1906967 - Firefox should offer to help when a user prints a page that has a viewport-sized embedded PDF, to avoid user frustration at only getting 1 page of printed output

Status: NEW

(Toolkit :: Printing, enhancement)

Description

[Daniel Holbert [:dholbert]]

Attachment: (PDF file used in testcase)

(Spinning this off from bug 1906953. Also not sure precisely where to place this; starting in PDF viewer for now, but maybe it belongs elsewhere?)

STR:

1. Load attached testcase (coming up), which looks to a user like it's just a 3-page PDF.
2. Ctrl+P (or Cmd+P, or File|Print) to print. (do not use the print button in the PDF viewer UI)

ACTUAL RESULTS:
Firefox pops up a print dialog showing only 1 page of output.

EXPECTED RESULTS:
Firefox should help you discover why it's only showing you 1 page of output, and offer some help on how to print all 3 pages. (See below)

NOTES
It's technically correct that we (and other browsers -- I've tested Chrome at least) only offer 1 page of output, but it's not obvious to a user. The testcase here (based on United Airlines' actual boarding-pass-printing part of their website) is a trivial HTML document which has a 100%-sized <object> tag that embeds a PDF document. So Ctrl+P is printing that html document, with the object tag sized to fill a single page.

Users who invoke the print functionality here almost certainly want to print the PDF (the contents of the object tag), not the outer document.

It would be nice to clue them in to what's going on -- in particular, because we have a relatively straightforward workaround that we could point them at -- the print icon inside of the PDF embed itself (at the top-right). Alternately, we could suggest right-click+open-in-new-tab on the embedded document, or we could offer a button to do that directly.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: screenshot showing how this ends up looking right now (print preview / print only gives 1 page of output, with no obvious way to get the other 2 pages)

Comment 3

[Calixte Denizet (:calixte)]

I don't really know what we could do... I tend to think that's probably a bug from the website creator who obviously didn't think about the ctrl+P case.
That said, if we want to do something, we could probably display a popup asking something like "What do you really want to print ? .... blah blah" which seems to me to be a bit too much technical, I mean who can really understand that they're printing a html page embedding a pdf taking all the page area.
Maybe, we could just pretend that if an embedded object takes all the area then the page is "equal" to the object and then dispatch the ctrl+P to the object itself but I suppose it's something which should be specified.
Anyway, I'm not sure it's a pdf.js bug since the ctrl+P isn't triggered in the pdf viewer context.

Comment 4

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:calixte, could you have a look please?

For more information, please visit BugBot documentation.

Comment 5

[Calixte Denizet (:calixte)]

:dholbert, what could we do at the pdf.js level ?

Comment 6

[Daniel Holbert [:dholbert]]

If PDF.js has no way to intercept the Ctrl+P in this case (and probably it has no way, per last line of comment 3), then any hypothetical intervention here would probably want to happen at a higher level, e.g. as some analysis that gets run when Firefox handles a Ctrl+P/File|Print operation in an outer document and is getting ready to spawn a print dialog.

--> Reclassifying to Toolkit|Printing

Comment 7

[Calixte Denizet (:calixte)]

With the "normal" viewer, we intercept ctrl+P, I don't know why we don't in this case (even when the active element is in the viewer).
That said, if there are several <object> containing a pdf or not, I don't think we want to have one intercepting ctrl+P and even if it was possible the <object> would have to know if it can do that.

Comment 8

[Mark Striemer [:mstriemer]]

This feels like an enhancement. I'm not totally sure of the best way to handle this. The first thing that pops into my mind is detecting that there's an embedded PDF and offering an option like "Embedded PDF" in the "Format" section

This isn't very discoverable though, so maybe some more explicit message at the top of the dialog might make more sense ("This document has an embedded PDF, you may want to print from the PDF toolbar button"?)