Merge PR #3828: Add thumbnail size controls to the Pages inspector

Conflicts: - crates/ui-egui/src/i18n/*.tsv: union of both sides' new keys - ATTRIBUTION.toml: ours; hashes recomputed at the end of the track - ROADMAP.md, docs/roadmap.md: both progress-log entries, newest first - parity/acrobat-features.toml (organize page grid): main's evidence and remembered-size note, with the PR's Pages inspector sentence
2026-10-30 21:17:55 -06:00 · 2026-10-22 01:45:41 +00:00
parent ffaf312358 1f78e2f37d
commit b1986fe954
34 changed files with 300 additions and 6 deletions
@@ -140,6 +140,8 @@ Right-click a PDF tab to close it, reopen the last closed file-backed tab, or re

 Bookmarks, page thumbnails and the document's own page labels (i, ii, 1, 2…) keep you oriented in long documents. Search bookmark titles in the Bookmarks panel to find nested entries even when their parents are collapsed. Matches keep their ancestors for context; Clear restores the unfiltered tree without changing its expansion state.

+In **Inspector > Pages**, use **Thumbnail size** and the smaller/larger buttons to show more pages or inspect larger previews (50–150%). This changes only the thumbnails, keeping multi-page selection and the current page in view. The size belongs to the open document view and survives reloading its file; it is not remembered after restarting. Agents can set it with `ui.set {"key":"thumbnail-zoom","value":"75"}` and read `active.thumbnail_zoom` from `ui.state`.
+
 <table>
 <tr>
 <td width="50%"><img src="docs/images/pdfcraft-find.png" alt="The find bar showing match 10 of 16 for the word 'type', highlighted in the Expressive Type chapter heading"></td>
@@ -1,5 +1,7 @@
 # PdfCraft roadmap

+> **Last reviewed:** 2026-10-21 · **Last updated:** 2026-10-21 · **Change:** minor (M3, #3808: the Pages inspector has an independent 50–150% thumbnail size slider and buttons; selection and current-page following are retained, with headless ui.set coverage. Estimates unchanged.)
+
 **Stage: alpha** · next: beta, ~25% (ready for real work 50% → 75%) and ~400–700 h away

 > **Last reviewed:** 2026-10-18 · **Last updated:** 2026-10-18 · **Change:** minor (M5, PR #1971: bounded nested FDF export excludes source page/page-tree dictionaries; refreshed against upstream 4db6ac4a; estimates unchanged)
@@ -172,6 +174,7 @@ Ranked; detail and the full milestone table in [docs/roadmap.md](docs/roadmap.md

 ## Progress log

+- **2026-10-21 (M3, #3808):** Page thumbnails in the Inspector can be resized independently from the document and Organize, with a slider, buttons and `thumbnail-zoom` control option. Selection, page following and reload are covered by regressions. Estimates unchanged.
 - **2026-10-20 (M6, calculation order page):** Prepare a form ▸ Calculation order, a page of its own, lists the calculated fields in the order they calculate with their formulas and values, moved with Up/Down arrows (as Acrobat's Set Field Calculation Order), Alt+↑/↓ or by dragging. A card says what is wrong with the order and holds Fix order; a loop has a card of its own that opens one of its formulas. On the page, each calculated field shows its step, and arrows show what the field in focus reads and what reads it. Estimates unchanged.
 - **2026-10-20 (M6, calculation order):** The order a form's fields calculate in (`/CO`) is read, checked, fixed and set headlessly with `form_calculation_order`: it says which fields read one calculated later (they show stale values), which read each other in a loop, and which the PDF's order leaves out; Fix order moves only what must move, in one undo step, and the form recalculates. Editing a formula no longer moves its field to the end of the order, and a field the order lists twice calculates once. Estimates unchanged.
 - **2026-10-19 (M6, renames keep formulas):** Renaming a field renames it in every calculation that reads it, in the same undo step: `AFSimple_Calculate` field lists, simplified field notation (the comment and the JavaScript after it) and `getField` calls naming it in one string literal; the rest of each script is kept as written. A sum used to drop the renamed field, notation read it as 0 and a script kept a stale value. Field Properties says how many formulas changed and `form_set_props` lists them as `formulas_updated`. Names built at run time and other events' scripts are not rewritten. Estimates unchanged.
@@ -565,6 +565,8 @@ pub struct DocView {
    /// The current page the Pages panel last followed: it scrolls to the current page's
    /// thumbnail only when the page changes.
    pub(crate) panel_followed: Option<usize>,
+    /// Scale of the thumbnails in the Pages inspector, independent of document and grid zoom.
+    thumbnail_zoom: f32,
    /// How large the page grid draws its pages (1.0 = the usual thumbnails).
    grid_zoom: f32,
    /// A zoom asked for this frame (toolbar, pinch, keys); the grid applies it once it has laid
@@ -603,6 +605,8 @@ pub struct DocView {

 /// The page grid's zoom range and the step of its buttons and keys.
 pub const GRID_ZOOM_RANGE: std::ops::RangeInclusive<f32> = 0.5..=3.0;
+/// Thumbnail size in the Pages inspector, relative to its usual size.
+pub const THUMBNAIL_ZOOM_RANGE: std::ops::RangeInclusive<f32> = 0.5..=1.5;
 const GRID_ZOOM_STEP: f32 = 1.25;
 /// How far a sharp grid render may be from the size drawn before it is redone: a pinch changes
 /// the size on every frame, and a slightly soft or slightly large image is fine meanwhile.
@@ -785,6 +789,7 @@ impl DocView {
            pages_panel: None,
            panel_gap: None,
            panel_followed: None,
+            thumbnail_zoom: 1.0,
            grid_zoom: 1.0,
            grid_zoom_request: None,
            grid_anchor: None,
@@ -862,6 +867,7 @@ impl DocView {
        fresh.current = self.current;
        fresh.organize = self.organize;
        fresh.grid_zoom = self.grid_zoom;
+        fresh.thumbnail_zoom = self.thumbnail_zoom;
        // Same document id, so the scroll offset egui keeps for it is still this document's.
        fresh.shown = self.shown;
        fresh.highlight_fields = self.highlight_fields;
@@ -1498,6 +1504,23 @@ impl DocView {
        self.grid_zoom
    }

