Added --help in ibus tool.

Add --help in ibus tool.


TEST=Linux desktop

[Peng, 2012-03-21 13:02:20]

Also think this CL could be split into two. we could submit i18n related change
first.

https://codereview.appspot.com/5868046/diff/1/tools/main.vala
File tools/main.vala (right):

https://codereview.appspot.com/5868046/diff/1/tools/main.vala#newcode132
tools/main.vala:132: { "engine", 'e', OptionFlags.OPTIONAL_ARG,
OptionArg.CALLBACK,
Looks like it will change current argument pattern. I think it is better to keep
origin one.

[fujiwara, 2012-03-22 06:33:32]

On 2012/03/21 13:02:20, Peng wrote:
> Also think this CL could be split into two. we could submit i18n related
change
> first.
> 
> https://codereview.appspot.com/5868046/diff/1/tools/main.vala
> File tools/main.vala (right):
> 
> https://codereview.appspot.com/5868046/diff/1/tools/main.vala#newcode132
> tools/main.vala:132: { "engine", 'e', OptionFlags.OPTIONAL_ARG,
> OptionArg.CALLBACK,
> Looks like it will change current argument pattern. I think it is better to
keep
> origin one.

If we don't have '--engine', '--help' does not list the sub command, does it?
It seems '--' is hard-codded in goption.c

If we would have a common option likes '--get engine', '--get list-engine',
GOptionEntry.description would explain all the sub commands?
e.g.
Application Options:
  -g, --get=SUB_COMMAND     Get SUB_COMMAND which is one of engine, list-engine,
name-only.
  -r  --run=SUB_COMMAND

I'm not sure if no '--' is useful.
My main purpose is that '--help' lists the available options.

[Peng, 2012-03-22 14:21:13]

On 2012/03/22 06:33:32, fujiwara wrote:
> On 2012/03/21 13:02:20, Peng wrote:
> > Also think this CL could be split into two. we could submit i18n related
> change
> > first.
> > 
> > https://codereview.appspot.com/5868046/diff/1/tools/main.vala
> > File tools/main.vala (right):
> > 
> > https://codereview.appspot.com/5868046/diff/1/tools/main.vala#newcode132
> > tools/main.vala:132: { "engine", 'e', OptionFlags.OPTIONAL_ARG,
> > OptionArg.CALLBACK,
> > Looks like it will change current argument pattern. I think it is better to
> keep
> > origin one.
> 
> If we don't have '--engine', '--help' does not list the sub command, does it?
> It seems '--' is hard-codded in goption.c
> 
> If we would have a common option likes '--get engine', '--get list-engine',
> GOptionEntry.description would explain all the sub commands?
> e.g.
> Application Options:
>   -g, --get=SUB_COMMAND     Get SUB_COMMAND which is one of engine,
list-engine,
> name-only.
>   -r  --run=SUB_COMMAND
> 
> I'm not sure if no '--' is useful.
> My main purpose is that '--help' lists the available options.

I think the mixing all sub commands help together is not clear. I prefer to git
style sub command. And it is also easy for bash-completion. You may check
completion script in ibus/tools/ibus.bash.

[Peng, 2012-03-23 02:15:24]

lgtm