[saurik]

As someone who works in PDFs constantly (due to work in local government), I would say the point of a PDF is to be able to reproduce the result given a file, not to assume the file cannot be changed... you can easily edit and save PDF files using Acrobat, for example.

It is common that when you "print to PDF" you take the output of the printer and serialize that to PDF. I use this feature often on my Mac (which I think many would claim has excellent support for dealing with PDF files) to build a PDF that is stripped of any interactive forms: so as to get an output which is only the PDF "as printed".

[bdowling]

The built-in MacOS support for PDF is great. Any app that can print to a printer can print to a PDF file. And the Preview app, despite its name, can edit PDFs to add annotations (text, graphics), add or remove pages, etc. There's also a feature by which you sign your name on a piece of paper, hold it up to the camera, and it will capture it and insert it into a the document. It's convenient that these are built in and don't require paying for something bloated like Acrobat Pro.

[msarnoff]

I worked on Preview at Apple from 2008-2011 and created the signature capture feature. It's always cool to hear people talk about it!

[jaredhansen]

Thank you! It was a tremendous addition to the product and I still benefit from it many times every week. It's such a great detail - very nicely done.

[rdslw]

Man, this signature thing, PLUS ability to delete selected pages from big PDF is a killer on Preview.

I cry every day I'm on windows and need to do those simple things which Preview made so easy while being light.

Thank you for this!

[granda]

I've demonstrated and gotten literally hundreds of users to fall in love with it. Thanks for that!

[msarnoff]

That's so amazing to hear! It pretty much flew under the company radar--most people didn't find out about it until the first reviews of the Lion beta came out.

I don't think it was very common at Apple for an individual engineer to conceive, implement, and ship a feature like this. There was a general sentiment on the team of "let's do something with signatures," but we knew that very few people had scanners. We thought about touchpad input, but decided against it at the time. (That came much later, in either 10.11 or 10.12)

I was thinking, "well, almost no one has a scanner, but practically everyone using this application has a camera in their Mac." I built the initial prototype in OpenCV and then ported it to Apple's vDSP/Accelerate frameworks.

My favorite detail, which doesn't seem to be present in 10.12, is that you could just click on a horizontal line in a PDF; since I recorded the signature's offset relative to the baseline superimposed on the camera image, it would place the signature exactly on the line, with descenders nicely descending.

I've since moved on from macOS/iOS development, but I had a really positive experience at Apple. Met so many amazingly talented people there.

[TheCoreh]

Thanks! It's one of my favorite features in Preview.

I used to hate PDFs before getting a Mac, but the first-class support in Preview, with features like that (along with the ability to tear out, reorder and attach pages) made me change my mind.

[martinald]

It's such an awesome feature. I don't use macOS as much as I used to but I will always switch to my Mac when I get a doc to sign, which is a lot.

It must have saved many many millions of sheets of paper.

[CMay]

To be fair, on a Microsoft Surface you would just use your pen to sign directly on the screen which is much more natural. It doesn't make any sense to me that Steve Jobs was so anti-pen, while also pushing for intuitive interaction.

[itazula]

Perhaps if someone added electromagnetic traction so that the screen provided some push-back to the pen tip, it would seem "natural," but as things are now, my on-screen signature is as good as a chicken scratch.

[TheCoreh]

you could get a very thin sheet of translucent paper, and put it on top of the screen. the pen should still work, and you'll get a more natural feel

[tinus_hn]

Providing a pen is an excuse to leave controls that are too small to use with your fingers. So while Windows now has a Touch mode where many controls are larger, many others which are also essential to using the system are tiny and hard or impossible to use by touch. That is what Steve Jobs was trying (successfully) to avoid.

[H4CK3RM4N]

That's how it works on an iPad. Touch/pen interfaces are terrible on the PC/Laptop form factor though. At best you gimp your desktop metaphor so it's functional with touch, at worst you have an unusable touch interface.

[simonh]

I think he was anti the crappy pens and digitising systems available at the time, the requirement to have a pen to use the device at all and the poor interface designs they encouraged.

[Andrenid]

Thanks! I use that feature almost every day. We try to be a paperless home so being able to sign PDF forms and return them without printing is one of my single favourite features of OSX. We even bought our house using that feature for all parties to sign it around my MacBook.

