Improve reading-colour preferences and add a settings shortcut (#2627)

* M3: improve reading-colour preferences and add settings shortcut * M3: clarify the disabled reading-colour preview * M3: adapt rebased preferences to current UI dependencies
2026-10-29 20:47:32 -06:00 · 2026-10-28 17:41:29 -04:00
parent 40c22e3ea5
commit 03996b1025
8 changed files with 154 additions and 110 deletions
@@ -69,10 +69,10 @@ pub fn tab_strip(app: &mut PdfCraftApp, ui: &mut egui::Ui) {
                    app.active = None;
                    app.combine_tab.focused = false;
                }
-                // Keep the two icon buttons, Discord's text/padding and three gaps outside the scrolling tabs.
+                // Reserve the three icon buttons, Discord and their gaps outside the scrolling tabs.
                let controls_width = ui.fonts_mut(|f| f.layout_no_wrap("Discord".into(), theme::medium(13.0), t.text).size().x)
-                    + 2.0 * button
-                    + 50.0
+                    + 3.0 * button
+                    + 54.0
                    + window_controls::width(&controls.right);
                // Open stays in sight after the tabs: its icon, text and padding, and the gaps around it.
                let open_width = ui.fonts_mut(|f| f.layout_no_wrap(tl!("Open").into(), theme::medium(13.0), t.text).size().x) + 38.0 + 12.0;
@@ -287,6 +287,9 @@ pub fn tab_strip(app: &mut PdfCraftApp, ui: &mut egui::Ui) {
                        });
                        ui.add_space(window_controls::SIDE_GAP - 4.0);
                    }
+                    if icons::button(ui, "settings", button, false, tl!("Preferences")).clicked() {
+                        app.execute("app.preferences");
+                    }
                    let (icon, label) = match app.theme_preference {
                        ThemePreference::System => ("monitor", tl!("Use system setting")),
                        ThemePreference::Light => ("sun", tl!("Light gray")),
@@ -254,6 +254,10 @@ fn english(labeled: Labeled<'_>) -> Option<String> {
 }

 fn translate(english: &'static str) -> String {
+    // The bundled UI fonts do not all cover the menu's mathematical ellipsis.
+    if english == "\u{22ef}" {
+        return "...".to_owned();
+    }
    tl!(english).to_owned()
 }

@@ -265,18 +265,6 @@ pub(crate) fn document_js_body(ui: &mut egui::Ui, app: &mut PdfCraftApp, t: &Tok
    close
 }

-/// The label for a [`pdfcraft_render::ReadingColors`] mode name (`mode_name`).
-fn reading_mode_label(mode: &str) -> &'static str {
-    match mode {
-        "black-on-white" => "Black on white",
-        "white-on-black" => "White on black",
-        "yellow-on-black" => "Yellow on black",
-        "green-on-black" => "Green on black",
-        "custom" => "Custom",
-        _ => "Off",
-    }
-}
-
 /// The height the Preferences dialog keeps below its scrolling settings for the OK row: the
 /// button, and the space above it.
 pub(crate) const PREFERENCES_BUTTON_ROW: f32 = 52.0;
@@ -394,6 +382,8 @@ pub(crate) fn preferences_body(ui: &mut egui::Ui, app: &mut PdfCraftApp, t: &Tok
    ui.add_space(8.0);
    crate::appearance::preferences_section(ui, app, t);
    ui.add_space(8.0);
+    reading_colours_section(ui, app, t);
+    ui.add_space(8.0);
    ui.label(egui::RichText::new(tl!("Documents and view")).font(theme::semibold(13.0)));
    ui.horizontal(|ui| {
        ui.label(tl!("Default workspace mode"));
@@ -478,70 +468,6 @@ pub(crate) fn preferences_body(ui: &mut egui::Ui, app: &mut PdfCraftApp, t: &Tok
            .on_hover_text(tl!("Show a basic title bar for the window buttons instead of the tab strip. GNOME doesn't draw title bars for apps, so this one doesn't follow its theme."));
    }
    ui.add_space(8.0);
-    // Reading colours (Acrobat: Replace Document Colors): solid text and line-art paints are
-    // remapped while rendering, and the page clears to the background colour. The preference
-    // is app-wide: every open document follows it, and documents open with it.
