com.itextpdf.tool.xml.css.parser.CssSelectorParser Maven / Gradle / Ivy
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package com.itextpdf.tool.xml.css.parser;
import com.itextpdf.tool.xml.Tag;
import com.itextpdf.tool.xml.css.CssSelectorItem;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class CssSelectorParser {
private static final String selectorPatternString =
"(\\*)|([_a-zA-Z][\\w-]*)|(\\.[_a-zA-Z][\\w-]*)|(#[_a-z][\\w-]*)|(\\[[_a-zA-Z][\\w-]*(([~^$*|])?=((\"[\\w-]+\")|([\\w-]+)))?\\])|(:[\\w()-]*)|( )|(\\+)|(>)|(~)";
private static final Pattern selectorPattern = Pattern.compile(selectorPatternString);
private static final int a = 1 << 16;
private static final int b = 1 << 8;
private static final int c = 1;
public static List createCssSelector(String selector) {
List cssSelectorItems = new ArrayList();
Matcher itemMatcher = selectorPattern.matcher(selector);
boolean isTagSelector = false;
int crc = 0;
while(itemMatcher.find()) {
String selectorItem = itemMatcher.group(0);
crc += selectorItem.length();
switch (selectorItem.charAt(0)) {
case '#':
cssSelectorItems.add(new CssIdSelector(selectorItem.substring(1)));
break;
case '.':
cssSelectorItems.add(new CssClassSelector(selectorItem.substring(1)));
break;
case '[':
cssSelectorItems.add(new CssAttributeSelector(selectorItem));
break;
case ':':
cssSelectorItems.add(new CssPseudoSelector(selectorItem));
break;
case ' ':
case '+':
case '>':
case '~':
if (cssSelectorItems.size() == 0) return null;
CssSelectorItem lastItem = cssSelectorItems.get(cssSelectorItems.size() - 1);
CssSelectorItem currItem = new CssSeparatorSelector(selectorItem.charAt(0));
if (lastItem instanceof CssSeparatorSelector) {
if (selectorItem.charAt(0) == ' ')
break;
else if (lastItem.getSeparator() == ' ')
cssSelectorItems.set(cssSelectorItems.size() - 1, currItem);
else
return null;
} else {
cssSelectorItems.add(currItem);
isTagSelector = false;
}
break;
default: //and case '*':
if (isTagSelector)
return null;
isTagSelector = true;
cssSelectorItems.add(new CssTagSelector(selectorItem));
break;
}
}
if (selector.length() == 0 || selector.length() != crc)
return null;
return cssSelectorItems;
}
static class CssTagSelector implements CssSelectorItem {
private String t;
private boolean isUniversal;
CssTagSelector(String t) {
this.t = t;
isUniversal = this.t.equals("*") ? true : false;
}
public boolean matches(Tag t){
return isUniversal || this.t.equals(t.getName());
}
public char getSeparator() {
return 0;
}
public int getSpecificity() {
if (isUniversal) return 0;
return CssSelectorParser.c;
}
@Override
public String toString() {
return t;
}
}
static class CssClassSelector implements CssSelectorItem {
private String className;
CssClassSelector(String className) {
this.className = className;
}
public boolean matches(Tag t){
String classAttr = t.getAttributes().get("class");
if (classAttr == null || classAttr.length() == 0)
return false;
String[] classNames = classAttr.split(" ");
for (String currClassName: classNames)
if (this.className.equals(currClassName.trim()))
return true;
return false;
}
public char getSeparator() {
return 0;
}
public int getSpecificity() {
return CssSelectorParser.b;
}
@Override
public String toString() {
return "." + className;
}
}
static class CssIdSelector implements CssSelectorItem {
private String id;
CssIdSelector(String id) {
this.id = id;
}
public boolean matches(Tag t){
String id = t.getAttributes().get("id");
return id != null && this.id.equals(id.trim());
}
public char getSeparator() {
return 0;
}
public int getSpecificity() {
return CssSelectorParser.a;
}
@Override
public String toString() {
return "#" + id;
}
}
static class CssAttributeSelector implements CssSelectorItem {
private String property;
private char matchSymbol = 0;
private String value = null;
CssAttributeSelector(String attrSelector) {
int indexOfEqual = attrSelector.indexOf('=');
if (indexOfEqual == -1) {
property = attrSelector.substring(1, attrSelector.length() - 1);
} else {
if (attrSelector.charAt(indexOfEqual + 1) == '"')
value = attrSelector.substring(indexOfEqual + 2, attrSelector.length() - 2);
else
value = attrSelector.substring(indexOfEqual + 1, attrSelector.length() - 1);
matchSymbol = attrSelector.charAt(indexOfEqual - 1);
if ("~^$*|".indexOf(matchSymbol) == -1) {
matchSymbol = 0;
property = attrSelector.substring(1, indexOfEqual);
} else {
property = attrSelector.substring(1, indexOfEqual - 1);
}
}
}
public char getSeparator() {
return 0;
}
public boolean matches(Tag t) {
if (t == null)
return false;
String attrValue = t.getAttributes().get(property);
if (attrValue == null) return false;
if (value == null) return true;
switch (matchSymbol) {
case '|':
String pattern = String.format("^%s-?", value);
if (Pattern.compile(pattern).matcher(attrValue).find())
return true;
break;
case '^':
if (attrValue.startsWith(value))
return true;
break;
case '$':
if (attrValue.endsWith(value))
return true;
break;
case '~':
pattern = String.format("(^%s\\s+)|(\\s+%s\\s+)|(\\s+%s$)", value, value, value);
if (Pattern.compile(pattern).matcher(attrValue).find())
return true;
break;
case 0:
if (attrValue.equals(value))
return true;
break;
case '*':
if (attrValue.contains(value))
return true;
break;
}
return false;
}
public int getSpecificity() {
return CssSelectorParser.b;
}
@Override
public String toString() {
StringBuilder buf = new StringBuilder();
buf.append('[').append(property);
if (matchSymbol != 0)
buf.append(matchSymbol);
if (value != null)
buf.append('=').append('"').append(value).append('"');
buf.append(']');
return buf.toString();
}
}
static class CssPseudoSelector implements CssSelectorItem {
private String selector;
CssPseudoSelector(String selector) {
this.selector = selector;
}
public boolean matches(Tag t) {
return false;
}
public char getSeparator() {
return 0;
}
public int getSpecificity() {
return 0;
}
@Override
public String toString() {
return selector;
}
}
static class CssSeparatorSelector implements CssSelectorItem {
private char separator;
CssSeparatorSelector(char separator) {
this.separator = separator;
}
public char getSeparator() {
return separator;
}
public boolean matches(Tag t){
return false;
}
public int getSpecificity() {
return 0;
}
@Override
public String toString() {
return String.valueOf(separator);
}
}
}
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