the hook_focus is triggered only if there's already a bind
for example the buflist already have a mouse bind so
/trigger add buflist_click focus buflist "" "" "/print -core clicked on buflist item"
then click on the buflist, the message is print
the time item in the status bar doesn't have any bind by default so
/trigger add time_click focus time "" "" "/print -core clicked on time item"
doesn't print anything
but create a bind
/key bindctxt mouse @item(time):button1 /print -core hello
then click on the item and now "clicked on time item" is printed