User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:121.0) Gecko/20100101 Firefox/121.0

Steps to reproduce:

Choose to print a complex multi-page document. I was using a PDF of a Google Slides presentation. In the print dialog, choose to print a custom page range, and enter a page range towards the end of the document (e.g. 5-10 in a 10-page document). Then change "Format" to "Simplified".

Actual results:

Changing the format changed the number of pages, which invalidated the custom page range, which caused the "Format" control to be disabled. This prevented changing it back to "Original". I had to first set a page range that was valid in the simplified document (e.g. "1"), then change "Format" back to "Simplified", then change the page range back to what I wanted.

Expected results:

The "Format" control should not be disabled.

Seems like this is an outcome of the fact that if the Custom page range field is in an invalid state, all the other controls are disabled until the invalid entry is corrected/removed.

Perhaps it would be better not to disable the other controls, except for the actual Print button, when the Custom field is invalid. So the user would be more free to modify the settings in any convenient order, though they'd still need to resolve any invalid settings before actually submitting a print job.

Maybe Sam or Mark would have thoughts on this...

(In reply to Josh Triplett from comment #0)

Changing the format changed the number of pages, which invalidated the custom page range, which caused the "Format" control to be disabled.

We should probably clamp the page range to the number of available pages when settings are updated, and not get into this state in the first place.

(In reply to Sam Foster [:sfoster] (he/him) from comment #2)

(In reply to Josh Triplett from comment #0)

Changing the format changed the number of pages, which invalidated the custom page range, which caused the "Format" control to be disabled.

We should probably clamp the page range to the number of available pages when settings are updated, and not get into this state in the first place.

I don't think you should modify the custom page range when changing the settings, because that could destroy a user's carefully written page range.

Users should be able to experiment with options like these to learn what they do, without getting punished for it.

(In reply to Jonathan Kew [:jfkthame] from comment #1)

Seems like this is an outcome of the fact that if the Custom page range field is in an invalid state, all the other controls are disabled until the invalid entry is corrected/removed.

Perhaps it would be better not to disable the other controls, except for the actual Print button, when the Custom field is invalid. So the user would be more free to modify the settings in any convenient order, though they'd still need to resolve any invalid settings before actually submitting a print job.

I think that'd be the perfect fix. Highlight the custom page range in red, add help text that says "there are only N pages", but leave the other controls enabled other than the print button.