Clean 'Fullscreen' look in a window?

I’m pretty sure I used to have a macro that hid toolbars and the menu, and left a clean rectangle for composing in Writer, as it is in Fullscreen, but it’s lost now. Is there any way to do this?

I could use Fullscreen, but on my dual monitor setup in Linux/KDE, when I invoke it LO jumps to the main monitor and hides the programs there, which I usually want to refer to while I’m writing.

Indeed it jumps to the main monitor.Then either you put your other programs on the second monitor or you move manually LO fullscreen to the other monitor. Not sure, but it may be an issue with KDE.