fix(pptx): apply style-matrix outlines (lnRef) to shapes

crates/office2pdf/src/parser/pptx_shape_style_tests.rs

@@ -613,3 +613,44 @@ fn test_split_textbox_preserves_alignment() {
         typst_output.source,
     );
 }
+
+#[test]
+fn test_shape_style_lnref_outline_resolves_width_and_shaded_color() {
+    // A shape whose outline comes only from <p:style><a:lnRef idx=..> with a
+    // shaded scheme color (a Start-event color) must render a stroke: width
+    // from the theme lnStyleLst, color from the resolved scheme (issue #318).
+    let theme_xml = r#"<?xml version="1.0"?>
+<a:theme xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main">
+  <a:themeElements>
+    <a:clrScheme name="X">
+      <a:dk1><a:srgbClr val="000000"/></a:dk1><a:lt1><a:srgbClr val="FFFFFF"/></a:lt1>
+      <a:accent1><a:srgbClr val="4472C4"/></a:accent1>
+    </a:clrScheme>
+    <a:fontScheme name="X"><a:majorFont><a:latin typeface="Calibri"/></a:majorFont><a:minorFont><a:latin typeface="Calibri"/></a:minorFont></a:fontScheme>
+    <a:fmtScheme name="X"><a:lnStyleLst>
+      <a:ln w="6350"><a:solidFill><a:schemeClr val="phClr"/></a:solidFill></a:ln>
+      <a:ln w="12700"><a:solidFill><a:schemeClr val="phClr"/></a:solidFill></a:ln>
+      <a:ln w="19050"><a:solidFill><a:schemeClr val="phClr"/></a:solidFill></a:ln>
+    </a:lnStyleLst></a:fmtScheme>
+  </a:themeElements>
+</a:theme>"#;
+    let shape = r#"<p:sp><p:nvSpPr><p:cNvPr id="2" name="Shape"/><p:cNvSpPr/><p:nvPr/></p:nvSpPr><p:spPr><a:xfrm><a:off x="0" y="0"/><a:ext cx="914400" cy="914400"/></a:xfrm><a:prstGeom prst="rect"><a:avLst/></a:prstGeom><a:solidFill><a:srgbClr val="4472C4"/></a:solidFill></p:spPr><p:style><a:lnRef idx="2"><a:schemeClr val="accent1"><a:shade val="50000"/></a:schemeClr></a:lnRef><a:fillRef idx="1"><a:schemeClr val="accent1"/></a:fillRef></p:style></p:sp>"#.to_string();
+    let slide = make_slide_xml(&[shape]);
+    let data = build_test_pptx_with_theme(SLIDE_CX, SLIDE_CY, &[slide], theme_xml);
+
+    let parser = PptxParser;
+    let (doc, _warnings) = parser.parse(&data, &ConvertOptions::default()).unwrap();
+    let page = first_fixed_page(&doc);
+    let FixedElementKind::Shape(ref s) = page.elements[0].kind else {
+        panic!("expected shape");
+    };
+    let stroke = s.stroke.as_ref().expect("lnRef must produce a stroke");
+    // idx=2 → theme lnStyleLst[1] = 12700 EMU = 1pt.
+    assert!(
+        (stroke.width - 1.0).abs() < 0.01,
+        "outline width from theme lnStyleLst idx 2, got {}",
+        stroke.width
+    );
+    // accent1 (4472C4) shaded 50% ≈ half each channel.
+    assert_eq!(stroke.color, Color::new(0x22, 0x39, 0x62));
+}

