[immodule-qt] introducing QT_IM_SWITCHER environment variable

[YamaKen]

Hi Takumi,

At Mon, 09 Aug 2004 15:23:05 +0900,
yamaken at bp.iij4u.or.jp wrote:
> At Fri, 6 Aug 2004 23:48:45 +0900,
> takumi at asaki.jp wrote:

> To satisfy these contradictive two requirements, I suggest
> following new scheme.
> 
> - Introduce 'imsw-none' switcher plugin
> 
> - 'imsw-none' reads QT_IM_MODULE or the equivalent of qtrc, and
>   create the specified input context using
>   QInputContextFactory
> 
> - Once the input context has been created, imsw-none does
>   nothing further. It only participates with instantiation
>   rather than proxing QInputContext like QMultiInputContext
> 
> The imsw-none isolates IM-switcher issues from libqt, and it's
> benefical for developers as I said in the 'pluggable
> IM-switcher' opinion. For example, input method developers may
> be agreed with introducing generic environment variable to
> specify default input method regardless of GUI-toolkits such as
> IM_MODULE. We can easily follow the new convention without
> updating libqt itself if imsw-none is adopted. Only updating
> imsw-none plugin is required.

I've implemented imsw-none as described above. See r66 of the
trunk. Now we can disable IM-switcher by following
configuration.

setenv QT_IM_SWITCHER imsw-none
setenv QT_IM_MODULE xim

> Although user and developer requirements can almost be satisfied
> with above scheme, a little compromise is required.
> 
> Although the variables are configured as follows,
> 
> setenv QT_IM_SWITCHER imsw-none
> setenv QT_IM_MODULE xim
> 
> Following configuration is still also valid and works properly.
> 
> setenv QT_IM_SWITCHER xim
> 
> It confuses ordinary users. Although ordinary users will not
> imagine such configuration, weird users will favor such
> configuration and publish their configuration memo to the
> world. It will confuse victims that googled with 'QT_IM_MODULE'.
> 
> To prevent such unwanted happening, we should restrict the
> plugins that can be specified by QT_IM_SWITCHER as real
> IM-switchers. It can be actualized by checking whether the
> specified plugin has the 'imsw-' prefix.

Above restriction is also implemented. See r67 of the
trunk. This restriction has changed the configuration convention
for system integrators as follows.

- valid configuration

  setenv QT_IM_SWITCHER imsw-none
  setenv QT_IM_MODULE iiimqcf

- following configuration has become invalid

  setenv QT_IM_SWITCHER iiimqcf

> > But there is one problem, If delete qtrc support.
> > How can I get list of InputMethods I can set to QT_IM_* env?
> 
> I can't imagine good solution. Any ideas?
> 
> Generate the list and save it into a file such as
> 'inputmethods.dir' may be sufficient. But when should we execute
> it? What should executes it?

I still have no idea about it. But I've brought a incomplete
solution. The filename of input method plugins are renamed as
following simple form. You can get a identifier name of the
input method by stripping 'libq' prefix from the filename.

$ ls $QTDIR/lib/plugins/input
libqimsw-multi.so
libqimsw-none.so
libqsimple.so
libqxim.so

The simple naming convention rather than long
'qfooinputcontextplugin.so' style name is preferable for Qt
plugin. See following result.

$ grep -h TARGET immqt/immodule-qt-x11/trunk/plugins/src/*/*/*.pro

Although the naming convention provides identifier name of the
input methods, this is not a solution for some input method
plugin that contains multiple input methods such as uim.

-------------------------------
YamaKen  yamaken at bp.iij4u.or.jp