[How To] Two finger touch for right click

[JimmyN]

Credit goes to @gadgetoid for finding the method, testing it, and confirming that it works in this thread. viewtopic.php?f=108&t=121602&start=25 I'm just adding some polish.

Since "right click" is a popular feature that was lost with the upgrade to Jessie I thought I'd post this with an appropriate title, to make it easier to find, and step by step instructions that anyone can follow. Hopefully it will be a help for those wanting a "right click" function again.

uname -a reports: Linux rpi4 4.1.18+ #846 Thu Feb 25 14:11:56 GMT 2016 armv6l GNU/Linux so that's what I'm using.

First we'll need to fetch the files, I created a temp directory to work in, and afterward it can be deleted. So open a terminal and get started.

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mkdir ~/temp
cd ~/temp
wget http://plippo.de/dwl/twofing/twofing-0.1.2.tar.gz

That should report that "twofing-0.1.2.tar.gz" was saved.

Now we'll add some needed packages, if any of these are already installed it's OK. We'll update first, and then install them with the following commands.

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sudo apt-get update
sudo apt-get install build-essential libx11-dev libxtst-dev libxi-dev x11proto-randr-dev libxrandr-dev

Now that those are in place we can extract the downloaded twofing-0.1.2.tar.bz file and compile the binary using "make".

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tar -xvzf twofing-0.1.2.tar.gz
cd twofing-0.1.2
make

-- Below has been EDITED to fix /dev/input problem--

Next we need to create a .rules file in "/etc/udev/rules.d"

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sudo nano /etc/udev/rules.d/70-touchscreen-egalax.rules

Put this line in the file, then save and exit.

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KERNEL=="event*",ATTRS{name}=="FT5406 memory based driver",SYMLINK+="twofingtouch",RUN+="/bin/chmod a+r /dev/twofingtouch"

Now copy "twofing" to /usr/bin

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sudo cp twofing /usr/bin/

Now reboot and then we can give it a test.
Test it using the debug switch. If you have no errors you'll get a calibration screen, press <CTRL> C to exit.

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twofing --debug

If that went OK then start twofing again, without the debug switch, and touching two fingers on the window titlebar should give you a "right click" dropdown menu.

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twofing 

Now you'll probably want to start it up when the desktop starts, so let's add it to the autostart file.

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nano ~/.config/lxsession/LXDE-pi/autostart

Scroll down to the bottom and add this line.

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@/usr/bin/twofing 

Save the change, reboot again, and it should be working. If so you can delete the /temp directory and everything in it.

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rm -r ~/temp

Have fun!

[adastre]

In fact you can solve the problem of choosing the input by changing the udev rules.
Remplace the content of the file 70-touchscreen-egalax.rules by

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KERNEL=="event*",ATTRS{name}=="FT5406 memory based driver",SYMLINK+="twofingtouch",RUN+="/bin/chmod a+r /dev/twofingtouch"

This will automatic link the good /dev/input/event to /dev/twofingtouch (For the official 7" touchsreen)

[JimmyN]

Thanks, I knew somebody would come along that knew what to do about the changing inputs. I guess I should edit the instructions to include editing the .rules file, and specifying the alternate input is no longer needed if using "/dev/twofingtouch".

[deerewright]

When I do the debug entry I get this:

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~$ twofing --debug
twofing, the two-fingered daemon
Version 0.1.2.20120708

ERROR: Couldn't connect to X server

I then tried without the debug, but am not getting any response on my screen.

[JimmyN]

Using --debug shows you any errors. If it doesn't run with the --debug switch it won't run without it.

You have to run "twofing" from a terminal on the desktop to test it. The "couldn't connect to x server" sounds like you are trying to start it from Putty or some other remote login.

[gadgetoid]

Nice work, JimmyN!

Glad the right udev rules cropped up via adastre. I looked blankly at the udev stuff for a long time before deciding I had no chance of figuring it out without an extensive google adventure.