crates/office2pdf/src/parser/pptx_slides.rs

@@ -557,6 +557,9 @@ struct ShapeState {
     adj_values: Vec<f64>,
     /// Fallback line color from `<p:style><a:lnRef>` scheme reference.
     style_ln_color: Option<Color>,
+    /// `<a:lnRef idx>` (1-based) into the theme line style list, for the
+    /// fallback outline width when no explicit `<a:ln w>` is present.
+    style_ln_idx: Option<usize>,
     /// Fallback fill color from `<p:style><a:fillRef>` scheme reference.
     style_fill_color: Option<Color>,
     /// Fallback text color from `<p:style><a:fontRef>` scheme reference.
@@ -595,6 +598,7 @@ impl Default for ShapeState {
             tail_end: ArrowHead::None,
             adj_values: Vec::new(),
             style_ln_color: None,
+            style_ln_idx: None,
             style_fill_color: None,
             style_font_color: None,
             explicit_no_fill: false,
@@ -613,6 +617,7 @@ impl ShapeState {
 /// Finalize a shape element when `</p:sp>` is reached.
 /// Returns elements to add: for shapes with text AND non-rectangular geometry,
 /// returns two elements (shape background + transparent text overlay).
+#[allow(clippy::too_many_arguments)]
 fn finalize_shape(
     shape: &mut ShapeState,
     paragraphs: &mut Vec<PptxParagraphEntry>,
@@ -621,7 +626,20 @@ fn finalize_shape(
     text_box_no_wrap: bool,
     text_box_auto_fit: bool,
     text_box_text_rotation_deg: Option<f64>,
+    theme_line_style_widths: &[i64],
 ) -> Vec<FixedElement> {
+    // Outline width: explicit `<a:ln w>` when present, otherwise the theme
+    // line style referenced by `<a:lnRef idx>` (issue #318).
+    let effective_ln_width_emu: i64 = if shape.ln_width_emu > 0 {
+        shape.ln_width_emu
+    } else {
+        shape
+            .style_ln_idx
+            .and_then(|idx| theme_line_style_widths.get(idx - 1).copied())
+            .unwrap_or(shape.ln_width_emu)
+    };
+    let effective_ln_width_pt: f64 = emu_to_pt(effective_ln_width_emu);
+
     // Resolve effective fill: explicit > noFill > style fallback.
     let effective_fill: Option<Color> = if shape.fill.is_some() {
         shape.fill
@@ -640,7 +658,7 @@ fn finalize_shape(
         // Use explicit line color, falling back to style-based color from <p:style><a:lnRef>.
         let effective_ln_color: Option<Color> = shape.ln_color.or(shape.style_ln_color);
         let stroke: Option<BorderSide> = effective_ln_color.map(|color| BorderSide {
-            width: emu_to_pt(shape.ln_width_emu),
+            width: effective_ln_width_pt,
             color,
             style: shape.ln_dash_style,
         });
@@ -749,7 +767,7 @@ fn finalize_shape(
         // Use explicit line color, falling back to style-based color from <p:style><a:lnRef>.
         let effective_ln_color: Option<Color> = shape.ln_color.or(shape.style_ln_color);
         let stroke: Option<BorderSide> = effective_ln_color.map(|color| BorderSide {
-            width: emu_to_pt(shape.ln_width_emu),
+            width: effective_ln_width_pt,
             color,
             style: shape.ln_dash_style,
         });
@@ -1380,9 +1398,27 @@ impl<'a> SlideXmlParser<'a> {
                     &mut self.pic,
                 );
             }
+            // Style-matrix ref colors (`<a:lnRef>`/`<a:fillRef>`/`<a:fontRef>`)
+            // can carry shade/tint transforms, which arrive as Start events;
+            // the Empty-event arms below would miss them.
+            b"srgbClr" | b"schemeClr" | b"sysClr" if self.in_style_ln_ref => {
+                let parsed = parse_color_from_start(reader, e, self.theme, self.color_map);
+                self.shape.style_ln_color = parsed.color;
+            }
+            b"srgbClr" | b"schemeClr" | b"sysClr" if self.in_style_fill_ref => {
+                let parsed = parse_color_from_start(reader, e, self.theme, self.color_map);
+                self.shape.style_fill_color = parsed.color;
+            }
+            b"srgbClr" | b"schemeClr" | b"sysClr" if self.in_style_font_ref => {
+                let parsed = parse_color_from_start(reader, e, self.theme, self.color_map);
+                self.shape.style_font_color = parsed.color;
+            }
             // `<a:lnRef>` inside `<p:style>` provides fallback line color.
             b"lnRef" if self.in_shape && !self.shape.in_sp_pr && !self.in_txbody => {
                 self.in_style_ln_ref = true;
+                self.shape.style_ln_idx = get_attr_str(e, b"idx")
+                    .and_then(|value| value.parse::<usize>().ok())
+                    .filter(|idx| *idx > 0);
             }
             // `<a:fillRef>` inside `<p:style>` provides fallback fill color.
             b"fillRef" if self.in_shape && !self.shape.in_sp_pr && !self.in_txbody => {
@@ -1730,6 +1766,7 @@ impl<'a> SlideXmlParser<'a> {
                             self.text_box_no_wrap,
                             self.text_box_auto_fit,
                             self.text_box_text_rotation_deg,
+                            &self.theme.line_style_widths,
                         ));
                     }
                     self.in_shape = false;

crates/office2pdf/src/parser/pptx_theme.rs

@@ -17,6 +17,9 @@ pub(super) struct ThemeData {
     /// Raw XML of each `<a:fmtScheme>/<a:bgFillStyleLst>` entry, for
     /// `<p:bgRef>` idx ≥ 1001 resolution.
     pub(super) bg_fill_styles: Vec<String>,
+    /// Line widths (EMU) of each `<a:fmtScheme>/<a:lnStyleLst>/<a:ln>` entry,
+    /// for `<a:lnRef idx="N">` outline width resolution.
+    pub(super) line_style_widths: Vec<i64>,
 }
 
