From Bugzilla Helper: User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:0.9.8) Gecko/20020204 BuildID: 2002020406 both the media="print" stylesheets that are attached to the page fail to render either when selected via View->Use Stylesheet or when the doc is printed. Instead a document with no styles attached is printed. NOTE: The print works when the media="screen" <link> elements are omitted. Reproducible: Always Steps to Reproduce: 1. Choose grey screen stylesheet and advanced print stylesheet on the form 2.submit the form. the look should be "grey". 3.print preview. Actual Results: The doc shown has no styles attached. IE5.x and opera6 behave as expected. Expected Results: the doc should have a a margin line, be mainly white like this: http://www.richdoughty.net/bugzilla/home_print.htm This page has the reference to the other stylesheets removed. print preview and it works. Does this come under the umbrella of Bug 72321 ?

This is related to the fact that we use an entirely new styleset for printing. We probably need some parts to be shared and some parts to be new -- perhaps it needs to be split into two objects or part moved to another object.

Ok... there are two separate issues here: 1) View menu. We show alternate sheets that are print-medium-only in the view menu. When these are selected, they are enabled but still not applied since we are in the wrong medium. It seems to me that we don't want to show sheets that don't apply to the screen medium in print preview. 2) Printing. Here the problem is that there are two preferred sheets with different titles in that document -- one for print media and one for screen media. The HTML spec does not really clarify what should happen in that situation; the language there seems to assume that there is one and only one preferred sheet. It would make _sense_ for the screen preferred sheet to be default in the screen medium and the print preferred sheet to be default in the print medium, but I'm not sure what we should actually be doing there... We should focus this bug on one of those two issues and file a separate bug on the other one.

1) The view menu functionality wasn't really what i had in mind when I reported this. personally I only use it for debugging :-) 2) This is what I was getting at. Opera and IE both use the media="screen" for browser rendering and media="print" when printed. this behaviour makes most sense IMHO. one thing, why does it make a difference whether the stylesheet is titled or not?

A titled stylesheet is one of a set of alternate stylesheets. Only one of a set of alternates can be applied at once. An untitled stylesheet a persistent sheet. It is always applied (whenever one is in the correct medium). Maybe we should consider having separate lists of alternates for separate media or something.... Right now we only have a single alternate list of mutually exclusive sheets. I'm not sure what the HTML spec is really saying here, if anything.... Ian? Bug 129884 filed on the side issue with the "Use Stylesheet" menu.

http://www.w3.org/TR/html4/present/styles.html#h-14.3.1 The spec seems pretty clear on this. I think this boils down to my misuse of the title attribute. I've a feeling Moz is right on this one...

Agreed. Changing the preferred stylesheet based on the media attribute is not correct per HTML4. It will also make things even more complicated once media queries come about and whether a stylesheet applies depends on more than just a string comparison. I think it's up to the author to provide stylesheets that cover the various media for each alternate stylesheets set. Lack of an explicit stylesheet is still a valid stylesheet -- it just means "use the UA's values". If you switch to a different media you're going to want to be using the same stylesheet set. How would the author specify that the "print" version of an alternate stylesheet set was the UA's defaults, otherwise?

I'll update my site then (eventually). apologies for the spam :-/ at least i know about stylesheet sets now ;-)

This sounds like not-a-bug (i.e., INVALID), then, but lemme make sure I'm on the same page (so to speak), first: If you want one stylesheet for viewing on the screen (screen.css) and a different stylesheet for printouts (print.css), you can link to them with <link type="text/css" rel="stylesheet" media="screen" href="screen.css"/> <link type="text/css" rel="stylesheet" media="print" href="print.css"/> being sure to use no title="" tags so they always get applied when the media matches. Then for browsing, the screen one gets applied, for printing the print one gets applied, the user doesn't even know there are stylesheets at work, and everybody's happy. Right? This seems to work for me in Mozilla, and also in IE5.1/Mac (modulo some apparent IE printing bugs), so I'm inclined to think it's correct...

Ken, that's correct. Marking invalid, since everyone seems to agree that our behavior is the right one...

What about comment 6?

What about it? It seems to be saying that what we do is correct...

*** Bug 183724 has been marked as a duplicate of this bug. ***

I'm confused. HTML4.01:14.3.1 clearly states: "User agents must respect media descriptors when applying any style sheet." It seems clear to me that means that even a preferred style sheet should apply to the medium for which it's intended. In other words, I don't see why we're ignoring the media descriptor when HTML4.01 says we must respect it in all cases.

We're respecting it by not applying the stylesheet. However, the algorithm for choosing the preferred set doesn't consider media attributes, so the preferred set has no sheets that apply when the medium is screen.

We aren't ignoring it. We're following it... That's why the style rules are not applied. Compare these two situations (lots of needed attrs left out for clarity): <link title="bar" media="print" href="one"> <link title="foo" media="screen" href="two"> and <link title="bar" media="print" href="one"> <link title="foo" media="screen" href="two"> <link title="bar" media="screen" href="three"> What style sets should be applied (which is _not_ the same thing as what sheets should be applied in each style set).

Ah, I see. I was indeed confused. Sorry about the spam.

*** Bug 198778 has been marked as a duplicate of this bug. ***