* This class handles the following scenarios: *
* These all involve a unary operation with one element type, or a binary * operation with two elements. These are very simple and can be checked * in a simple way without a DFA and without the overhead of setting up a * DFA for such a simple check. * */ public class SimpleContentModel implements ContentModelValidator { // // Constants // /** CHOICE */ public static final short CHOICE = -1; /** SEQUENCE */ public static final short SEQUENCE = -1; // // Data // /** * The element decl pool indices of the first (and optional second) * child node. The operation code tells us whether the second child * is used or not. */ private QName fFirstChild = new QName(); /** * The element decl pool indices of the first (and optional second) * child node. The operation code tells us whether the second child * is used or not. */ private QName fSecondChild = new QName(); /** * The operation that this object represents. Since this class only * does simple contents, there is only ever a single operation * involved (i.e. the children of the operation are always one or * two leafs.) This is one of the XMLDTDParams.CONTENTSPECNODE_XXX values. */ private int fOperator; /* this is the EquivClassComparator object */ //private EquivClassComparator comparator = null; // // Constructors // /** * Constructs a simple content model. * * @param operator The content model operator. * @param firstChild The first child index. * @param secondChild The second child index. * @param dtd if it is for a DTDGrammar. * */ public SimpleContentModel(short operator, QName firstChild, QName secondChild) { // // Store away the children and operation. This is all we need to // do the content model check. // // The operation is one of the ContentSpecNode.NODE_XXX values! // fFirstChild.setValues(firstChild); if (secondChild != null) { fSecondChild.setValues(secondChild); } else { fSecondChild.clear(); } fOperator = operator; } // // ContentModelValidator methods // /** * Check that the specified content is valid according to this * content model. This method can also be called to do 'what if' * testing of content models just to see if they would be valid. *
* A value of -1 in the children array indicates a PCDATA node. All other
* indexes will be positive and represent child elements. The count can be
* zero, since some elements have the EMPTY content model and that must be
* confirmed.
*
* @param children The children of this element. Each integer is an index within
* the StringPool of the child element name. An index
* of -1 is used to indicate an occurrence of non-whitespace character
* data.
* @param offset Offset into the array where the children starts.
* @param length The number of entries in the children array.
*
* @return The value -1 if fully valid, else the 0 based index of the child
* that first failed. If the value returned is equal to the number
* of children, then the specified children are valid but additional
* content is required to reach a valid ending state.
*
*/
public int validate(QName[] children, int offset, int length) {
//
// According to the type of operation, we do the correct type of
// content check.
//
switch(fOperator)
{
case XMLContentSpec.CONTENTSPECNODE_LEAF :
// If there is not a child, then report an error at index 0
if (length == 0)
return 0;
// If the 0th child is not the right kind, report an error at 0
if (children[offset].rawname != fFirstChild.rawname) {
return 0;
}
// If more than one child, report an error at index 1
if (length > 1)
return 1;
break;
case XMLContentSpec.CONTENTSPECNODE_ZERO_OR_ONE :
//
// If there is one child, make sure its the right type. If not,
// then its an error at index 0.
//
if (length == 1) {
if (children[offset].rawname != fFirstChild.rawname) {
return 0;
}
}
//
// If the child count is greater than one, then obviously
// bad, so report an error at index 1.
//
if (length > 1)
return 1;
break;
case XMLContentSpec.CONTENTSPECNODE_ZERO_OR_MORE :
//
// If the child count is zero, that's fine. If its more than
// zero, then make sure that all children are of the element
// type that we stored. If not, report the index of the first
// failed one.
//
if (length > 0)
{
for (int index = 0; index < length; index++) {
if (children[offset + index].rawname != fFirstChild.rawname) {
return index;
}
}
}
break;
case XMLContentSpec.CONTENTSPECNODE_ONE_OR_MORE :
//
// If the child count is zero, that's an error so report
// an error at index 0.
//
if (length == 0)
return 0;
//
// Otherwise we have to check them all to make sure that they
// are of the correct child type. If not, then report the index
// of the first one that is not.
//
for (int index = 0; index < length; index++) {
if (children[offset + index].rawname != fFirstChild.rawname) {
return index;
}
}
break;
case XMLContentSpec.CONTENTSPECNODE_CHOICE :
//
// There must be one and only one child, so if the element count
// is zero, return an error at index 0.
//
if (length == 0)
return 0;
// If the zeroth element isn't one of our choices, error at 0
if ((children[offset].rawname != fFirstChild.rawname) &&
(children[offset].rawname != fSecondChild.rawname)) {
return 0;
}
// If there is more than one element, then an error at 1
if (length > 1)
return 1;
break;
case XMLContentSpec.CONTENTSPECNODE_SEQ :
//
// There must be two children and they must be the two values
// we stored, in the stored order.
//
if (length == 2) {
if (children[offset].rawname != fFirstChild.rawname) {
return 0;
}
if (children[offset + 1].rawname != fSecondChild.rawname) {
return 1;
}
}
else {
if (length > 2) {
return 2;
}
return length;
}
break;
default :
throw new RuntimeException("ImplementationMessages.VAL_CST");
}
// We survived, so return success status
return -1;
} // validate
} // class SimpleContentModel