QT_PLUGIN_PATH (Re: Install kimgio plugins in the Qt image format plugins dir)

[Andreas Pakulat]

On 27.10.07 11:42:54, Brad Hards wrote:
> On Saturday 27 October 2007 09:26:43 am Andreas Pakulat wrote:
> > On 27.10.07 09:14:34, Brad Hards wrote:
> > > On Saturday 27 October 2007 02:51:41 am Thiago Macieira wrote:
> > > > - make it configurable via -D switch in the cmake command-line
> > > > - default to something inside ${CMAKE_INSTALL_PREFIX}
> > > > - print at the end of configure that you need to set QT_PLUGIN_PATH
> > > > - do not check Qt's plugin path, ever
> > >
> > > My concern is that this will cause breakage at run-time (when QCA can't
> > > find its plugins, it doesn't really do much), because people won't set
> > > the plugin path, or will change it to something else when they install
> > > kdelibs to a different prefix.
> >
> > How about a warning if QCA can't find _any_ plugin telling the user to
> > check what he has in his QT_PLUGIN_PATH?
> OK, but how? QCA has no GUI. 

Well, I don't know QCA, but an error signal sent in this case would come
to mind. Apps that use QCA can then connect to that signal and use it.

> > > Why do you think that we shouldn't expect people who build from source to
> > > be able to install it to the same place that they installed Qt?
> >
> > Because they might want to use their system Qt.
> And they can. If they also want to use QCA, they can either use their system 
> QCA, or they can install QCA to the default location (i.e. under the Qt 
> plugin directory), or if they don't have install privileges, they can install 
> to another location and set a magic environment variable.
> 
> The simplest thing for the user is to use system QCA. The next most easy is to 
> sudo the installation. Setting environment variables is the hardest.
> 
> I proposed a solution, which Thiago counterproposed an option without 
> explaining why my solution isn't OK.

Ok, I guess I didn't follow this closely enough, so I'll just shut up.

Ideally there'd be a make-time check for write-access to the qt plugin
path and if it doesn't exist print a message that QT_PLUGIN_PATH needs
to be set and install the plugins to cmake-prefix/lib/plugins/crypto/
(not sure if the hierarchy is completely right). But I think thats more
work than its worth, so a simple cmake variable to define the plugin
path would be good I think.

Andreas

-- 
Don't hate yourself in the morning -- sleep till noon.