org.eclipse.help/Eclipse Help/org/eclipse/help/internal/contributors/xml/XMLContextContributor.java

package org.eclipse.help.internal.contributors.xml;

/*
 * Licensed Materials - Property of IBM,
 * WebSphere Studio Workbench
 * (c) Copyright IBM Corp 2000
 */

import org.xml.sax.*;
import java.util.*;
import org.eclipse.core.runtime.*;
import org.eclipse.help.internal.contributors.*;
import org.eclipse.help.internal.contributions.*;
import org.eclipse.help.internal.contributions.xml.*;
import org.eclipse.help.internal.util.*;

/**
 * Context contributor
 */
public class XMLContextContributor
	extends XMLContributor
	implements ContextContributor {
	static class ContextContributionFactory extends ContributionFactory {
		// Override the super class static field
		protected static final ContextContributionFactory instance =
			new ContextContributionFactory();
		/**
		 * ContributionFactory constructor comment.
		 */
		public ContextContributionFactory() {
			super();
		}

		public Contribution createContribution(String name, Attributes atts) {
			Contribution e = null;
			// NOTE: we don't create an element for the description
			if (name.equals(ContextContributor.CONTEXTS_ELEM))
				e = new HelpContribution(atts);
			else
				if (name.equals(ContextContributor.CONTEXT_ELEM))
					e = new HelpContext(atts);
				else
					if (name.equals(ContextContributor.RELATED_ELEM))
						e = new HelpTopic(atts);
					else
						return null;

			return e;
		}

		public static ContributionFactory instance() {
			return instance;
		}
	}

	static class ContextContributionParser extends ContributionParser {
		StringBuffer buffer = new StringBuffer();
		boolean seenDescription = false;

		public ContextContributionParser() {
			super(ContextContributionFactory.instance());
		}

		public void characters(char ch[], int start, int length) throws SAXException {
			if (seenDescription)
				buffer.append(ch, start, length);

			if (Logger.DEBUG)
				Logger.logDebugMessage(
					"XMLContextContributor",
					"got char from parser= "
						+ new StringBuffer().append(ch, start, length).toString());

		}

		public void endElement(String namespaceURI, String localName, String qName)
			throws SAXException {
			// make sure that no error has already occurred before adding to stack.
			if (!FATAL_ERROR_OCCURRED) {
				// We don't create a description element
				if (qName.equals(ContextContributor.DESC_ELEM)) {
					seenDescription = false;
					((HelpContext) elementStack.peek()).setDescription(buffer.toString());
					buffer.setLength(0);
				} else
					if (qName.equals(ContextContributor.DESC_TXT_BOLD)) {
						// pop the starting bold tag
						elementStack.pop();
						if (!(elementStack.peek()).equals(ContextContributor.BOLD_TAG))
							buffer.append(ContextContributor.BOLD_CLOSE_TAG);

					} else
						super.endElement(namespaceURI, localName, qName);
			}
		}

		public void startElement(
			String namespaceURI,
			String localName,
			String qName,
			Attributes atts)
			throws SAXException {
			// make sure that no error has already occurred before adding to stack.
			if (!FATAL_ERROR_OCCURRED) {
				// We don't create a description element
				if (qName.equals(ContextContributor.DESC_ELEM))
					seenDescription = true;
				else
					if (qName.equals(ContextContributor.DESC_TXT_BOLD)) {

						// peek into stack to findout if a bold tag element already
						// exists. If we find one, then we do not add the bold tag to
						// the current StringBuffer of description.
						// ie: there are many bold start tags in the stack, but we appended
						// the tag only once to the description string.
						// eg: (b) some text (b) more test (/b) more text (/b) will result 
						// in all of the sentence being bold.

						if (!(elementStack.peek()).equals(ContextContributor.BOLD_TAG))
							buffer.append(ContextContributor.BOLD_TAG);
						elementStack.push(ContextContributor.BOLD_TAG);
					} else
						super.startElement(namespaceURI, localName, qName, atts);
			}
		}
	}

	/**
	 * XMLViewContributor constructor comment.
	 * @param plugin com.ibm.itp.core.api.plugins.IPluginDescriptor
	 * @param configuration com.ibm.itp.core.api.plugins.IConfigurationElement
	 */
	public XMLContextContributor(
		IPluginDescriptor plugin,
		IConfigurationElement configuration) {
		super(plugin, configuration);
	}
	/**
	 * getViews method comment.
	 */
	public Contribution getContribution() {
		return getContribution(NAME_ATTR);
	}
	/**
	 * Returns the contribution factory.
	 * Use the default contribution factory, but certain contributors can
	 * provide specialized subclasses.
	 */
	protected ContributionParser getContributionParser() {
		if (contributionParser == null)
			contributionParser = new ContextContributionParser();
		return contributionParser;
	}
	/**
	 * @return String
	 */
	public String getType() {
		return ContextContributor.MAP_ELEM;
	}
	/**
	 */
	protected void preprocess(Contribution contrib) {
		// update the ids and href only for child Topics (ie: related topics).
		// we know that we a Context contributrion to start with.
		// this is stored as a HelpContribution)
		for (Iterator children = contrib.getChildren(); children.hasNext();) {
			// update the id and href only for Topic node.
			// may need to revist! we may need to update the ids of Context also.
			Object child = children.next();
			if (child instanceof Topic) {
				updateIDs((Contribution) child);
				updateHrefs((Topic) child);
			} else
				if (child instanceof Context) {
					preprocess((Contribution) child);
				}
		}
	}
	/**
	 * Utility method that scans the topics for all href attributes and update them
	 * to include the plugin id (i.e. create a help url).
	 */
	protected void updateHrefs(Topic topic) {
		// set the href on the input contribution   
		String href = topic.getHref();
		if (href == null)
			 ((HelpTopic) topic).setHref("");
		else {
			if (!href.equals("") // no empty link
				&& !href.startsWith("/") // no help url
				&& href.indexOf(':') == -1) // no other protocols
				{
				((HelpTopic) topic).setHref("/" + plugin.getUniqueIdentifier() + "/" + href);
			}
		}

		// recurse to children
		for (Iterator topics = topic.getChildren(); topics.hasNext();) {
			updateHrefs((Topic) topics.next());
		}
	}
}