org.eclipse.help.webapp/src/org/eclipse/help/internal/webapp/servlet/IndexFragmentServlet.java - platform/eclipse.platform.ua - Git at Google

 /*******************************************************************************
  * Copyright (c) 2007, 2017 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Yaroslav Nikolaiko <nikolaiko.yaroslav@gmail.com> - [webapp][base] Bugs related to Search Scope for filtering content in The Eclipse platform's help infocenter - http://bugs.eclipse.org/441407
  *******************************************************************************/
 package org.eclipse.help.internal.webapp.servlet;

 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.WeakHashMap;

 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 import org.eclipse.help.IIndex;
 import org.eclipse.help.IIndexEntry;
 import org.eclipse.help.IIndexEntry2;
 import org.eclipse.help.IIndexSee;
 import org.eclipse.help.IIndexSubpath;
 import org.eclipse.help.ITopic;
 import org.eclipse.help.base.AbstractHelpScope;
 import org.eclipse.help.internal.HelpPlugin;
 import org.eclipse.help.internal.base.scope.ScopeUtils;
 import org.eclipse.help.internal.webapp.WebappResources;
 import org.eclipse.help.internal.webapp.data.ActivitiesData;
 import org.eclipse.help.internal.webapp.data.RequestScope;
 import org.eclipse.help.internal.webapp.data.UrlUtil;
 import org.eclipse.osgi.util.NLS;

 import com.ibm.icu.text.Collator;

 /*
  * Creates xml representing selected parts of the index
  * Parameter "start" represents the part of the index to start reading from
  * Parameter "size" indicates the number of entries to read, no size parameter
  * or a negative size parameter indicates that all entries which match the start
  * letters should be displayed.
  * Parameter "offset" represents the starting point relative to the start
  */
 public class IndexFragmentServlet extends HttpServlet {

 	private static final long serialVersionUID = 1L;
 	private static Map<String, String> locale2Response = new WeakHashMap<>();
 	private String startParameter;
 	private String sizeParameter;
 	private String entryParameter;
 	private String modeParameter;
 	private String showAllParameter;
 	private int size;
 	private int entry;
 	private static final String NEXT = "next"; //$NON-NLS-1$
 	private static final String PREVIOUS = "previous"; //$NON-NLS-1$
 	private static final String SIZE = "size"; //$NON-NLS-1$
 	private static final String MODE = "mode"; //$NON-NLS-1$
 	private static final String ENTRY = "entry"; //$NON-NLS-1$
 	private static final String SHOW_ALL = "showAll"; //$NON-NLS-1$
 	private Collator collator = Collator.getInstance();

 	@Override
 	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
 			throws ServletException, IOException {
 		// set the character-set to UTF-8 before calling resp.getWriter()
 		resp.setContentType("application/xml; charset=UTF-8"); //$NON-NLS-1$
 		resp.getWriter().write(processRequest(req, resp));
 	}

 	protected String processRequest(HttpServletRequest req, HttpServletResponse resp)
 			throws ServletException, IOException {
 		String locale = UrlUtil.getLocale(req, resp);
 		startParameter = req.getParameter("start"); //$NON-NLS-1$
 		if (startParameter != null) {
 			startParameter = startParameter.toLowerCase();
 		}

 		size = 30;
 		sizeParameter = req.getParameter(SIZE);
 		if (sizeParameter != null) {
 			try {
 			    size = Integer.parseInt(sizeParameter);
 			} catch (NumberFormatException n) {
 			}
 		}

 		entry = -1;
 		entryParameter = req.getParameter(ENTRY);
 		if (entryParameter != null) {
 			try {
 			    entry = Integer.parseInt(entryParameter);
 			} catch (NumberFormatException n) {
 			}
 		}

 		modeParameter = req.getParameter(MODE);
 		showAllParameter = req.getParameter(SHOW_ALL);
 		if (showAllParameter != null) {
 			// Use activities data to toggle the show all state
 			new ActivitiesData(this.getServletContext(), req, resp);
 		}

 		req.setCharacterEncoding("UTF-8"); //$NON-NLS-1$
 		// Cache suppression required because the set of in scope
 		// topics could change between requests

 		resp.setHeader("Cache-Control","no-cache");   //$NON-NLS-1$//$NON-NLS-2$
 		resp.setHeader("Pragma","no-cache");  //$NON-NLS-1$ //$NON-NLS-2$
 		resp.setDateHeader ("Expires", 0); 	 //$NON-NLS-1$

