toggle method
inherited
Adds the class value
to the element if it is not on it, removes it if it
is.
If shouldAdd
is true, then we always add that value
to the element. If
shouldAdd
is false then we always remove value
from the element.
Implementation
bool toggle(String value, [bool shouldAdd]) {
_validateToken(value);
Set<String> s = readClasses();
bool result = false;
if (shouldAdd == null) shouldAdd = !s.contains(value);
if (shouldAdd) {
s.add(value);
result = true;
} else {
s.remove(value);
}
writeClasses(s);
return result;
}