Add function ibus_bus_new_async to create a new IBusBus object and asynchronously connect to the IB…

Add function ibus_bus_new_async to create a new IBusBus object and asynchronously connect to the IBus daemon.


BUG=http://code.google.com/p/ibus/issues/detail?id=1452
TEST=Manually

[Peng, 2012-05-08 15:09:36]

https://codereview.appspot.com/6159047/diff/1/src/ibusbus.c
File src/ibusbus.c (right):

https://codereview.appspot.com/6159047/diff/1/src/ibusbus.c#newcode317
src/ibusbus.c:317: g_signal_emit (bus, bus_signals[DISCONNECTED], 0);
Is it necessary to fire a DISCONNECTED signal here?

[jason.conti, 2012-05-08 17:45:51]

On 2012/05/08 15:09:36, Peng wrote:
> https://codereview.appspot.com/6159047/diff/1/src/ibusbus.c
> File src/ibusbus.c (right):
> 
> https://codereview.appspot.com/6159047/diff/1/src/ibusbus.c#newcode317
> src/ibusbus.c:317: g_signal_emit (bus, bus_signals[DISCONNECTED], 0);
> Is it necessary to fire a DISCONNECTED signal here?

Not necessary.

With the synchronous version, as soon as ibus_bus_new returns, we can check
ibus_bus_is_connected to see if connecting to dbus failed. With
ibus_bus_new_async, we need to wait for the CONNECTED signal, which may never
arrive. I thought we should include a notification that connecting to dbus
failed, although a connect-failed signal or similar may be better than reusing
DISCONNECTED.

The line can be dropped and it will still work, it is only used in the
ibus-bus-async.c test to fail if we fail to connect to dbus.

[Peng, 2012-05-08 17:58:05]

On 2012/05/08 17:45:51, jason.conti wrote:
> On 2012/05/08 15:09:36, Peng wrote:
> > https://codereview.appspot.com/6159047/diff/1/src/ibusbus.c
> > File src/ibusbus.c (right):
> > 
> > https://codereview.appspot.com/6159047/diff/1/src/ibusbus.c#newcode317
> > src/ibusbus.c:317: g_signal_emit (bus, bus_signals[DISCONNECTED], 0);
> > Is it necessary to fire a DISCONNECTED signal here?
> 
> Not necessary.
> 
> With the synchronous version, as soon as ibus_bus_new returns, we can check
> ibus_bus_is_connected to see if connecting to dbus failed. With
> ibus_bus_new_async, we need to wait for the CONNECTED signal, which may never
> arrive. I thought we should include a notification that connecting to dbus
> failed, although a connect-failed signal or similar may be better than reusing
> DISCONNECTED.
> 
> The line can be dropped and it will still work, it is only used in the
> ibus-bus-async.c test to fail if we fail to connect to dbus.

I see. I would like to remove it for now. I will do it, and commit this CL for
you.