 		AbstractHelpScope scope = RequestScope.getScope(req, resp, false);
 		Serializer serializer = new Serializer(locale, scope);
 		String response = serializer.generateIndexXml();
 		locale2Response.put(locale, response);

 		return response;
 	}

 	/*
 	 * Class which creates the xml file based upon the request parameters
 	 */
 	private class Serializer {

 		private IIndex index;
 		private StringBuilder buf;
 		private int count = 0;
 		private String locale;
 		private List<Integer> entryList;
 		private IIndexEntry[] entries;
 		private boolean enablePrevious = true;
 		private boolean enableNext = true;
 		private AbstractHelpScope scope;

 		public Serializer(String locale, AbstractHelpScope scope) {
 			this.locale = locale;
 			this.scope = scope;
 			index = HelpPlugin.getIndexManager().getIndex(locale);
 			buf = new StringBuilder();
 		}

 		/*
 		 * There are three modes of generation, current page, next page and previous page.
 		 * Current page returns a screenful of entries starting at the startParameter.
 		 * Next page returns a screenful of entries starting after but not including the start parameter.
 		 * Previous page returns a screenful of entries going back from the start parameter
 		 */
 		private String generateIndexXml() {

 			entries = index.getEntries();
 			if (entries.length == 0) {
 				generateEmptyIndexMessage();
 			} else {
 				entryList = new ArrayList<>();
 				int nextEntry = findFirstEntry(entries);
 				if (PREVIOUS.equals(modeParameter)) {
 					int remaining = getPreviousEntries(nextEntry, size);
 					getNextEntries(nextEntry, remaining);
 				} else {
 					int remaining = getNextEntries(nextEntry, size);
 					if (remaining == size) {
 						// Generate just the last entry
 						size = 1;
 						getPreviousEntries(nextEntry, 1);
 					}
 				}
 				for (Integer entryId : entryList) {
 					generateEntry(entries[entryId.intValue()], 0, "e" + entryId.intValue()); //$NON-NLS-1$
 				}
 			}
 			String header = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<tree_data enableNext = \"" //$NON-NLS-1$
 				+ Boolean.toString(enableNext) + "\" enablePrevious = \"" + Boolean.toString(enablePrevious) + "\">\n"; //$NON-NLS-1$ //$NON-NLS-2$
 			buf.append("</tree_data>\n"); //$NON-NLS-1$
 			return header + buf.toString();
 		}

 		private int getCategory(String keyword) {
 			if (keyword != null && keyword.length() > 0) {
 				char c = keyword.charAt(0);
 				if (Character.isDigit(c)) {
 					return 2;
 				} else if (Character.isLetter(c)) {
 					return 3;
 				}
 				return 1;
 			}
 			return 4;
 		}

 		private int compare (String left, String right) {
 			int catLeft = getCategory(left);
 			int catRight = getCategory(right);
 			if (catLeft != catRight) {
 				return catLeft - catRight;
 			} else {
 				return collator.compare(left, right);
 			}
 		}

