If you are like me, maybe you have recently updated your Linux laptop and found out that right click had stopped working on the touchpad. It took me half an hour to figure out why. I was looking at low-level stuff until I realized
libinput debug-events saw the right thing:
event11 POINTER_BUTTON +3.35s BTN_RIGHT (273) pressed, seat count: 1 event11 POINTER_BUTTON +3.49s BTN_RIGHT (273) released, seat count:
It turns out Gnome decided to change the default behavior of touchpads in version 3.28:
All touchpads now use a gesture for secondary click (the equivalent to right click on a mouse) by default. To use the gesture, keep one finger in contact with the touchpad and tap with another finger. In many cases this replaces tapping areas of the touchpad as the default secondary click method. A choice between the two behaviors is available in the Tweaks application.
Of course the new behavior is terrible if you use physical clicks, plus you have to re-train your muscle memory... To revert to clicks in the bottom-right corner, you can use the gnome-tweaks application as advised, or simply this gsettings command:
gsettings set org.gnome.desktop.peripherals.touchpad \ click-method areas
But seriously, Gnome developers, if you are going to change an important default like that, why not at least add an option in the obvious place where it belongs?