Printing on any paper size in Linux

Some time ago I needed to print a document on a non-standard size paper. I did not even expect this to be so difficult. Now I would like to tell you how I solved this problem. I found a workaround, but in a good way, I need to fix the print module kde so that no crutches are needed. The purpose of this article is to share the information that I have gathered. At least it will be useful to someone, but as a maximum - there will be a person who will correct this situation.



Anyone interested, please under the cat.



So, I need to print a document that is smaller than standard A4 paper. Suppose the paper size on which I want to print is 10 by 20 cm. Let me create a document with such a paper size in the LibreOffice Writer. Go to the menu Format → Page and set the desired size. Save the document. After I prepared the document, I saved it and put the paper of the same size in the printer tray. But, as it turned out when sending to print, I can not set an arbitrary paper size. LibreOffice has its own dialog interface, which I will discuss at the end.





Now we just export to pdf and print it with Okular - this is the standard pdf viewer surrounded by kde.

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As you can see, from those sizes that are offered in the list, nothing suits me. And to set your own arbitrary size is not possible (the option “special” / “custom” is present, although for some reason it is not selected).



I began to google how to be in such a situation. I found a video of how such a problem is solved on windows. There is a very obscure way, through a lot of clicks in the windows you need to get to a certain field, which without this video you just can not find. But, nevertheless, there is such an opportunity on Windows.



What about Linux? As long as I did not search, I did not find anything like it.



Of course, such a crutch immediately comes to mind as the re-creation of a document in such a way that it is located on the top of a page of usual size A4. And when printing it just would get to the right place. But first, for this, you have to tinker with formatting the document again, and secondly, it’s interesting to figure out how to do it in a normal way. I began to understand, and came to the conclusion that I need to rewrite the printer driver.



Each printer has its own so-called driver - ppd file. This is essentially just a text file with a specific syntax that describes the capabilities of the printer, including which paper sizes it supports.



Let's find the file that describes my printer. I have a printer from the company hp and I installed a special package (hplip) in the system, which contains drivers for their printers. In my case, the drivers are in / usr / share / ppd / HP.





True, they gzip'nuty, so you need to unpack my driver. Let's open our file and see what's inside.





Having a little studied the file structure, you can guess how to add a paper of your own size here, or you can change the values ​​of any paper size that does not interest you. I will add my own.



But before we enter the value of the width and height of our paper, we must specify the features associated with the units of measurement that are used in the ppd files. Unfortunately, you can not just enter the size in millimeters.



These files use their own units of measurement - postscript points. Each such point is 1/72 of an inch. We are also interested in millimeters. Let's calculate the coefficient by which we will multiply our millimeters for conversion to postscript points. In inch 25.4 mm. Expressing millimeters, we get a coefficient equal to 72 / 25.4, i.e. approximately 2,834. We translate the length and width of our paper size from mm to points:



100 * 2.834 = 283.4 points,

200 * 2,834 = 566.8 points.



Thus, in the language PostScript paper size will be described by the numbers 283 and 566.



Great, now we need to add our paper description to this file. This should be done in four places. All by analogy with existing formats, just append your own.

PageSize, PageRegion, ImageableArea, PaperDimension.



I haven’t studied in detail what these parameters describe, but, as you can see, everywhere except for the ImageableArea parameter, the same sizes are indicated. And in the rows of ImageableArea two times in a row goes the number 12, and then the paper size, reduced by 12 points. I guess this parameter is responsible for the zone in which the printer is capable of printing. If you translate 12 points in mm, you get about 4.2 mm. Most likely - this space is overlapped by wheels with which the printer pulls in the paper. Let's enter our values, which we also reduce by 12. Now save the file.



I would rather try to install it as a printer driver, but do not rush. Let's first check the file with the cupstestppd utility. As you can see, we do not have translations of the name of the paper format. They need to be created for each language. I honestly do not need this at all, but the rules are rules. Without their observance, the file is considered incorrect. If you don’t feel like bothering at all, you can simply comment out the cupsLanguages ​​line. But I still create these translations. More precisely, I will create only translation lines.