+    /// Scale of the thumbnails in the Pages inspector (1.0 is the usual size).
+    pub fn thumbnail_zoom(&self) -> f32 {
+        self.thumbnail_zoom
+    }
+
+    /// Resize the inspector thumbnails, keeping the current page in view after layout.
+    /// Out-of-range values are clamped; non-finite values are ignored.
+    pub fn set_thumbnail_zoom(&mut self, zoom: f32) {
+        if zoom.is_finite() {
+            let zoom = zoom.clamp(*THUMBNAIL_ZOOM_RANGE.start(), *THUMBNAIL_ZOOM_RANGE.end());
+            if zoom != self.thumbnail_zoom {
+                self.thumbnail_zoom = zoom;
+                self.panel_followed = None;
+            }
+        }
+    }
+
    /// Zoom the page grid; out-of-range values are clamped and nonsense is ignored.
    pub fn set_grid_zoom(&mut self, zoom: f32) {
        if zoom.is_finite() {
@@ -680,6 +680,7 @@ impl Host for crate::PdfCraftApp {
                "layout": format!("{:?}", v.layout),
                "organize": v.organize,
                "grid_zoom": v.grid_zoom(),
+                "thumbnail_zoom": v.thumbnail_zoom(),
                // Pages picked in the organize grid or the Pages panel (empty: the current page).
                "selected_pages": v.selected.iter().map(|p| p + 1).collect::<Vec<_>>(),
                "auto_scrolling": v.auto_scrolling(),
@@ -2757,3 +2757,6 @@ certificate	Version	الإصدار
 	Paragraph spacing	تباعد الفقرات
 	Less	أقل
 	Other options	خيارات أخرى
+	Thumbnail size	حجم الصور المصغرة
+	Smaller thumbnails	تصغير الصور المصغرة
+	Larger thumbnails	تكبير الصور المصغرة
@@ -2444,3 +2444,6 @@ animation effects	Off	Изключени
 	Paragraph spacing	Разстояние между абзаците
 	Less	По-малко
 	Other options	Други опции
+	Thumbnail size	Размер на миниатюрите
+	Smaller thumbnails	По-малки миниатюри
+	Larger thumbnails	По-големи миниатюри
@@ -2555,3 +2555,6 @@ animation effects	Off	Vypnuto
 	Paragraph spacing	Mezera mezi odstavci
 	Less	Méně
 	Other options	Další možnosti
+	Thumbnail size	Velikost miniatur
+	Smaller thumbnails	Menší miniatury
+	Larger thumbnails	Větší miniatury
@@ -2482,3 +2482,6 @@ animation effects	Off	Aus
 	Paragraph spacing	Absatzabstand
 	Less	Weniger
 	Other options	Weitere Optionen
+	Thumbnail size	Miniaturgröße
+	Smaller thumbnails	Kleinere Miniaturen
+	Larger thumbnails	Größere Miniaturen
@@ -2487,3 +2487,6 @@ animation effects	Off	Ανενεργά
 	Paragraph spacing	Απόσταση παραγράφων
 	Less	Λιγότερα
 	Other options	Άλλες επιλογές
+	Thumbnail size	Μέγεθος μικρογραφιών
+	Smaller thumbnails	Μικρότερες μικρογραφίες
+	Larger thumbnails	Μεγαλύτερες μικρογραφίες
@@ -2621,3 +2621,6 @@ animation effects	Off	Desactivados
 # Historical snapshot notice bar (View signed version / View revision).
 	You are viewing the signed version of “{from}” (revision {rev}). It is a snapshot: changes here won't affect the original.	Estás viendo la versión firmada de «{from}» (revisión {rev}). Es una instantánea: los cambios aquí no afectarán al original.
 	You are viewing revision {rev} of “{from}”. It is a snapshot: changes here won't affect the original.	Estás viendo la revisión {rev} de «{from}». Es una instantánea: los cambios aquí no afectarán al original.
+	Thumbnail size	Tamaño de las miniaturas
+	Smaller thumbnails	Miniaturas más pequeñas
+	Larger thumbnails	Miniaturas más grandes
@@ -2481,3 +2481,6 @@ animation effects	Off	Désactivés
 	Paragraph spacing	Espacement des paragraphes
 	Less	Moins
 	Other options	Autres options
+	Thumbnail size	Taille des vignettes
+	Smaller thumbnails	Réduire les vignettes
+	Larger thumbnails	Agrandir les vignettes
@@ -2480,3 +2480,6 @@ animation effects	Off	Ki
 	Paragraph spacing	Bekezdéstávolság
 	Less	Kevesebb
 	Other options	Egyéb beállítások
+	Thumbnail size	Bélyegképek mérete
+	Smaller thumbnails	Kisebb bélyegképek
+	Larger thumbnails	Nagyobb bélyegképek
@@ -2693,3 +2693,6 @@ certificate	SHA-256 digest	Impronta SHA-256
 	Paragraph spacing	Spaziatura paragrafi
 	Less	Meno
 	Other options	Altre opzioni
+	Thumbnail size	Dimensione miniature
+	Smaller thumbnails	Miniature più piccole
+	Larger thumbnails	Miniature più grandi
@@ -2481,3 +2481,6 @@ animation effects	Off	オフ
 	Paragraph spacing	段落間隔
 	Less	折りたたむ
 	Other options	その他のオプション
+	Thumbnail size	サムネイルのサイズ
+	Smaller thumbnails	サムネイルを小さく
+	Larger thumbnails	サムネイルを大きく
@@ -2479,3 +2479,6 @@ animation effects	Off	Өшірулі
 	Paragraph spacing	Абзац аралығы
 	Less	Азырақ
 	Other options	Басқа параметрлер
+	Thumbnail size	Нобай өлшемі
+	Smaller thumbnails	Кішірек нобайлар
+	Larger thumbnails	Үлкенірек нобайлар
@@ -2731,3 +2731,6 @@ theme	Appearance	Išvaizda
 	Paragraph spacing	Tarpas tarp pastraipų
 	Less	Mažiau
 	Other options	Kitos parinktys
+	Thumbnail size	Miniatiūrų dydis
+	Smaller thumbnails	Mažesnės miniatiūros
+	Larger thumbnails	Didesnės miniatiūros
@@ -2457,3 +2457,6 @@ animation effects	Off	Wyłączone
 	Paragraph spacing	Odstęp między akapitami
 	Less	Mniej
 	Other options	Inne opcje
+	Thumbnail size	Rozmiar miniatur
+	Smaller thumbnails	Mniejsze miniatury
+	Larger thumbnails	Większe miniatury
@@ -2495,3 +2495,6 @@ animation effects	Off	Desativados
 	Paragraph spacing	Espaçamento entre parágrafos
 	Less	Menos
 	Other options	Outras opções
+	Thumbnail size	Tamanho das miniaturas
+	Smaller thumbnails	Miniaturas menores
+	Larger thumbnails	Miniaturas maiores
@@ -2394,3 +2394,6 @@ animation effects	Off	Выкл
 	Paragraph spacing	Интервал между абзацами
 	Less	Меньше
 	Other options	Другие параметры
+	Thumbnail size	Размер миниатюр
+	Smaller thumbnails	Уменьшить миниатюры
+	Larger thumbnails	Увеличить миниатюры
@@ -2486,3 +2486,6 @@ animation effects	Off	Izklopljeni
 	Paragraph spacing	Razmik med odstavki
 	Less	Manj
 	Other options	Druge možnosti
+	Thumbnail size	Velikost sličic
+	Smaller thumbnails	Manjše sličice
+	Larger thumbnails	Večje sličice
@@ -2390,3 +2390,6 @@ animation effects	Off	ఆఫ్
 	Paragraph spacing	పేరా అంతరం
 	Less	తక్కువ
 	Other options	ఇతర ఎంపికలు
+	Thumbnail size	థంబ్‌నెయిల్ పరిమాణం
+	Smaller thumbnails	చిన్న థంబ్‌నెయిల్‌లు
+	Larger thumbnails	పెద్ద థంబ్‌నెయిల్‌లు
@@ -2477,3 +2477,6 @@ animation effects	Off	Kapalı
 	Paragraph spacing	Paragraf aralığı
 	Less	Daha az
 	Other options	Diğer seçenekler
+	Thumbnail size	Küçük resim boyutu
+	Smaller thumbnails	Küçük resimleri küçült
+	Larger thumbnails	Küçük resimleri büyüt
@@ -2503,3 +2503,6 @@ animation effects	Off	Вимкнено
 	Paragraph spacing	Інтервал між абзацами
 	Less	Менше
 	Other options	Інші параметри
+	Thumbnail size	Розмір мініатюр
+	Smaller thumbnails	Зменшити мініатюри
+	Larger thumbnails	Збільшити мініатюри
@@ -2733,3 +2733,6 @@ key	Space	Space
 # Historical snapshot notice bar (View signed version / View revision).
 	You are viewing the signed version of “{from}” (revision {rev}). It is a snapshot: changes here won't affect the original.	Bạn đang xem phiên bản đã ký của “{from}” (bản sửa đổi {rev}). Đây là ảnh nhanh: các thay đổi ở đây không được áp dụng đến bản gốc.
 	You are viewing revision {rev} of “{from}”. It is a snapshot: changes here won't affect the original.	Bạn đang xem bản sửa đổi {rev} của “{from}”. Đây là ảnh nhanh: các thay đổi ở đây không được áp dụng đến bản gốc.
+	Thumbnail size	Kích thước hình thu nhỏ
+	Smaller thumbnails	Giảm kích thước hình thu nhỏ
+	Larger thumbnails	Tăng kích thước hình thu nhỏ
@@ -2445,3 +2445,6 @@ animation effects	Off	关
 	Paragraph spacing	段落间距
 	Less	收起
 	Other options	其他选项
+	Thumbnail size	缩略图大小
+	Smaller thumbnails	缩小缩略图
+	Larger thumbnails	放大缩略图
@@ -2431,3 +2431,6 @@ animation effects	Off	關
 	Paragraph spacing	段落間距
 	Less	收起
 	Other options	其他選項
+	Thumbnail size	縮圖大小
+	Smaller thumbnails	縮小縮圖
+	Larger thumbnails	放大縮圖
@@ -2649,6 +2649,14 @@ impl PdfCraftApp {
                    v.open_organize();
                }
            }
+            // Inspector thumbnail size, in percent, independent of document and grid zoom.
+            ("thumbnail-zoom", Some(v)) => {
+                let percent = value.trim_end_matches('%').parse::<f32>().map_err(|e| e.to_string())?;
+                if !percent.is_finite() || !canvas::THUMBNAIL_ZOOM_RANGE.contains(&(percent / 100.0)) {
+                    return Err("thumbnail-zoom must be between 50 and 150".into());
+                }
+                v.set_thumbnail_zoom(percent / 100.0);
+            }
            // `--grid-zoom 150`: the size of the pages in the organize grid, in percent.
            ("grid-zoom", Some(v)) => {
                let percent = value.trim_end_matches('%').parse::<f32>().map_err(|e| e.to_string())?;
@@ -2790,6 +2798,7 @@ impl PdfCraftApp {
                    "cover",
                    "organize",
                    "grid-zoom",
+                    "thumbnail-zoom",
                    "fields",
                    "find",
                    "rotate",
@@ -786,6 +786,10 @@ pub fn right_panel(app: &mut PdfCraftApp, ui: &mut egui::Ui) {
                        ancestor.pop();
                    }
                }
+                if panel == RightPanel::Pages {
+                    let enabled = !modal && view.panel_drag.is_none();
+                    thumbnail_size(ui, &t, view, enabled);
+                }
                egui::ScrollArea::vertical().auto_shrink([false, false]).show(ui, |ui| match panel {
                    RightPanel::Comments => {
                        if let Some(e) = crate::comments_panel::show(ui, &t, info, view, prefs, comment_allowed, &mut nav) {
@@ -1187,6 +1191,57 @@ fn outline_item(ui: &mut egui::Ui, t: &Tokens, info: &DocInfo, item: &OutlineIte
    }
 }