-    ui.label(egui::RichText::new(tl!("Reading colours")).font(theme::semibold(13.0)));
-    ui.horizontal(|ui| {
-        let label = ui.label(tl!("Replace document colours"));
-        let mode = app.reading_colors.mode_name();
-        craft_ui::ComboBox::from_id_salt("reading-colors")
-            .selected_text(tl!(reading_mode_label(mode)))
-            .show_ui(ui, |ui| {
-                for (m, label) in [
-                    ("off", "Off"),
-                    ("black-on-white", "Black on white"),
-                    ("white-on-black", "White on black"),
-                    ("yellow-on-black", "Yellow on black"),
-                    ("green-on-black", "Green on black"),
-                    ("custom", "Custom"),
-                ] {
-                    if ui.selectable_label(mode == m, tl!(label)).clicked() {
-                        match m {
-                            "off" => app.set_reading_colors(pdfcraft_render::ReadingColors::default()),
-                            "custom" => {
-                                // Custom starts from the colours already chosen, or black on white.
-                                let colors = app.reading_colors.params.map_or(pdfcraft_render::ReadingColors::BLACK_ON_WHITE, |params| {
-                                    pdfcraft_render::ReadingColors { params: Some(params) }
-                                });
-                                app.set_reading_colors(colors);
-                            }
-                            // `parse` knows these names; a preset comes with its own flags.
-                            preset => {
-                                if let Ok(colors) = pdfcraft_render::ReadingColors::parse(preset, None, None, None, None) {
-                                    app.set_reading_colors(colors);
-                                }
-                            }
-                        }
-                        ui.close();
-                    }
-                }
-            })
-            .response
-            .labelled_by(label.id);
-    });
-    if app.reading_colors.params.is_some() {
-        let mut changed = false;
-        if let Some(params) = app.reading_colors.params.as_mut() {
-            ui.horizontal(|ui| {
-                let text = ui.label(tl!("Text"));
-                changed |= ui.color_edit_button_srgb(&mut params.text).labelled_by(text.id).changed();
-                let background = ui.label(tl!("Page background"));
-                changed |= ui.color_edit_button_srgb(&mut params.background).labelled_by(background.id).changed();
-            });
-            if ui.add(crate::widgets::checkbox(&mut params.only_black, tl!("Only change the colour of black text or line art"))).changed() {
-                changed = true;
-            }
-            if ui.add(crate::widgets::checkbox(&mut params.line_art, tl!("Change the colour of line art as well as text"))).changed() {
-                changed = true;
-            }
-        }
-        if changed {
-            app.set_reading_colors(app.reading_colors);
-        }
-    }
-    ui.label(egui::RichText::new(tl!("Colours are remapped while rendering; the document itself never changes.")).small().color(t.text_muted));
-    ui.add_space(8.0);
    // Identity: the author of new comments (Acrobat: Preferences ▸ Identity).
    ui.label(egui::RichText::new(tl!("Identity")).font(theme::semibold(13.0)));
    ui.horizontal(|ui| {
@@ -679,6 +605,75 @@ fn date_format(ui: &mut egui::Ui, app: &mut PdfCraftApp, t: &Tokens) {
    );
 }

+fn reading_colours_section(ui: &mut egui::Ui, app: &mut PdfCraftApp, t: &Tokens) {
+    // Reading colours (Acrobat: Replace Document Colors): solid text and line-art paints are
+    // remapped while rendering, and the page clears to the background colour. The preference
+    // is app-wide: every open document follows it, and documents open with it.
