/*
* Copyright 2009 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.common.css.compiler.passes;
import com.google.common.css.compiler.ast.CssCompilerPass;
import com.google.common.css.compiler.ast.CssRulesetNode;
import com.google.common.css.compiler.ast.DefaultTreeVisitor;
import com.google.common.css.compiler.ast.MutatingVisitController;
/**
* A compiler pass that eliminates the empty ruleset nodes.
*
* @author oana@google.com (Oana Florescu)
*/
public class EliminateEmptyRulesetNodes extends DefaultTreeVisitor
implements CssCompilerPass {
private final MutatingVisitController visitController;
public EliminateEmptyRulesetNodes(MutatingVisitController visitController) {
this.visitController = visitController;
}
@Override
public boolean enterRuleset(CssRulesetNode node) {
if (node.getDeclarations().isEmpty()) {
visitController.removeCurrentNode();
return false;
}
return true;
}
@Override
public void runPass() {
visitController.startVisit(this);
}
}