KeyboardEvent.key implementation has been updated for the latest DOM3 Events spec, and key values have been changed accordingly. For example,
" " while
"+". Also, printable, generic keys now return the actual characters instead of
"MozPrintableKey". Read the document for details.
Note that the legacy
KeyboardEvent.which properties are deprecated, and developers should consider using
KeyboardEvent.key once the spec and implementation become stable.