Setting up multi-touch scrolling for Ubuntu 9.10 Karmic Koala Linux on Asus Eee 1005HA netbook

This post is specific to Asus Eee 1005HA netbook, but the technique explained here can be used on any computer having Synaptics touchpad.

Multi-touch gestures allow you to perform user interface actions by doing two finger gestures on touchpad. Apple introduced this feature on Macbooks and after you get used to it, it greatly enhances your web browsing on mouseless netbook. The most important gesture is scroll text by swiping the touchpad with two fingers.

Apple has also many patents related to the gestures so they are not enabled by default.

The real multi-finger touch support needs multi-finger aware (capacitive) touchpad. Most PC laptops are not equipped with one. Luckily some of the simple gestures, like two finger scrolling, can be emulated on normal pressure point sensitive touchpad via clever calculations and other tricks.

Note: Ubuntu HAL support for Synaptics seem to be broken. Only shell script at the end of the post will work. HAL options in FDI file are being ignored.

1. Setting up Synaptics driver

Type in terminal

gksudo gedit /etc/hal/fdi/policy/11-x11-synaptics.fdi

Create and save file with this content:

<?xml version="1.0" encoding="ISO-8859-1"?>
<deviceinfo version="0.2">
 <device>
   <match key="info.capabilities" contains="input.touchpad">
       <merge key="input.x11_driver" type="string">synaptics</merge>
       <merge key="input.x11_options.SHMConfig" type="string">On</merge>

       <merge key="input.x11_options.EmulateTwoFingerMinZ" type="string">40</merge>
       <merge key="input.x11_options.VertTwoFingerScroll" type="string">1</merge>
       <merge key="input.x11_options.HorizTwoFingerScroll" type="string">1</merge>
       <merge key="input.x11_options.TapButton1" type="string">1</merge>
       <merge key="input.x11_options.TapButton2" type="string">3</merge>  <!--two finger tap -> middle clieck(3) -->
       <merge key="input.x11_options.TapButton3" type="string">2</merge>  <!--three finger tap -> right click(2). almost impossible to click -->
   </match>
 </device>
</deviceinfo>

This allows us to use synclient utility to watch touchpad real-time data in console window.

Now restart X

sudo /etc/init.d/gdm restart

And open terminal again.

Type in command

synclient -m 100

And you should see data like this scrolling in the terminal:

129.355  2912 3469  59 1  4  0 0 0 0 0  00000000   0  0  0   0   0
 129.455  2952 3529  59 1  4  1 0 0 0 0  00000000   0  0  0   0   0
 time     x    y   z f  w  l r u d m     multi  gl gm gr gdx gdy
 129.555  3283 3516  60 1  4  1 0 0 0 0  00000000   0  0  0   0   0
 129.656  3928 3517  60 1  4  1 0 0 0 0  00000000   0  0  0   0   0
 129.756  4364 3637  60 1  4  1 0 0 0 0  00000000   0  0  0   0   0
 129.856  4020 3329  49 1  4  0 0 0 0 0  00000000   0  0  0   0   0
 129.956  3634 3122  58 1  4  0 0 0 0 0  00000000   0  0  0   0   0
 130.057  3320 2957  60 1  4  0 0 0 0 0  00000000   0  0  0   0   0
 130.157  2779 3312  61 1  4  0 0 0 0 0  00000000   0  0  0   0   0
 130.257  2557 3739  61 1  4  0 0 0 0 0  00000000   0  0  0   0   0
 130.358  2636 3485  39 1  4  0 0 0 0 0  00000000   0  0  0   0   0
 130.458  2659 3104  60 1  4  0 0 0 0 0  00000000   0  0  0   0   0
 130.558  2671 2988  60 1  4  0 0 0 0 0  00000000   0  0  0   0   0

f column tells the number of fingers. w is the touched area width. z is the pressure.

If you put two fingers on touchpad and you see value f=2 then your hardware has multi-touch aware touchpad. Unfortunately Asus Eee 1005HA doesn’t seem to have one 🙁

2. Emulation approach

Synaptics driver can emulate two-finger touch with the following conditions

  • Touched area width exceeds certain threshold (min width)
  • Touch pressure exceeds certain thresholds

When the conditions are met the driver thinks “Wow looks this guy is pressing us really hard. maybe he is using two fingers?” Note that touchpad values are touchpad specific and values applying for one model don’t work on another computer.

Synaptics driver settings are described here. Synaptic driver settings can be modified run-time using xinput command. Run synclient -m 100 in one terminal window and change threshold values in other until you find correct emulation parameters for your laptop. Below is my xinput tests. Test scrolling on Firefox and any long web page.

moo@huiskuttaja:~$ xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Width" 32 7
moo@huiskuttaja:~$ xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Pressure" 32 280
moo@huiskuttaja:~$ xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Width" 32 11
moo@huiskuttaja:~$ xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Pressure" 32 50
moo@huiskuttaja:~$

Looks like the following parameters are good for two finger emulation for Asus Eee 1005HA:

  • Width: 8
  • Pressure (Z): 10

You can also use command synclient -l to dump the current settings.

Below is the final script you need to run during log-in (see note about broken HAL at the beginning of the post):

#!/bin/sh
#!/bin/sh # # Use xinput --list-props "SynPS/2 Synaptics TouchPad" to extract data # # Set multi-touch emulation parameters xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Pressure" 32 10 xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Width" 32 8 xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Two-Finger Scrolling" 8 1 xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Scrolling" 8 1 1 # Disable edge scrolling xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Synaptics Edge Scrolling" 8 0 0 0 # This will make cursor not to jump if you have two fingers on the touchpad and you list one # (which you usually do after two-finger scrolling) xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Synaptics Jumpy Cursor Threshold" 32 110
Jumpy cursor after two finger scroll

When you do a two-finger scroll and lift your one finger before the other the mouse cursor/scrolling may jump. Synaptics driver does not seem to have an option to filter out this bad event. If anyone knows solution for this please comment.

3. Other resources

Cannot sort custom content item in Plone folder listing

Bug: Plone folder manual sorting does not move items even though you try all tricks. The first suspect would be a Javascript bug, but it isn’t.

It is bug 8161.

Your custom content meta_type must not contain spaces.

You can fix this on-line by editing meta type in portal_types in ZMI and remove all spaces from meta type name.

Subversion global-ignores and .egg-info in Python/Plone development

Subversion does a good job by ignoring most of build/temporary/unwanted files by default.

However, there is one exception still existing at least in Subversion 1.6: Python egg folders. All folders whose name ends up with .egg-info should not committed or considered in version controlling actions. your.package.name.egg-info folder is generated inside your Python egg source folder when you run setup.py / setuptools.

If you are working with Python source code eggs, add the following line to your ~/.subversion/config

global-ignores = *.o *.lo *.la #*# .*.rej *.rej .*~ *~ .#* .DS_Store *.egg-info *.pyc *.pyo .project .pydevproject

Otherwise development tools like Mr. Developer might get confused.