org.w3c.dom.traversal.NodeFilter#SHOW_ELEMENT源码实例Demo

/**
 * Given a {@link Node}, return the appropriate constant for whatToShow.
 *
 * @param node the node
 * @return the whatToShow constant for the type of specified node
 */
static int getFlagForNode(final Node node) {
    switch (node.getNodeType()) {
        case Node.ELEMENT_NODE:
            return NodeFilter.SHOW_ELEMENT;
        case Node.ATTRIBUTE_NODE:
            return NodeFilter.SHOW_ATTRIBUTE;
        case Node.TEXT_NODE:
            return NodeFilter.SHOW_TEXT;
        case Node.CDATA_SECTION_NODE:
            return NodeFilter.SHOW_CDATA_SECTION;
        case Node.ENTITY_REFERENCE_NODE:
            return NodeFilter.SHOW_ENTITY_REFERENCE;
        case Node.ENTITY_NODE:
            return NodeFilter.SHOW_ENTITY;
        case Node.PROCESSING_INSTRUCTION_NODE:
            return NodeFilter.SHOW_PROCESSING_INSTRUCTION;
        case Node.COMMENT_NODE:
            return NodeFilter.SHOW_COMMENT;
        case Node.DOCUMENT_NODE:
            return NodeFilter.SHOW_DOCUMENT;
        case Node.DOCUMENT_TYPE_NODE:
            return NodeFilter.SHOW_DOCUMENT_TYPE;
        case Node.DOCUMENT_FRAGMENT_NODE:
            return NodeFilter.SHOW_DOCUMENT_FRAGMENT;
        case Node.NOTATION_NODE:
            return NodeFilter.SHOW_NOTATION;
        default:
            return 0;
    }
}
 

/**
 * Given a {@link Node}, return the appropriate constant for whatToShow.
 *
 * @param node the node
 * @return the whatToShow constant for the type of specified node
 */
static int getFlagForNode(final Node node) {
    switch (node.getNodeType()) {
        case Node.ELEMENT_NODE:
            return NodeFilter.SHOW_ELEMENT;
        case Node.ATTRIBUTE_NODE:
            return NodeFilter.SHOW_ATTRIBUTE;
        case Node.TEXT_NODE:
            return NodeFilter.SHOW_TEXT;
        case Node.CDATA_SECTION_NODE:
            return NodeFilter.SHOW_CDATA_SECTION;
        case Node.ENTITY_REFERENCE_NODE:
            return NodeFilter.SHOW_ENTITY_REFERENCE;
        case Node.ENTITY_NODE:
            return NodeFilter.SHOW_ENTITY;
        case Node.PROCESSING_INSTRUCTION_NODE:
            return NodeFilter.SHOW_PROCESSING_INSTRUCTION;
        case Node.COMMENT_NODE:
            return NodeFilter.SHOW_COMMENT;
        case Node.DOCUMENT_NODE:
            return NodeFilter.SHOW_DOCUMENT;
        case Node.DOCUMENT_TYPE_NODE:
            return NodeFilter.SHOW_DOCUMENT_TYPE;
        case Node.DOCUMENT_FRAGMENT_NODE:
            return NodeFilter.SHOW_DOCUMENT_FRAGMENT;
        case Node.NOTATION_NODE:
            return NodeFilter.SHOW_NOTATION;
        default:
            return 0;
    }
}
 

/**
 * Creates map of declarations assigned to each element of a DOM tree
 * 
 * @param doc
 *            DOM document
 * @param media
 *            Media type to be used for declarations
 * @param inherit
 *            Inheritance (cascade propagation of values)
 * @return Map of elements as keys and their declarations
 */
protected DeclarationMap assingDeclarationsToDOM(Document doc, MediaSpec media, final boolean inherit) {

	// classify the rules
    classifyAllSheets(media);
	
	// resulting map
	DeclarationMap declarations = new DeclarationMap();
	
       // if the holder is empty skip evaluation
       if(rules!=null && !rules.isEmpty()) {
           
   		Traversal<DeclarationMap> traversal = new Traversal<DeclarationMap>(
   				doc, (Object) rules, NodeFilter.SHOW_ELEMENT) {
   			protected void processNode(DeclarationMap result,
   					Node current, Object source) {
   				assignDeclarationsToElement(result, walker, (Element) current,
   						(Holder) source);
   			}
   		};
   
   		// list traversal will be enough
   		if (!inherit)
   			traversal.listTraversal(declarations);
   		// we will do level traversal to economize blind returning
   		// in tree
   		else
   			traversal.levelTraversal(declarations);
       }

	return declarations;
}
 

@Override
public int getWhatToShow() {
    return NodeFilter.SHOW_ELEMENT;
}
 

/**
 * This is the same as {@link CSSFactory#assignDOM(Document, String, URL, MediaSpec, boolean)} 
 * with the possibility of specifying a custom network processor for obtaining data from URL
 * resources.
 * 
 * @param doc
 *            DOM tree
 * @param encoding
 *            The default encoding used for the referenced style sheets
 * @param network
 *            Custom network processor
 * @param base
 *            Base URL against which all files are searched
 * @param media
 *            Current media specification used for evaluating the media queries
 * @param useInheritance
 *            Whether inheritance will be used to determine values
 * @param matchCond
 *            The match condition to match the against.
 * @return Map between DOM element nodes and data structure containing CSS
 *         information
 */ 
public static final StyleMap assignDOM(Document doc, String encoding, NetworkProcessor network,
        URL base, MediaSpec media, boolean useInheritance, final MatchCondition matchCond) {

    SourceData pair = new SourceData(base, network, media);

    Traversal<StyleSheet> traversal = new CSSAssignTraversal(doc, encoding,
            pair, NodeFilter.SHOW_ELEMENT);

    StyleSheet style = (StyleSheet) getRuleFactory().createStyleSheet()
            .unlock();
    traversal.listTraversal(style);

    Analyzer analyzer = new Analyzer(style);
    if (matchCond != null) {
        analyzer.registerMatchCondition(matchCond);
    }
    return analyzer.evaluateDOM(doc, media, useInheritance);
}
 

/**
 * Loads all the style sheets used from the specified DOM tree.
 * The following style specifications are evaluated:
 * <ul>
 * <li>The style sheets included using the <code>link</code> and <code>style</code> tags.
 * <li>Inline styles specified using the <code>style</code> element attribute.
 * <li><strong>Proprietary extension:</strong> Default styles defined using the <code>XDefaultStyle</code>
 *     element attribute. These styles behave the same way as the inline styles but they have the lowest priority
 *     (the values are used only when not redefined by any other way)
 *  </ul>   
 * 
 * @param doc
 *            DOM tree
 * @param encoding
 *            The default encoding used for the referenced style sheets
 * @param base
 *            Base URL against which all files are searched
 * @param media
 *            Selected media for style sheet
 * @return the rules of all the style sheets used in the document including the inline styles
 */
public static final StyleSheet getUsedStyles(Document doc, String encoding, URL base, MediaSpec media, NetworkProcessor network)
{
    SourceData pair = new SourceData(base, network, media);

    Traversal<StyleSheet> traversal = new CSSAssignTraversal(doc, encoding,
            pair, NodeFilter.SHOW_ELEMENT);

    StyleSheet style = (StyleSheet) getRuleFactory().createStyleSheet().unlock();
    traversal.listTraversal(style);
    return style;
}