+/// Size controls stay above the scroll area, so they remain reachable on long documents.
+fn thumbnail_size(ui: &mut egui::Ui, t: &Tokens, view: &mut crate::DocView, enabled: bool) {
+    let before = view.thumbnail_zoom();
+    let mut zoom = before;
+    let label = ui
+        .horizontal(|ui| {
+            let label = ui.label(egui::RichText::new(tl!("Thumbnail size")).small().color(t.text_muted));
+            ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
+                ui.label(egui::RichText::new(format!("{:.0}%", before * 100.0)).small().color(t.text_muted));
+            });
+            label
+        })
+        .inner;
+    ui.add_enabled_ui(enabled, |ui| {
+        ui.spacing_mut().slider_width = (ui.available_width() - 52.0 - 2.0 * ui.spacing().item_spacing.x).max(1.0);
+        ui.horizontal(|ui| {
+            if ui
+                .add_enabled_ui(zoom > *crate::canvas::THUMBNAIL_ZOOM_RANGE.start(), |ui| {
+                    icons::button(ui, "zoom-out", 26.0, false, tl!("Smaller thumbnails"))
+                })
+                .inner
+                .clicked()
+            {
+                zoom -= 0.25;
+            }
+            let mut percent = zoom * 100.0;
+            let range = (*crate::canvas::THUMBNAIL_ZOOM_RANGE.start() * 100.0)..=(*crate::canvas::THUMBNAIL_ZOOM_RANGE.end() * 100.0);
+            ui.scope(|ui| {
+                // The regular field fill blends into this panel; keep the slider's full rail visible.
+                ui.visuals_mut().widgets.inactive.bg_fill = t.border;
+                let slider = ui.add(egui::Slider::new(&mut percent, range).step_by(1.0).show_value(false).trailing_fill(true)).labelled_by(label.id);
+                slider.widget_info(|| egui::WidgetInfo::slider(ui.is_enabled(), f64::from(percent), tl!("Thumbnail size")));
+            });
+            zoom = percent / 100.0;
+            if ui
+                .add_enabled_ui(zoom < *crate::canvas::THUMBNAIL_ZOOM_RANGE.end(), |ui| {
+                    icons::button(ui, "zoom-in", 26.0, false, tl!("Larger thumbnails"))
+                })
+                .inner
+                .clicked()
+            {
+                zoom += 0.25;
+            }
+        });
+    });
+    if zoom != before {
+        view.set_thumbnail_zoom(zoom);
+    }
+    ui.add_space(6.0);
+}
+
 /// The page thumbnails. A click goes to the page; ⌘/Ctrl-click and ⇧-click pick several pages
 /// (the selection page commands and Print act on) without moving the document. Right-click
 /// offers Extract, Cut, Copy and Paste on the selection, or on the page clicked; dragging
@@ -1215,7 +1270,9 @@ fn pages(ui: &mut egui::Ui, t: &Tokens, info: &DocInfo, view: &mut crate::DocVie
    // scroll bar dragged by the user already wins over a scroll to a place in egui.
    let follow = view.panel_followed != Some(view.current) && view.panel_drag.is_none();
    view.panel_followed = Some(view.current);
-    let w = (ui.available_width() - 40.0).min(150.0);
+    let available = (ui.available_width() - 16.0).max(1.0);
+    let usual = (ui.available_width() - 40.0).clamp(1.0, 150.0);
+    let w = (usual * view.thumbnail_zoom()).min(available);
    let count = info.pages.len();
    let mut rows: Vec<Rect> = Vec::with_capacity(info.pages.len());
    let mut dropped = false;
@@ -86,6 +86,31 @@ fn ok(h: &mut Harness<'static, PdfCraftApp>, c: &ControlClient, method: &str, pa
    call(h, c, method, params).unwrap_or_else(|e| panic!("{method}: {e}"))
 }

