com.gargoylesoftware.css.parser.selector.SelectorSpecificity Maven / Gradle / Ivy
/*
* Copyright (c) 2018 Ronald Brill.
*
* 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.gargoylesoftware.css.parser.selector;
import java.io.Serializable;
import com.gargoylesoftware.css.parser.condition.AttributeCondition;
import com.gargoylesoftware.css.parser.condition.BeginHyphenAttributeCondition;
import com.gargoylesoftware.css.parser.condition.Condition;
import com.gargoylesoftware.css.parser.condition.OneOfAttributeCondition;
import com.gargoylesoftware.css.parser.condition.PrefixAttributeCondition;
import com.gargoylesoftware.css.parser.condition.SubstringAttributeCondition;
import com.gargoylesoftware.css.parser.condition.SuffixAttributeCondition;
/**
* Calculates a selector's specificity.
* @see W3C CSS21
*
* @author Marc Guillemot
* @author Ronald Brill
*/
public class SelectorSpecificity implements Comparable, Serializable {
/**
* The specificity for declarations made in the style attributes of an element.
*/
public static final SelectorSpecificity FROM_STYLE_ATTRIBUTE = new SelectorSpecificity(1, 0, 0, 0);
/**
* The specificity for browser defaults.
*/
public static final SelectorSpecificity DEFAULT_STYLE_ATTRIBUTE = new SelectorSpecificity(0, 0, 0, 0);
private int fieldA_;
private int fieldB_;
private int fieldC_;
private int fieldD_;
/**
* Ctor.
* @param selector the selector to read from
*/
public SelectorSpecificity(final Selector selector) {
readSelectorSpecificity(selector);
}
private SelectorSpecificity(final int a, final int b, final int c, final int d) {
fieldA_ = a;
fieldB_ = b;
fieldC_ = c;
fieldD_ = d;
}
private void readSelectorSpecificity(final Selector selector) {
switch (selector.getSelectorType()) {
case DESCENDANT_SELECTOR:
final DescendantSelector ds = (DescendantSelector) selector;
readSelectorSpecificity(ds.getAncestorSelector());
readSelectorSpecificity(ds.getSimpleSelector());
return;
case CHILD_SELECTOR:
final ChildSelector cs = (ChildSelector) selector;
readSelectorSpecificity(cs.getAncestorSelector());
readSelectorSpecificity(cs.getSimpleSelector());
return;
case ELEMENT_NODE_SELECTOR:
final ElementSelector es = (ElementSelector) selector;
if (es.getLocalName() != null) {
fieldD_++;
}
if (es.getConditions() != null) {
for (Condition condition : es.getConditions()) {
readSelectorSpecificity(condition);
}
}
return;
case PSEUDO_ELEMENT_SELECTOR:
final PseudoElementSelector pes = (PseudoElementSelector) selector;
final String pesName = pes.getLocalName();
if (pesName != null) {
fieldD_++;
}
return;
case DIRECT_ADJACENT_SELECTOR:
final DirectAdjacentSelector das = (DirectAdjacentSelector) selector;
readSelectorSpecificity(das.getSelector());
readSelectorSpecificity(das.getSimpleSelector());
return;
case GENERAL_ADJACENT_SELECTOR:
final GeneralAdjacentSelector gas = (GeneralAdjacentSelector) selector;
readSelectorSpecificity(gas.getSelector());
readSelectorSpecificity(gas.getSimpleSelector());
return;
default:
throw new RuntimeException("Unhandled CSS selector type for specificity computation: '"
+ selector.getSelectorType() + "'.");
}
}
private void readSelectorSpecificity(final Condition condition) {
switch (condition.getConditionType()) {
case ID_CONDITION:
fieldB_++;
return;
case CLASS_CONDITION:
fieldC_++;
return;
case ATTRIBUTE_CONDITION:
if ("id".equalsIgnoreCase(((AttributeCondition) condition).getLocalName())) {
fieldB_++;
}
else {
fieldC_++;
}
return;
case SUBSTRING_ATTRIBUTE_CONDITION:
if ("id".equalsIgnoreCase(((SubstringAttributeCondition) condition).getLocalName())) {
fieldB_++;
}
else {
fieldC_++;
}
return;
case SUFFIX_ATTRIBUTE_CONDITION:
if ("id".equalsIgnoreCase(((SuffixAttributeCondition) condition).getLocalName())) {
fieldB_++;
}
else {
fieldC_++;
}
return;
case PREFIX_ATTRIBUTE_CONDITION:
if ("id".equalsIgnoreCase(((PrefixAttributeCondition) condition).getLocalName())) {
fieldB_++;
}
else {
fieldC_++;
}
return;
case BEGIN_HYPHEN_ATTRIBUTE_CONDITION:
if ("id".equalsIgnoreCase(((BeginHyphenAttributeCondition) condition).getLocalName())) {
fieldB_++;
}
else {
fieldC_++;
}
return;
case ONE_OF_ATTRIBUTE_CONDITION:
if ("id".equalsIgnoreCase(((OneOfAttributeCondition) condition).getLocalName())) {
fieldB_++;
}
else {
fieldC_++;
}
return;
case PSEUDO_CLASS_CONDITION:
fieldD_++;
return;
case LANG_CONDITION:
fieldC_++;
return;
default:
throw new RuntimeException("Unhandled CSS condition type for specifity computation: '"
+ condition.getConditionType() + "'.");
}
}
/**
* {@inheritDoc}
*/
@Override
public String toString() {
return fieldA_ + "," + fieldB_ + "," + fieldC_ + "," + fieldD_;
}
/**
* {@inheritDoc}
*/
@Override
public int compareTo(final SelectorSpecificity other) {
if (fieldA_ != other.fieldA_) {
return fieldA_ - other.fieldA_;
}
else if (fieldB_ != other.fieldB_) {
return fieldB_ - other.fieldB_;
}
else if (fieldC_ != other.fieldC_) {
return fieldC_ - other.fieldC_;
}
else if (fieldD_ != other.fieldD_) {
return fieldD_ - other.fieldD_;
}
return 0;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + fieldA_;
result = prime * result + fieldB_;
result = prime * result + fieldC_;
result = prime * result + fieldD_;
return result;
}
@Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final SelectorSpecificity other = (SelectorSpecificity) obj;
if (fieldA_ != other.fieldA_) {
return false;
}
if (fieldB_ != other.fieldB_) {
return false;
}
if (fieldC_ != other.fieldC_) {
return false;
}
if (fieldD_ != other.fieldD_) {
return false;
}
return true;
}
}