/*******************************************************************************
* Copyright (c) 2005, 2007 Intel 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:
* Intel Corporation - initial API and implementation
* IBM Corporation - 122967 [Help] Remote help system
* 163558 Dynamic content support for all UA
* 165168 [Help] Better control of how help content is arranged and ordered
*******************************************************************************/
package org.eclipse.help.internal.index;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Preferences;
import org.eclipse.help.AbstractIndexProvider;
import org.eclipse.help.IIndex;
import org.eclipse.help.IIndexContribution;
import org.eclipse.help.internal.HelpData;
import org.eclipse.help.internal.HelpPlugin;
import org.eclipse.help.internal.UAElementFactory;
public class IndexManager {
private static final String EXTENSION_POINT_ID_INDEX = HelpPlugin.PLUGIN_ID + ".index"; //$NON-NLS-1$
private static final String ELEMENT_NAME_INDEX_PROVIDER = "indexProvider"; //$NON-NLS-1$
private static final String ATTRIBUTE_NAME_CLASS = "class"; //$NON-NLS-1$
private Map indexContributionsByLocale = new HashMap();
private Map indexesByLocale = new HashMap();
private AbstractIndexProvider[] indexProviders;
public synchronized IIndex getIndex(String locale) {
Index index = (Index)indexesByLocale.get(locale);
if (index == null) {
List contributions = new ArrayList(Arrays.asList(getIndexContributions(locale)));
filterIndexContributions(contributions);
IndexAssembler assembler = new IndexAssembler();
index = assembler.assemble(contributions, locale);
indexesByLocale.put(locale, index);
}
return index;
}
/*
* Returns all index contributions for the given locale, from all
* providers.
*/
public synchronized IndexContribution[] getIndexContributions(String locale) {
IndexContribution[] cached = (IndexContribution[])indexContributionsByLocale.get(locale);
if (cached == null) {
List contributions = new ArrayList();
AbstractIndexProvider[] providers = getIndexProviders();
for (int i=0;i<providers.length;++i) {
IIndexContribution[] contrib;
try {
contrib = providers[i].getIndexContributions(locale);
}
catch (Throwable t) {
// log, and skip the offending provider
String msg = "Error getting help keyword index data from provider: " + providers[i].getClass().getName() + " (skipping provider)"; //$NON-NLS-1$ //$NON-NLS-2$
HelpPlugin.logError(msg, t);
continue;
}
// check for nulls and root element
for (int j=0;j<contrib.length;++j) {
if (contrib[j] == null) {
String msg = "Help keyword index provider \"" + providers[i].getClass().getName() + "\" returned a null contribution (skipping)"; //$NON-NLS-1$ //$NON-NLS-2$
HelpPlugin.logError(msg);
}
else if (contrib[j].getIndex() == null) {
String msg = "Help keyword index provider \"" + providers[i].getClass().getName() + "\" returned a contribution with a null root element (expected a \"" + Index.NAME + "\" element; skipping)"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
HelpPlugin.logError(msg);
}
else {
IndexContribution contribution = new IndexContribution();
contribution.setId(contrib[j].getId());
contribution.setLocale(contrib[j].getLocale());
IIndex index = contrib[j].getIndex();
contribution.setIndex(index instanceof Index ? (Index)index : (Index)UAElementFactory.newElement(index));
contributions.add(contribution);
}
}
}
cached = (IndexContribution[])contributions.toArray(new IndexContribution[contributions.size()]);
indexContributionsByLocale.put(locale, cached);
}
return cached;
}
/*
* Clears all cached contributions, forcing the manager to query the
* providers again next time a request is made.
*/
public void clearCache() {
indexContributionsByLocale.clear();
indexesByLocale.clear();
}
/*
* Internal hook for unit testing.
*/
public AbstractIndexProvider[] getIndexProviders() {
if (indexProviders == null) {
List providers = new ArrayList();
IExtensionRegistry registry = Platform.getExtensionRegistry();
IConfigurationElement[] elements = registry.getConfigurationElementsFor(EXTENSION_POINT_ID_INDEX);
for (int i=0;i<elements.length;++i) {
IConfigurationElement elem = elements[i];
if (elem.getName().equals(ELEMENT_NAME_INDEX_PROVIDER)) {
try {
AbstractIndexProvider provider = (AbstractIndexProvider)elem.createExecutableExtension(ATTRIBUTE_NAME_CLASS);
providers.add(provider);
}
catch (CoreException e) {
// log and skip
String msg = "Error instantiating help keyword index provider class \"" + elem.getAttribute(ATTRIBUTE_NAME_CLASS) + '"'; //$NON-NLS-1$
HelpPlugin.logError(msg, e);
}
}
}
indexProviders = (AbstractIndexProvider[])providers.toArray(new AbstractIndexProvider[providers.size()]);
}
return indexProviders;
}
/*
* Returns whether or not the index has been completely loaded for the
* given locale yet or not.
*/
public boolean isIndexLoaded(String locale) {
return indexesByLocale.get(locale) != null;
}
/*
* Internal hook for unit testing.
*/
public void setIndexProviders(AbstractIndexProvider[] indexProviders) {
this.indexProviders = indexProviders;
}
/*
* Filters the given contributions according to product preferences. If
* either the contribution's id or its category's id is listed in the
* ignoredIndexes, filter the contribution.
*/
private void filterIndexContributions(List unfiltered) {
Set indexesToFilter = getIgnoredIndexContributions();
ListIterator iter = unfiltered.listIterator();
while (iter.hasNext()) {
IIndexContribution contribution = (IIndexContribution)iter.next();
if (indexesToFilter.contains(contribution.getId())) {
iter.remove();
}
}
}
private Set getIgnoredIndexContributions() {
HelpData helpData = HelpData.getProductHelpData();
if (helpData != null) {
return helpData.getHiddenIndexes();
}
else {
HashSet ignored = new HashSet();
Preferences pref = HelpPlugin.getDefault().getPluginPreferences();
String preferredIndexes = pref.getString(HelpPlugin.IGNORED_INDEXES_KEY);
if (preferredIndexes.length() > 0) {
StringTokenizer suggestdOrderedInfosets = new StringTokenizer(preferredIndexes, " ;,"); //$NON-NLS-1$
while (suggestdOrderedInfosets.hasMoreTokens()) {
ignored.add(suggestdOrderedInfosets.nextToken());
}
}
return ignored;
}
}
}