+#[test]
+fn thumbnail_size_is_settable_and_inspectable_through_the_control_channel() {
+    let (mut h, c) = harness();
+    ok(&mut h, &c, "ui.set", json!({"key": "panel", "value": "pages"}));
+    ok(&mut h, &c, "ui.set", json!({"key": "thumbnail-zoom", "value": "50"}));
+    let state = ok(&mut h, &c, "ui.state", json!({}));
+    assert_eq!(state["active"]["thumbnail_zoom"], 0.5);
+    assert_eq!(state["active"]["grid_zoom"], 1.0);
+    assert_eq!(state["documents"][0]["dirty"], false);
+    let controls = ok(&mut h, &c, "ui.inspect", json!({"query": "thumbnails"}));
+    let widgets = controls["widgets"].as_array().unwrap();
+    assert!(widgets.iter().any(|w| w["label"] == "Larger thumbnails"));
+    assert!(widgets.iter().any(|w| w["label"] == "Smaller thumbnails" && w["enabled"] == false));
+    assert!(call(&mut h, &c, "ui.set", json!({"key": "thumbnail-zoom", "value": "NaN"})).is_err());
+    ok(&mut h, &c, "ui.click", json!({"label": "Larger thumbnails"}));
+    h.run_steps(3);
+    assert_eq!(ok(&mut h, &c, "ui.state", json!({}))["active"]["thumbnail_zoom"], 0.75);
+    let sliders = ok(&mut h, &c, "ui.inspect", json!({"query": "Thumbnail size", "role": "Slider"}));
+    let slider = sliders["widgets"].as_array().unwrap().first().expect("the thumbnail size slider is labelled");
+    ok(&mut h, &c, "ui.focus", json!({"id": slider["id"]}));
+    ok(&mut h, &c, "ui.key", json!({"key": "ArrowRight"}));
+    h.run_steps(3);
+    assert!(ok(&mut h, &c, "ui.state", json!({}))["active"]["thumbnail_zoom"].as_f64().unwrap() > 0.75);
+}
+
 #[test]
 fn control_resize_reports_observed_dimensions_and_rejects_invalid_sizes() {
    let (mut h, c) = harness();
@@ -3854,6 +3854,28 @@ fn dragging_pages_panel_thumbnails_reorders_pages() {
    assert!(view.panel_drag.is_none());
 }

