Is it possible that pdf.js starts always in fullscreen mode?
What I need is that when starting a pdf, it appears automatically in fullscreen (=presentation) mode instead of showing the toolbar above. In former versions of Firefox it was possible to install a Plugin called "Nitro pdf" which enabled pdf documents to be started in fullscreen mode immediately after using the F11 button. Is there a similar function available with pdf.js or an alternative solution with "regedit"?
Wšě wotmołwy (3)
Without know what site or what kinda of pdf file that is no one is going to really know how it is affecting the Browser. Any addons like nitro would have to ask their support on their software and how it interacts with pdf files.
Wot WestEnd změnjeny
I've never heard of a method of doing that.
Websites can add parameters to the PDF link for zoom level and sidebar visibility, but full-screen is not going to be added, per https://github.com/mozilla/pdf.js/issues/10343
In recent versions of Firefox, extensions are not able to touch the contents of the PDF viewer, so I don't think an extension could "click" the presentation mode button or otherwise trigger it.
PDF plugins do not run in Firefox 52 or later, except Firefox 52 ESR, which is no longer supported.
I think for now, you need to use the button.
There is the Ctrl+Alt+P keyboard shortcut if you do not want to click the button.