IDML: Q ruler units are Q, as InDesign writes them (#1360)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013phQ3ekq6uGBEWD6FjFYG2

crates/idml/src/import.rs

@@ -593,11 +593,17 @@ impl<'r> Importer<'r> {
                     self.default_margins = Some((m, c));
                 }
                 "ViewPreference" => {
-                    if let Some(u) = e.get("HorizontalMeasurementUnits") {
-                        self.settings.horizontal_units = names::unit_in(u);
-                    }
-                    if let Some(u) = e.get("VerticalMeasurementUnits") {
-                        self.settings.vertical_units = names::unit_in(u);
+                    for (attr, ruler) in [("HorizontalMeasurementUnits", "horizontal"), ("VerticalMeasurementUnits", "vertical")] {
+                        let Some(u) = e.get(attr) else { continue };
+                        let unit = names::unit_in(u).unwrap_or_else(|| {
+                            self.warnings.push(format!("{ruler} ruler units `{u}` are not available; read as points"));
+                            designcraft_geom::Unit::Points
+                        });
+                        if ruler == "horizontal" {
+                            self.settings.horizontal_units = unit;
+                        } else {
+                            self.settings.vertical_units = unit;
+                        }
                     }
                     if let Some(v) = e.num("CursorKeyIncrement") {
                         self.settings.keyboard_increment = v;

crates/idml/src/names.rs

@@ -634,6 +634,8 @@ pub fn number_style_in(s: &str) -> NumberStyle {
     }
 }
 
+/// IDML `MeasurementUnits` of a unit. Q is `Q`; `U` is a different unit, which DesignCraft
+/// doesn't have.
 pub fn unit_out(u: Unit) -> &'static str {
     match u {
         Unit::Points => "Points",
@@ -645,27 +647,14 @@ pub fn unit_out(u: Unit) -> &'static str {
         Unit::Ciceros => "Ciceros",
         Unit::Agates => "Agates",
         Unit::Pixels => "Pixels",
-        Unit::Q => "U",
+        Unit::Q => "Q",
         Unit::Ha => "Ha",
     }
 }
-pub fn unit_in(s: &str) -> Unit {
-    [
-        Unit::Points,
-        Unit::Picas,
-        Unit::Inches,
-        Unit::InchesDecimal,
-        Unit::Millimeters,
-        Unit::Centimeters,
-        Unit::Ciceros,
-        Unit::Agates,
-        Unit::Pixels,
-        Unit::Q,
-        Unit::Ha,
-    ]
-    .into_iter()
-    .find(|u| unit_out(*u) == s)
-    .unwrap_or(Unit::Points)
+/// The unit an IDML `MeasurementUnits` value names, if DesignCraft has it (not `U`, `Bai`,
+/// `Mils`, `AmericanPoints` or `Custom`).
+pub fn unit_in(s: &str) -> Option<Unit> {
+    Unit::ALL.into_iter().find(|u| unit_out(*u) == s)
 }
 
 /// IDML layer colour enumeration names for our layer colour table.

crates/idml/src/tests.rs

@@ -2773,6 +2773,38 @@ fn round_trips_the_zero_point_and_ruler_origin() {
     assert_eq!(fixture("NaN 4").settings.zero_point, [0.0, 0.0]);
 }
 
+/// Q is `Q` in IDML, as InDesign writes it (`U` is another unit). Units DesignCraft lacks are
+/// read as points, and the import report says so.
+#[test]
+fn ruler_units_in_q_and_ha_round_trip_and_unknown_units_are_reported() {
+    use designcraft_geom::Unit;
+    let mut d = Document::new(&NewDocument::default());
+    for (h, v) in [(Unit::Q, Unit::Ha), (Unit::Ha, Unit::Q), (Unit::Millimeters, Unit::Points)] {
+        (d.settings.horizontal_units, d.settings.vertical_units) = (h, v);
+        let bytes = export_idml(&d);
+        let back = import_idml(&bytes).unwrap();
+        assert_eq!((back.settings.horizontal_units, back.settings.vertical_units), (h, v));
+    }
+    d.settings.horizontal_units = Unit::Q;
+    let prefs = zip_text(&export_idml(&d), "Resources/Preferences.xml");
+    assert!(prefs.contains(r#"HorizontalMeasurementUnits="Q""#), "{prefs}");
+
+    let prefs =
+        PREFS.replace("<MarginPreference", r#"<ViewPreference HorizontalMeasurementUnits="U" VerticalMeasurementUnits="Q"/><MarginPreference"#);
+    let zip = zip_files(&[
+        ("designmap.xml", DESIGNMAP),
+        ("Resources/Graphic.xml", GRAPHIC),
+        ("Resources/Styles.xml", STYLES),
+        ("Resources/Preferences.xml", &prefs),
+        ("MasterSpreads/MasterSpread_m1.xml", MASTER),
+        ("Spreads/Spread_sp1.xml", SPREAD),
+        ("Stories/Story_s1.xml", STORY),
+    ]);
+    let r = import_idml_report(&zip, &|_| None).unwrap();
+    assert_eq!((r.document.settings.horizontal_units, r.document.settings.vertical_units), (Unit::Points, Unit::Q));
+    assert!(r.warnings.iter().any(|w| w.contains("horizontal ruler units `U`")), "{:?}", r.warnings);
+}
+
 #[test]
 fn kenten_shatai_and_grid_settings_import_and_round_trip() {
     use designcraft_doc::cjk::CharacterAlignment;