+#[test]
+fn resized_pages_panel_thumbnails_reorder_multiple_pages_and_undo() {
+    let mut h = harness(4, |app| {
+        app.right = Some(pdfcraft_ui_egui::RightPanel::Pages);
+        app.set_option("thumbnail-zoom", "50").unwrap();
+    });
+    let before = page_texts(h.state());
+    h.state_mut().views[0].select_pages(&[1, 2]);
+    h.run_steps(2);
+    let from = panel_thumb_rect(&h, "Page 2").center();
+    let to = panel_thumb_rect(&h, "Page 1").center_top() + egui::vec2(0.0, 4.0);
+    drag(&mut h, from, to);
+    h.run_steps(4);
+    assert_eq!(page_texts(h.state()), vec![before[1].clone(), before[2].clone(), before[0].clone(), before[3].clone()]);
+    assert_eq!(h.state().views[0].target_pages(), vec![0, 1]);
+    assert_eq!(h.state().views[0].thumbnail_zoom(), 0.5);
+    assert!(h.state_mut().execute("edit.undo"));
+    h.run_steps(4);
+    assert_eq!(page_texts(h.state()), before);
+    assert_eq!(h.state().views[0].thumbnail_zoom(), 0.5);
+}
+
 #[test]
 fn a_thumbnail_drag_that_ends_off_the_panel_or_outlives_the_pages_is_dropped() {
    let mut h = harness(4, |app| app.right = Some(pdfcraft_ui_egui::RightPanel::Pages));
@@ -1408,6 +1408,86 @@ fn in_panel_view(h: &Harness<'static, PdfCraftApp>, r: egui::Rect) -> bool {
    h.state().views[0].pages_panel.expect("the Pages panel is shown").contains_rect(r)
 }

+#[test]
+fn pages_panel_thumbnail_size_controls_show_more_pages_and_keep_the_selection() {
+    let mut h = pages_panel_harness(&[(200, 300); 30]);
+    h.state_mut().views[0].select_pages(&[0, 1]);
+    h.run_steps(2);
+    let usual = thumbnail_rect(&h, 1).width();
+    let zoom = h.state().views[0].zoom;
+    let visible = |h: &Harness<'static, PdfCraftApp>| (1..=30).filter(|n| in_panel_view(h, thumbnail_rect(h, *n))).count();
+    let before = visible(&h);
+    h.get_by_label("Smaller thumbnails").click();
+    h.run_steps(4);
+    assert!(thumbnail_rect(&h, 1).width() < usual);
+    assert!(visible(&h) > before, "smaller thumbnails show more complete pages");
+    assert_eq!(h.state().views[0].target_pages(), vec![0, 1]);
+    assert_eq!(h.state().views[0].current, 0);
+    assert_eq!(h.state().views[0].zoom, zoom, "only the thumbnails are resized");
+    assert!(!h.state().session.get(h.state().views[0].id).unwrap().dirty);
+    if let Ok(dir) = std::env::var("PDFCRAFT_THUMBNAIL_SHOTS") {
+        h.render().unwrap().save(format!("{dir}/small.png")).unwrap();
+    }
+    h.get_by_label("Larger thumbnails").click();
+    h.run_steps(4);
+    assert!((thumbnail_rect(&h, 1).width() - usual).abs() < 0.1);
+    h.get_by_label("Larger thumbnails").click();
+    h.run_steps(4);
+    assert!(thumbnail_rect(&h, 1).width() > usual);
+    assert_eq!(h.state().views[0].target_pages(), vec![0, 1]);
+    if let Ok(dir) = std::env::var("PDFCRAFT_THUMBNAIL_SHOTS") {
+        h.render().unwrap().save(format!("{dir}/large.png")).unwrap();
+        h.state_mut().set_option("theme", "dark").unwrap();
+        h.run_steps(4);
+        h.render().unwrap().save(format!("{dir}/large-dark.png")).unwrap();
+    }
+}
+
+#[test]
+fn pages_panel_thumbnail_zoom_is_bounded_independent_and_survives_reload() {
+    let mut h = pages_panel_harness(&[(200, 300); 6]);
+    let usual = thumbnail_rect(&h, 1).width();
+    let zoom = h.state().views[0].zoom;
+    h.state_mut().set_option("grid-zoom", "200").unwrap();
+    h.state_mut().set_option("thumbnail-zoom", "50%").unwrap();
+    h.run_steps(4);
+    let small = thumbnail_rect(&h, 1).width();
+    assert!(small < usual);
+    for invalid in ["0", "49", "151", "NaN", "inf", "nope"] {
+        assert!(h.state_mut().set_option("thumbnail-zoom", invalid).is_err(), "reject {invalid}");
+    }
+    h.run_steps(3);
+    assert_eq!(thumbnail_rect(&h, 1).width(), small);
+    assert_eq!(h.state().views[0].grid_zoom(), 2.0);
+    assert_eq!(h.state().views[0].zoom, zoom);
+    let info = h.state().session.get(h.state().views[0].id).unwrap().info.clone();
+    h.state_mut().views[0].document_replaced(&info);
+    h.run_steps(4);
+    assert_eq!(thumbnail_rect(&h, 1).width(), small, "file reload keeps the chosen thumbnail size");
+    h.state_mut().views[0].set_thumbnail_zoom(f32::NAN);
+    assert_eq!(h.state().views[0].thumbnail_zoom(), 0.5);
+    h.state_mut().views[0].set_thumbnail_zoom(f32::MAX);
+    assert_eq!(h.state().views[0].thumbnail_zoom(), 1.5);
+    assert!(!h.state().session.get(h.state().views[0].id).unwrap().dirty);
+    let mut empty = PdfCraftApp::new();
+    assert!(empty.set_option("thumbnail-zoom", "100").is_err());
+}
+
+#[test]
+fn pages_panel_thumbnail_zoom_keeps_a_far_current_page_visible() {
+    let mut h = pages_panel_harness(&[(200, 300); 30]);
+    h.state_mut().views[0].go_to_page(24);
+    h.run_steps(4);
+    for size in ["50", "150", "80", "100"] {
+        h.state_mut().set_option("thumbnail-zoom", size).unwrap();
+        h.run_steps(4);
+        assert!(in_panel_view(&h, thumbnail_rect(&h, 25)), "page 25 stays visible at {size}%");
+        assert_eq!(h.state().views[0].current, 24);
+        h.get_by_label("Smaller thumbnails");
+        h.get_by_label("Larger thumbnails");
+    }
+}
+
 /// #2781: as in Acrobat, going to a page whose thumbnail is out of sight scrolls the Pages
 /// panel to show it.
 #[test]
@@ -1,5 +1,7 @@
 # PdfCraft roadmap: milestones and what's next

