img: add ImagePart.from_image()

Steve Canny · Steve Canny · commit 4151eb9a9100 · 2013-12-29T00:20:29.000-08:00
Also, changing the call of from_image() to require partname required
some tweaks to the ImageParts._add_image_part() tests.
diff --git a/docx/package.py b/docx/package.py
@@ -79,7 +79,8 @@ def _add_image_part(self, image):
         Return an |ImagePart| instance newly created from image and appended
         to the collection.
         """
-        image_part = ImagePart.from_image(image)
+        partname = self._next_image_partname
+        image_part = ImagePart.from_image(image, partname)
         self.append(image_part)
         return image_part
 
@@ -92,3 +93,11 @@ def _get_by_sha1(self, sha1):
             if image_part.sha1 == sha1:
                 return image_part
         return None
+
+    @property
+    def _next_image_partname(self):
+        """
+        The next available image partname, starting from
+        ``/word/media/image1.{ext}`` where unused numbers are reused.
+        """
+        raise NotImplementedError
diff --git a/docx/parts/image.py b/docx/parts/image.py
@@ -22,6 +22,20 @@ def __init__(self, blob, filename):
         self._blob = blob
         self._filename = filename
 
+    @property
+    def blob(self):
+        """
+        The bytes of the image 'file'
+        """
+        return self._blob
+
+    @property
+    def content_type(self):
+        """
+        The MIME type of the image, e.g. 'image/png'.
+        """
+        raise NotImplementedError
+
     @property
     def filename(self):
         """
@@ -73,11 +87,12 @@ def filename(self):
         raise NotImplementedError
 
     @classmethod
-    def from_image(cls, image):
+    def from_image(cls, image, partname):
         """
-        Return an |ImagePart| instance newly created from *image*.
+        Return an |ImagePart| instance newly created from *image* and
+        assigned *partname*.
         """
-        raise NotImplementedError
+        return ImagePart(partname, image.content_type, image.blob, image)
 
     @property
     def height(self):
diff --git a/tests/parts/test_image.py b/tests/parts/test_image.py
@@ -14,7 +14,9 @@
 from docx.package import Package
 from docx.parts.image import Image, ImagePart
 
-from ..unitutil import instance_mock, method_mock, test_file
+from ..unitutil import (
+    initializer_mock, instance_mock, method_mock, test_file
+)
 
 
 class DescribeImage(object):
@@ -52,12 +54,32 @@ def it_is_used_by_PartFactory_to_construct_image_part(self, load_fixture):
         )
         assert part is image_part_
 
+    def it_can_construct_from_image_instance(self, from_image_fixture):
+        image_, partname_, ImagePart__init__ = from_image_fixture
+        image_part = ImagePart.from_image(image_, partname_)
+        ImagePart__init__.assert_called_once_with(
+            partname_, image_.content_type, image_.blob, image_
+        )
+        assert isinstance(image_part, ImagePart)
+
     # fixtures -------------------------------------------------------
 
     @pytest.fixture
     def blob_(self, request):
         return instance_mock(request, str)
 
+    @pytest.fixture
+    def from_image_fixture(self, image_, partname_, ImagePart__init__):
+        return image_, partname_, ImagePart__init__
+
+    @pytest.fixture
+    def image_(self, request):
+        return instance_mock(request, Image)
+
+    @pytest.fixture
+    def ImagePart__init__(self, request):
+        return initializer_mock(request, ImagePart)
+
     @pytest.fixture
     def image_part_(self, request):
         return instance_mock(request, ImagePart)
diff --git a/tests/test_package.py b/tests/test_package.py
@@ -8,10 +8,13 @@
 
 import pytest
 
+from docx.opc.packuri import PackURI
 from docx.package import ImageParts, Package
 from docx.parts.image import Image, ImagePart
 
-from .unitutil import class_mock, docx_path, instance_mock, method_mock
+from .unitutil import (
+    docx_path, class_mock, instance_mock, method_mock, property_mock
+)
 
 
 class DescribePackage(object):
@@ -38,11 +41,11 @@ def it_can_add_a_new_image_part(self, add_image_part_fixture):
 
     def it_can_really_add_a_new_image_part(
             self, really_add_image_part_fixture):
-        image_parts, image_, ImagePart_, image_part_ = (
+        image_parts, image_, ImagePart_, partname_, image_part_ = (
             really_add_image_part_fixture
         )
         image_part = image_parts._add_image_part(image_)
-        ImagePart_.from_image.assert_called_once_with(image_)
+        ImagePart_.from_image.assert_called_once_with(image_, partname_)
         assert image_part in image_parts
         assert image_part is image_part_
 
@@ -101,9 +104,20 @@ def new_image_part_(self, request):
         return instance_mock(request, ImagePart)
 
     @pytest.fixture
-    def really_add_image_part_fixture(self, image_, ImagePart_, image_part_):
+    def _next_image_partname_(self, request):
+        return property_mock(request, ImageParts, '_next_image_partname')
+
+    @pytest.fixture
+    def partname_(self, request):
+        return instance_mock(request, PackURI)
+
+    @pytest.fixture
+    def really_add_image_part_fixture(
+            self, _next_image_partname_, partname_, image_, ImagePart_,
+            image_part_):
         image_parts = ImageParts()
-        return image_parts, image_, ImagePart_, image_part_
+        _next_image_partname_.return_value = partname_
+        return image_parts, image_, ImagePart_, partname_, image_part_
 
     @pytest.fixture
     def sha1(self):
