1985667 - Simplify GTK CUPS monochrome implementation

Status: RESOLVED FIXED

(Core :: Printing: Output, task)

Comment 1

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 1985667 - Simplify GTK CUPS monochrome implementation. r=dholbert,alaskanemily

I was trying to figure out why monochrome printing didn't work on my
family's HP DeskJet 4200 series printer. Turns out that the general
monochrome settings we try to apply doesn't work. The PPD has:

  *OpenUI *ColorModel/Output Mode: PickOne
  *OrderDependency: 10 AnySetup *ColorModel
  *DefaultColorModel: RGB
  *ColorModel RGB/Color: "<</cupsColorSpace 17/cupsBitsPerColor 8/cupsRowStep 0>>setpagedevice"
  *ColorModel CMYGray/High Quality Grayscale: "<</cupsColorSpace 1/cupsBitsPerColor 8/cupsRowStep 1>>setpagedevice"
  *ColorModel KGray/Black Only Grayscale: "<</cupsColorSpace 1/cupsBitsPerColor 8/cupsRowStep 2>>setpagedevice"
  *CloseUI: *ColorModel

I.e., we should set ColorModel=KGray or so rather than Gray.

However, looking closer at this whole set-up, it seems CUPS does provide
a simpler option for this that does just what we want and works fine.

So if this works (and I think it should), we can simplify our monochrome
printing set-up significantly. But keep the old code at least for a bit
since this area is prone to device-specific behavior.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/e1c532da2d4d
https://hg.mozilla.org/integration/autoland/rev/fc7803c2f170
Simplify GTK CUPS monochrome implementation. r=jwatt

Comment 3

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/fc7803c2f170

Comment 5

[Daniel Holbert [:dholbert]]

This may have regressed monochrome printing for some users... bug 2030650 at least seems to be a case where monochrome printing works in 140 but doesn't work in 149 (it produces a color printout), for a particular Linux user.

Comment 6

[Emilio Cobos Álvarez [:emilio]]

It also fixed others like bug 2017594, grr... :(

Comment 7

[Emilio Cobos Álvarez [:emilio]]

(Well, and my printer, :P)