[Makro]

Nice job JimmyN! Thanks for this sharing! I'm realy glad to see that RPI community is so dynamic!
Now every one can have a complet functional display on Jessie.

This step by step worked well for my.
Unless the part for runding twofing at boot. For now I can't figure out what the problem is. I'll first search by myself.

[CraigV]

Thank you Jimmy and all others that contributed!

[JimmyN]

Thanks everyone, I see I'm not the only one that really missed having "right click" context menus.

[ZakAttacks]

When setting this up in Ubuntu MATE, everything is the same until you get to the auto start. Ubuntu MATE uses MATE instead of LXDE so obviusly we can't use the method used in this guide. Instead use this:

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mate-session-properties

Click 'Add'

and fill it in

et voila! twofing will now start at boot!

I am proud to say I wrote this entire post on my pi! I actually used twofing to paste the links to the images. Thanks to everyone involved to getting this working!
Also if you have a pi 2 or 3 try out MATE because Ubuntu has better touch support, and it comes with Onboard, which is better than any onscreen keyboard in rasbian.

[huczas]

How to enable it on different touch screens? I mean my touch screen - http://www.waveshare.com/wiki/7inch_HDMI_LCD_(C)

[RaspberryPink]

Thanks so much for the post. I am getting an error when I run: "twofing --debug"

Here is the output:

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twofing, the two-fingered daemon
Version 0.1.2.20120708

/dev/twofingtouch: No such file or directory

I have verified that my configuration file (/etc/udev/rules.d/70-touchscreen-egalax.rules) is matching the instructions.

I'm running Raspbian Jessie. Any help would be appreciated, thanks!

[JimmyN]

Try this and see what it shows. twofingtouch should be a linked to an input event

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ls -l /dev/twofingtouch
lrwxrwxrwx 1 root root 12 Jul 14 18:53 /dev/twofingtouch -> input/event0

If that isn't correct it must be something in the "/etc/udev/rules.d/70-touchscreen-egalax.rules" file as that creates the link.
What does the file listing looks like for the rules file?

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ls -l /etc/udev/rules.d/70-touchscreen-egalax.rules
-rw-r--r-- 1 root root 124 Mar  5 07:09 /etc/udev/rules.d/70-touchscreen-egalax.rules

I'm sure you've checked it, probably more than once, but also post the line from your .rules file.

[johalareewi]

Works for me too with my 22 inch Iiyama ProLite T2252MTS touchscreen (aka Quanta OpticalTouchScreen ).
After making twofing, I only needed to create the symlink between /dev/input/event0 and /dev/twofingtouch
The udev stuff wasn't required and I only have the touchscreen (no mouse) so it is always on event0.
Works with Raspbian Jessie and UbuntuMATE 16.04

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cd /tmp
wget http://plippo.de/dwl/twofing/twofing-0.1.2.tar.gz
sudo apt-get update
sudo apt-get install build-essential libx11-dev libxtst-dev libxi-dev x11proto-randr-dev libxrandr-dev
tar -xvzf twofing-0.1.2.tar.gz
cd twofing-0.1.2
make
sudo cp twofing /usr/bin
sudo ln -s /dev/input/event0 /dev/twofingtouch
twofing

But:-
- The /dev/twofintouch link doesn't survive a reboot.
- Some HTML5 web applications that recognise a long mouse click (in Firefox/IceWeasel) don't when twofing is running

And with UbuntuMATE the top menu bar is not easy to two finger click on but when you manage to do it (or use a mouse) there is an option to make the menu bar thicker which makes it easier (I set mine to 40px).

[Siggi]

Hello,

unfortunately, the discribed autostart procedure didn't work for me.
But the variant to implement a autostart command described at adafruit helped me:
https://learn.adafruit.com/adafruit-ras ... at-startup

Just replace

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$ nano tightvnc.desktop

with

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$ nano twofing.desktop

and

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[Desktop Entry]
2.Type=Application
3.Name=TightVNC
4.Exec=vncserver :1
5.StartupNotify=false

with

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[Desktop Entry]
2.Type=Application
3.Name=Twofing
4.Exec=twofing
5.StartupNotify=false

Hope this is helpful for some people.