 		private int findFirstEntry(IIndexEntry[] entries) {
 			if (NEXT.equals(modeParameter)) {
 				if (entry >= entries.length - 1) {
 					return entries.length - 1;
 				} else {
 					return entry + 1;
 				}
 			}
 			if (PREVIOUS.equals(modeParameter)) {
 				if (entry <= 0) {
 					return 0;
 				} else {
 					return entry - 1;
 				}
 			}
 			if (startParameter == null) {
 				return 0;
 			}
 			int nextEntry = 0;
 			while (nextEntry < entries.length) {
 			    String keyword = entries[nextEntry].getKeyword().toLowerCase();
 				if (keyword != null) {
 					if (compare(startParameter, keyword) <= 0) {
 				        break;
 					}
 				}
 				nextEntry++;
 			}
 			return nextEntry;
 		}

 		private int getNextEntries(int nextEntry, int remaining) {
 			while (nextEntry < entries.length) {
 				int entrySize = enabledEntryCount(entries[nextEntry]);
 				if (remaining == size || remaining > entrySize) {
                     entryList.add(Integer.valueOf(nextEntry));
                     setFlags(nextEntry);
                     remaining -= entrySize;
 				} else {
 					break;
 				}
 				nextEntry++;
 			}
 			return remaining;
 		}

 		private int getPreviousEntries(int nextEntry, int remaining) {
 			nextEntry--;
 			while (nextEntry >= 0) {
 				int entrySize = enabledEntryCount(entries[nextEntry]);
 				if (remaining == size || remaining > entrySize) {
                     entryList.add(0, Integer.valueOf(nextEntry));

                     setFlags(nextEntry);
                     remaining -= entrySize;
 				} else {
 					break;
 				}
 				nextEntry--;
 			}
 			return remaining;
 		}

 		private void setFlags(int nextEntry) {
 			if (nextEntry == 0) {
 				enablePrevious = false;
 			}
 			if (nextEntry == entries.length - 1) {
 				enableNext = false;
 			}
 		}

 		private int enabledEntryCount(IIndexEntry entry) {
 			if (!ScopeUtils.showInTree(entry, scope)) return 0;
 			if (entry.getKeyword() == null || entry.getKeyword().length() == 0) {
 				return 0;
 			}
 			int count = 1;
 		    int topicCount = enabledTopicCount(entry);

 			IIndexEntry[] subentries = entry.getSubentries();
 		    int subentryCount = 0;
 			for (IIndexEntry subentrie : subentries) {
 				count += enabledEntryCount(subentrie);
 			}

 			int seeCount = 0;
 			IIndexSee[] sees = entry instanceof IIndexEntry2 ? ((IIndexEntry2)entry).getSees() : new IIndexSee[0];
 			for (IIndexSee see : sees) {
 				if (ScopeUtils.showInTree(see, scope)) {
 					seeCount++;
 				}
 			}

 			if (topicCount + subentryCount + seeCount > 1) {
 				count += topicCount;
 			}
 			count += subentryCount;
 			count += seeCount;
             return count;
 		}

 		private int enabledTopicCount(IIndexEntry entry) {
 			int topicCount = 0;
 		    ITopic[] topics = entry.getTopics();
 		    for (ITopic topic : topics) {
 		    	if (scope.inScope(topic)) {
 		    		topicCount++;
 		    	}
 		    }
 			return topicCount;
 		}

 		private void generateEmptyIndexMessage() {
 			buf.append("<node"); //$NON-NLS-1$
 			buf.append('\n' + "      title=\"" + XMLGenerator.xmlEscape(WebappResources.getString("IndexEmpty", UrlUtil.getLocale(locale))) + '"'); //$NON-NLS-1$ //$NON-NLS-2$
 			buf.append('\n' + "      id=\"no_index\""); //$NON-NLS-1$
 			buf.append(">\n"); //$NON-NLS-1$
 			buf.append("</node>\n"); //$NON-NLS-1$
 			enableNext = false;
 			enablePrevious = false;
 		}

