com.google.common.css.compiler.ast.SkippingTreeVisitor Maven / Gradle / Ivy
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Show all versions of closure-stylesheets Show documentation
Show all versions of closure-stylesheets Show documentation
Closure Stylesheets is an extension to CSS that adds variables,
functions,
conditionals, and mixins to standard CSS. The tool also supports
minification, linting, RTL flipping, and CSS class renaming.
/*
* 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.ast;
import com.google.common.collect.ImmutableSet;
import java.util.Set;
/**
* Any compiler pass which derives from this is able to skip
* processing rules that contain specific property names.
*
* TODO(user): Should we move these functions to the DefaultVisitController?
*
*/
public class SkippingTreeVisitor extends DefaultTreeVisitor {
private boolean skipping = false;
/**
* The rules which contain any of these property names will be skipped,
* if skipping is set to true.
*/
Set propertyNamesToSkip = ImmutableSet.of("display");
// TODO(user): Possible more needed property names (which can trigger
// hasLayout in IE): zoom, position, float
/**
* Constructor of a skipping tree visitor which sets the skipping property.
* @param skip
*/
public SkippingTreeVisitor(boolean skip) {
skipping = skip;
}
/**
* This method checks if the given ruleset is safe to be changed.
* @return {@code false} if the ruleset is not safe to be modified (because
* it contains any of the pre-defined property names when skipping is turned
* on), true otherwise.
*/
public boolean canModifyRuleset(CssRulesetNode ruleset) {
// If skipping is on and the rule contains a property from the set : skip.
if (skipping) {
for (String propNameToSkip : propertyNamesToSkip) {
for (CssNode child : ruleset.getDeclarations().childIterable()) {
if (!(child instanceof CssDeclarationNode)) {
continue;
}
CssDeclarationNode decl = (CssDeclarationNode) child;
if (decl.getPropertyName().getPropertyName().equals(propNameToSkip)) {
return false;
}
}
}
}
return true;
}
public boolean isSkipping() {
return skipping;
}
}