 	Convert Notes	Преобразовать сноски
+	Hide White Space	Скрыть пустое место между страницами
 	All pages	Все страницы
 	Current page	Текущая страница
 	Selected pages	Выбранные страницы

crates/ui-egui/src/i18n/sr-latn.tsv

@@ -1692,6 +1692,7 @@
 	Continuous numbering	Neprekidna numeracija
 	Apply	Primeni
 	Convert Notes	Pretvori napomene
+	Hide White Space	Sakrij prazan prostor
 	All pages	Sve stranice
 	Current page	Trenutna stranica
 	Selected pages	Izabrane stranice

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

@@ -1696,6 +1696,7 @@
 	Continuous numbering	Непрекидна нумерација
 	Apply	Примени
 	Convert Notes	Претвори напомене
+	Hide White Space	Сакриј празан простор
 	All pages	Све странице
 	Current page	Тренутна страница
 	Selected pages	Изабране странице

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

@@ -1749,6 +1749,7 @@
 	Continuous numbering	Sürekli numaralandırma
 	Apply	Uygula
 	Convert Notes	Notları Dönüştür
+	Hide White Space	Boşluğu gizle
 	All pages	Tüm sayfalar
 	Current page	Geçerli sayfa
 	Selected pages	Seçili sayfalar

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

@@ -1694,6 +1694,7 @@
 	Continuous numbering	Наскрізна нумерація
 	Apply	Застосувати
 	Convert Notes	Перетворити примітки
+	Hide White Space	Приховати порожній простір
 	All pages	Усі сторінки
 	Current page	Поточна сторінка
 	Selected pages	Вибрані сторінки

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

@@ -1694,6 +1694,7 @@
 	Continuous numbering	连续编号
 	Apply	应用
 	Convert Notes	转换注释
+	Hide White Space	隐藏空白
 	All pages	所有页面
 	Current page	当前页
 	Selected pages	所选页面

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

@@ -1683,6 +1683,7 @@
 	Continuous numbering	連續編號
 	Apply	套用
 	Convert Notes	轉換附註
+	Hide White Space	隱藏空白
 	All pages	所有頁面
 	Current page	目前頁面
 	Selected pages	所選頁面

crates/ui-egui/src/ribbon.rs

@@ -1501,6 +1501,10 @@ fn view(app: &mut WordApp, ui: &mut Ui) {
             if ui.checkbox(&mut n, tl!("Navigation Pane")).changed() {
                 let _ = app.run("view.navigationPane", json!({"value": n}));
             }
+            let mut w = v.hide_white_space;
+            if ui.checkbox(&mut w, tl!("Hide White Space")).changed() {
+                let _ = app.run("view.hideWhiteSpace", json!({"value": w}));
+            }
         });
     });
     group(ui, "Zoom", None, app, |ui, app| {