+    ui.label(egui::RichText::new(tl!("Reading colours")).font(theme::semibold(13.0)));
+    let mode = app.reading_colors.mode_name();
+    ui.horizontal_wrapped(|ui| {
+        for (name, label, colors) in [
+            ("off", "Off", pdfcraft_render::ReadingColors::default()),
+            ("black-on-white", "Black on white", pdfcraft_render::ReadingColors::BLACK_ON_WHITE),
+            ("white-on-black", "White on black", pdfcraft_render::ReadingColors::WHITE_ON_BLACK),
+            ("yellow-on-black", "Yellow on black", pdfcraft_render::ReadingColors::YELLOW_ON_BLACK),
+            ("green-on-black", "Green on black", pdfcraft_render::ReadingColors::GREEN_ON_BLACK),
+        ] {
+            let params = colors.params.unwrap_or(pdfcraft_render::ReadingParams {
+                text: [0, 0, 0],
+                background: [255, 255, 255],
+                only_black: false,
+                line_art: true,
+            });
+            ui.vertical(|ui| {
+                ui.set_width(104.0);
+                let sample = egui::RichText::new("Aa").size(22.0).color(egui::Color32::from_rgb(params.text[0], params.text[1], params.text[2]));
+                let button = egui::Button::new(sample)
+                    .fill(egui::Color32::from_rgb(params.background[0], params.background[1], params.background[2]))
+                    .min_size(egui::vec2(94.0, 44.0))
+                    .stroke(egui::Stroke::new(if mode == name { 2.0 } else { 1.0 }, if mode == name { t.accent } else { t.border }));
+                let response = ui.add(button);
+                response.widget_info(|| egui::WidgetInfo::selected(egui::Role::Button, true, mode == name, tl!(label)));
+                if response.clicked() {
+                    app.set_reading_colors(colors);
+                }
+                ui.label(tl!(label));
+            });
+        }
+    });
+    ui.add_space(8.0);
+    if let Some(params) = app.reading_colors.params {
+        let text = egui::Color32::from_rgb(params.text[0], params.text[1], params.text[2]);
+        let background = egui::Color32::from_rgb(params.background[0], params.background[1], params.background[2]);
+        egui::Frame::new().fill(background).inner_margin(16.0).show(ui, |ui| {
+            ui.set_min_width((ui.available_width() - 32.0).max(0.0));
+            ui.label(egui::RichText::new(tl!("Reading colours")).size(18.0).color(text));
+            ui.label(egui::RichText::new(tl!("Colours are remapped while rendering; the document itself never changes.")).color(text));
+        });
+    } else {
+        ui.label(tl!("Original"));
+    }
+    egui::CollapsingHeader::new(tl!("Custom")).default_open(mode == "custom").show(ui, |ui| {
+        let mut colors = if app.reading_colors.params.is_some() { app.reading_colors } else { pdfcraft_render::ReadingColors::BLACK_ON_WHITE };
+        let mut changed = false;
+        if let Some(params) = colors.params.as_mut() {
+            ui.horizontal(|ui| {
+                let text = ui.label(tl!("Text"));
+                changed |= ui.color_edit_button_srgb(&mut params.text).labelled_by(text.id).changed();
+                let background = ui.label(tl!("Page background"));
+                changed |= ui.color_edit_button_srgb(&mut params.background).labelled_by(background.id).changed();
+            });
+            changed |= ui.add(crate::widgets::checkbox(&mut params.only_black, tl!("Only change the colour of black text or line art"))).changed();
+            changed |= ui.add(crate::widgets::checkbox(&mut params.line_art, tl!("Change the colour of line art as well as text"))).changed();
+        }
+        if changed {
+            app.set_reading_colors(colors);
+        }
+    });
+    ui.label(egui::RichText::new(tl!("Colours are remapped while rendering; the document itself never changes.")).small().color(t.text_muted));
+    ui.add_space(8.0);
+}
+
 #[cfg(test)]
 mod tests {
    use super::*;
@@ -29,7 +29,7 @@ fn ok_is_on_screen_without_scrolling_at_any_window_height() {
        let h = harness(height);
        let ok = h.get_by_label("OK").rect();
        assert!(on_screen(ok, height), "{height}: OK at {ok:?} is off the {height} pt window");
-        let title = h.get_by_label("Preferences").rect();
+        let title = h.get_by(|n| n.role() == egui::accesskit::Role::Label && n.value().as_deref() == Some("Preferences")).rect();
        assert!(on_screen(title, height), "{height}: the title at {title:?} is off the window");
        // The OK row sits below the scrolled settings, never over them: the settings' last visible
        // row ends above it. The title is above everything.
@@ -43,13 +43,13 @@ fn ok_closes_the_dialog_in_a_short_window_and_the_settings_still_scroll() {
    // A setting far down the list starts out below the visible settings; scrolling brings it in
    // between the title and the OK row, and OK did not move.
