Keyboard and mouse are remotes too: Customizing controls

I use wireless numpad and wireless trackball to control Kodi, but unlike VLC, it seems difficult to assign buttons/keys to concrete functions.

For example, I’ve tried to create a file as ~/.kodi/userdata/keymaps/mouse.xml with this content (replace “[” by “<”) with no effect:

[keymap]
[FullscreenVideo]
[mouse]
[wheelup]VolumeUp[/wheelup]
[wheeldown]VolumeDown[/wheeldown]
[/mouse]
[/FullscreenVideo]
[/keymap]

Where can I find solid documentation about this?

Start searching here

This mouse.xml file I described is consistent with that documentation, but it doesn’t work.
I’ve tried “Keymap editor” plugin, but it’s not useful for mouse.