 		private void generateEntry(IIndexEntry entry, int level, String id) {
 			if (!ScopeUtils.showInTree(entry, scope)) return;
 			if (entry.getKeyword() != null && entry.getKeyword().length() > 0) {
 				ITopic[] topics = ScopeUtils.inScopeTopics(entry.getTopics(), scope);
 				IIndexEntry[] subentries = ScopeUtils.inScopeEntries(entry.getSubentries(), scope);
 				IIndexSee[] sees;
 				if (entry instanceof IIndexEntry2) {
 					sees = ((IIndexEntry2)entry).getSees();
 				} else {
 					sees = new IIndexSee[0];
 				}
 				boolean multipleTopics = topics.length > 1;
 				boolean singleTopic = topics.length == 1;

 				buf.append("<node"); //$NON-NLS-1$
 				if (entry.getKeyword() != null) {
 					buf.append('\n' + "      title=\"" + XMLGenerator.xmlEscape(entry.getKeyword()) + '"'); //$NON-NLS-1$
 				}

 				buf.append('\n' + "      id=\"" + id + '"'); //$NON-NLS-1$

 				String href;
 				if (singleTopic) {
 					href = UrlUtil.getHelpURL((topics[0]).getHref());
 				    buf.append('\n' + "      href=\"" +  //$NON-NLS-1$
 				    	XMLGenerator.xmlEscape(href) + "\""); //$NON-NLS-1$
 				}
 				buf.append(">\n"); //$NON-NLS-1$

 				if (multipleTopics || subentries.length > 0 || sees.length > 0) {
 					if (multipleTopics) generateTopicList(entry);
 					generateSubentries(entry, level + 1);
 					generateSees(sees);
 				}

 				buf.append("</node>\n"); //$NON-NLS-1$
 			}
 		}

 		private void generateSubentries(IIndexEntry entry, int level) {
 			IIndexEntry[] subentries = entry.getSubentries();
 			for (IIndexEntry subentrie : subentries) {
 				generateEntry(subentrie, level, "s" + count++); //$NON-NLS-1$
 			}
 		}

 		private void generateTopicList(IIndexEntry entry) {
 			ITopic[] topics = entry.getTopics();

 			for (ITopic topic : topics) {
 				if (ScopeUtils.showInTree(topic, scope)) {
 					//
 					String label = UrlUtil.htmlEncode(topic.getLabel());
 					if (label == null) {
 						label = UrlUtil.htmlEncode(topic.getLabel());
 					}

 					buf.append("<node"); //$NON-NLS-1$
 					if (entry.getKeyword() != null) {
 						buf.append('\n' + "      title=\"" + label + '"'); //$NON-NLS-1$
 					}

 					count++;
 					buf.append('\n' + "      id=\"i" + count + '"'); //$NON-NLS-1$
 					String href = UrlUtil.getHelpURL(topic.getHref());
 					buf.append('\n' + "      href=\"" //$NON-NLS-1$
 							+ XMLGenerator.xmlEscape(href) + "\""); //$NON-NLS-1$
 					buf.append(">\n"); //$NON-NLS-1$
 					buf.append("</node>\n"); //$NON-NLS-1$
 				}
 			}
 		}

 		private void generateSees(IIndexSee[] sees) {
 	        for (IIndexSee see : sees) {
 	        	if (ScopeUtils.showInTree(see, scope)) {
 					//
 					String key = see.isSeeAlso() ? "SeeAlso" : "See"; //$NON-NLS-1$ //$NON-NLS-2$
 					String seePrefix = WebappResources.getString(key, UrlUtil
 							.getLocale(locale));
 					String seeTarget = see.getKeyword();
 					IIndexSubpath[] subpathElements = see.getSubpathElements();
 					for (IIndexSubpath subpathElement : subpathElements) {
 						seeTarget += ", "; //$NON-NLS-1$
 						seeTarget += subpathElement.getKeyword();
 					}
 					String label = NLS.bind(seePrefix, seeTarget);
 					String encodedLabel = UrlUtil.htmlEncode(label);
 					buf.append("<node"); //$NON-NLS-1$

