/**
* Given an element in this list, check if the weight has changed (since the element was added to
* the graph or was last validated, whichever is more recent), and if so, change the current
* mapping of a weight to the element or remove the element from the set of unweighted elements.
*
* @param element The graph element.
* @return True if the weight associated with the element has changed as determined by the equals
* method.
*/
public boolean changeWeight(Element element) {
boolean weightValueHasChanged = false;
boolean found = false;
Object newWeight = element.hasWeight() ? element.getWeight() : null;
if (_unweightedSet.contains(element)) {
weightValueHasChanged = (newWeight != null);
if (weightValueHasChanged) {
_unweightedSet.remove(element);
registerWeight(element);
}
} else {
// Find the weight that was previously associated with this
// element, if there was one.
Iterator weights = _weightMap.keySet().iterator();
Object nextWeight = null;
List nextList = null;
while (weights.hasNext() && !found) {
nextWeight = weights.next();
nextList = (List) _weightMap.get(nextWeight);
found = nextList.contains(element);
}
if (found) {
// Note that the weight can change without the weight
// comparison here changing (if the change does not affect
// comparison under the equals method).
weightValueHasChanged = !nextWeight.equals(newWeight);
if (weightValueHasChanged) {
nextList.remove(element);
if (nextList.size() == 0) {
_weightMap.remove(nextWeight);
}
registerWeight(element);
}
} else {
// FIXME: use an internal error exception here.
throw new RuntimeException(
"Internal error: the specified "
+ _descriptor
+ " is neither unweighted nor associated "
+ "with a weight."
+ GraphException.elementDump(element, _graph));
}
}
return weightValueHasChanged;
}
public void startElement(String uri, String localName, String name, Attributes attributes)
throws SAXException {
if (name.equals("graph")) {
System.out.println("Creating graph " + attributes.getValue("name"));
graphContener = new GraphContener(attributes.getValue("name"));
graphContener.setFilePath(filePath);
} else if (name.equals("v")) {
try {
graphContener.addVertex(attributes.getValue("id"));
} catch (GraphException e) {
e.printStackTrace();
}
} else if (name.equals("e")) {
try {
graphContener.addEdge(
graphContener.getVertex(attributes.getValue("from")),
graphContener.getVertex(attributes.getValue("to")));
} catch (GraphException e) {
e.printStackTrace();
}
} else if (name.equals("coord")) {
try {
graphContener.setHasCoordinates(true);
graphContener
.getVertex(attributes.getValue("id"))
.setX(Integer.parseInt(attributes.getValue("x")));
graphContener
.getVertex(attributes.getValue("id"))
.setY(Integer.parseInt(attributes.getValue("y")));
} catch (Exception e) {
e.printStackTrace();
}
} else {
System.out.println("Unknown tag : " + name);
}
}
