My laptop has a button to toggle the touchpad on and off. It's an
XF86TouchpadToggle button and on its own it's useless. You need
something which binds to it and makes it do things. Most desktop environments have
an utility which listens to keyboard presses and then toggles the touchpad …
NOTE: as of Firefox 71 (perhaps even earlier), the screensaver/DPMS
are automatically suspended when watching videos. This tool is therefore
deprecated.
Watching videos on YouTube always proved to be problematic because
my DPMS settings would kick in and the screen would turn off. Firefox
didn't suspend them automatically when …