[Bug-apl] Keyboard layout alternative

[David B. Lamkins]

As an alternative to the apl.xmodmap provided with GNU APL, GNOME and
Ubuntu users may use the following technique to enable an APL keyboard.

>From a user (not root) shell, do

$ gsettings set org.gnome.libgnomekbd.desktop load-extra-items true

This will enable the keyboard layout applet to show layouts which are
defined but not normally displayed, including APL layouts.

The following layouts apply to various APLs:

apl2
APL Keyboard Symbols
aplplusII
aplx
dyalog
dyalog without box or op-codes
sax

To add a layout, follow these steps:

  1. Find the layout dialog via either the Keyboard applet or the Region
and Language applet.
  2. Click the '+' button, then choose an appropriate (see below) APL
layout.
  3. Click the 'Options' button and set the 'Key(s) to change layout'. I
prefer 'Right Alt (while pressed)' since it leaves the Left Alt free as
a meta key for Emacs and GNOME.

The first time these settings are changed, it may be necessary to log
out and back in for GNOME's UI to render the keyboard indicator's menu
properly.

I haven't done enough research to know for certain which keyboard layout
is best suited for GNU APL. My initial guess is to use the apl2 layout.

Note that all of the above depends upon use of a reasonably recent
GNU/Linux release. I believe that Ubuntu 12.04 and Debian 6 are both new
enough, but I haven't attempted to find out where APL layouts were first
introduced.

The following thread (which is where I learned this technique) says that
APL keyboard layouts are supported in other GNU/Linux releases:

http://forums.dyalog.com/viewtopic.php?f=20&t=210