Wednesday, February 6, 2019

Switching between 3 languages with i3

I type in 3 languages: English, Ukrainian, and Russian. It turns out, I never have to switch directly between Russian and Ukrainian. However, when typing in either Russian or Ukrainian I often switch to English to type email addresses, URLs, Unix commands, etc. In such scenario using standard X11 keyboard switching mechanism with setxkbmap specifying all 3 languages is impractical. It cycles through them sequentially! For comparison, MacOS handles this situation nicely with cycling only through the last 2 most recently used keyboard layouts. I already posted a solution for standard Ubuntu window manager, but now I wanted to make it work with i3 window manager.

The idea is to have two typing models "us/ru" and "us/ua". You can switch between them using a key combination. Within each mode, you can switch between the languages using Alt+SPACE (or another key).

First, download this script and copy it into your ~/bin/ directory. Then add the following 3 lines to your ~/.config/i3/config:

bindsym Mod1+space exec "xkb-switch -n; pkill -x --signal=SIGUSR1 i3status"

exec_always "setxkbmap -layout us,ru -variant ,mac"

bindsym $mod+z exec "~/bin/ /dev/shm/kbd2.txt 'setxkbmap -layout us,ru -variant ,mac' 'setxkbmap -layout us,ua' ; pkill -x --signal=SIGUSR1 i3status"

This is assuming you are using i3status keyboard indication method described in my previous post. Using it will also get the instant status bar update of the current keyboard languages. If you do not use i3status or do not need keyboard indicator you can use the following 2 lines instead:

exec_always "setxkbmap -layout us,ru -option grp:alt_space_toggle 

bindsym $mod+z exec "~/bin/ /dev/shm/kbd2.txt 'setxkbmap -layout us,ru -variant ,mac -option grp:alt_space_toggle' 'setxkbmap -layout us,ua -option grp:alt_space_toggle'

Now you can use WindowsKey+Z to switch between "us/ua" and "us/ru" modes and Alt+SPACE to switch between en and either ru or ua layouts.

Keyboard layout indicator for i3 with i3status

I am using i3 window manager with i3status bar. This post describes how to set up a responsive keyboard layout indicator if you are using multiple keyboard layouts. It looks like this:

In the screenshot above it shows that I have 2 keyboard layouts: American English (us) and Ukrainian (ua) and currently the first one is active.

Display part is implemented by this script. It depends on xkblayout-state utility. Save this script and compiled version of xkblayout-state to your ~/bin/ directory.

In your ~/.config/i3status/config add "output_format = i3bar" line to general section:

general {
        colors = true
        interval = 5
        output_format = i3bar        

In ~/.config/i3/config add:

bar {
    status_command ~/bin/
    output primary
    tray_output primary


exec_always "setxkbmap -layout us,ua -option 'grp:alt_space_toggle'"

This will allow you to switch keyboard with Alt+SPACE, and the indicator will display the current status.

So far, so good, but the problem is that the status bar is updated every 5 seconds. We would want keyboard layout indicator to update immediately. This could be done. It will require another command line utility: xkb-switch (available via apt on Ubuntu Linux). The idea is to implement switching via i3 hotkey, which will also trigger an instant status bar update. Here is  a section of i3 config:

exec_always "setxkbmap -layout us,ua"

bindsym Mod1+space exec "xkb-switch -n; pkill -x --signal=SIGUSR1 i3status"

We removed ALT+SPACE toggle option from setxkbmap, and implemented it as bindsym. Sending USR1 signal to i3status triggers the immediate update.

Thursday, January 31, 2019

Dell XPS-13 Touchpad problem (analysis and solution)

I recently switched to DELL XPS 13 as my primary laptop. In addition slick design and modern specs, the extra bonus is that there is good Linux support thanks to Dell's Project Sputnik.

However, I quickly discovered that it is plagued by a common problem of random touchpad clicks. It is reported by numerous users and various workarounds were proposed. It exhibits as follows: while I type my touchpad randomly detects a click and my cursor jumps to a random position in the text while I continue typing. Pressing Ctrl-Z and re-typing from the last good position becomes a reflex you exercise a hundred times a day. It is so annoying I was considering going back to my old laptop.

I never had this problem on my previous laptop (Lenovo X260) or on several MacBook's I've owned before that. Both Lenovo and DELL are using Synaptic touchpad with the same driver. I decided to investigate.

I am right-handed and I while typing sometimes I reach with my right hand to left side of the keyboard. For example, to type $ sign, I hold left SHIFT button with my left thumb and reach to $ with my right hand's index finger. Doing this puts my thumb above the touchpad which in my theory could be causing an erroneous click. Perhaps this is not a proper typing technique but it is too late for me to change my habits.

Now, let us look at touchpad location for both laptops:

Lenovo X260
Dell XPS 13

And superimpose their respective touchpad/keyboard layouts:

As you can see Lenovo's touchpad is narrower and positioned to the left off center. Also, it has two physical buttons on the top, which I never use, but they put active touchpad area further from the spacebar vertically. Kudo's their ergonomic team!

So, how do I fix this? We can use synclient(1) utility to adjust the size of DELL's touchpad active area. First, the geometry of the touchpad could be queried with the following command (the values may be different on our computer):

$ synclient -l                                        
Parameter settings:
    LeftEdge                = 48
    RightEdge               = 1168
    TopEdge                 = 36
    BottomEdge              = 644

The origin of the coordinate system (0,0) is in the upper right corner with X-axis extending to the right and Y away from the screen. Now we can move the right and bottom edges a bit with the following commands:

$ synclient AreaRightEdge=1000
$ synclient AreaTopEdge=130  
$ synclient PalmDetect=1

We've moved the right edge from 1168 to 1000, cutting off a vertical stripe 1168 pixels wide. Also, we've moved the top from 36 to 130, cutting off the horizontal strip 94 pixels high. We've also enabled palm detection, for the cases where you still manage to touch the touchpad with part of your palm. The changes to the geometry are shown below. The part shown in red is no longer sensitive to touches. 

These numbers work for me but you may need to adjust for your liking. It does not fully eliminate the problem but certainly makes things better, at least for me.

P.S. There is a known issue with 2 touchpad drivers activated at the same time. From this forum post:

If command `xinput --list` shows something like this:

⎡ Virtual core pointer  id=2 [master pointer (3)]
⎜   ↳ Virtual core XTEST pointer  id=4 [slave pointer (2)]
⎜   ↳ ELAN24F0:00 04F3:24F0  id=12 [slave pointer (2)]
⎜   ↳ DELL07E6:00 06CB:76AF Touchpad  id=13 [slave pointer (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad id=14    [slave pointer (2)]

   Which includes two touchpad devices, one needs to be disabled. Use following commands:

   cd /etc/X11
   sudo mkdir xorg.conf.d
   cd xorg.conf.d/
   sudo vi 51-synaptics.conf

Then type:

   Section "InputClass"
   Identifier "touchpad ignore SynPS/2 Synaptics duplicate"
   MatchProduct "SynPS/2 Synaptics TouchPad" 
   Option "Ignore" "on" 
   Then, restart X11.