[bdowling]

Thanks. It's a great feature, and one that adds a lot to the overall Mac OS experience. It's too bad that most people have no idea that it exists, since no other OS has it. But for those who know, it's a huge time and paper saver. Excellent work.

[gregschlom]

I just found out about this feature a couple of days ago, after being a Mac user for 4 years. My first thought was it's incredibly neat - shame I didn't learn about it before.

[pducks32]

Thank you so much!

[rileytg]

thank you! i wish apple promoted it more. what a gem.

[cptskippy]

Doesn't Quartz use PostScript for rendering the MacOS desktop?

[watersb]

NeXT used Display PostScript, and I would create widgets by writing PostScript code.

Quartz is like QuickTime plus something like OpenGL shaders plus something like NeXTStep "display PDF". I have no idea if this encouraged PDF integration into the display model.

Rather, I would say that NeXT, and then Apple, had some great IP and cross-licensing of PostScript and PDF display tech, and so they could ship the OS distribution with PDF as the printing model.

That is, one reason Windows might today re-render PDF → XPS → PDF is that they had needed to create display tech like PDF anyway, and so they did, and this was after humans had been playing with HTML for a while... Silverlight was pretty.

[jahewson]

> PDF → XPS → PDF

That's not what's happening unless you have a printer which directly supports PDF. Most likely what is happening on Windows is either:

    PDF → XPS → PCL
    PDF → XPS → PostScript

Depending on the printer. Which makes far more sense and is analogous to what OS X does:

    PDF → Quartz → PCL
    PDF → Quartz → PostScript

There's really no notable difference between these two approaches as both Quartz and XPS are based on the same printing model as PDF. Don't confuse Quartz with PDF just because it offers import/export to PDF - Quartz has its own internal imaging model.

[simonh]

NeXT Step did, but they switched to 'Display PDF' in OSX to save licensing costs as PDF is free to use.

[jdmichal]

Absolutely right. PDF fixes the problem Word documents have where different versions of Word tends to render the document ever so differently. Usually in a way that seems to mess up all those beautiful page breaks you meticulously planned. It does this by every element having absolute positioning.

[Maarten88]

Most people don't know you can open a PDF in Word 2016 and edit it, just like a .doc/.docx file...

Of course, reflowing the document is really painful with that source.

[MichaelGG]

And is the scourge of every paper I want to read on my Kindle. Everyone publishes their PDFs and there seems to be no reliable way to reflow them.

[r00fus]

Which is why ePub and other digital book formats exist. I'm glad there is a format that prioritizes WYSIWYG over reflow (though the part of the spec where the introduced scripting is a bit dodgy)

[CoryG89]

The "Reading Mode" on the Adobe's Acrobat app for Android does a pretty good job of reflowing most of the PDFs I've thrown at it.

[jdmichal]

Should be able to easily reflow text as long as it's using newline operators (T*, ', "). Might still need some basic heuristics for paragraph breaks. But much better than the alternative of attempting to correlate individual lines of text together based on positioning.

[H4CK3RM4N]

I use calibri for my E-Books, and it seems to do a pretty good job of reflowing PDFs(and exporting to mobi). YMMV though, especially if headers/footers are badly done.

[PhasmaFelis]

Off-topic, but you seem like you might know: why does text copied from PDFs sometimes have messed-up spaces? It seems to guess where the spaces should go based on kerning, so with justified text, a widely-spaced line may come out with a space between each letter, while a narrowly-spaced one has no spaces at all.

(Also the thing where it inserts line breaks at the end of every print line is maddening)

[mnw21cam]

That's often caused by the font specified in the PDF not being available on the platform where the PDF viewer is running, so a different font has been used instead.

[PhasmaFelis]

Hmm. I may have been unclear--the PDF reads fine, but if I copy and paste some text into a text editor, I get the messed-up spaces. It seems as if the PDF doesn't encode text as text but just as a series of characters and locations, leaving spaces unrecorded, so when copy-pasting the reader has to guess from the distance between letters.

[derefr]

> I use this feature often on my Mac (which I think many would claim has excellent support for dealing with PDF files) to build a PDF that is stripped of any interactive forms: so as to get an output which is only the PDF "as printed".

Interesting; sort of like taking an old Fireworks .fw.png file, and then exporting it to PNG, to get rid of the Fireworks project data. Never thought of using "Print to PDF" this way!