what is touchpad equivalent to mouse middle button click

Ubuntu 19.04

A mouse middle button click on any window top title bar will lower window so it goes behind all other open windows yet stays open ... How to perform this action without using a mouse ? I have tried every combination with touchpad to no avail

three finger tap on touchpad on window top boarder does nothing

I was hoping to find help here ... alas no

here is output of running xev in a terminal then three finger click on that windows top title bar

EnterNotify event, serial 37, synthetic NO, window 0x5600001, root 0x23e, subw 0x0, time 5462506, (69,10), root:(69,74), mode NotifyNormal, detail NotifyAncestor, same_screen YES, focus YES, state 0
KeymapNotify event, serial 37, synthetic NO, window 0x0, keys: 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

that window just sat there and did not get lowered as desired

3 Answers

Three finger tap is the equivalent of a mouse middle click in libinput that is default in Ubuntu. Provided that your touchpad supports multi-finger action.

Button 1 (Left Click), Button 3 (Right Click) and Button 2 (Middle Click) can be performed with one-finger, two-finger, and three-finger taps (respectively) on touchpads.

You can test this by opening xev in a terminal and testing these taps out. You can look over Synaptic Touchpad Ubuntu documentation to learn more. If you run into a specific issue, please update or ask that specific question. Some people have started using libinput instead of Synaptics. You'll have to look at the current differences and decide which works best for you.

I had HP Probook 440 G5 and clicking on the title bar in the middle of touchpad; does exactly what you are asking for (put in behind other windows without closing it.

Opposite to you, I am getting crazy with this feature. Can someone tell me how to disable this feature ?

Found a cure in Tweaks (Ubuntu 20.04.2 LTS)

1. Window Titlebars > Titlebar Actions > Middle-Click > select none from the available options.

2. Also found another solution on this thread. Disable "middle click to lower window" behaviour on gnome