com.google.common.css.SplittingSubstitutionMap Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
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.

There is a newer version: 20160212

Show newest version

/*
 * 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;

import com.google.common.base.Preconditions;
import com.google.common.base.Splitter;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Maps;
import java.util.Map;

/**
 * The CSS class substitution map which splits CSS class names on the "-" (dash)
 * character and processes them separately using a delegate substitution map.
 *
 * @author [email protected] (Damian Gajda)
 */
public class SplittingSubstitutionMap implements
    MultipleMappingSubstitutionMap, SubstitutionMap.Initializable {
  private static final Splitter DASH = Splitter.on('-');
  private final SubstitutionMap delegate;

  public SplittingSubstitutionMap(SubstitutionMap substitutionMap) {
    this.delegate = substitutionMap;
  }

  @Override
  public void initializeWithMappings(Map newMappings) {
    if (!newMappings.isEmpty()) {
      ((SubstitutionMap.Initializable) delegate).initializeWithMappings(newMappings);
    }
  }

  @Override
  public String get(String key) {
    return getValueWithMappings(key).value;
  }

  @Override
  public ValueWithMappings getValueWithMappings(String key) {
    Preconditions.checkNotNull(key, "CSS key cannot be null");
    Preconditions.checkArgument(!key.isEmpty(), "CSS key cannot be empty");

    // Efficiently handle the common case with no dashes.
    if (key.indexOf('-') == -1) {
      String value = delegate.get(key);
      return ValueWithMappings.createForSingleMapping(key, value);
    }

    StringBuilder buffer = new StringBuilder();
    // Cannot use an ImmutableMap.Builder because the same key/value pair may be
    // inserted more than once in this loop.
    Map mappings = Maps.newLinkedHashMap();
    for (String part : DASH.split(key)) {
      if (buffer.length() != 0) {
        buffer.append('-');
      }

      String value = delegate.get(part);
      mappings.put(part, value);
      buffer.append(value);
    }

    String renamedClassComposedFromParts = buffer.toString();

    return ValueWithMappings.createWithValueAndMappings(
        renamedClassComposedFromParts,
        ImmutableMap.copyOf(mappings));
  }
}