 					buf.append('\n' + "      title=\"" + encodedLabel + '"'); //$NON-NLS-1$

 					count++;
 					buf.append('\n' + "      id=\"i" + count + '"'); //$NON-NLS-1$
 					String href = "see:" + seeTarget; //$NON-NLS-1$
 					buf.append('\n' + "      href=\"" //$NON-NLS-1$
 							+ XMLGenerator.xmlEscape(href) + "\""); //$NON-NLS-1$
 					buf.append(">\n"); //$NON-NLS-1$
 					buf.append("</node>\n"); //$NON-NLS-1$
 	        	}
 	        }
 		}
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2007, 2017 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	* Yaroslav Nikolaiko <nikolaiko.yaroslav@gmail.com> - [webapp][base] Bugs related to Search Scope for filtering content in The Eclipse platform's help infocenter - http://bugs.eclipse.org/441407
	*******************************************************************************/
	package org.eclipse.help.internal.webapp.servlet;

	import java.io.IOException;
	import java.util.ArrayList;
	import java.util.List;
	import java.util.Map;
	import java.util.WeakHashMap;

	import javax.servlet.ServletException;
	import javax.servlet.http.HttpServlet;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;

	import org.eclipse.help.IIndex;
	import org.eclipse.help.IIndexEntry;
	import org.eclipse.help.IIndexEntry2;
	import org.eclipse.help.IIndexSee;
	import org.eclipse.help.IIndexSubpath;
	import org.eclipse.help.ITopic;
	import org.eclipse.help.base.AbstractHelpScope;
	import org.eclipse.help.internal.HelpPlugin;
	import org.eclipse.help.internal.base.scope.ScopeUtils;
	import org.eclipse.help.internal.webapp.WebappResources;
	import org.eclipse.help.internal.webapp.data.ActivitiesData;
	import org.eclipse.help.internal.webapp.data.RequestScope;
	import org.eclipse.help.internal.webapp.data.UrlUtil;
	import org.eclipse.osgi.util.NLS;

	import com.ibm.icu.text.Collator;

	/*
	* Creates xml representing selected parts of the index
	* Parameter "start" represents the part of the index to start reading from
	* Parameter "size" indicates the number of entries to read, no size parameter
	* or a negative size parameter indicates that all entries which match the start
	* letters should be displayed.
	* Parameter "offset" represents the starting point relative to the start
	*/
	public class IndexFragmentServlet extends HttpServlet {

	private static final long serialVersionUID = 1L;
	private static Map<String, String> locale2Response = new WeakHashMap<>();
	private String startParameter;
	private String sizeParameter;
	private String entryParameter;
	private String modeParameter;
	private String showAllParameter;
	private int size;
	private int entry;
	private static final String NEXT = "next"; //$NON-NLS-1$
	private static final String PREVIOUS = "previous"; //$NON-NLS-1$
	private static final String SIZE = "size"; //$NON-NLS-1$
	private static final String MODE = "mode"; //$NON-NLS-1$
	private static final String ENTRY = "entry"; //$NON-NLS-1$
	private static final String SHOW_ALL = "showAll"; //$NON-NLS-1$
	private Collator collator = Collator.getInstance();

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
	throws ServletException, IOException {
	// set the character-set to UTF-8 before calling resp.getWriter()
	resp.setContentType("application/xml; charset=UTF-8"); //$NON-NLS-1$
	resp.getWriter().write(processRequest(req, resp));
	}

	protected String processRequest(HttpServletRequest req, HttpServletResponse resp)
	throws ServletException, IOException {
	String locale = UrlUtil.getLocale(req, resp);
	startParameter = req.getParameter("start"); //$NON-NLS-1$
	if (startParameter != null) {
	startParameter = startParameter.toLowerCase();
	}

	size = 30;
	sizeParameter = req.getParameter(SIZE);
	if (sizeParameter != null) {
	try {
	size = Integer.parseInt(sizeParameter);
	} catch (NumberFormatException n) {
	}
	}

