img: add Image.width and .height

Steve Canny · Steve Canny · commit 66fedd43444f · 2015-02-16T13:41:54.000-08:00
diff --git a/docx/image/image.py b/docx/image/image.py
@@ -11,8 +11,8 @@
 import os
 
 from ..compat import BytesIO, is_string
-from ..shared import lazyproperty
 from .exceptions import UnrecognizedImageError
+from ..shared import Inches, lazyproperty
 
 
 class Image(object):
@@ -117,6 +117,22 @@ def vert_dpi(self):
         """
         return self._image_header.vert_dpi
 
+    @property
+    def width(self):
+        """
+        A |Length| value representing the native width of the image,
+        calculated from the values of `px_width` and `horz_dpi`.
+        """
+        return Inches(self.px_width / self.horz_dpi)
+
+    @property
+    def height(self):
+        """
+        A |Length| value representing the native height of the image,
+        calculated from the values of `px_height` and `vert_dpi`.
+        """
+        return Inches(self.px_height / self.vert_dpi)
+
     def scaled_dimensions(self, width, height):
         """
         Return a (cx, cy) 2-tuple representing the native dimensions of this
diff --git a/tests/image/test_image.py b/tests/image/test_image.py
@@ -17,6 +17,7 @@
 from docx.image.png import Png
 from docx.image.tiff import Tiff
 from docx.opc.constants import CONTENT_TYPE as CT
+from docx.shared import Length
 
 from ..unitutil.file import test_file
 from ..unitutil.mock import (
@@ -71,7 +72,7 @@ def it_knows_the_image_content_type(self, content_type_fixture):
         image = Image(None, None, image_header_)
         assert image.content_type == content_type
 
-    def it_knows_the_image_dimensions(self, dimensions_fixture):
+    def it_knows_the_image_px_dimensions(self, dimensions_fixture):
         image_header_, px_width, px_height = dimensions_fixture
         image = Image(None, None, image_header_)
         assert image.px_width == px_width
@@ -83,6 +84,12 @@ def it_knows_the_horz_and_vert_dpi_of_the_image(self, dpi_fixture):
         assert image.horz_dpi == horz_dpi
         assert image.vert_dpi == vert_dpi
 
+    def it_knows_the_image_native_size(self, size_fixture):
+        image, width, height = size_fixture
+        assert (image.width, image.height) == (width, height)
+        assert isinstance(image.width, Length)
+        assert isinstance(image.height, Length)
+
     def it_knows_the_image_filename(self):
         filename = 'foobar.png'
         image = Image(None, filename, None)
@@ -182,6 +189,13 @@ def known_image_fixture(self, request):
         image_filename, characteristics = cases[request.param]
         return image_filename, characteristics
 
+    @pytest.fixture
+    def size_fixture(self, image_header_):
+        image_header_.px_width, image_header_.px_height = 150, 75
+        image_header_.horz_dpi, image_header_.vert_dpi = 72, 200
+        image = Image(None, None, image_header_)
+        return image, 1905000, 342900
+
     # fixture components ---------------------------------------------
 
     @pytest.fixture