[karazi]

Works for me too with my 22 inch Iiyama ProLite T2252MTS touchscreen (aka Quanta OpticalTouchScreen ).
After making twofing, I only needed to create the symlink between /dev/input/event0 and /dev/twofingtouch
The udev stuff wasn't required and I only have the touchscreen (no mouse) so it is always on event0.
Works with Raspbian Jessie and UbuntuMATE 16.04

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cd /tmp
wget http://plippo.de/dwl/twofing/twofing-0.1.2.tar.gz
sudo apt-get update
sudo apt-get install build-essential libx11-dev libxtst-dev libxi-dev x11proto-randr-dev libxrandr-dev
tar -xvzf twofing-0.1.2.tar.gz
cd twofing-0.1.2
make
sudo cp twofing /usr/bin
sudo ln -s /dev/input/event0 /dev/twofingtouch
twofing

But:-
- The /dev/twofintouch link doesn't survive a reboot.
- Some HTML5 web applications that recognise a long mouse click (in Firefox/IceWeasel) don't when twofing is running

And with UbuntuMATE the top menu bar is not easy to two finger click on but when you manage to do it (or use a mouse) there is an option to make the menu bar thicker which makes it easier (I set mine to 40px).

Were you able to figure out how to make the /dev/twofingtouch link survive reboot?

[flostein]

hel!po,
until now i realy get started everything with the raspi. but this one is too tricky for me. are all these tutorials concerning 2 finger touch right click on raspbian jessie fake? please, can someone send me a link to the working image? for this project i realy need the right click! thanks in advance, flo
my setup:
rp3
official 7"touch display

[JimmyN]

hel!po,
but this one is too tricky for me. are all these tutorials concerning 2 finger touch right click on raspbian jessie fake? please, can someone send me a link to the working image?

It's not that tricky, my first post at the top contains all the information, just go though it step by step in the correct sequence, all the commands are there, and it will work.

Why would you think this is fake?

There is no Raspbian image that contains the right click function, for the RPF display. No matter which image you use you'll have to add a right click function if you want it.

[flostein]

hi jimmy, after going through the process, i stuck here again:
"Now reboot and then we can give it a test.
Test it using the debug switch. If you have no errors you'll get a calibration screen, press <CTRL> C to exit."

- there is no calibration screen after reboot.
- what exactly do you mean by "debug switch"?

i am using the latest raspbian ( Raspbian Jessie with PIXEL)

please help, i need a simple walktrough. there have to be some basics, i dont get. sorry.

thanks in advance for your help! kind regards, flo

[JimmyN]

At the command prompt type

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twofing --debug

If you start it without using "--debug" and there is an error it will just die silently and you won't know what's wrong. Using "--debug" it will show any errors, and if there are none and it's working you'll get a calibration screen. There's nothing to calibrate though, so just exit it with a <CTLC> C.

Once you know it's working correctly start it manually with

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twofing

or add it to the autostart file

[flostein]

HERO OF THE DAY! tx a lot, flo

[newsordice]

Hey I just wanted to say my thanks to the OP and all other contributors. This has helped me successfully implement twofing as a right click alternative. Much appreciated

[lsegalla]

In my case, to have the right-menu working at startup I've added this to the .config/lxsession/LXDE-PI/autostart the following code:

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@sudo ln -s /dev/input/event0 /dev/twofingtouch
@lxterminal -e /usr/bin/twofing

[JimmyN]

That will work, but if you plug in a USB keyboard/mouse the touchscreen input event number will change and the two finger touch function will stop working. The udev rule assures that twofing uses the correct event number for the touchscreen regardless of other input devices that may or may not be plugged in, either before or after boot.

[danb1983]

I'm having an issue that when I try to two finger right click the mouse moves to the different spot. Is there a way that I can move the mouse to an item and then click with my other finger without the mouse moving?

Thanks,