Re: Unicode character entry

[Simos Xenitellis <simos lists googlemail com>]

On Tue, Jun 1, 2010 at 6:11 PM, Shaun McCance <shaunm gnome org> wrote:
> On Mon, 2010-05-31 at 22:50 -0700, Dylan McCall wrote:
>> > I found some advice to use ibus instead, but so far I've not been
>> able to
>> > get ibus to do what I need without having it interfere with my
>> normal
>> > typing. I just need a quick way to type common symbols found in
>> English text
>> > (e.g. an em-dash).
>>
>> Well, as a workaround, I suggest you stop torturing yourself with
>> memorized character codes and configure a compose key! In Gnome, that
>> can be turned on with Keyboard Preferences / the Configuration button
>> in the Layout section. Unfold the Compose Key section, and pick one. I
>> use Right Alt. (Sorry, I'm not in front of a Gnome desktop right now
>> so I can't be any clearer).
>>
>> Now you can input a special character by pressing the compose key,
>> followed by two characters that you think would combine to form it.
>> For example, Compose + o + c creates ©.
>> Your em-dash is compose + minus + minus.
>>
>> Basically anything you could possibly want is there, including opening
>> / closing quotation marks, fractions, some math symbols, super /
>> subscripts, and accented characters.
>
> The compose key is awesome, and I use it frequently. But it
> does not enable anything you could possibly want. It might
> contain everything you need if you only need Latin languages.
> Unicode is really, really big.

Currently there are quite a few compose sequences that cover more than
the Latin Unicode groups.
The majority however are indeed the Latin groups, which are also what
most people know about.
Here is the current list,
http://cgit.freedesktop.org/xorg/lib/libX11/tree/nls/en_US.UTF-8/Compose.pre
(~500KB HTML)
where you can find what is the resulting character you get and what's
the compose sequence you need to use.

What we miss is some sort of script that will read the compose
sequences and will produce easy to understand documentation,
documentation that can be added to GNOME documentation.

There have been no (known to me) significant efforts to cover more of
Unicode in XOrg,
which means that it is a field open to take up.
Some googling shows this external project,
http://github.com/leoboiko/pointless-xcompose

> /me wishes the compose key table were (easily) user-configurable.

Half of the functionality to get make the compose table
user-configurable is there.
See http://git.gnome.org/browse/gtk+/tree/gtk/gtkimcontextsimple.c#n1108
and https://bugzilla.gnome.org/show_bug.cgi?id=155010
With the above resources, it's possible for someone to write a GUI program
that adds on demand custom compose sequences.

Simos