| /* |
| * Copyright 2014 Google Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| * use this file except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations under |
| * the License. |
| */ |
| package com.google.gwt.resources.gss; |
| |
| import com.google.gwt.thirdparty.common.css.compiler.ast.CssBooleanExpressionNode; |
| import com.google.gwt.thirdparty.common.css.compiler.ast.CssBooleanExpressionNode.Type; |
| import com.google.gwt.thirdparty.common.css.compiler.ast.CssCompilerPass; |
| import com.google.gwt.thirdparty.common.css.compiler.ast.MutatingVisitController; |
| import com.google.gwt.thirdparty.guava.common.collect.ImmutableList; |
| |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Set; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| /** |
| * Visitor that collects the different permutation axis defined in a gss file. |
| */ |
| public class PermutationsCollector extends ExtendedConditionalNodeVisitor |
| implements CssCompilerPass { |
| static final Pattern IS_FUNCTION = |
| Pattern.compile("^is\\(([\"'])((?:(?!\\1).)*)\\1(?:,([\"'])((?:(?!\\3).)*)\\3)?\\)$"); |
| private static final String USER_AGENT_PERMUTATION = "user.agent"; |
| |
| private final MutatingVisitController delegate; |
| private final Set<String> permutationAxesSet; |
| |
| public PermutationsCollector(MutatingVisitController delegate) { |
| this.delegate = delegate; |
| permutationAxesSet = new HashSet<String>(); |
| } |
| |
| public void enterBooleanExpression(CssBooleanExpressionNode booleanExpressionNode) { |
| if (booleanExpressionNode.getType() == Type.CONSTANT && |
| booleanExpressionNode.getValue() != null) { |
| |
| Matcher m = IS_FUNCTION.matcher(booleanExpressionNode.getValue()); |
| |
| if (m.matches()) { |
| String permutationName = m.group(2); |
| String permutationValue = m.group(4); |
| |
| if (permutationValue == null) { |
| permutationValue = permutationName; |
| permutationName = USER_AGENT_PERMUTATION; |
| } |
| |
| booleanExpressionNode.setValue(permutationName + ":" + permutationValue); |
| |
| if (!permutationAxesSet.contains(permutationName)) { |
| permutationAxesSet.add(permutationName); |
| } |
| } |
| } |
| } |
| |
| public List<String> getPermutationAxes() { |
| return ImmutableList.copyOf(permutationAxesSet); |
| } |
| |
| @Override |
| public void runPass() { |
| delegate.startVisit(this); |
| } |
| } |