    let ok_before = h.get_by_label("OK").rect();
-    let title = h.get_by_label("Preferences").rect();
-    let far = h.get_by_label_contains("Reading colours").rect();
-    assert!(far.min.y >= ok_before.min.y, "Reading colours starts out of sight: {far:?} vs OK {ok_before:?}");
-    h.get_by_label_contains("Reading colours").scroll_to_me();
+    let title = h.get_by(|n| n.role() == egui::accesskit::Role::Label && n.value().as_deref() == Some("Preferences")).rect();
+    let far = h.get_by_label_contains("Enable Acrobat JavaScript").rect();
+    assert!(far.min.y >= ok_before.min.y, "JavaScript setting starts out of sight: {far:?} vs OK {ok_before:?}");
+    h.get_by_label_contains("Enable Acrobat JavaScript").scroll_to_me();
    h.run_steps(4);
-    let far = h.get_by_label_contains("Reading colours").rect();
-    assert!(far.min.y >= title.max.y && far.max.y <= ok_before.min.y, "Reading colours scrolled in between the title and OK: {far:?}");
+    let far = h.get_by_label_contains("Enable Acrobat JavaScript").rect();
+    assert!(far.min.y >= title.max.y && far.max.y <= ok_before.min.y, "JavaScript setting scrolled in between the title and OK: {far:?}");
    assert_eq!(h.get_by_label("OK").rect(), ok_before, "OK stays put while the settings scroll");
    assert!(h.state().dialog.is_some());
    h.get_by_label("OK").click();
@@ -64,9 +64,15 @@ fn the_dialog_opens_at_its_full_size_and_does_not_grow_afterwards() {
    // in its first frames landed on controls that were still moving.
    for height in [260.0, 560.0, 900.0] {
        let mut h = harness(height);
-        let settled = (h.get_by_label("Preferences").rect(), h.get_by_label("OK").rect());
+        let settled = (
+            h.get_by(|n| n.role() == egui::accesskit::Role::Label && n.value().as_deref() == Some("Preferences")).rect(),
+            h.get_by_label("OK").rect(),
+        );
        h.run_steps(8);
-        let later = (h.get_by_label("Preferences").rect(), h.get_by_label("OK").rect());
+        let later = (
+            h.get_by(|n| n.role() == egui::accesskit::Role::Label && n.value().as_deref() == Some("Preferences")).rect(),
+            h.get_by_label("OK").rect(),
+        );
        assert_eq!(settled, later, "{height}: the dialog moved after it had been shown for six frames");
    }
    // And it is in place within a few frames of opening, for the first click: a frame or two of
@@ -100,17 +100,6 @@ fn png() -> Vec<u8> {
    out
 }

-/// The Reading colours combo of the preferences dialog: it shows the chosen mode as its value,
-/// and no other combo in the dialog shows `Off` while the setting is off.
-fn combo(h: &mut Harness<'static, PdfCraftApp>) {
-    // The preferences dialog grew taller than the window, which leaves this combo below the
-    // fold where a click lands outside the dialog and dismisses it; scroll it into view and
-    // let the scroll settle before clicking.
-    h.get_by(|n| n.role() == Role::ComboBox && n.value().is_some_and(|v| v == "Off")).scroll_to_me();
-    h.run_steps(4);
-    h.get_by(|n| n.role() == Role::ComboBox && n.value().is_some_and(|v| v == "Off")).click();
-}
-
 #[test]
 fn reading_colours_preference_round_trips() {
    let mut h = Harness::builder().with_size(egui::vec2(1400.0, 900.0)).build_eframe(|_cc| {
@@ -122,11 +111,9 @@ fn reading_colours_preference_round_trips() {
    });
    h.run_steps(4);
    assert_eq!(h.state().reading_colors, ReadingColors::default());
-    // Switch the preset to white-on-black in the dialog's Reading colours combo. The open
-    // document keeps repainting, so run a fixed number of steps and let the popup settle.
-    combo(&mut h);
-    h.run_steps(20);
-    h.get_by_label("White on black").click();
+    h.get_by(|n| n.role() == Role::Button && n.label().as_deref() == Some("White on black")).scroll_to_me();
+    h.run_steps(4);
+    h.get_by(|n| n.role() == Role::Button && n.label().as_deref() == Some("White on black")).click();
    h.run_steps(2);
    assert_eq!(h.state().reading_colors, ReadingColors::WHITE_ON_BLACK);
    // The preference is app-wide: the already open document follows it too.
