Re: Glib::get_system_data_dirs() returns no useful result

[Mateusz Marzantowicz <mmarzantowicz osdf com pl>]

17.04.2012 13:48, Krzesimir Nowak:
> 2012/4/17 Mateusz Marzantowicz <mmarzantowicz osdf com pl>:
>> Hello,
>>
>> I was trying to use Glib::get_system_data_dirs() function which is a
>> wrapper over GTK+ function: g_get_system_data_dirs().
>>
>> GTK+ function works as expected and returns correct results (paths), the
>> glibmm C++ version returns empty vector (size() method on this vector == 0).
>>
>> After fighting some time, I checked the source code of glibmm library
>> and I'm now confused. Below is an extract form file:
>> glib/glibmm/miscutils.cc, lines 124-139 :
>>
>> --- START CODE ---
>> std::vector<std::string> get_system_data_dirs()
>> {
>>  //TODO: Use a utility function:
>>  std::vector<std::string> result;
>>  const char* const * cresult = g_get_system_data_dirs();
>>  if(cresult)
>>    return result;
>>
>>  for(const gchar* const * iter = cresult; *iter != 0; ++iter)
>>  {
>>    result.push_back(
>>      convert_const_gchar_ptr_to_stdstring(*iter));
>>  }
>>
>>  return result;
>> }
>> --- END CODE ---
>>
>> Now it is clear to me why it is not working as expected. The first if
>> checks for cresult being not null but returns empty result which never
>> at that point would contain data from g_get_system_data_dirs().
>>
>> Because I'm new to GTK+ and gtkmm/glibmm, sorry if the answer is obvious
>> but why the hell is this code like this? Maybe this function should be
>> used in some special manner that I'm not aware of?
> Seemingly this function was not used so often that no one noticed it
> before or didn't bother to ask about it or file a bug. Just a classic
> case of typo + copypasta.
>
> Fixed in master:
> http://git.gnome.org/browse/glibmm/commit/?id=64b20b098dd24aeb6cea9b95ea861ddd58fde778
Wow! How quick, thanks a lot for this solution and commit.

You wrote that this function is not used very often, but I'm curious
what is the recommended way of finding path to XML file for use in
Gtk::UIManager::add_ui_from_file() method? I was trying to obtain path
to data directory (/usr/local/share/ in my case.) If
Glib::get_system_data_dirs() is not used by people, is there a better
way of doing this? I found that in some projects base on GTK+ they use
automake/autoconf flags that are passed in compile time as preprocessor
macro to source file, but is it really better approach?


Mateusz Marzantowicz