	entry = -1;
	entryParameter = req.getParameter(ENTRY);
	if (entryParameter != null) {
	try {
	entry = Integer.parseInt(entryParameter);
	} catch (NumberFormatException n) {
	}
	}

	modeParameter = req.getParameter(MODE);
	showAllParameter = req.getParameter(SHOW_ALL);
	if (showAllParameter != null) {
	// Use activities data to toggle the show all state
	new ActivitiesData(this.getServletContext(), req, resp);
	}

	req.setCharacterEncoding("UTF-8"); //$NON-NLS-1$
	// Cache suppression required because the set of in scope
	// topics could change between requests

	resp.setHeader("Cache-Control","no-cache"); //$NON-NLS-1$//$NON-NLS-2$
	resp.setHeader("Pragma","no-cache"); //$NON-NLS-1$ //$NON-NLS-2$
	resp.setDateHeader ("Expires", 0); //$NON-NLS-1$

	AbstractHelpScope scope = RequestScope.getScope(req, resp, false);
	Serializer serializer = new Serializer(locale, scope);
	String response = serializer.generateIndexXml();
	locale2Response.put(locale, response);

	return response;
	}

	/*
	* Class which creates the xml file based upon the request parameters
	*/
	private class Serializer {

	private IIndex index;
	private StringBuilder buf;
	private int count = 0;
	private String locale;
	private List<Integer> entryList;
	private IIndexEntry[] entries;
	private boolean enablePrevious = true;
	private boolean enableNext = true;
	private AbstractHelpScope scope;

	public Serializer(String locale, AbstractHelpScope scope) {
	this.locale = locale;
	this.scope = scope;
	index = HelpPlugin.getIndexManager().getIndex(locale);
	buf = new StringBuilder();
	}

	/*
	* There are three modes of generation, current page, next page and previous page.
	* Current page returns a screenful of entries starting at the startParameter.
	* Next page returns a screenful of entries starting after but not including the start parameter.
	* Previous page returns a screenful of entries going back from the start parameter
	*/
	private String generateIndexXml() {

	entries = index.getEntries();
	if (entries.length == 0) {
	generateEmptyIndexMessage();
	} else {
	entryList = new ArrayList<>();
	int nextEntry = findFirstEntry(entries);
	if (PREVIOUS.equals(modeParameter)) {
	int remaining = getPreviousEntries(nextEntry, size);
	getNextEntries(nextEntry, remaining);
	} else {
	int remaining = getNextEntries(nextEntry, size);
	if (remaining == size) {
	// Generate just the last entry
	size = 1;
	getPreviousEntries(nextEntry, 1);
	}
	}
	for (Integer entryId : entryList) {
	generateEntry(entries[entryId.intValue()], 0, "e" + entryId.intValue()); //$NON-NLS-1$
	}
	}
	String header = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<tree_data enableNext = \"" //$NON-NLS-1$
	+ Boolean.toString(enableNext) + "\" enablePrevious = \"" + Boolean.toString(enablePrevious) + "\">\n"; //$NON-NLS-1$ //$NON-NLS-2$
	buf.append("</tree_data>\n"); //$NON-NLS-1$
	return header + buf.toString();
	}

	private int getCategory(String keyword) {
	if (keyword != null && keyword.length() > 0) {
	char c = keyword.charAt(0);
	if (Character.isDigit(c)) {
	return 2;
	} else if (Character.isLetter(c)) {
	return 3;
	}
	return 1;
	}
	return 4;
	}

	private int compare (String left, String right) {
	int catLeft = getCategory(left);
	int catRight = getCategory(right);
	if (catLeft != catRight) {
	return catLeft - catRight;
	} else {
	return collator.compare(left, right);
	}
	}

