* This is not actually a canvas item itself to avoid the dreaded diamond
* inheritance pattern, since various types of canvas items (Note (rect), Hit
* (diamond), etc) need to share this functionality but can't share an
* This is not actually a canvas item itself to avoid the dreaded diamond
* inheritance pattern, since various types of canvas items (Note (rect), Hit
* (diamond), etc) need to share this functionality but can't share an