Rather than imposing onclick, the map attribute whose value is returned
when retrieving a code is now a constructor argument
For the sake of backward compatibility, default is set to onclick
Signed-off-by: Pierre Mazière <pierre.maziere@gmail.com>
This method allows one to verify, before any decoding attempt,
if all the symbols given as arguments can be found in the
virtual keyboard.
Signed-off-by: Pierre Mazière <pierre.maziere@gmail.com>