@@ -151,6 +138,41 @@ fn reading_colours_preference_round_trips() {
    assert_eq!(fresh.reading_colors, ReadingColors::default());
 }

+#[test]
+fn reading_presets_follow_appearance_and_do_not_change_the_interface_theme() {
+    let mut h = Harness::builder().with_size(egui::vec2(1400.0, 1000.0)).build_eframe(|_cc| {
+        let mut app = PdfCraftApp::new();
+        app.set_option("language", "en").unwrap();
+        app.set_option("dialog", "preferences").unwrap();
+        app
+    });
+    h.run_steps(6);
+    assert!(h.query_by_label("Original").is_some());
+    let theme = h.state().theme_preference;
+    let appearance = h.get_by_label("Light theme").rect();
+    let preset = h.get_by(|n| n.role() == Role::Button && n.label().as_deref() == Some("White on black")).rect();
+    let documents = h.get_by_label("Documents and view").rect();
+    assert!(appearance.bottom() < preset.top() && preset.bottom() < documents.top());
+    for (label, expected) in [
+        ("White on black", ReadingColors::WHITE_ON_BLACK),
+        ("Yellow on black", ReadingColors::YELLOW_ON_BLACK),
+        ("Green on black", ReadingColors::GREEN_ON_BLACK),
+        ("Black on white", ReadingColors::BLACK_ON_WHITE),
+        ("Off", ReadingColors::default()),
+    ] {
+        h.get_by(|n| n.role() == Role::Button && n.label().as_deref() == Some(label)).scroll_to_me();
+        h.run_steps(4);
+        h.get_by(|n| n.role() == Role::Button && n.label().as_deref() == Some(label)).click();
+        h.run_steps(4);
+        assert_eq!(h.state().reading_colors, expected);
+        assert_eq!(h.state().theme_preference, theme);
+        assert_eq!(h.query_by_label("Original").is_some(), expected.params.is_none());
+    }
+    if let Ok(path) = std::env::var("PDFCRAFT_READING_SHOT") {
+        h.render().unwrap().save(path).unwrap();
+    }
+}
+
 #[test]
 fn reading_colours_seed_on_open() {
    let mut h = Harness::builder().with_size(egui::vec2(1400.0, 900.0)).build_eframe(|_cc| {
@@ -19,6 +19,20 @@ fn preference(h: &Harness<'static, PdfCraftApp>) -> String {
    format!("{:?}", h.state().theme_preference)
 }

+#[test]
+fn preferences_gear_is_right_of_theme_and_opens_preferences() {
+    let mut h = harness();
+    let theme = h.get_by_label("Display theme: Use system setting").rect();
+    let gear = h.get_by_label("Preferences").rect();
+    assert!(gear.left() >= theme.right());
+    h.get_by_label("Preferences").click();
+    h.run_steps(6);
+    assert!(h.query_by_label("Appearance mode").is_some());
+    assert!(h.query_by_label("Light theme").is_some());
+    assert!(h.query_by_label("Dark theme").is_some());
+    assert_eq!(preference(&h), "System");
+}
+
 #[test]
 fn a_click_cycles_the_theme_and_a_right_click_opens_the_menu() {
    let mut h = harness();
@@ -706,11 +706,11 @@ fn narrow_tab_strips_accept_vertical_wheel_scrolling() {
            app
        });
        h.run_steps(4);
-        let last = h.get_by_label("narrow-11.pdf").rect();
+        let last = h.get_by(|n| n.role() == egui::accesskit::Role::Tab && n.label().as_deref() == Some("narrow-11.pdf")).rect();
        assert!(last.center().x > 28.0 && last.right() < width - 100.0, "active tab: {last:?}");
        h.state_mut().active = Some(0);
        h.run_steps(4);
-        let first = h.get_by_label("narrow-00.pdf").rect();
+        let first = h.get_by(|n| n.role() == egui::accesskit::Role::Tab && n.label().as_deref() == Some("narrow-00.pdf")).rect();
        assert!(first.center().x > 28.0 && first.right() < width - 100.0);
        h.event(egui::Event::PointerMoved(first.center()));
        for _ in 0..8 {
@@ -723,9 +723,9 @@ fn narrow_tab_strips_accept_vertical_wheel_scrolling() {
            });
            h.run_steps(8);
        }
-        let last = h.get_by_label("narrow-11.pdf").rect();
+        let last = h.get_by(|n| n.role() == egui::accesskit::Role::Tab && n.label().as_deref() == Some("narrow-11.pdf")).rect();
        assert!(last.center().x > 28.0 && last.right() < width - 100.0, "scrolled tab: {last:?}");
-        h.get_by_label("narrow-11.pdf").click();
+        h.get_by(|n| n.role() == egui::accesskit::Role::Tab && n.label().as_deref() == Some("narrow-11.pdf")).click();
        h.run_steps(4);
        assert_eq!(h.state().active, Some(11));
        assert!(h.get_by_label_contains("Display theme:").rect().right() <= width);
@@ -9180,8 +9180,8 @@ milestone = "M12"
 status = "shipped"
 commands = []
 tools = ["view_reading_colors"]
