Preferences: field highlights on by default, with a toggle in Appearance (#2273)

New settings start with Highlight fields on. A stored choice is kept; a missing or
malformed value falls back to on. Preferences > Appearance gets the checkbox.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

crates/ui-egui/src/appearance.rs

@@ -139,6 +139,9 @@ pub fn preferences_section(ui: &mut egui::Ui, app: &mut PdfCraftApp, t: &Tokens)
             app.execute(mode_command(ThemePreference::Dark));
         }
     });
+    ui.add_space(4.0);
+    // Acrobat's "Highlight existing fields": shared with the toggle in the form bar.
+    ui.add(crate::widgets::checkbox(&mut app.view_defaults.highlight_fields, tl!("Highlight fields")));
 }
 
 #[cfg(test)]
@@ -176,6 +179,12 @@ mod tests {
             h.render().unwrap().save(path).unwrap();
         }
 
+        // The field-highlight preference is on for new settings, and the box turns it off.
+        assert!(h.state().view_defaults.highlight_fields);
+        h.get_by_label("Highlight fields").click();
+        h.run();
+        assert!(!h.state().view_defaults.highlight_fields);
+
         let combo = egui::accesskit::Role::ComboBox;
         h.get_by_role(combo).click();
         h.run();

crates/ui-egui/src/canvas.rs

@@ -174,14 +174,14 @@ pub struct ViewDefaults {
     /// The zoom with [`Fit::None`] (1.0 = 100%).
     pub zoom: f32,
     /// Highlight existing fields: a preference in Acrobat, so it carries over to the next
-    /// document and the next session.
+    /// document and the next session. On for new settings; a stored choice wins.
     pub highlight_fields: bool,
 }
 
 impl Default for ViewDefaults {
     fn default() -> Self {
         // Single page, scrolling continuously at fit width: the earlier "continuous" default.
-        Self { layout: PageLayout::Single, continuous: true, fit: Fit::Width, zoom: 1.0, highlight_fields: false }
+        Self { layout: PageLayout::Single, continuous: true, fit: Fit::Width, zoom: 1.0, highlight_fields: true }
     }
 }
 

crates/ui-egui/tests/view.rs

@@ -1059,6 +1059,8 @@ fn highlight_fields_tints_the_field_area() {
     let _gpu = gpu();
     let mut h = form_harness();
     h.state_mut().set_option("panel", "none").unwrap();
+    // Highlighting is on by default; start from plain fields.
+    h.state_mut().set_option("fields", "off").unwrap();
     for _ in 0..100 {
         h.run_steps(2);
         if !h.state().render_pending() {
@@ -1136,27 +1138,47 @@ fn required_radio_buttons_get_a_round_red_border() {
     assert!(!stroke(at(50.3, 339.7)), "the widget's corner, outside the circle, is not: {:?}", at(50.3, 339.7));
 }
 
-/// Acrobat's Highlight existing fields is a preference, not a per-document choice: turned on
-/// once, the next document (and the next session) opens with fields highlighted.
+/// Acrobat's Highlight existing fields is a preference, not a per-document choice: turned off
+/// once, the next document (and the next session) opens with fields plain. New settings start
+/// with it on.
 #[test]
-fn field_highlighting_is_remembered() {
+fn field_highlighting_is_on_by_default_and_remembered() {
     use egui_kittest::kittest::Queryable;
     let mut h = form_harness();
     h.state_mut().set_option("panel", "none").unwrap();
     h.run_steps(4);
-    assert!(!h.state().views[0].highlight_fields, "off by default");
-    h.get_by_label("Highlight fields").click();
+    assert!(h.state().views[0].highlight_fields, "on by default");
+    h.get_by_label("Hide field highlights").click();
     h.run_steps(4);
-    assert!(h.state().views[0].highlight_fields);
+    assert!(!h.state().views[0].highlight_fields);
     h.state_mut().open_bytes("radios.pdf", None, RADIOS.to_vec()).expect("opens");
     h.run_steps(4);
-    assert!(h.state().views[1].highlight_fields, "the next document opens highlighted");
+    assert!(!h.state().views[1].highlight_fields, "the next document opens plain");
     let saved = h.state().persist();
     let mut next = PdfCraftApp::new();
     next.set_option("language", "en").unwrap();
     next.restore(&saved);
     next.open_bytes("form.pdf", None, FORM.to_vec()).expect("opens");
-    assert!(next.views[0].highlight_fields, "and so does the next session");
+    assert!(!next.views[0].highlight_fields, "and so does the next session");
+}
+
+/// Settings saved before the default changed keep their stored choice; a missing or malformed
+/// value falls back to the default instead of failing.
+#[test]
+fn stored_field_highlight_choice_wins_over_the_default() {
+    for (stored, expected) in [
+        (r#"{"highlight_fields": false}"#, false),
+        (r#"{"highlight_fields": true}"#, true),
+        (r#"{}"#, true),
+        (r#"{"highlight_fields": "no"}"#, true),
+        (r#"{"highlight_fields": null}"#, true),
+    ] {
+        let mut app = PdfCraftApp::new();
+        app.set_option("language", "en").unwrap();
+        app.restore(stored);
+        app.open_bytes("form.pdf", None, FORM.to_vec()).expect("opens");
+        assert_eq!(app.views[0].highlight_fields, expected, "{stored}");
+    }
 }
 
 #[test]

parity/acrobat-features.toml

@@ -4392,8 +4392,8 @@ milestone = "M3"
 status = "shipped"
 commands = []
 tools = []
-evidence = ["crates/ui-egui/tests/view.rs::highlight_fields_tints_the_field_area", "crates/ui-egui/tests/view.rs::required_radio_buttons_get_a_round_red_border", "crates/ui-egui/tests/view.rs::field_highlighting_is_remembered", "crates/ui-egui/tests/editing.rs::a_secured_form_shows_its_form_notice_and_its_security"]
-notes = "offered on secured forms too; remembered for the next document and session; required fields get a red border (round for radio buttons); the tint is drawn over the field, where Acrobat paints the highlight colour behind it"
+evidence = ["crates/ui-egui/tests/view.rs::highlight_fields_tints_the_field_area", "crates/ui-egui/tests/view.rs::required_radio_buttons_get_a_round_red_border", "crates/ui-egui/tests/view.rs::field_highlighting_is_on_by_default_and_remembered", "crates/ui-egui/tests/view.rs::stored_field_highlight_choice_wins_over_the_default", "crates/ui-egui/tests/editing.rs::a_secured_form_shows_its_form_notice_and_its_security"]
+notes = "offered on secured forms too; on by default for new settings (a stored choice is kept) and remembered for the next document and session; toggled from the form bar and from Preferences > Appearance, where it sets the default for documents opened afterwards; required fields get a red border (round for radio buttons); the tint is drawn over the field, where Acrobat paints the highlight colour behind it"
 
 [[feature]]
 id = "form.field-appearance-display"