It was just an example, it's useless.
What do you mind by "remove hook" ? Is this linked to the fact that I had to manage manually widgets' focus (in the previous version of SFGUI donwloaded before this update) because I don't use container ?
Hooking was a mechanism used internally to make sure some widgets got high priority access to certain events. It bypassed most of the hierarchical event passing and was therefore removed to clean up the library a bit.
In principle all widgets were designed to be used within some sort of container be it a window or box etc. Adding your widgets to your application one by one without use of a root container isn't recommended because as you mentioned focus changing won't get handled properly, among other things. Please try to use windows as much as you can or if you don't want a window then a box as the root widget.
Wow an update!
I can configure e generate build files, but I obtain some annoying warnings, that don't allow me to build the library (with a lot of errors)
WARNING: Target "Box" requests linking to directory "C:/sfml/sfml2". Targets may link only to libraries. CMake is dropping the item.
WARNING: Target "Button" requests linking to directory "C:/sfml/sfml2". Targets may link only to libraries. CMake is dropping the item.
WARNING: Target "Entry" requests linking to directory "C:/sfml/sfml2". Targets may link only to libraries. CMake is dropping the item.
...
It seems like you set your SFML library file paths wrong. Instead of "C:/sfml/sfml2" you should set it to something like "C:/sfml/sfml2/lib/libsfml-window-s.a" for example (if you are using GCC). Note that it is a
FILE PATH and not a
DIRECTORY PATH. You have to give CMake the right path for each of the library files it needs. Hope this helps.