Re: Curse you, PDF!
Re: Curse you, PDF!
- Subject: Re: Curse you, PDF!
- From: "Dennis C. De Mars" <email@hidden>
- Date: Tue, 12 Jun 2001 22:52:54 -0000
email@hidden said:
>
When I'd first heard we were going to have some kind of PDF technology
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underlying the graphics in OSX, I asked around and generally heard
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that this meant any app would be able to read, write, and edit PDF
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files. That's really great, I thought, because it truly would be a big
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step towards a paperless office.
Not really true. PDF is used as the underlying standard for the graphics engine
(Quartz). This means that PDF is used internally by the OS to represent the graphics
that are rendered onto the screen. This doesn't mean that all apps have the ability to
read, write and edit PDF files, any more than any OS 9 app can read, write and edit
PICT files.
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But now that OSX is here, I see a distinct lack of support for PDF.
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I'd heard one Mac author say that any web page could be instantly
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converted into a pdf, but I can't find a browser that does this. Am I
I think any application on OS X that can print can create a PDF file. Issue a print
command and look at the pop-up menu with the various print options. There should be one
for output options that has a check box that says "Save as PDF file." If you check that
box, the output that would have been sent to the printer is instead saved as a PDF
file. You can now send your "printout" electronically to anyone with Acrobat Reader.
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missing something? Are there apps out there that let me edit PDF
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documents easily and intuitively, with the exception of Acrobat?
You can edit a text document with a text editor, web page with an HTML editor, etc. and
get the output as a PDF file. You don't have the control over the final output that you
would with Acrobat (you can't add a table of contents, for example).
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Can an app I write instantly gain the ability to edit a PDF document
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via some Cocoa library? If so, that's great, and where is the API? If
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not, can someone please explain the benefit of having PDF underlying
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the graphic display in OSX?
Here's an explanation of the benefit. The old NextStep OS used Display Postscript to
render screen graphics. It is a resolution independent system that allows each
application to render graphics that take full advantage of the resolution of all
display devices without the application having to know the details of the display
device.
Adobe licenses this system and it was not available to Apple for use in OS X at a price
they were willing to pay. PDF also comes from Adobe, but they have made it an "open"
standard, so it can be used without paying licensing fees. It is also a resolution
independent format and so Apple decided to use it as the basic descriptive language for
Quartz.
Its primary function is to be used for rendering graphics for immediate output to
display devices or printers. OS X is not necessarily using the full PDF specification,
only what it needs, although anything it uses conforms to the specification.
Since this is the way the graphics are generated, it is relatively easy to add the
printer option to output the graphics as a PDF file. However, it does not necessarily
follow that it is easier to create an app to edit PDF files or to take full advantage
of the PDF specification.
As for whether there is more PDF capability exposed in some API, I don't know.
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Also, I appologize in advance for twisting and distorting the truth
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about what is and is not possible in Cocoa, what I may and may not
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have heard, for possibly using the wrong words in the wrong order,
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offending people by the use of the word 'pustule' and generally being
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a Mac programmer who is now learning Cocoa. I bow the NSGods of the
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list and patiently await the answer to my humble question.
I'm sure you'll get replies from people who know more about this than me. There are a
couple of documents on Apple's web site, "Quartz Primer" and "Drawing with Quartz 2D"
that talk more about using the Quartz internals. You might want to look at those if you
are curious, although I don't know if they will tell you much more about the stuff you
are interested in.
- Dennis D.