	private int findFirstEntry(IIndexEntry[] entries) {
	if (NEXT.equals(modeParameter)) {
	if (entry >= entries.length - 1) {
	return entries.length - 1;
	} else {
	return entry + 1;
	}
	}
	if (PREVIOUS.equals(modeParameter)) {
	if (entry <= 0) {
	return 0;
	} else {
	return entry - 1;
	}
	}
	if (startParameter == null) {
	return 0;
	}
	int nextEntry = 0;
	while (nextEntry < entries.length) {
	String keyword = entries[nextEntry].getKeyword().toLowerCase();
	if (keyword != null) {
	if (compare(startParameter, keyword) <= 0) {
	break;
	}
	}
	nextEntry++;
	}
	return nextEntry;
	}

	private int getNextEntries(int nextEntry, int remaining) {
	while (nextEntry < entries.length) {
	int entrySize = enabledEntryCount(entries[nextEntry]);
	if (remaining == size \|\| remaining > entrySize) {
	entryList.add(Integer.valueOf(nextEntry));
	setFlags(nextEntry);
	remaining -= entrySize;
	} else {
	break;
	}
	nextEntry++;
	}
	return remaining;
	}

	private int getPreviousEntries(int nextEntry, int remaining) {
	nextEntry--;
	while (nextEntry >= 0) {
	int entrySize = enabledEntryCount(entries[nextEntry]);
	if (remaining == size \|\| remaining > entrySize) {
	entryList.add(0, Integer.valueOf(nextEntry));

	setFlags(nextEntry);
	remaining -= entrySize;
	} else {
	break;
	}
	nextEntry--;
	}
	return remaining;
	}

	private void setFlags(int nextEntry) {
	if (nextEntry == 0) {
	enablePrevious = false;
	}
	if (nextEntry == entries.length - 1) {
	enableNext = false;
	}
	}

	private int enabledEntryCount(IIndexEntry entry) {
	if (!ScopeUtils.showInTree(entry, scope)) return 0;
	if (entry.getKeyword() == null \|\| entry.getKeyword().length() == 0) {
	return 0;
	}
	int count = 1;
	int topicCount = enabledTopicCount(entry);

	IIndexEntry[] subentries = entry.getSubentries();
	int subentryCount = 0;
	for (IIndexEntry subentrie : subentries) {
	count += enabledEntryCount(subentrie);
	}

	int seeCount = 0;
	IIndexSee[] sees = entry instanceof IIndexEntry2 ? ((IIndexEntry2)entry).getSees() : new IIndexSee[0];
	for (IIndexSee see : sees) {
	if (ScopeUtils.showInTree(see, scope)) {
	seeCount++;
	}
	}

	if (topicCount + subentryCount + seeCount > 1) {
	count += topicCount;
	}
	count += subentryCount;
	count += seeCount;
	return count;
	}

	private int enabledTopicCount(IIndexEntry entry) {
	int topicCount = 0;
	ITopic[] topics = entry.getTopics();
	for (ITopic topic : topics) {
	if (scope.inScope(topic)) {
	topicCount++;
	}
	}
	return topicCount;
	}

	private void generateEmptyIndexMessage() {
	buf.append("<node"); //$NON-NLS-1$
	buf.append('\n' + " title=\"" + XMLGenerator.xmlEscape(WebappResources.getString("IndexEmpty", UrlUtil.getLocale(locale))) + '"'); //$NON-NLS-1$ //$NON-NLS-2$
	buf.append('\n' + " id=\"no_index\""); //$NON-NLS-1$
	buf.append(">\n"); //$NON-NLS-1$
	buf.append("</node>\n"); //$NON-NLS-1$
	enableNext = false;
	enablePrevious = false;
	}

	private void generateEntry(IIndexEntry entry, int level, String id) {
	if (!ScopeUtils.showInTree(entry, scope)) return;
	if (entry.getKeyword() != null && entry.getKeyword().length() > 0) {
	ITopic[] topics = ScopeUtils.inScopeTopics(entry.getTopics(), scope);
	IIndexEntry[] subentries = ScopeUtils.inScopeEntries(entry.getSubentries(), scope);
	IIndexSee[] sees;
	if (entry instanceof IIndexEntry2) {
	sees = ((IIndexEntry2)entry).getSees();
	} else {
	sees = new IIndexSee[0];
	}
	boolean multipleTopics = topics.length > 1;
	boolean singleTopic = topics.length == 1;

