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Comment by _bxg1 | Hacker News Reader

The good news is, unlike Windows, macOS has a fantastic default PDF viewer ("Preview") and I don't know why anyone would ever install Acrobat on it

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Preview has issues with PDFs with form fields right now. It causes a bunch of people to need to install Acrobat for that use case. :(

Installed Acrobat a few weeks ago for this use case specifically. I feel like Preview used to be a lot better at editing fields, recently it has been a real pain.

Are there not any alternatives to Adobe Acrobat Reader on macOS for editing fields and other use cases listed in the other comments?

Apple's Preview does a pretty good job with generic pdf forms. Unfortunately, Adobe has created multiple types of pdf forms using different technologies and very complex specs. Apple does not support all of these. (You can also find many cases of PDF forms using Adobe tools that do not round trip between platforms).

PDF Export does a good job of filing in the gaps.

https://pdfexpert.com

Not just complex specs. Some of them are proprietary.

There's some non-free options:

Editing/Form Fill/etc: Nitro[1]

Signing: Nitro[1], HelloSign[2], airSlate[3], Smallpdf[4] (limited functionality)

[1] https://www.gonitro.com

[2] https://www.hellosign.com

[3] https://www.airslate.com

[4] https://smallpdf.com

PDF has two types of forms: native and JS driven. I'd bet that the problems are with the JS. I'd also be willing to bet that Adobe makes Acrobat author forms in a way that intentionally breaks third party readers.

<airquotes>P</airquotes>DF

OTOH, Preview renders PDFs way better than Adobe Reader does. Tweaking the settings in AR didn't help either.

I only wish Preview would do two things:

- open files in "maximized" view.

- when opening a file, Left/Right arrow keys don't let you navigate the pages. Instead, they move the current page a few pixels left/right! (they work like horizontal scrollers)

What about Skim? It is the one I use.

It's good, but creates additional files for your annotations and comments - which btw, cannot be read in other software.

Yea, that is right.

That’s interesting. The iPad version works extremely well for editing.

Luckily other PDF editors do well with form fields and don't bundle a JS VM into their runtime.

People keep saying this, but the form-filling tools are basically identical to Reader's. I don't get it.

What Preview doesn't support is JavaScript, as far as I can tell, so it can't work with "smart" PDF's, e.g. that will do calculations for you.

Is that what you're referring to? Or I'd love to know any specific issue you've run into with form fields.

The problem is that if the PDF forms where create with an Adobe program even things which should work with generic PDF might not do so because the Adobe program used JS or whatever below the cover.

EDIT: I looked into some of the PDFs again and it seems I had been wrong. Not sure what they use but it doesn't seem to be js.

EDIT EDIT: But I found other forms which where affected see my response below.

Is that a real thing?

I've encountered JavaScript-heavy PDF's before, but which were obviously so. (Automatically calculating values for one form field based on another, generating QR codes, etc.)

I've never come across a seemingly "normal" form PDF but which secretly used JavaScript for normal things like form filling, so that normal form-filling tools didn't work. I don't understand why the normal PDF type-in-a-text-box tool wouldn't work.

Have you actually come across this? Can you point to any examples?

I have run into this with regard to basic, but "slightly" more advanced features then text fields on forms in my university.

You can be sure that even Adobe won't add JS for forms with plain text fields. ;=)

EDIT: I looked into some of the PDFs again and it seems I had been wrong. Not sure what they use but it doesn't seem to be js.

Sorry about this.

Yes, as another commenter pointed out, Canadian govt citizenship forms, e.g. https://www.canada.ca/en/immigration-refugees-citizenship/se...

While (like it can be seen in the EDIT) the forms I found where not affected with JS. Other forms from my uni where.

For example I found following:

`/JS (if $this.getField\("inst1"$.value == "bitte auswählen"\){\r\nthis.getField$"Hinweis"$.display = 2\r\n} else\r\n{\r\nthis.getField$"Hinweis"$.display = 1\r\n}\r\n)$ /S /JavaScript`

This (in the given PDF) causes a "notice" overlapped on top of other form fields to disappear once the first multiple choice field was selected.

So if you try to fill it out without JS some form fields are not visible (but selectable by tab). Luckily it's not included in prints.

The Canadian govt forms like Visa application forms or Tax forms don't work on any Linux pdf tool that I tested with. The pdf would display empty with a JS error message. This was a few years ago though.

Had to install the linux version of Adobe, which is many years out of date now.

There is quite a bunch of "PDF" features around forms which basically only work with Adobe PDF and maybe one or two other ones. But good luck if non of them are available for you.

Worse many "office" people which create PDF's with form fields use Adobe tools, so they never see that what they hand out to thousends of students isn't working with >90% of PDF viewers....

