def createSequentialAccessDPForURL(url):
success, pathString = Cocoa.CFURLGetFileSystemRepresentation(url, True, None, 1024)
pathString = pathString.rstrip(b"\0")
if not success:
print("Couldn't get the path name C string!")
return None
fp = open(pathString, "rb")
if fp is None:
print("Couldn't open path to file %s!" % (pathString,))
return None
imageDataInfoP = MyImageDataInfo()
imageDataInfoP.fp = fp
provider = Quartz.CGDataProviderCreate(
imageDataInfoP,
(
getBytesSequentialAccessDP,
skipBytesSequentialAccessDP,
rewindSequentialAccessDP,
releaseSequentialAccessDP,
),
)
if provider is None:
print("Couldn't create data provider!")
# Release the info data and cleanup.
releaseSequentialAccessDP(imageDataInfoP)
return None
return provider
def createMyIncrementalDataFromURL(url, myDataP):
myDataP.data = None
myDataP.dataSize = 0
myDataP.repCount = 0
success, pathString = Cocoa.CFURLGetFileSystemRepresentation(
url, True, None, 1024)
pathString = pathString.rstrip(b"\0")
if success and len(pathString):
fp = open(pathString, "rb")
myDataP.data = fp.read()
fp.close()
myDataP.dataSize = len(myDataP.data)
if myDataP.dataSize > 0:
myDataP.chunkSize = myDataP.dataSize / 10 # 10 chunks
def createEPSPreviewImage(url):
# The CGImage used as the preview needs to have the
# same width and height as the EPS data it will
# be associated with. This sample code doesn't attempt
# to use any preview image associated with the EPS
# data but instead simply draws a box of an appropriate
# size. Your code would most likely create an image
# that reflects a PICT or TIFF preview present in the
# EPS data.
result, path = Cocoa.CFURLGetFileSystemRepresentation(url, True, None, 1024)
if not result:
print("Couldn't get the path for EPS file!")
return None
path = path.rstrip(b"\0")
epsRect = getEPSBBox(path)
# Check whether the EPS bounding box is empty.
if epsRect == Quartz.CGRectZero:
print("Couldn't find BoundingBox comment!")
return None
wantDisplayColorSpace = False
needsTransparentBitmap = True
# Create a bitmap context to draw to in order to
# create the preview image. Use the routine
# createRGBBitmapContext from the earlier chapter.
bitmapContext = BitmapContext.createRGBBitmapContext(
epsRect.size.width,
epsRect.size.height,
wantDisplayColorSpace,
needsTransparentBitmap,
)
if bitmapContext is None:
print("Couldn't create bitmap context")
return None
epsRect.origin.x = epsRect.origin.y = 0
# Draw the contents of the preview. The preview consists
# of two lines and a stroke around the bounding box. One
# of the two lines is drawn from the lower-left corner to
# the upper-right corner of the bounding box and the other
# line is from the lower-right corner to the upper-left
# corner of the bounding box.
Quartz.CGContextBeginPath(bitmapContext)
Quartz.CGContextMoveToPoint(bitmapContext, 0, 0)
Quartz.CGContextAddLineToPoint(
bitmapContext, epsRect.size.width, epsRect.size.height
)
Quartz.CGContextMoveToPoint(bitmapContext, epsRect.size.width, 0)
Quartz.CGContextAddLineToPoint(bitmapContext, 0, epsRect.size.height)
Quartz.CGContextStrokePath(bitmapContext)
# Stroke the bounding rectangle, inset so that the stroke is
# completely contained in the EPS bounding rect.
Quartz.CGContextStrokeRect(bitmapContext, Quartz.CGRectInset(epsRect, 0.5, 0.5))
# Now create an image from the bitmap raster data. This image
# has a data provider that releases the image raster data when
# the image is released. Use the createImageFromBitmapContext
# from Chapter 12. Calling createImageFromBitmapContext
# gives up ownership of the raster data used by the context.
epsPreviewImage = BitmapContext.createImageFromBitmapContext(bitmapContext)
if epsPreviewImage is None:
print("Couldn't create preview image!")
return None
return epsPreviewImage