-evidence = ["crates/automation/tests/it/automation.rs::reading_colors_through_tools", "crates/render/src/raster/tests.rs::reading_colors_map_solid_paints_and_leave_images", "crates/render/src/raster/tests.rs::reading_colors_tiles_match_full_render", "crates/render/src/raster/tests.rs::print_preview_requests_render_with_reading_colors_off", "crates/render/src/raster/tests.rs::reading_colors_keep_highlight_annotations_readable", "crates/ui-egui/tests/it/reading_colors.rs::reading_colours_preference_round_trips", "crates/ui-egui/tests/it/reading_colors.rs::reading_colours_seed_on_open", "crates/ui-egui/tests/it/reading_colors.rs::pending_pages_use_document_reading_background"]
-notes = "View only, off by default: Preferences ▸ Reading colours holds the app-wide preference, seeded into every document as it opens (including created ones), and view_reading_colors reads and sets it per document (Acrobat's Replace Document Colors). Solid text paints and, by default, line-art paints (including stencil-mask image paints) are remapped by luminance — each lerps between the preset's text and background colour by how dark or light the original paint is — while images, shadings and tiling patterns pass through untouched. Annotations keep the colours they were given (both /AP appearances and the no-/AP Highlight fallback), so a Multiply highlight over a dark background shows the marked-up words in the highlight's colour instead of a flat bar that hides them (#1548). Presets: black on white, white on black, yellow on black, green on black, or a custom #RRGGBB pair; only_black limits the mapping to near-black paints (a 10% luminance threshold — our choice; Acrobat's was not observed). Display only: the document is not changed and print and export are unaffected; print previews and view snapshots render with the document's true colours (a preview matches the uncoloured printout, and a snapshot is an export surface), so reading colours apply to the reading view only. Pending canvas pages use the configured reading background before their raster arrives (#2059). Closes #897 (duplicate #488)."
+evidence = ["crates/automation/tests/it/automation.rs::reading_colors_through_tools", "crates/render/src/raster/tests.rs::reading_colors_map_solid_paints_and_leave_images", "crates/render/src/raster/tests.rs::reading_colors_tiles_match_full_render", "crates/render/src/raster/tests.rs::print_preview_requests_render_with_reading_colors_off", "crates/render/src/raster/tests.rs::reading_colors_keep_highlight_annotations_readable", "crates/ui-egui/tests/it/reading_colors.rs::reading_colours_preference_round_trips", "crates/ui-egui/tests/it/reading_colors.rs::reading_colours_seed_on_open", "crates/ui-egui/tests/it/reading_colors.rs::pending_pages_use_document_reading_background", "crates/ui-egui/tests/it/reading_colors.rs::reading_presets_follow_appearance_and_do_not_change_the_interface_theme", "crates/ui-egui/tests/it/theme_button.rs::preferences_gear_is_right_of_theme_and_opens_preferences"]
+notes = "View only, off by default: Preferences ▸ Reading colours, directly below Appearance, offers colour samples and a live preview; the gear beside the theme button opens Preferences. Reading colours holds the app-wide preference, seeded into every document as it opens (including created ones), and view_reading_colors reads and sets it per document (Acrobat's Replace Document Colors). Solid text paints and, by default, line-art paints (including stencil-mask image paints) are remapped by luminance — each lerps between the preset's text and background colour by how dark or light the original paint is — while images, shadings and tiling patterns pass through untouched. Annotations keep the colours they were given (both /AP appearances and the no-/AP Highlight fallback), so a Multiply highlight over a dark background shows the marked-up words in the highlight's colour instead of a flat bar that hides them (#1548). Presets: black on white, white on black, yellow on black, green on black, or a custom #RRGGBB pair; only_black limits the mapping to near-black paints (a 10% luminance threshold — our choice; Acrobat's was not observed). Display only: the document is not changed and print and export are unaffected; print previews and view snapshots render with the document's true colours (a preview matches the uncoloured printout, and a snapshot is an export surface), so reading colours apply to the reading view only. Pending canvas pages use the configured reading background before their raster arrives (#2059). Closes #897 (duplicate #488)."

 [[feature]]
 id = "a11y.reflow-tagged"