It's because of this. Adobe hates us.

https://en.wikipedia.org/wiki/XFA

Further reading: https://eclecticlight.co/2019/06/18/pdf-without-adobe-23-the...

For sure, however it seems like vast majority of use of PDF, (which is to view a printed document as it is) is addressed by Preview.

For stuff like sign a PDF and form are not things normal people need to use.

so the only people doing that are abby normal?

This sounds like a page in a playbook for a company that wants to maintain their monopoly.

- it is plausibly open

- there are enough edge cases that your tool is the only one that does it reliably.

This is similar to doc format - apple tools or openoffice can open it, but screw it up for everyone if they try to write it.

There is a wonderful rant about another adobe file format .PSD in this code here:

https://github.com/gco/xee/blob/master/XeePhotoshopLoader.m

That's beautiful. However, if I weren't an only child in two weeks I would take exception to that "old" bit describing the Uncle.

Why would anyone in their right mind create a PDF form?

They are actually quite handy when the only allowed method of submission is via snail mail or fax. Much better than the alternative of printing an empty form and filling it all in by hand.

Man I don’t know what industry you’re in but I get 3-4 PDF’s a week.

Preview can't digitally sign PDFs. I have to do this on a near daily basis.

EDIT: I mean sign with a certificate, not add an image. Personally I would prefer to not have any adobe software on my mac.

By "digitally sign", do you mean insert a picture of your handwritten signature? It can do that: https://www.macrumors.com/how-to/digitally-sign-a-pdf-using-.... If you mean cryptographically sign, then disregard my comment.

Yeah, the latter: keychain certificate (under "Certificates").

This lack of differentiation really grinds my gears. Why in the world do both of these activities share a name? It would be really interesting to take a random sample of the population and ask them some basic context like their occupation/education, and ask them whether a digital signature comprises a graphic of handwriting (validated with eyeballs) or something more sophisticated (validated with math).

There will be some obvious trends, but I suspect there will also be some surprises.

The point of a signature is to affirm the authenticity of something. When you sign something by hand, you're showing that you reviewed it. If you cryptographically sign something, you're doing the same thing to a bunch of bits, and arguably in a way that's a less easy to forge.

You're referring to "term overloading". This is pervasive throughout all domains of engineering, but more so in software because there are so many conflicting standards, definitions and citations. It's really hard to get a handle on. Like, I would assume that posting on HN the audience would assume I would not confuse "overlaying pixels of my signature on a document," with, say ECDSA sign & verify. But I was wrong to assume that. So, barring a common definition, should we speak with increased precision thus verbosity? Perhaps. But if THIS example grinds your gears, hooo boy, hang of for a ride.... :)

To my own surprise, it was a pretty pleasant read and I didn't realize you were intentionally being over-verbose until "overlaying pixels".

Just dealt with this yesterday. It’s too bad because I really like the signatures I have saved under Preview.

So I sign all signatures on a lease with Preview except for the very last one, which I did using a digital signature under Adobe Reader. it was a self-signed one certificate but the goal is still to have the other person feel comfortable with doing a contract over email than in person anyways.

What’s the benefit of signing the pdf itself rather than the distribution? If there’s a large need for this seems like an easy way to make a bit of money cutting out adobe.

Could you use JSignPDF instead?

https://github.com/kwart/jsignpdf

The good news is, unlike Windows, macOS has a fantastic default PDF viewer ("Preview") and I don't know why anyone would ever install Acrobat on it

I, too, prefer Preview to Acrobat. But part of my workflow occasionally involves copying text from a PDF to create a web page. Preview cannot be counted on to reliably or accurately copy that text. It seems to have particular problems with the letter "f" when next to a letter "s," in addition to other flaws.

Acrobat, on the other hand, always copies the text correctly.

Aside from this one use, however, I always employ Preview because otherwise it is far superior.

It seems to have particular problems with the letter "f" when next to a letter "s," in addition to other flaws.

That's such a weird bug. I wonder if Preview is trying to be too cute with "less common" stylistic ligatures. Try some of the other ones mentioned in Wiki: https://en.wikipedia.org/wiki/Orthographic_ligature#Stylisti...

Windows 10 has had a built in PDF viewer for at least 5 years. It's the Edge browser which is now based on Chromium. You can sign and save documents too.

It still can't form fill. Edge's pdf viewer is definitely a lot more pleasant to use than anything else I've used.

I really like Firefox's built in PDF viewer. It even shows the table of contents where available.

Yes it's pretty good. I actually used PDF.js to debug a malformed issue at work once. The javascript console error log gave a clue about the issue where no other tools said anything.

So does Preview. So does Acrobat Reader.

Preview is such a great app. For simple image editing too... I used to have to get gimp to crop, rotate, and resize images, preview does the task simply and well.

