SVG: do not draw an element with display="none"

CHANGELOG.md

@@ -23,6 +23,7 @@ This can also be enabled programmatically with `warnings.simplefilter('default',
 ### Fixed
 * SVG: `currentColor` and `inherit` are now read regardless of case, like the color keywords, so `fill="currentcolor"`, as in the Font Awesome icons of many web pages, no longer fails with `ValueError: unsupported color specification currentcolor` - thanks to @RavSinghChandan
 * SVG: black or gray text no longer fails with an `AssertionError` when it is in a `<tspan>` that has its own style, as in every text written by Inkscape: the check on the text color left out `DeviceGray`, the color fpdf2 uses for black and gray - thanks to @RavSinghChandan
+* SVG: an element or group with `display="none"`, set as an attribute, in its `style` or by a CSS class, such as a hidden Inkscape layer, is no longer drawn; an element inside it can still be drawn by a `<use>` - thanks to @RavSinghChandan
 * SVG: an image without an `xmlns` declaration no longer fails with `ValueError: substring not found` when it contains a tag that is not supported, such as `<title>` or `<script>`; the tag is skipped with a warning, as in an image that declares the namespace - thanks to @RavSinghChandan
 * `FPDF.text()` raises a clear `ValueError` for a NaN or infinite `x` or `y`, like `FPDF.set_xy()`, instead of writing `nan` or `inf` into the page, which is not a valid PDF number - thanks to @RavSinghChandan
 * SVG: `clip-path="none"`, as written by Inkscape, no longer fails with an `AssertionError`, and a `url(#id)` reference to a clip path whose id contains a `-` or a `.`, or that is quoted, now finds that clip path, instead of failing with a `KeyError` or clipping with another one whose id is the part before the `-` or `.` - thanks to @RavSinghChandan

fpdf/svg.py

@@ -2232,6 +2232,11 @@ def _build_group_child(
         inherited_style: dict[str, Any],
     ) -> None:
         """Convert one graphics child while preserving its parent's style."""
+        display = _get_attr_or_style(child, "display", self._style_map_for(child))
+        if display is not None and display.strip().lower() == "none":
+            # The element and its children are not drawn, as for a hidden Inkscape
+            # layer. It is still built, so that ids inside it can be referenced.
+            pdf_group = GraphicsContext()
         if child.tag in xmlns_lookup("svg", "defs"):
             self.handle_defs(child)
         elif child.tag in xmlns_lookup(

test/svg/test_svg.py

@@ -546,6 +546,45 @@ def test_svg_text_gray_color_in_styled_tspan(
         svg.draw_to_page(pdf)
         assert f"{color_operators} [] 0 d BT" in bytes(pdf.output()).decode("latin-1")
 
+    @pytest.mark.parametrize(
+        "hidden_rect",
+        [
+            '<rect width="10" height="10" display="none"/>',
+            # a hidden Inkscape layer
+            '<g style="display:none"><rect width="10" height="10"/></g>',
+            (
+                "<style>.hidden { display: none }</style>"
+                '<rect class="hidden" width="10" height="10"/>'
+            ),
+        ],
+    )
+    def test_svg_display_none(self, hidden_rect):
+        svg = fpdf.svg.SVGObject(
+            '<svg xmlns="http://www.w3.org/2000/svg" width="50" height="50">'
+            f'{hidden_rect}<circle cx="25" cy="25" r="3"/></svg>'
+        )
+        pdf = fpdf.FPDF()
+        pdf.compress = False
+        pdf.add_page()
+        svg.draw_to_page(pdf)
+        output = bytes(pdf.output()).decode("latin-1")
+        assert " re " not in output  # the rectangle
+        assert " c " in output  # the circle
+
+    def test_svg_display_none_referenced(self):
+        """An element in a hidden group can still be drawn by a <use>."""
+        svg = fpdf.svg.SVGObject(
+            '<svg xmlns="http://www.w3.org/2000/svg" width="50" height="50">'
+            '<g display="none"><rect id="square" width="10" height="10"/></g>'
+            '<use href="#square" x="20"/></svg>'
+        )
+        pdf = fpdf.FPDF()
+        pdf.compress = False
+        pdf.add_page()
+        svg.draw_to_page(pdf)
+        output = bytes(pdf.output()).decode("latin-1")
+        assert output.count(" re ") == 1
+
     def test_svg_symbol(self):
         svg_data = (
             '<svg xmlns="http://www.w3.org/2000/svg" '