In certain situations (my specific case a web application which uses css to size out elements on the page), print preview does not show the Portrait/ Landscape buttons. On loading of the print preview plane - for a very brief moment I see the buttons but as soon as the page is rendered, the buttons disappear and I am unable to print in landscape mode. I am not sure which version of FF introduced this problem but version 92 and backwards are ok.

Was it was a problem in Firefox 94 last month, assuming you keep Firefox up-to-date?

The following preference sounds relevant:

layout.css.page-size.enabled

Firefox 95 just switched its default value from false to true.

I wonder where one might find a test page to confirm whether that is the issue. (This is a value one can toggle between true and false in about:config, the advanced Configuration Editor for Firefox.)

I have the same problem. I'm printing a page that I've printed numerous times before in previous versions and I could always switch to landscape (the page prints much better in landscape), but I can't in 95.0. I checked layout.css.page-size.enabled but it's still true for me in 95. I tried switching it to false and that made no difference.

Hi Brian, did you try switching layout.css.page-size.enabled to false (which is what it would have been in Firefox 94) by double-clicking it?

Yes. It was true, I don't know if I did that at some point in the past or if it was the default pre-95, but I double-clicked it to false.

Hi Brian, Firefox changed from false in Firefox 94 to true in Firefox 95. You probably didn't change anything yourself there.

After rolling it back to false, was there any change in your experience with the print settings -- did you get your choice back?

Hi Brian, did you try switching layout.css.page-size.enabled to false (which is what it would have been in Firefox 94) by double-clicking it?

HI jscher2000

Yes, that toggle (setting to FALSE) solved it for me (The portrait / landscape button reappeared). However I now need to figure out my CSS

jscher2000 said

Hi Brian, did you try switching layout.css.page-size.enabled to false (which is what it would have been in Firefox 94) by double-clicking it?

HI jscher2000

Yes, that toggle (setting to FALSE) solved it for me (The portrait / landscape button reappeared). However I now need to figure out my CSS

What is your @page {} code? Does it set an orientation or dimensions?

Note: if you want to paste code here, please use a <pre> before and </pre> after to avoid having it interpreted as wiki syntax.

After rolling it back to false, was there any change in your experience with the print settings -- did you get your choice back?

I didn't, although now that I think about it, I didn't restart the browser after changing it (I did reload the page), is layout.css.page-size.enabled only read at startup, or whenever css is loaded?

Unfortunately the page is only available every few months, so it will be a while before I can test it again, although there may be other pages on the site that do the same thing, so I'll try printing some other pages with the setting true and see if I can find one where the portrait/landscape setting isn't available.

Here's a demo page where setting a paper size -- without also setting the orientation -- locks the orientation to portrait:

https://www.jeffersonscher.com/res/pagesize.html

That doesn't seem right. I'm going to check whether there is a bug on file.

I filed a bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1746803

Please do not add comments unless the developers have questions you can answer, or there is another public URL you want to share as a demonstration. Excessive chatter discourages people from subscribing and working on bugs.

pradeep.arjuna said

jscher2000 said

Hi Brian, did you try switching layout.css.page-size.enabled to false (which is what it would have been in Firefox 94) by double-clicking it?

HI jscher2000

Yes, that toggle (setting to FALSE) solved it for me (The portrait / landscape button reappeared). However I now need to figure out my CSS

What is your @page {} code? Does it set an orientation or dimensions?

Note: if you want to paste code here, please use a <pre> before and </pre> after to avoid having it interpreted as wiki syntax.

It's a single page application. The same page changes to different documents of which some are printed in landscape and some are printed in portrait. The printed dimensions are hard coded to the target page size in a div enclosing the printed content. Its was just a matter of selecting portrait versus landscape in the print preview for correct printing.

I don't know why FF decide to use this switch. At the end of the day according to this link link text FF doesn't support page orientation. Why can't the browser preview just show the print orientation buttons to enable the user to print it as intended

I don't know why FF decide to use this switch.

In the bug I filed, the developer said that specifying a paper size sets a width and height for the content and if landscape isn't specified, portrait is always used. In the "standards" document (I think it might still be a draft), you can find this example:

EXAMPLE 25

@page {
  size: 8.5in 11in; /* width height */
}

The above example sets the width of the page box to be 8.5 inches and the height to be 11 inches. This indicates that the page sheet size should be 8.5"x11" and the orientation portrait.

Based on that, the implementation is correct.

Why can't the browser preview just show the print orientation buttons to enable the user to print it as intended

Do you mean the page author intended that it be printed landscape, and messed up their style rule, or you want the option to override the author's design? They told me if the user were to switch the orientation, the content would shrink to fit instead of reflowing to a different shape because the content shape is fixed by the rule in the page. So the page author needs to fix it if they intended the content to be 8.5in TALL and 11in WIDE instead of the standard orientation.

For now, it is simplest to turn off support for @page{size} in about:config using layout.css.page-size.enabled. If it is helpful to you for other reasons, you could look at possibly modifying the style rule when you encounter a problem page (inject an overriding rule).

WARNING: Changing preferences through this interface not officially supported Hidden settings edited using the about:config tool are explicitly not supported, which means that Mozilla makes no guarantees they will be supported in the future, or that Mozilla will fix them if they break. Mozilla does not test these preferences, and will not in the future. That includes security and performance testing which these preferences may affect.