Have you tried using { Ctrl + P } to initiate printing without going thru the Print Preview window?

See this to learn how to build an extension: https://developer.mozilla.org/en-US/Add-ons/WebExtensions

Sounds like this extension: https://addons.mozilla.org/firefox/addon/seamless-print/

Built-in Features

If you want to skip Print Preview and display the print dialog, you can do that using either:

• Ctrl+p
• (menu bar) File > Print

If you want to skip both Print Preview AND the Print dialog, Firefox has an internal setting for that, but it's a little work to create.

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste silent and pause while the list is filtered

(3) If the print.always_print_silent preference exists and is set to false: double-click it to set it to true

(4) If the print.always_print_silent preference does not exist:

(A) Select and copy the preference name:

print.always_print_silent

(B) right-click a blank area of the about:config page > New > Boolean

(C) Paste the preference name and click OK

(D) Choose true and click OK

After that you can test. I recommend a PDF printer as your default to avoid killing too many trees...

Thanks for yours valuable comments but i want to create my own plugin fro this like seamless printing so that when user click on print button of my website it directly go to the printer to print...

You want visitors to your site to have to load an add-on in order to print? That's annoying, to me anyway.

Seamless Print is open source licensed under the GPL license. If you want to create a new variation on it, you have the right to do that, however, the GPL is a sticky license and you will also need to give away your code under the GPL.

If you want to start from scratch, you'll need help that this particular forum doesn't provide. Please follow the link provided earlier to the MDN site.

Thanks Jscher for your information

If you have any other way so that visitors won't install any add-on. so please share with me ... like within the application if we can add any other way to achieve one click printing without print preview.