[Pkg-ime-devel] Bug#686612: Bug#686612: Bug#686612: ibus-m17n: <AltGr> and <Shift>-non-ascii do not work

[Tore Ferner]

On 07. sep. 2012 09:41, Daiki Ueno wrote:
> Tore Ferner <torfer at pvv.org> writes:
>
>> > In wheezy:
>> > Turning off "Use system keyboard layout" gives me an American
keyboard -
>> > except that all default Norwegian AltGr-characters still works, both
>> > shifted and unshifted. Seems AltGr just bypasses ibus.
> It is more likely ibus rather than ibus-m17n which causes the
> difference.

OK.

> Which target application are you testing on?

My goal is to make multilingual documents with Emacs/Latex/Xetex with
source in utf-8, but for now I am testing in Gedit.

> Perhaps the key snooper change might affect the behavior:
> https://github.com/ibus/ibus/commit/9ae13a3d

Case 4-c applies to me then?:

$ set | grep -i ibus
CLUTTER_IM_MODULE=ibus
GTK_IM_MODULE=ibus
QT4_IM_MODULE=ibus
XMODIFIERS=@im=ibus


$ IBUS_SNOOPER_APPS=gedit gedit &
No difference.


$ IBUS_DISABLE_SNOOPER="1" gedit &
No difference.


>
>> > This also suggests that AltGr should work, at least upstream, see bug
>> > BZ#652201:
>> >
https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Enterprise_Linux/6/html/6.1_Technical_Notes/ibus-m17n.html
> I'm the one who worked on the bug.  As far as I remember, RHEL6
> ibus-m17n simply assumes that AltGr is mapped to Mod5.  So, the
> assumption might not be true on Norwegian keyboard.

If xkb is what defines my AltGr in an ibus relevant way:

My default layout is in /usr/share/X11/xkb/symbols/no:

partial default alphanumeric_keys
xkb_symbols "basic" {


 [snip]

    include "nbsp(level3n)"
    include "keypad(ossmath)"
    include "kpdl(comma)"

    include "level3(ralt_switch)"
};


and /usr/share/X11/xkb/symbols/level3 contains:

default partial modifier_keys
xkb_symbols "ralt_switch" {
  key <RALT> {
    type[Group1]="ONE_LEVEL",
    symbols[Group1] = [ ISO_Level3_Shift ]
    };
  modifier_map Mod5   { ISO_Level3_Shift };
};

---

xev gives for AltGr:

KeyPress event, serial 37, synthetic NO, window 0x5200001,
    root 0xae, subw 0x0, time 182617031, (920,172), root:(922,295),
    state 0x0, keycode 108 (keysym 0xfe03, ISO_Level3_Shift),
same_screen YES,
    XKeysymToKeycode returns keycode: 92
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

---

se, dk, fi de, fr, es, it... also use "level3(ralt_switch)".

> Unfortunately there is no reliable mechanism to map such a virtual
> modifier to physical modifer in IBus and the upstream does not want IME
> to depend on X11.
>  I'll consider again if this would be really useful.

1)
>From a phonetic viewpoint using more modifiers makes sense, I think. In
Hindi fx, many sounds vary orthogonally along at least 2 "dimensions" in
a systematic fashion, dimensions that are hardly represented in the
latin alphabet at all.

You have for example 4 d sounds.
Make Shift mean "aspirated" and unshifted mean "unaspirated".
AltGr could mean "further back in the mouth", typically retroflex or
glottal.
Then the d key could represent Hindi's 4 d sounds:

द = d
ध = Shift d (aspirated d)
ड = AltGr d (retroflex d)
ढ = Shift AltGr d (aspirated retroflex d)

Similarly for t, k, n, l.
Analogously for i, u, æ (or e), å, for other reasons though.

Other languages may have other orthogonal "dimensions" that could be
useful to combine in a similar fashion.

And then there are some Hindi sounds that more or less correspond to
Norwegian ones (å/Å, æ/Æ) that would be nice to map. (That's not
directly AltGr relevant, but I haven't figured out how to map Æ, Ø and Å
yet. If Shift cannot be used, why not use AltGr instead?)

But that was perhaps not what you meant by useful...?

Can such orthogonal combination be done just as easily with
pre-/post-composition?
Or maybe I should use a different input mechanism?

2)
Anyway, if AltGr cannot be used and you cannot remap
<Shift>-non-ascii-letter, things get rather cramped.
And although things would work, the user experience for a non-technical
user is bad: I must either change the mim file for the symbols in the
American layout that I access with AltGr in my layout (i.e. change to
use some other symbols/letters), or I must use the American layout and
many symbols will be located elsewhere than the signs on my keyboard show.


Best regards
Tore