	buf.append("<node"); //$NON-NLS-1$
	if (entry.getKeyword() != null) {
	buf.append('\n' + " title=\"" + XMLGenerator.xmlEscape(entry.getKeyword()) + '"'); //$NON-NLS-1$
	}

	buf.append('\n' + " id=\"" + id + '"'); //$NON-NLS-1$

	String href;
	if (singleTopic) {
	href = UrlUtil.getHelpURL((topics[0]).getHref());
	buf.append('\n' + " href=\"" + //$NON-NLS-1$
	XMLGenerator.xmlEscape(href) + "\""); //$NON-NLS-1$
	}
	buf.append(">\n"); //$NON-NLS-1$

	if (multipleTopics \|\| subentries.length > 0 \|\| sees.length > 0) {
	if (multipleTopics) generateTopicList(entry);
	generateSubentries(entry, level + 1);
	generateSees(sees);
	}

	buf.append("</node>\n"); //$NON-NLS-1$
	}
	}

	private void generateSubentries(IIndexEntry entry, int level) {
	IIndexEntry[] subentries = entry.getSubentries();
	for (IIndexEntry subentrie : subentries) {
	generateEntry(subentrie, level, "s" + count++); //$NON-NLS-1$
	}
	}

	private void generateTopicList(IIndexEntry entry) {
	ITopic[] topics = entry.getTopics();

	for (ITopic topic : topics) {
	if (ScopeUtils.showInTree(topic, scope)) {
	//
	String label = UrlUtil.htmlEncode(topic.getLabel());
	if (label == null) {
	label = UrlUtil.htmlEncode(topic.getLabel());
	}

	buf.append("<node"); //$NON-NLS-1$
	if (entry.getKeyword() != null) {
	buf.append('\n' + " title=\"" + label + '"'); //$NON-NLS-1$
	}

	count++;
	buf.append('\n' + " id=\"i" + count + '"'); //$NON-NLS-1$
	String href = UrlUtil.getHelpURL(topic.getHref());
	buf.append('\n' + " href=\"" //$NON-NLS-1$
	+ XMLGenerator.xmlEscape(href) + "\""); //$NON-NLS-1$
	buf.append(">\n"); //$NON-NLS-1$
	buf.append("</node>\n"); //$NON-NLS-1$
	}
	}
	}

	private void generateSees(IIndexSee[] sees) {
	for (IIndexSee see : sees) {
	if (ScopeUtils.showInTree(see, scope)) {
	//
	String key = see.isSeeAlso() ? "SeeAlso" : "See"; //$NON-NLS-1$ //$NON-NLS-2$
	String seePrefix = WebappResources.getString(key, UrlUtil
	.getLocale(locale));
	String seeTarget = see.getKeyword();
	IIndexSubpath[] subpathElements = see.getSubpathElements();
	for (IIndexSubpath subpathElement : subpathElements) {
	seeTarget += ", "; //$NON-NLS-1$
	seeTarget += subpathElement.getKeyword();
	}
	String label = NLS.bind(seePrefix, seeTarget);
	String encodedLabel = UrlUtil.htmlEncode(label);
	buf.append("<node"); //$NON-NLS-1$

	buf.append('\n' + " title=\"" + encodedLabel + '"'); //$NON-NLS-1$

	count++;
	buf.append('\n' + " id=\"i" + count + '"'); //$NON-NLS-1$
	String href = "see:" + seeTarget; //$NON-NLS-1$
	buf.append('\n' + " href=\"" //$NON-NLS-1$
	+ XMLGenerator.xmlEscape(href) + "\""); //$NON-NLS-1$
	buf.append(">\n"); //$NON-NLS-1$
	buf.append("</node>\n"); //$NON-NLS-1$
	}
	}
	}
	}

	}