Add basic support for adding SVG pictures to docx files

See issues python-openxml#351, python-openxml#651, python-openxml#659.

docx/image/__init__.py

@@ -14,6 +14,7 @@
 from docx.image.jpeg import Exif, Jfif
 from docx.image.png import Png
 from docx.image.tiff import Tiff
+from docx.image.svg import Svg
 
 
 SIGNATURES = (
@@ -26,4 +27,5 @@
     (Tiff, 0, b'MM\x00*'),  # big-endian (Motorola) TIFF
     (Tiff, 0, b'II*\x00'),  # little-endian (Intel) TIFF
     (Bmp,  0, b'BM'),
+    (Svg,  0, b'<svg '),
 )

docx/image/constants.py

@@ -102,6 +102,7 @@ class MIME_TYPE(object):
     JPEG = 'image/jpeg'
     PNG = 'image/png'
     TIFF = 'image/tiff'
+    SVG = 'image/svg+xml'
 
 
 class PNG_CHUNK_TYPE(object):

docx/image/svg.py

@@ -0,0 +1,49 @@
+# encoding: utf-8
+
+from __future__ import absolute_import, division, print_function
+
+import xml.etree.ElementTree as ET
+
+from .constants import MIME_TYPE
+from .image import BaseImageHeader
+
+
+class Svg(BaseImageHeader):
+    """
+    Image header parser for SVG images.
+    """
+
+    @classmethod
+    def from_stream(cls, stream):
+        """
+        Return |Svg| instance having header properties parsed from SVG image
+        in *stream*.
+        """
+        px_width, px_height = cls._dimensions_from_stream(stream)
+        return cls(px_width, px_height, 72, 72)
+
+    @property
+    def content_type(self):
+        """
+        MIME content type for this image, unconditionally `image/svg+xml` for
+        SVG images.
+        """
+        return MIME_TYPE.SVG
+
+    @property
+    def default_ext(self):
+        """
+        Default filename extension, always 'svg' for SVG images.
+        """
+        return "svg"
+
+    @classmethod
+    def _dimensions_from_stream(cls, stream):
+        stream.seek(0)
+        data = stream.read()
+        root = ET.fromstring(data)
+        # FIXME: The width could be expressed as '4cm'
+        # See https://www.w3.org/TR/SVG11/struct.html#NewDocument
+        width = int(root.attrib["width"])
+        height = int(root.attrib["height"])
+        return width, height

docx/oxml/__init__.py

@@ -122,6 +122,8 @@ def OxmlElement(nsptag_str, attrs=None, nsdecls=None):
 )
 register_element_cls('a:blip',        CT_Blip)
 register_element_cls('a:ext',         CT_PositiveSize2D)
+register_element_cls('a:extLst',      CT_Transform2D)
+register_element_cls('asvg:svgBlip',  CT_Transform2D)
 register_element_cls('a:graphic',     CT_GraphicalObject)
 register_element_cls('a:graphicData', CT_GraphicalObjectData)
 register_element_cls('a:off',         CT_Point2D)

docx/oxml/ns.py

@@ -24,6 +24,7 @@
     "wp": "http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing",
     "xml": "http://www.w3.org/XML/1998/namespace",
     "xsi": "http://www.w3.org/2001/XMLSchema-instance",
+    "asvg": "http://schemas.microsoft.com/office/drawing/2016/SVG/main",
 }
 
 pfxmap = dict((value, key) for key, value in nsmap.items())

docx/oxml/shape.py

@@ -23,6 +23,7 @@ class CT_Blip(BaseOxmlElement):
     """
     embed = OptionalAttribute('r:embed', ST_RelationshipId)
     link = OptionalAttribute('r:link', ST_RelationshipId)
+    extLst = ZeroOrOne('a:extLst')
 
 
 class CT_BlipFillProperties(BaseOxmlElement):
@@ -98,7 +99,7 @@ def _inline_xml(cls):
             '  <a:graphic>\n'
             '    <a:graphicData uri="URI not set"/>\n'
             '  </a:graphic>\n'
-            '</wp:inline>' % nsdecls('wp', 'a', 'pic', 'r')
+            '</wp:inline>' % nsdecls('wp', 'a', 'pic', 'r', 'asvg')
         )
 
 
@@ -136,7 +137,7 @@ def new(cls, pic_id, filename, rId, cx, cy):
         pic = parse_xml(cls._pic_xml())
         pic.nvPicPr.cNvPr.id = pic_id
         pic.nvPicPr.cNvPr.name = filename
-        pic.blipFill.blip.embed = rId
+        pic.blipFill.blip.extLst.ext.svgBlip.embed = rId
         pic.spPr.cx = cx
         pic.spPr.cy = cy
         return pic
@@ -150,7 +151,13 @@ def _pic_xml(cls):
             '    <pic:cNvPicPr/>\n'
             '  </pic:nvPicPr>\n'
             '  <pic:blipFill>\n'
-            '    <a:blip/>\n'
+            '    <a:blip>\n'
+            '      <a:extLst>\n'
+            '        <a:ext uri="{96DAC541-7B7A-43D3-8B79-37D633B846F1}">\n'
+            '          <asvg:svgBlip/>\n'
+            '        </a:ext>\n'
+            '      </a:extLst>\n'
+            '    </a:blip>\n'
             '    <a:stretch>\n'
             '      <a:fillRect/>\n'
             '    </a:stretch>\n'
@@ -162,7 +169,7 @@ def _pic_xml(cls):
             '    </a:xfrm>\n'
             '    <a:prstGeom prst="rect"/>\n'
             '  </pic:spPr>\n'
-            '</pic:pic>' % nsdecls('pic', 'a', 'r')
+            '</pic:pic>' % nsdecls('pic', 'a', 'r', 'asvg')
         )
 
 
@@ -189,6 +196,7 @@ class CT_PositiveSize2D(BaseOxmlElement):
     """
     cx = RequiredAttribute('cx', ST_PositiveCoordinate)
     cy = RequiredAttribute('cy', ST_PositiveCoordinate)
+    svgBlip = ZeroOrOne('asvg:svgBlip')
 
 
 class CT_PresetGeometry2D(BaseOxmlElement):
@@ -258,6 +266,7 @@ class CT_Transform2D(BaseOxmlElement):
     """
     off = ZeroOrOne('a:off', successors=('a:ext',))
     ext = ZeroOrOne('a:ext', successors=())
+    embed = OptionalAttribute('r:embed', ST_RelationshipId)
 
     @property
     def cx(self):