Dtyjlui

I recently got a new Dell XPS 15 9550, and I followed the instructions of the OP in this thread https://ubuntuforums.org/showthread.php?t=2317843 to set it up to dual boot Windows 10 and Ubuntu 16.04. (Basically just disable safe boot and fast boot, change from RAID to AHCI in BIOS, then install Ubuntu and make sure graphics and other drivers work). Everything works pretty well immediately after installation.

I want to disable the "TapAndDragGesture" which is enabled by default in synaptics. But when I use synclient to do so: synclient TapAndDragGesture=0 the gesture does not completely go away. The behavior is that now, if I double tap, it will drag for a brief period of time (about half a second, as opposed to dragging for however long I keep my finger on the touchpad).

This is still very irritating as the amount of time it drags is still enough for me to accidentally move tabs around (as I tend to do when quickly tapping to switch tabs).

Has anyone experienced this issue or something similar? And does anyone know how to fix it? Thanks in advance.

On Wayland (Ubuntu 17.10) I disabled tap-and-drag gesture with

gsettings set org.gnome.desktop.peripherals.touchpad tap-and-drag false

And logged out and back in.

I use the synclient MaxTapMove=0 to solve the problem. Although I am really not sure it is the right solution.

I was able to resolve this issue by installing and using libinput instead of synaptics for my input driver.

This post describes the installation process very simply for 15.04+ (I am on 16.04).

After following these steps, you can verify that your touchpad uses libinput: in the terminal type xinput list to get the device id of your touchpad, then:

xinput list-props <device_id>

Most of the properties in the list should have "libinput" as part of the name.

Finally, to disable the "Tap and Drag gesture", simply edit the file /usr/share/X11/xorg.conf.d/90-libinput.conf. Find the section for the touchpad and disable the tapping drag option:

Section "InputClass"

    Identifier "libinput touchpad catchall"

    MatchIsTouchpad "on"

    MatchDevicePath "/dev/input/event*"

    Driver "libinput"

    Option "TappingDrag" "false"

EndSection

There are many other useful options that can be changed or tweaked, which is well documented here

Once the options are set, save the file, log out, log in, and enjoy!

I have exactly the same frustration, but just from single tapping in order to focus something, then releasing and dragging the pointer away which causes the newly focused tab (for example) to be dragged across. Super annoying. I have a solution which seems to be more a work-around, but stops this from happening.

xinput set-prop [touchpad ID] "Synaptics Gestures" 0

(Find out the ID of your touchpad by running xinput without passing any arguments.)

I can still see the tabs/windows being attempted to drag, but then stop immediately and "snap back". Kind of a fluke perhaps, but it works.

As far as I know that option is only about tap-and-drag:

Option "TapAndDragGesture" "boolean"

        Switch on/off the tap-and-drag gesture. This gesture is an alternative way of dragging. It is performed by tapping (touching and releasing the finger), then touching again and moving the finger on the touchpad. The gesture is enabled by default and can be disabled by setting the TapAndDragGesture option to false. Property: "Synaptics Gestures"

Synaptics Gestures

        8 bit (BOOL), 1 value, tap-and-drag.

Source: synaptics(4) - ftp://www.x.org/pub/X11R7.5/doc/man/man4/synaptics.4.html

Easiest solution for those using Ubuntu 16.04!

To list all actions your Synaptics Touchpad has:

synclient

To change an option:

synclient PARAMETER=#

EXAMPLE:
Disabling Tap and Drag:

synclient TapAndDragGesture=0

After trying everything above, synclient SingleTapTimeout=0 finally worked for me. If that doesn't work, I'd encourage you to just type synclient into the terminal and mess with some of the settings. You'll likely find what you need.