We created all the translations and check the file again. The file is valid. You can not pay attention to vorningi, they simply indicate how to name the paper format according to the canons of Adobe. I think that there is nothing wrong with violating this canon, since even the formats that existed in this file already violated it.



Let's go to the printer settings. If you are asked for a root password, add yourself to the sys group, it will be much more convenient. Now we specify our file as a printer driver. It seems that now it will be possible to print on our paper without any problems. But not everything is so simple.



If now try to print something on our paper, we will fail. We see our paper size in the list, but we cannot select it. This is obviously a bug. Experiencedly, I was able to achieve our size here. To do this, in the printer settings, you must specify our paper size as the default. Now we can really choose our paper size and print on it.



Actually, on this we can assume that the problem is solved. But I try not to get past the bugs, especially when such research has already been done. Therefore, if you are interested in developing Linux, join and let's improve the world together.



Please note that the Width and Height fields are activated for input when selecting my paper size. That is, we can set here an arbitrary size, as I wanted from the very beginning. In theory, they should be activated when choosing the “Special” size, but it is also not selected. And if we switch to any of the presented sizes, we will not be able to switch back to my size and do it again only by restarting this dialog. Of course, this is no good, and it is necessary to at least inform the community about this bug.



I checked various programs from the kde environment, they all use this print module, and accordingly they all suffer from the described bugs. But the good news is that in order to fix them, you need to fix the code of just one module.

Not kde program

I also checked how some non-kde-shny programs behave when printing. LibreOffice uses some of its bells and whistles and does not allow you to choose the size of the paper when printing. This applies to all components of the libra that I checked: Writer, Calc, Impress, Draw.



But there are moments that have pleased. In many gtk programs, the custom size selection functionality is implemented. Let's look at some of them.



Let's start with the chromium web browser. If we press ctrl + P, we have a print dialog. This is not a standard window, but an in-browser web page. There is no possibility of interest in it. However, there is the possibility of calling the system dialog box. And here it is already possible to set a custom size. I did not understand what the size custom means, because When choosing it, I can not set my size. But look, there is an item Manage custom sizes. Click it, and as you can see, here we can set an arbitrary size. These sizes are even saved, and then will be available in other gtk applications when choosing a paper size. That's exactly what I expected from the kde-shny print manager.



Gimp uses the same menu and, as I said, it is possible to select a custom size that you specified earlier. Also, gimp has the ability to print using the gutenprint drivers, and there you can also specify your size.



But, and the dwarves, too, was not without glitches. There are programs that use almost the same print menu, but for some reason my printer is not visible in it. These include Eye of Gnome, Evince and Firefox. I said almost the same, because I'm not sure, maybe this is some other menu. It has much larger paper sizes than the gimp. And here is another set of custom sizes. The rest of the menu looks the same.



Well, Firefox has the opportunity to turn the document upside down before printing. I also lack this in the print manager kde and I had to use PDF Shuffler to pre-flip the document.



Also, the gnome has programs that do not allow changing the size of the paper at all. Take, for example, Inkscape. The printer is visible, but you cannot select a paper size. And I checked the case with a Windows program running through wine (for example, PDFxChange). It uses its own interface and there is no possibility to set an arbitrary size. I think for such curved cases it would be possible to get confused with the rewriting of ppd, and then it would be easier to just save the pdf and print from a normal linux program.

Conclusion

So, I showed you what problems there are in Linux if you want to print a document on any paper size. I had an idea as a temporary solution to write a utility that would generate the necessary ppd for the user and install it as a printer driver, so that the user would not have to poke around in the ppd structure and expect something. But it seems to me that it would be more correct and easier to fix the kde-shny print manager. I think it is not very difficult. If you care about it and you have experience developing under kde, then please help with this. And if not, you can just write comments about what you think about it.



Thank you for your attention, I hope you were interested.