/* * Copyright 2010, 2011, 2012 mapsforge.org * * This program is free software: you can redistribute it and/or modify it under the * terms of the GNU Lesser General Public License as published by the Free Software * Foundation, either version 3 of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but WITHOUT ANY * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License along with * this program. If not, see <http://www.gnu.org/licenses/>. */ package org.mapsforge.android.maps.rendertheme; import java.util.Stack; import java.util.logging.Logger; final class RuleOptimizer { private static final Logger LOGGER = Logger.getLogger(RuleOptimizer.class.getName()); private static AttributeMatcher optimizeKeyMatcher(AttributeMatcher attributeMatcher, Stack<Rule> ruleStack) { for (int i = 0, n = ruleStack.size(); i < n; ++i) { if (ruleStack.get(i) instanceof PositiveRule) { PositiveRule positiveRule = (PositiveRule) ruleStack.get(i); if (positiveRule.keyMatcher.isCoveredBy(attributeMatcher)) { return AnyMatcher.getInstance(); } } } return attributeMatcher; } private static AttributeMatcher optimizeValueMatcher(AttributeMatcher attributeMatcher, Stack<Rule> ruleStack) { for (int i = 0, n = ruleStack.size(); i < n; ++i) { if (ruleStack.get(i) instanceof PositiveRule) { PositiveRule positiveRule = (PositiveRule) ruleStack.get(i); if (positiveRule.valueMatcher.isCoveredBy(attributeMatcher)) { return AnyMatcher.getInstance(); } } } return attributeMatcher; } static AttributeMatcher optimize(AttributeMatcher attributeMatcher, Stack<Rule> ruleStack) { if (attributeMatcher instanceof AnyMatcher || attributeMatcher instanceof NegativeMatcher) { return attributeMatcher; } else if (attributeMatcher instanceof SingleKeyMatcher) { return optimizeKeyMatcher(attributeMatcher, ruleStack); } else if (attributeMatcher instanceof SingleValueMatcher) { return optimizeValueMatcher(attributeMatcher, ruleStack); } else if (attributeMatcher instanceof MultiKeyMatcher) { return optimizeKeyMatcher(attributeMatcher, ruleStack); } else if (attributeMatcher instanceof MultiValueMatcher) { return optimizeValueMatcher(attributeMatcher, ruleStack); } throw new IllegalArgumentException("unknown AttributeMatcher: " + attributeMatcher); } static ClosedMatcher optimize(ClosedMatcher closedMatcher, Stack<Rule> ruleStack) { if (closedMatcher instanceof AnyMatcher) { return closedMatcher; } for (int i = 0, n = ruleStack.size(); i < n; ++i) { if (ruleStack.get(i).closedMatcher.isCoveredBy(closedMatcher)) { return AnyMatcher.getInstance(); } else if (!closedMatcher.isCoveredBy(ruleStack.get(i).closedMatcher)) { LOGGER.warning("unreachable rule (closed)"); } } return closedMatcher; } static ElementMatcher optimize(ElementMatcher elementMatcher, Stack<Rule> ruleStack) { if (elementMatcher instanceof AnyMatcher) { return elementMatcher; } for (int i = 0, n = ruleStack.size(); i < n; ++i) { if (ruleStack.get(i).elementMatcher.isCoveredBy(elementMatcher)) { return AnyMatcher.getInstance(); } else if (!elementMatcher.isCoveredBy(ruleStack.get(i).elementMatcher)) { LOGGER.warning("unreachable rule (e)"); } } return elementMatcher; } /** * Private constructor to prevent instantiation from other classes. */ private RuleOptimizer() { // do nothing } }