+> **Last reviewed:** 2026-10-21 · **Last updated:** 2026-10-21 · **Change:** minor (M3, #3808: the Pages inspector has an independent 50–150% thumbnail size slider and buttons; selection and current-page following are retained, with headless ui.set coverage. Estimates unchanged.)
+
 > **Last reviewed:** 2026-10-18 · **Last updated:** 2026-10-18 · **Change:** minor (M5, PR #1971: bounded nested FDF export excludes source page/page-tree dictionaries; refreshed against upstream 4db6ac4a; estimates unchanged)
 > **Last reviewed:** 2026-10-15 · **Last updated:** 2026-10-15 · **Change:** minor (M14/#2383 GPU-limit candidate; estimates unchanged) · **Target:** Adobe Acrobat Pro (Acrobat DC, continuous track 26.002.21931, macOS)
 > **Last reviewed:** 2026-10-15 · **Last updated:** 2026-10-15 · **Change:** minor (M7: the Edit text caret is as tall as the row it is on; estimates unchanged) · **Target:** Adobe Acrobat Pro (Acrobat DC, continuous track 26.002.21931, macOS)
@@ -116,7 +118,7 @@ total matches the parity estimate.
 | M2 | Model, render, text | 200–350 | 15% | 130–230 | hayro bootstrap renderer (vendored patches); inspector predictor scratch is bounded by available input, and JPX sample rescaling handles 1–32 bits safely. Text extraction reaches word-F1 0.98 against pdftotext. Short same-line redraws split before placement rather than interleaving. Missing: model crate, fonts, DisplayList, renderer independent of hayro. Inspector page-label traversal and output are resource-bounded, with physical-number fallback warnings. Packed TIFF-predictor RGB rows retain later rows in decoding and rendering. Page marks, added content and print output retain small page-unit transform coefficients when serialized. |
 | M2 | Model, render, text | 200–350 | 15% | 130–230 | hayro bootstrap renderer (vendored patches); inspector predictor scratch is bounded by available input, and JPX sample rescaling handles 1–32 bits safely. Text extraction reaches word-F1 0.98 against pdftotext. Short same-line redraws split before placement rather than interleaving. Missing: model crate, fonts, DisplayList, renderer independent of hayro. Inspector page-label traversal and output are resource-bounded, with physical-number fallback warnings. Packed TIFF-predictor RGB rows retain later rows in decoding and rendering. The renderer keeps its one-point crop-size floor in physical points after UserUnit scaling, with regression coverage for crop origins, rotations and f32 reciprocal rounding. Existing unit policy and nearly-zero fallback are retained. |
 | M2 | Model, render, text | 200–350 | 15% | 130–230 | hayro bootstrap renderer (vendored patches); inspector predictor scratch is bounded by available input, and JPX sample rescaling handles 1–32 bits safely. Text extraction reaches word-F1 0.98 against pdftotext. Short same-line redraws split before placement rather than interleaving. Missing: model crate, fonts, DisplayList, renderer independent of hayro. Inspector page-label traversal and output are resource-bounded, with physical-number fallback warnings |
-| M3 | Viewer app (native + web) | 80–150 | 90% | 10–20 | Acrobat-style shell, find, select, panels, tiles, web build, UI control channel for agents (opt-in). Missing: 60 fps test on a 500-page document, snapshot tests of every panel<br>Done since: fit visible, document title in the window; Linux middle-button scrolling; shared three-state theme preferences in the toolbar, View menu and control channel; numeric Linux portal events and idle wakeups completing #881, with native appearance inheritance retained (#446); late browser startup downloads preserve the current document and Save target (#171). Selected-text Copy in Edit and the canvas context menu is covered by focused regressions and native clipboard checks (#1225); document copy restrictions apply to the floating action too. #1364 candidate: absolute local GoToR links ask before target access; headless callers explicitly opt in. Native-opening candidate: chosen tools survive preparation and password retries; startup intake waits for pending preparation. Page-label navigation displays logical labels, retains the current page on unchanged submission and refreshes focused same-document replacements; clean file-watcher reload preserves the chosen scrolling mode, preventing a Single Page reader from jumping to page 1 during replacement. Synthetic control regressions cover these behaviors. #3149: page-list changes discard render demand based on old geometry; actual raster dimensions are checked against the GPU limit before upload. Synthetic crash and continued-rendering regressions cover the replacement path. Save-prompt shortcuts yield to dialogs above them; stacked link-consent UI regression covers Escape and Return. |
+| M3 | Viewer app (native + web) | 80–150 | 90% | 10–20 | Acrobat-style shell, find, select, panels, tiles, web build, UI control channel for agents (opt-in). #3808: the Pages inspector offers a 50–150% thumbnail slider and buttons, also available through `ui.set`. Missing: 60 fps test on a 500-page document, snapshot tests of every panel<br>Done since: fit visible, document title in the window; Linux middle-button scrolling; shared three-state theme preferences in the toolbar, View menu and control channel; numeric Linux portal events and idle wakeups completing #881, with native appearance inheritance retained (#446); late browser startup downloads preserve the current document and Save target (#171). Selected-text Copy in Edit and the canvas context menu is covered by focused regressions and native clipboard checks (#1225); document copy restrictions apply to the floating action too. #1364 candidate: absolute local GoToR links ask before target access; headless callers explicitly opt in. Native-opening candidate: chosen tools survive preparation and password retries; startup intake waits for pending preparation. Page-label navigation displays logical labels, retains the current page on unchanged submission and refreshes focused same-document replacements; clean file-watcher reload preserves the chosen scrolling mode, preventing a Single Page reader from jumping to page 1 during replacement. Synthetic control regressions cover these behaviors. #3149: page-list changes discard render demand based on old geometry; actual raster dimensions are checked against the GPU limit before upload. Synthetic crash and continued-rendering regressions cover the replacement path. Save-prompt shortcuts yield to dialogs above them; stacked link-consent UI regression covers Escape and Return. |
 | M3 | Viewer app (native + web) | 80–150 | 90% | 10–20 | Acrobat-style shell, find, select, panels, tiles, web build, UI control channel for agents (opt-in). Missing: 60 fps test on a 500-page document, snapshot tests of every panel<br>Done since: fit visible, document title in the window; Linux middle-button scrolling; shared three-state theme preferences in the toolbar, View menu and control channel; numeric Linux portal events and idle wakeups completing #881, with native appearance inheritance retained (#446); late browser startup downloads preserve the current document and Save target (#171). Selected-text Copy in Edit and the canvas context menu is covered by focused regressions and native clipboard checks (#1225); document copy restrictions apply to the floating action too. #1364 candidate: absolute local GoToR links ask before target access; headless callers explicitly opt in. Native-opening candidate: chosen tools survive preparation and password retries; startup intake waits for pending preparation. Page-label navigation displays logical labels, retains the current page on unchanged submission and refreshes focused same-document replacements; clean file-watcher reload preserves the chosen scrolling mode, preventing a Single Page reader from jumping to page 1 during replacement. Synthetic control regressions cover these behaviors. Wrapped revision buttons stay above Binding in Document Properties (#2739); a synthetic UI test checks layout and saved revision content. |
 | M3 | Viewer app (native + web) | 80–150 | 90% | 10–20 | Acrobat-style shell, find, select, panels, tiles, web build, UI control channel for agents (opt-in). Missing: 60 fps test on a 500-page document, snapshot tests of every panel<br>Done since: fit visible, document title in the window; Linux middle-button scrolling; shared three-state theme preferences in the toolbar, View menu and control channel; numeric Linux portal events and idle wakeups completing #881, with native appearance inheritance retained (#446); late browser startup downloads preserve the current document and Save target (#171). #1364 candidate: absolute local GoToR links ask before target access; headless callers explicitly opt in. Native-opening candidate: chosen tools survive preparation and password retries; startup intake waits for pending preparation. Later native-open replies stay queued while a modal or picker owns the foreground; regressions cover recipient ownership, completion/cancellation and one-shot wakes. |
 | M3 | Viewer app (native + web) | 80–150 | 90% | 10–20 | Acrobat-style shell, find, select, panels, tiles, web build, UI control channel for agents (opt-in). Missing: 60 fps test on a 500-page document, snapshot tests of every panel<br>Done since: fit visible, document title in the window; Linux middle-button scrolling; shared three-state theme preferences in the toolbar, View menu and control channel; numeric Linux portal events and idle wakeups completing #881, with native appearance inheritance retained (#446); late browser startup downloads preserve the current document and Save target (#171). #1364 candidate: absolute local GoToR links ask before target access; headless callers explicitly opt in. Native-opening candidate: chosen tools survive preparation and password retries; startup intake waits for pending preparation. #1980: exact quit modifiers preserve Ctrl+Alt+Q email input; Ctrl+Q/Cmd+Q asks before discarding unsaved documents. |
@@ -202,6 +204,7 @@ M2 (renderer), M7 (content editing), M10 (OCR and Office), M11 (Preflight and st

