I am not asking this question from a web developer but from an end-user.
I am using several web sites (google drive, evernote and so on) that have context menu that activates upon a right click event. However, on my browser (Firefox), if I right click it opens my navigator context menu on top of the context menu implemented by the web developer(s) of the website. If I right click a second time, then the navigator context menu disapears, leaving space for the web app context menu.
How can I, as an end-user, disable right clicks on specific websites? And if possible, I would like to have this possibility "on-demand", ie being able to reactivate right clicks when I want to.