GNOME3.8 – How to Remap Keys Using xmodmap

gnome3keyboardxmodmap

I want to remap some keys on my keyboard, specifically: page up key to home and page down to end.

On previous versions of GNOME 3 I just created a .xinitrc file that contained:

cat .xinitrc 
xmodmap -e "keycode  117 = End"
xmodmap -e "keycode  112 = Home"

and that was all.

On GNOME 3.8.4 this file takes no effect, and I have to manually: bash .xinitrc, moreover xmodmap settings are lost when I restart gnome shell (which I do sometimes because of a GNOME 3 bug), and also are lost spuriously from time to time.

What is the proper way to remap keys when using GNOME 3.8?

Best Answer

Sourcing commands during login

I've not tried either .xinitrc or .xsession files to do this, but I have done it using a custom launcher that gets run when I login. You can access the dialog that allows you to do this a couple of ways, I usually just launch it from the command line like so.

$ gnome-session-properties

The GUI looks like this.

ss of gnome session props

From here you can create your own custom startup launchers and then point them to shell scripts that contain what ever commands you need to invoke. Here I've created my own Dropbox launcher script that gets executed when I log in.

Mapping keys to run commands

If on the other hand you're looking to create shortcut key combinations that will launch commands, I've successfully been using XBindKeys on GNOME 3.8.4 for this very purpose.

My use has been modest but I like to create keyboard shortcuts for Nautilus to launch with certain directories opened.

Example

You'll need to first make sure the packages xbindkeys is installed.

Then you'll need to run the following command, one time only, to create a template xbindkeys configuration file.

$ xbindkeys --defaults > /home/saml/.xbindkeysrc

With the file created you can open it in a text editor and add a rule like this:

"nautilus --browser /home/saml/projects/path/to/some/dir"
  Mod4+shift + q

With the above change made we need to kill xbindkeys if it's already running and then restart it.

$ killall xbindkeys
$ xbindkeys

Now with this running any time I type Mod+Shift+Q Nautilus will open with the corresponding folder opened.

Why isn't .xsession or .xinit getting sourced

I believe the ultimate issue lies with this post, titled: Quickly Setting up Awesome with Gnome. It discusses methods for getting GDM (GNOME's Display Manager) into loading these files, which to me implies that it doesn't by default.

My Fedora 19 system contains this file: /usr/share/xsessions/gnome.desktop which contains these lines:

Exec=gnome-session
TryExec=gnome-session
Icon=
Type=Application

I believe gnome-session doesn't source your .xsession file by default, and the .xinit is meant to be sourced if you invoke GNOME using startx.

Be sure to look through the section titled: with GDM, which shows this in more details.

References

Trying to understand what's happenning

If I type xmodmap without argument (to get modifier list), I get:

xmodmap:  up to 4 keys per modifier, (keycodes in parentheses):

shift       Shift_L (0x32),  Shift_R (0x3e)
lock        Caps_Lock (0x42)
control     Control_L (0x25)
mod1        Alt_L (0x40),  Meta_L (0xcd)
mod2        Num_Lock (0x4d)
mod3        ISO_Level5_Shift (0x69)
mod4        Super_L (0x85),  Super_R (0x86),  Super_L (0xce),  Hyper_L (0xcf)
mod5        ISO_Level3_Shift (0x5c),  Mode_switch (0xcb)

The important part is for mod4. That's where Super_L is.

Now, I run : xmodmap -e "keycode 133 = Tab Super_L" && xmodmap | grep mod4, and I get:

mod4        Tab (0x85),  Super_R (0x86),  Super_L (0xce),  Hyper_L (0xcf)

The mod4 line changed and added Tab. That's why your key 133 still open the window menu.

By the way, I'm trying this on I3WM so the results can be a bit different.
For example, if I press the key 133 on a terminal or text editor, it both write a tab and becomes a modifier.

I also noticed I don't have a different behavior with Shift because the type of the key is ONE_LEVEL.

You can also run xev | grep key to see what happens with some key combinations.

Solution

But xmodmap also tells you can't have more than 4 keys per modifier, so a solution (the only one that worked for me so far) is to sacrifice a key you don't use / don't have, make it become a Super_L.

If you use QWERTY, you can modify the layout located on /usr/share/X11/xkb/symbols/us (it's usually another file of the same folder if you're using another layout), and write:

key.type[Group1] = "TWO_LEVEL";
key <MENU>{[Super_L]}; // ONE or TWO level, assuming MENU key isn't used
key <LWIN>{[ Tab, Super_L]}; // should be TWO_LEVEL
key.type[Group1] = "ONE_LEVEL";

instead of (probably line 14 of the file)

 key <LWIN>{[Super_L]};

Then, update your keyboard layout with setxkbmap us && xmodmap | grep mod4.
You will get something like:

mod4        Super_R (0x86),  Super_L (0x87),  Super_L (0xce),  Hyper_L (0xcf)

If you still get Tab, you should probably sacrifice another key. Note that 0x85 is the hexadecimal value of 133, that mean this key will not be a direct mod4 but it still can behave like window key if Shift is pressed.