 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-21 | minor | M3, #3808: the Pages inspector has an independent 50–150% thumbnail size slider and buttons; selection and current-page following are retained, with headless ui.set coverage. Estimates unchanged. |
 | 2026-10-20 | minor | M6: Prepare a form ▸ Calculation order: formulas and values, what is wrong and Fix order, Up/Down, Alt+↑/↓ and drag, links on the page. Estimates unchanged. |
 | 2026-10-20 | minor | M6: `form_calculation_order` reads, checks, fixes and sets the calculation order; an edited formula keeps its place in `/CO`. Estimates unchanged. |
 | 2026-10-19 | minor | M6: renaming a field renames it in the calculations that read it; `form_set_props` returns `formulas_updated` and Field Properties says how many changed. Estimates unchanged. |
@@ -1,5 +1,7 @@
 # UI and interaction parity

+> **Last reviewed:** 2026-10-21 · **Last updated:** 2026-10-21 · **Change:** minor (M3, #3808: the Pages inspector has an independent 50–150% thumbnail size slider and buttons; selection and current-page following are retained, with headless ui.set coverage. Estimates unchanged.)
+
 > **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-11 · **Change:** minor (column select #740, multi-object move #844, Shift-⌘-G #810 fixed) · **Target:** Adobe Acrobat Pro (Acrobat DC, continuous track 26.002.21931, macOS)

