You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

90 lines
2.6 KiB

# encoding: utf-8
"""
The proxy class for an image part, and related objects.
"""
from __future__ import (
absolute_import, division, print_function, unicode_literals
)
import hashlib
from docx.image.image import Image
from docx.opc.part import Part
from docx.shared import Emu, Inches
class ImagePart(Part):
"""
An image part. Corresponds to the target part of a relationship with type
RELATIONSHIP_TYPE.IMAGE.
"""
def __init__(self, partname, content_type, blob, image=None):
super(ImagePart, self).__init__(partname, content_type, blob)
self._image = image
@property
def default_cx(self):
"""
Native width of this image, calculated from its width in pixels and
horizontal dots per inch (dpi).
"""
px_width = self.image.px_width
horz_dpi = self.image.horz_dpi
width_in_inches = px_width / horz_dpi
return Inches(width_in_inches)
@property
def default_cy(self):
"""
Native height of this image, calculated from its height in pixels and
vertical dots per inch (dpi).
"""
px_height = self.image.px_height
horz_dpi = self.image.horz_dpi
height_in_emu = 914400 * px_height / horz_dpi
return Emu(height_in_emu)
@property
def filename(self):
"""
Filename from which this image part was originally created. A generic
name, e.g. 'image.png', is substituted if no name is available, for
example when the image was loaded from an unnamed stream. In that
case a default extension is applied based on the detected MIME type
of the image.
"""
if self._image is not None:
return self._image.filename
return 'image.%s' % self.partname.ext
@classmethod
def from_image(cls, image, partname):
"""
Return an |ImagePart| instance newly created from *image* and
assigned *partname*.
"""
return ImagePart(partname, image.content_type, image.blob, image)
@property
def image(self):
if self._image is None:
self._image = Image.from_blob(self.blob)
return self._image
@classmethod
def load(cls, partname, content_type, blob, package):
"""
Called by ``docx.opc.package.PartFactory`` to load an image part from
a package being opened by ``Document(...)`` call.
"""
return cls(partname, content_type, blob)
@property
def sha1(self):
"""
SHA1 hash digest of the blob of this image part.
"""
return hashlib.sha1(self._blob).hexdigest()