/**
* With start inparam being the first significant token in a selector, build the selector group
* (aka comma separated selectors), expected return when iter.last is '{'. On error, issue to
* errorlistener, and return (caller will forward).
*
* @return A syntactically valid CssSelector list, or null if fail.
* @throws CssException
*/
private List<CssSelector> handleSelectors(
CssToken start, CssTokenIterator iter, CssErrorHandler err) throws CssException {
List<CssSelector> selectors = Lists.newArrayList();
boolean end = false;
while (true) { // comma loop
CssSelector selector = new CssSelector(start.location);
while (true) { // combinator loop
CssSimpleSelectorSequence seq =
CssSelectorConstructFactory.createSimpleSelectorSequence(start, iter, err);
if (seq == null) {
// errors already issued
return null;
}
selector.components.add(seq);
int idx = iter.index();
start = iter.next();
if (MATCH_OPENBRACE.apply(start)) {
end = true;
break;
}
if (MATCH_COMMA.apply(start)) {
break;
}
CssSelectorCombinator comb = CssSelectorConstructFactory.createCombinator(start, iter, err);
if (comb != null) {
selector.components.add(comb);
start = iter.next();
} else if (iter.list.get(idx + 1).type == CssToken.Type.S) {
selector.components.add(new CssSelectorCombinator(' ', start.location));
} else {
err.error(
new CssGrammarException(
GRAMMAR_UNEXPECTED_TOKEN, iter.last.location, iter.last.chars));
return null;
}
} // combinator loop
selectors.add(selector);
if (end) {
break;
}
if (debug) {
checkState(MATCH_COMMA.apply(start));
}
start = iter.next();
} // comma loop
return selectors;
}
/**
* With iter.last at '{', discover the at-rule type. The contents is a ruleset if '{' comes before
* ';' or '}'.
*/
private boolean hasRuleSet(CssAtRule atRule, CssTokenIterator iter) {
int debugIndex;
if (debug) {
checkArgument(iter.last.getChar() == '{');
debugIndex = iter.index();
}
List<CssToken> list = iter.list;
for (int i = iter.index() + 1; i < list.size(); i++) {
CssToken tk = list.get(i);
if (MATCH_OPENBRACE.apply(tk)) {
return true;
} else if (MATCH_SEMI_CLOSEBRACE.apply(tk)) {
return false;
}
}
if (debug) {
checkState(iter.last.getChar() == '{');
checkState(iter.index() == debugIndex);
}
return false;
}
/**
* With start token required to be an ATKEYWORD, collect at-rule parameters if any, and if the
* at-rule has a block, invoke those handlers.
*/
private void handleAtRule(
CssToken start, CssTokenIterator iter, CssContentHandler doc, CssErrorHandler err)
throws CssException {
if (debug) {
checkArgument(start.type == CssToken.Type.ATKEYWORD);
checkArgument(iter.index() == iter.list.indexOf(start));
checkArgument(iter.filter() == FILTER_S_CMNT);
}
CssAtRule atRule = new CssAtRule(start.getChars(), start.location);
CssToken tk;
try {
while (true) {
tk = iter.next();
if (MATCH_SEMI_OPENBRACE.apply(tk)) {
// ';' or '{', expected end
atRule.hasBlock = tk.getChar() == '{';
break;
} else {
CssConstruct param = handleAtRuleParam(tk, iter, doc, err);
if (param == null) {
// issue error, forward, then return
err.error(
new CssGrammarException(
GRAMMAR_UNEXPECTED_TOKEN, iter.last.location, iter.last.chars));
// skip to atrule closebrace, ignoring any inner blocks
int stack = 0;
while (true) {
CssToken tok = iter.next();
if (MATCH_SEMI.apply(tok) && stack == 0) {
return; // a non-block at rule
} else if (MATCH_OPENBRACE.apply(tok)) {
stack++;
} else if (MATCH_CLOSEBRACE.apply(tok)) {
if (stack == 1) {
break;
}
stack--;
}
}
return;
} else {
atRule.components.add(param);
}
}
}
} catch (NoSuchElementException nse) {
// UAs required to close any open constructs on premature EOF
doc.startAtRule(atRule);
err.error(
new CssGrammarException(
GRAMMAR_PREMATURE_EOF, iter.last.location, "';' " + Messages.get("or") + " '{'"));
doc.endAtRule(atRule.getName().get());
throw new PrematureEOFException();
}
if (debug) {
checkArgument(MATCH_SEMI_OPENBRACE.apply(iter.last));
checkArgument(iter.filter() == FILTER_S_CMNT);
}
// ending up here only on expected end
doc.startAtRule(atRule);
if (atRule.hasBlock) {
try {
if (hasRuleSet(atRule, iter)) {
while (!MATCH_CLOSEBRACE.apply(iter.next())) {
if (iter.last.type == CssToken.Type.ATKEYWORD) {
handleAtRule(iter.last, iter, doc, err);
} else {
handleRuleSet(iter.last, iter, doc, err);
}
}
} else {
handleDeclarationBlock(iter.next(), iter, doc, err);
}
} catch (NoSuchElementException nse) {
err.error(new CssGrammarException(GRAMMAR_PREMATURE_EOF, iter.last.location, "'}'"));
doc.endAtRule(atRule.name.get());
throw new PrematureEOFException();
}
}
doc.endAtRule(atRule.name.get());
}