@Override
public void start() {
assert predicateResult != Boolean.FALSE;
assert !finished;
if (event.hasInstantListener(expression)) {
if (listener instanceof LocationEvaluation)
predicateChain = ((LocationEvaluation) listener).predicateChain;
else predicateChain = 0;
if (predicateEvaluation != null) predicateChain++;
}
if (predicateEvaluation != null) {
Expression predicate = predicateEvaluation.expression;
if (predicate.scope() != Scope.DOCUMENT) predicateEvaluation.start();
}
eventID.addListener(event, currentStep, this);
}
@Override
public void onHit(EventID eventID) {
assert !finished : "getting events even after finish";
final LocationExpression expression = this.expression;
if (!lastStep) {
if (eventID.isEmpty(expression.locationPath.steps[index + 1].axis)) return;
}
final Event event = this.event;
if (positionTracker != null) {
event.positionTrackerStack.addFirst(positionTracker);
positionTracker.addEvaluation(event);
}
LinkableEvaluation childEval = null;
Expression predicate = currentStep.predicateSet.getPredicate();
Object predicateResult = predicate == null ? Boolean.TRUE : event.evaluate(predicate);
if (predicateResult == Boolean.TRUE) {
if (lastStep) consume(event);
else childEval = new LocationEvaluation(expression, index + 1, event, eventID);
} else if (predicateResult == null) {
Evaluation predicateEvaluation = event.evaluation;
if (lastStep) {
childEval =
new PredicateEvaluation(
expression,
event.order(),
expression.getResultItem(event),
event,
predicate,
predicateEvaluation);
if (nodeSetListener != null) nodeSetListener.mayHit();
} else
childEval =
new LocationEvaluation(
expression, index + 1, event, eventID, predicate, predicateEvaluation);
}
if (childEval != null) {
if (childEval instanceof LocationEvaluation)
((LocationEvaluation) childEval).nodeSetListener = nodeSetListener;
else ((PredicateEvaluation) childEval).nodeSetListener = nodeSetListener;
childEval.addListener(this);
if (pendingEvaluationTail != null) {
pendingEvaluationTail.next = childEval;
childEval.previous = pendingEvaluationTail;
pendingEvaluationTail = childEval;
} else pendingEvaluationHead = pendingEvaluationTail = childEval;
childEval.start();
}
if (positionTracker != null) {
positionTracker.startEvaluation();
event.positionTrackerStack.pollFirst();
}
if (exactPosition && predicateResult == Boolean.TRUE) {
manuallyExpired = true;
expired();
}
}