public static boolean isSubElement(FormIndex parent, FormIndex child) {
while (!parent.isTerminal() && !child.isTerminal()) {
if (parent.getLocalIndex() != child.getLocalIndex()) {
return false;
}
if (parent.getInstanceIndex() != child.getInstanceIndex()) {
return false;
}
parent = parent.nextLevel;
child = child.nextLevel;
}
// If we've gotten this far, at least one of the two is terminal
if (!parent.isTerminal() && child.isTerminal()) {
// can't be the parent if the child is earlier on
return false;
} else if (parent.getLocalIndex() != child.getLocalIndex()) {
// Either they're at the same level, in which case only
// identical indices should match, or they should have
// the same root
return false;
} else if (parent.getInstanceIndex() != -1
&& (parent.getInstanceIndex() != child.getInstanceIndex())) {
return false;
}
// Barring all of these cases, it should be true.
return true;
}
/**
* Trims any negative indices from the end of the passed in index.
*
* @param index
* @return
*/
public static FormIndex trimNegativeIndices(FormIndex index) {
if (!index.isTerminal()) {
return new FormIndex(trimNegativeIndices(index.nextLevel), index);
} else {
if (index.getLocalIndex() < 0) {
return null;
} else {
return index;
}
}
}