Hi Enrico,
I guess that what i’ve done now is probably what you are looking for, change mouse theme when weston shows the “left_ptr” on the screen. (Note, that im using weston on wayland!!!)
What i’ve done is create a fully transparent left_ptr with xcursorgen, with basicly:
- Create a directory called transparent_cursor
- Create a fully transparent transparent_cursor.png inside this folder (i used photoshop) with size 32x32
- create a configuration file named transparent.cfg with the following content: 32 0 0 transparent_cursor.png
- Now call xcursorgen tool: xcursorgen transparent.cfg left_ptr , the new file left_ptr will be available now on the roots folder
- Copy left_ptr file to your active theme folder (ex: /usr/share/icons/hicolor/cursors/) (* if don’t have this cursors folder, create it by hand)
- Change your theme on weston configuration file (mine is at: /etc/xdg/weston/weston.ini) by change [shell] settings:
[shell]
locking=false
cursor-theme=hicolor
cursor-size=32
- Now restart weston, and your “mouse icon” should be “invisible” but the touch-events still work perfectly.
Hope that it helps 
Regards