 How PdfCraft's tools, panels, shortcuts and feel compare with Acrobat Pro's current interface (the
@@ -33,7 +35,7 @@ No dump of Acrobat's menu tree has been diffed against the registry yet (gap 24)
 | Split window, spreadsheet split | yes | no | planned |
 | Read mode, full screen | yes | yes | shipped; presentation options planned |
 | Light, dark, system theme | yes | yes | shipped |
-| Side panels: thumbnails, bookmarks, attachments, layers, comments, fields, signatures | yes | yes; panels keep their width (#704) | shipped |
+| Side panels: thumbnails, bookmarks, attachments, layers, comments, fields, signatures | yes | yes; panels keep their width (#704); the Pages inspector has a 50–150% thumbnail size slider and buttons (#3808) | shipped |
 | Destinations, articles, model tree, Tags, Order, Content panels | yes | no | planned |
 | Message bars (restricted, signed, PDF/A, forms) | yes | restricted and signed; no PDF/A view mode | partial |

@@ -81,5 +83,6 @@ No dump of Acrobat's menu tree has been diffed against the registry yet (gap 24)

 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-21 | minor | Pages inspector thumbnail sizing (#3808), separate from page and Organize zoom; view setting retained on reload and exposed through UI control. Not persisted between sessions. |
 | 2026-10-11 | minor | Column select shipped (#740, PR #765); several objects move together on one page (#844, PR #907); Shift-⌘-G goes back (#810, PR #835) |
 | 2026-10-10 | major | Created from the command registry, automation tools, the View area of the checklist and open UI issues |
@@ -1262,8 +1262,8 @@ milestone = "M3"
 status = "shipped"
 commands = []
 tools = []
-evidence = ["crates/ui-egui/tests/ui.rs::theme_and_view_options_apply", "crates/ui-egui/tests/viewer.rs::going_to_a_far_page_scrolls_its_thumbnail_into_view", "crates/ui-egui/tests/viewer.rs::going_to_a_page_in_view_leaves_the_pages_panel_still", "crates/ui-egui/tests/viewer.rs::a_page_change_while_thumbnails_are_dragged_does_not_scroll_the_pages_panel"]
-notes = "The panel follows the current page (#2781): a page whose thumbnail is out of sight scrolls it into view, as little as it takes; a thumbnail already in view, or clicked, leaves the panel still, and a page change while the user scrolls the panel or drags thumbnails does not move it."
+evidence = ["crates/ui-egui/tests/editing.rs::resized_pages_panel_thumbnails_reorder_multiple_pages_and_undo", "crates/ui-egui/tests/viewer.rs::pages_panel_thumbnail_zoom_is_bounded_independent_and_survives_reload", "crates/ui-egui/tests/viewer.rs::pages_panel_thumbnail_size_controls_show_more_pages_and_keep_the_selection", "crates/ui-egui/tests/viewer.rs::pages_panel_thumbnail_zoom_keeps_a_far_current_page_visible", "crates/ui-egui/tests/control.rs::thumbnail_size_is_settable_and_inspectable_through_the_control_channel", "crates/ui-egui/tests/ui.rs::theme_and_view_options_apply", "crates/ui-egui/tests/viewer.rs::going_to_a_far_page_scrolls_its_thumbnail_into_view", "crates/ui-egui/tests/viewer.rs::going_to_a_page_in_view_leaves_the_pages_panel_still", "crates/ui-egui/tests/viewer.rs::a_page_change_while_thumbnails_are_dragged_does_not_scroll_the_pages_panel"]
+notes = "Thumbnail size: 50–150% with a slider and buttons above the scroll area (#3808), independent of document and Organize zoom. Accessible through ui.set thumbnail-zoom and ui.state active.thumbnail_zoom; retained on file reload, not persisted between sessions. The panel follows the current page (#2781): a page whose thumbnail is out of sight scrolls it into view, as little as it takes; a thumbnail already in view, or clicked, leaves the panel still, and a page change while the user scrolls the panel or drags thumbnails does not move it."

 [[feature]]
 id = "view.thumbnail-context-ops"
@@ -2885,7 +2885,7 @@ status = "shipped"
 commands = ["page.organize"]
 tools = []
 evidence = ["crates/ui-egui/tests/editing.rs::page_grid_zooms_with_its_buttons_keys_and_pinch", "crates/ui-egui/tests/editing.rs::a_zoomed_page_grid_still_inserts_and_moves_at_the_right_gap", "crates/ui-egui/tests/editing.rs::zoomed_pages_in_view_are_rendered_at_the_size_drawn", "crates/ui-egui/tests/editing.rs::page_grid_size_is_remembered_for_every_document_and_restart"]
-notes = "Organize page grid: 50–300% with toolbar buttons (and a percentage that resets to 100%), trackpad pinch or Ctrl/⌘ + wheel about the page under the pointer, and ⌘+ / ⌘− / ⌘0; pages drawn larger than their thumbnails are rendered at the size drawn while they are in view (the thumbnail stands in until then, and after an edit), so text stays sharp however long the document is. As in Acrobat, the size last chosen is one for every document and kept in the settings across restarts (also set by --grid-zoom). Missing: a slider as in Acrobat; the Pages side panel has no size control."
+notes = "Organize page grid: 50–300% with toolbar buttons (and a percentage that resets to 100%), trackpad pinch or Ctrl/⌘ + wheel about the page under the pointer, and ⌘+ / ⌘− / ⌘0; pages drawn larger than their thumbnails are rendered at the size drawn while they are in view (the thumbnail stands in until then, and after an edit), so text stays sharp however long the document is. As in Acrobat, the size last chosen is one for every document and kept in the settings across restarts (also set by --grid-zoom). Missing in Organize: a slider as in Acrobat. The Pages inspector has its own 50–150% slider and buttons (#3808)."

 [[feature]]
 id = "organize.split-every-n"