 /// Effective scheme-color aliases for a slide part.
@@ -452,10 +455,46 @@ pub(super) fn parse_theme_xml(xml: &str) -> ThemeData {
 
     theme.fill_styles = extract_fill_style_entries(xml, b"fillStyleLst");
     theme.bg_fill_styles = extract_fill_style_entries(xml, b"bgFillStyleLst");
+    theme.line_style_widths = extract_line_style_widths(xml);
 
     theme
 }
 
+/// Extract the `w` (EMU) of each `<a:ln>` inside the theme `<a:lnStyleLst>`.
+fn extract_line_style_widths(xml: &str) -> Vec<i64> {
+    let mut reader = Reader::from_str(xml);
+    let mut widths: Vec<i64> = Vec::new();
+    let mut in_list = false;
+    loop {
+        match reader.read_event() {
+            Ok(Event::Start(ref e)) => match e.local_name().as_ref() {
+                b"lnStyleLst" => in_list = true,
+                b"ln" if in_list => {
+                    widths.push(line_width_attr(e));
+                }
+                _ => {}
+            },
+            Ok(Event::Empty(ref e)) if in_list && e.local_name().as_ref() == b"ln" => {
+                widths.push(line_width_attr(e));
+            }
+            Ok(Event::End(ref e)) if e.local_name().as_ref() == b"lnStyleLst" => break,
+            Ok(Event::Eof) => break,
+            Err(_) => break,
+            _ => {}
+        }
+    }
+    widths
+}
+
+fn line_width_attr(e: &BytesStart<'_>) -> i64 {
+    e.attributes()
+        .flatten()
+        .find(|attr| attr.key.local_name().as_ref() == b"w")
+        .and_then(|attr| attr.unescape_value().ok())
+        .and_then(|value| value.parse::<i64>().ok())
+        .unwrap_or(0)
+}
+
 /// Extract the raw XML of each top-level fill entry (`<a:solidFill>`,
 /// `<a:gradFill>`, ...) inside the named `<a:fmtScheme>` list.
 fn extract_fill_style_entries(xml: &str, list_tag: &[u8]) -> Vec<String> {

crates/office2pdf/src/parser/pptx_theme_tests.rs

@@ -627,3 +627,25 @@ fn test_layout_shape_uses_master_color_map_with_luminance_offset() {
     let shape = get_shape(&page.elements[0]);
     assert_eq!(shape.fill, Some(Color::new(0x80, 0x80, 0x80)));
 }
+
+#[test]
+fn test_parse_theme_line_style_widths() {
+    // Theme lnStyleLst widths back <a:lnRef idx="N"> outline resolution
+    // (issue #318): idx=1/2/3 map to the 1st/2nd/3rd entry's EMU width.
+    let theme_xml = r#"<?xml version="1.0"?>
+<a:theme xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main">
+  <a:themeElements>
+    <a:clrScheme name="X"><a:dk1><a:srgbClr val="000000"/></a:dk1></a:clrScheme>
+    <a:fontScheme name="X"><a:majorFont><a:latin typeface="Calibri"/></a:majorFont><a:minorFont><a:latin typeface="Calibri"/></a:minorFont></a:fontScheme>
+    <a:fmtScheme name="X">
+      <a:lnStyleLst>
+        <a:ln w="6350"><a:solidFill><a:schemeClr val="phClr"/></a:solidFill></a:ln>
+        <a:ln w="12700"><a:solidFill><a:schemeClr val="phClr"/></a:solidFill></a:ln>
+        <a:ln w="19050"><a:solidFill><a:schemeClr val="phClr"/></a:solidFill></a:ln>
+      </a:lnStyleLst>
+    </a:fmtScheme>
+  </a:themeElements>
+</a:theme>"#;
+    let theme = parse_theme_xml(theme_xml);
+    assert_eq!(theme.line_style_widths, vec![6350, 12700, 19050]);
+}