To change the behavior of the Synaptics / Alps
touch pad, use Control Panel - Desktop - Adjust Touch Pad. If Adjust Touch Pad errors when you launch it, your
touch pad is probably not supported yet, see synaptics below.
By default "tap-to-click" is disabled as some touchpads are overly sensitive, making the system impossible to use if it is left on. To turn it back on:
Here's a couple popular options to adjust :
Option "Tapping" "false" This option sets the tap-to-click behavior. Setting this to "false" disables tap-to-click behaviour (which is the default). If you want tap-to-click, change this to "true" to start with and adjust as needed.
Option "AccelSpeed" "0.00" This option sets how fast the mouse moves as you drag your finger across the pad. A smaller number is slower, a bigger number is faster. Ranges from -1 to 1.
If you need more configuration options, take
a look at the man page for xf86-input-libinput.
If libinput doesn't support your touchpad,
use the Gslapt package manager to install xf86-input-synaptics
and flSynclient then restart X. Synaptics is an older
driver for touchpad and may not work properly for newer
devices; however if your hardware is old it may support it
better than libinput (or not - you just have to try). It also
has a lot more options. Use flSynclient to control its
settings. If you don't like it, you can always uninstall it
and Xorg will automatically revert to using libinput.
Synaptics can also be configured using a
configuration file like above. You can find the details for
synaptics driver here.
If libinput or synaptics doesn't support your touchpad properly, use the Gslapt package manager to install xf86-input-mtrack and then restart X. Mtrack is an alternative driver that uses Linux kernel multitouch driver directly. Some touchpad works better with mtrack than libinput, some worse. Just like synaptic, you will just have to try to see if it works. There are reports that it works better for multitouch gestures (two- and three-finger gestures), but of course YMMV. If you don't like it, you can always uninstall it and Xorg will automatically revert to using libinput.
Mtrack has a lot
of options, but it does not have a GUI configuration to change
these. You have to manually do it. To do so, copy the file /usr/share/X11/xorg.conf.d/55-mtrack.conf
to /etc/X11/xorg.conf.d/55-mtrack.conf and then edit
this copy. All the available options as listed (as comments)
inside that file. Remember you need to restart X in order for
the change to take effect. Alternatively, you can make the
changes using the xinput program, but these changes
will only last until you reboot the system.
Note 1: if you uninstall mtrack,
please don't forget to delete the copy of the configuration
file /etc/X11/xorg.conf.d/55-mtrack.conf or otherwise
your your touchpad will stop working altogether as Xorg tries
to use a non-existent driver for your touchpad.
Note 2: If you install both mtrack
and synaptics driver, the synaptics driver will take
precedence and be used instead of mtrack. So if you want to
try mtrack and has previously installed synaptics, remember to
uninstall synaptics first.
You can find the details about for the
mtrack driver here.
Yet another driver is xf86-input-mtev but this is a very old
driver that was originally meant for multi-touch touchscreen,
not touchpad. It may or may not work for you. In fact, most
probably it won't. So don't try it unless you are absolutely
desperate. Try all other options first. That being said, in
order to use it, install it from Gslapt, then create a file
called /etc/X11/xorg.conf.d/60-mtev.conf which contains
Identifier "Multitouch Touchpad"
As usual, if you decide to uninstall it, don't forget to remove
the configuration file.