It seems crazy, but Preview is genuinely a big part of keeping me stuck in the Apple ecosystem. That iOS doesn't have anything like it is the main thing keeping me from ditching macOS for iOS (+ remote Linux VMs), even. It's a sign of how crap the UX is or has become on Windows or Linux that it's so surprising to have a basic utility program function so reliably, so well, and with such light resource use, while consistently delighting with its versatility.

I have similar feelings about their office suite. In general their add-on and utility software is just great. I'd miss all of it on any other platform (and do, when I use those—yes, even the file manager, which is still less crashy, less prone to weird interface bugginess, and more consistent than any featureful equivalent I've used on Linux, and I've used... oh, all the big ones, over the last 20 years, and I don't find it any worse than Windows Explorer, aside from preferring some of the latter's hotkeys) but of all of them... yeah, Preview may be #1, which was not something I expected when I first started using OSX/macOS about 10 years ago.

Yeah, preview for simple annotation or cropping, photopea for heavier tasks. I haven't installed 3rd party photo editors in years.

Windows uses Edge IIRC, and it does pretty well.

It does a decent job for heavily text based pdfs like legal forms or manuals and even lets you annotate the document with a pen or highlighter but it chokes on more image based pdfs like slide decks or schematics.

Old Edge was a great PDF reader and EPUB viewer. New edge... well it's just the same as Chrome, which is to say that it's fine.

Because PDFs in Preview are blurry on external screens ever since Sierra. Acrobat works fine. I hate most third-party PDF viewers, but here we are.

That’s...odd. I’ve never noticed it, and I’m viewing an AWS user guide right now on a 4K display (MacBook Pro, Mojave) with no crispness issues.

> 4K display

That’s your answer. Apple being Apple either have no lower-res screens to test on, or once again have decided to force the industry forward.

This page may help.

https://www.howtogeek.com/358596/how-to-fix-blurry-fonts-on-...

Thanks. I’ve tried about a million different tricks at the time, none of which worked. I’ve given up on it. There has been a Twitter thread by an Apple engineer which I won’t be able to locate now, but the crux was that they know they’re breaking things for non-4K screens, but they don’t care enough/don’t have the resources (lol) to fix that.

You buy Acrobat DC the impacted product because you’re using it as more than a reader. OCR image to text (laying the text invisibly within the pdf as metadata behind the image) is a common use case. Slim down a bloated pdf eg that came out of a scanner driver. Properly redact sensitive information (legal, govt, journalism context).

The software is flawed even beyond security issues but for creating or editing PDF files there is not much competition. (There is some and I’ve used that too and it’s mostly worse. It’s a hard problem apparently.)

As a general rule, Acrobat ignores and silently fixes a lot of issues with PDFs that more stricter implementations will complain about (it goes beyond the spec to be accommodating). This unfortunately means a lot of programs out there are making malformed PDFs but their users don't know because "it works here on Acrobat!". So that's one reason I have to install it despite alternatives on Windows, but maybe Preview is the same in this regard and fine for general users.

as far as I know the macOS display subsystem was built around the PDF specification. You'd think the OS can handle viewing documents without much additional third-party overhead:

https://en.wikipedia.org/wiki/Quartz_2D

https://en.wikipedia.org/wiki/Quartz_(graphics_layer)#Use_of...

It uses the same drawing primitives as PDF, but it certainly isn’t built around the PDF specification, which is enormous.

To give a few examples, there is no JavaScript interpreter in Quartz (https://www.adobe.com/devnet/acrobat/javascript.html), nor does it have 3D graphics rendering built in (https://helpx.adobe.com/acrobat/using/displaying-3d-models-p...), or a Flash engine (https://helpx.adobe.com/acrobat/using/flash-player-needed-ac...; this has bee removed from the Acrobat install, but used to ship with it)

To support PDFs fully, all of that would have to be implemented on top of Quartz.

If you're on Win10, the Xodo PDF app is the best/fastest - and it allows editing and page order changes. And it's free.

And it's a dream to use on a touch screen. Trying to open the same high quality/density PDFs in Adobe (even just the reader) is an unresponsive nightmare.

I don't even understand how there can be such a significant difference in performance when Adobe created the format....

That's interesting. I've been using SumatraPDF for years. I might give this a try.

Preview doesn't support a lot of stuff such dynamic forms. Most of the gov documents I need to sign are not displayed in preview.

PDFs with XFA forms are not supported by Preview

Redaction, for one, is a desired feature that don't usually come with free PDF viewers on macOS like Preview.

A good open-source PDF reader I've used in the past on Windows is Sumatra. Very lightweight and functional.

https://www.sumatrapdfreader.org/free-pdf-reader.html

Def check out Xodo PDF reader. It's been my favourite in terms of speed/functionality. It has been the best for use on Win10 touch screen.

Windows has a default PDF viewer that works very well. Try it!

To fill out government forms.

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