ltk/org.eclipse.statet.ltk.ui/src/org/eclipse/statet/ltk/ui/sourceediting/assist/ContentAssistComputerRegistry.java - statet/org.eclipse.statet-ltk - Git at Google

 /*=============================================================================#
  # Copyright (c) 2008, 2020 Stephan Wahlbrink and others.
  #
  # This program and the accompanying materials are made available under the
  # terms of the Eclipse Public License 2.0 which is available at
  # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
  # which is available at https://www.apache.org/licenses/LICENSE-2.0.
  #
  # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
  #
  # Contributors:
  #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
  #=============================================================================*/

 package org.eclipse.statet.ltk.ui.sourceediting.assist;

 import static org.eclipse.statet.jcommons.lang.ObjectUtils.nonNullAssert;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 import org.osgi.framework.Bundle;

 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtensionRegistry;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.jface.resource.ImageDescriptor;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.ui.statushandlers.StatusManager;

 import org.eclipse.statet.jcommons.collections.ImCollections;
 import org.eclipse.statet.jcommons.collections.ImList;
 import org.eclipse.statet.jcommons.lang.Disposable;
 import org.eclipse.statet.jcommons.lang.NonNull;
 import org.eclipse.statet.jcommons.lang.NonNullByDefault;
 import org.eclipse.statet.jcommons.lang.Nullable;

 import org.eclipse.statet.ecommons.preferences.PreferencesUtil;
 import org.eclipse.statet.ecommons.preferences.SettingsChangeNotifier;
 import org.eclipse.statet.ecommons.preferences.SettingsChangeNotifier.ManageListener;
 import org.eclipse.statet.ecommons.preferences.core.Preference;
 import org.eclipse.statet.ecommons.preferences.core.Preference.StringArrayPref;
 import org.eclipse.statet.ecommons.preferences.core.Preference.StringSetPref;
 import org.eclipse.statet.ecommons.preferences.core.PreferenceAccess;
 import org.eclipse.statet.ecommons.preferences.core.util.PreferenceUtils;
 import org.eclipse.statet.ecommons.ui.SharedUIResources;

 import org.eclipse.statet.internal.ltk.ui.AdvancedExtensionsInternal;


 /**
  * Registry of contributions for {@link ContentAssistProcessor}s for a single content type.
  */
 @NonNullByDefault
 public class ContentAssistComputerRegistry implements ManageListener, Disposable {


 	public static String DEFAULT_DISABLED= "assist.default.disabled_categories.ids"; //$NON-NLS-1$
 	public static String CIRCLING_ORDERED= "assist.circling.ordered_categories.ids:enabled"; //$NON-NLS-1$


 	public static final Bundle getBundle(final IConfigurationElement element) {
 		final String namespace= element.getDeclaringExtension().getContributor().getName();
 		final Bundle bundle= Platform.getBundle(namespace);
 		return nonNullAssert(bundle);
 	}

 	protected static final Map<String, ContentAssistCategory> createCategoryByIdMap(final List<ContentAssistCategory> categories) {
 		final Map<String, ContentAssistCategory> map= new HashMap<>();
 		for (final ContentAssistCategory category : categories) {
 			map.put(category.getId(), category);
 		}
 		return map;
 	}


 	/**
 	 * The description of an {@link ContentAssistComputer}
 	 */
 	final class ComputerDescriptor {


 		/** The identifier of the extension. */
 		private final String id;

 		private final Set<String> partitions;

 		/** The configuration element of this extension. */
 		private final IConfigurationElement configurationElement;

 		/** The computer, if instantiated, <code>null</code> otherwise. */
 		private @Nullable ContentAssistComputer computer;

 		/** Tells whether we tried to load the computer. */
 		private boolean triedLoadingComputer= false;


 		/**
 		 * Creates a new descriptor with lazy loaded computer
 		 */
 		ComputerDescriptor(final String id, final Set<String> partitions, final IConfigurationElement configurationElement) {
 			this.id= id;
 			this.partitions= partitions;
 			this.configurationElement= configurationElement;
 		}


 		/**
 		 * Returns the identifier of the described extension.
 		 *
 		 * @return Returns the id
 		 */
 		public String getId() {
 			return this.id;
 		}

 		/**
 		 * Returns the partition types of the described extension.
 		 *
 		 * @return the set of partition types (element type: {@link String})
 		 */
 		public Set<String> getPartitions() {
 			return this.partitions;
 		}

 		/**
 		 * Returns a cached instance of the computer
 		 */
 		public @Nullable ContentAssistComputer getComputer() {
 			if (this.computer == null && !this.triedLoadingComputer && this.configurationElement != null) {
 				this.triedLoadingComputer= true;
 				try {
 					this.computer= (ContentAssistComputer) this.configurationElement.createExecutableExtension(AdvancedExtensionsInternal.CONFIG_CLASS_ATTRIBUTE_NAME);
 				}
 				catch (final CoreException e) {
 					StatusManager.getManager().handle(new Status(IStatus.ERROR, SharedUIResources.BUNDLE_ID, -1,
 							NLS.bind("Loading Content Assist Computer ''{0}'' failed (contributed by= '' {1}'').", //$NON-NLS-1$
 									this.id, this.configurationElement.getDeclaringExtension().getContributor().getName() ),
 							e ));
 				}
 			}
 			return this.computer;
 		}

 	}

 	class CategoryPreferences {

 		public final List<ContentAssistCategory> allCategories;
 		public final List<ContentAssistCategory> defaultEnabledCategories;
 		public final List<ContentAssistCategory> circlingOrderedCategories;
 		public final List<ContentAssistCategory> circlingOrderedEnabledCategories;


 		public CategoryPreferences(final List<ContentAssistCategory> categories) {
 			this.allCategories= categories;
 			this.defaultEnabledCategories= new ArrayList<>(categories.size());
 			this.circlingOrderedCategories= new ArrayList<>(categories.size());
 			this.circlingOrderedEnabledCategories= new ArrayList<>(categories.size());
 		}

 	}


 	private final String contentTypeId;

 	private final String qualifier;
 	private final StringSetPref prefDisabledCategoryIds;
 	private final StringArrayPref prefOrderedCategoryIds;

 	private @Nullable ImList<ComputerDescriptor> computers;
 	private @Nullable ImList<ContentAssistCategory> categories;


 	public ContentAssistComputerRegistry(final String contentTypeId, final String prefQualifier) {
 		this.contentTypeId= contentTypeId;
 		this.qualifier= prefQualifier;
 		this.prefDisabledCategoryIds= new StringSetPref(prefQualifier, DEFAULT_DISABLED);
 		this.prefOrderedCategoryIds= new StringArrayPref(prefQualifier, CIRCLING_ORDERED);

 		PreferencesUtil.getSettingsChangeNotifier().addManageListener(this);
 	}


 	@Override
 	public void dispose() {
 		final SettingsChangeNotifier notifier= PreferencesUtil.getSettingsChangeNotifier();
 		if (notifier != null) {
 			notifier.removeManageListener(this);
 		}
 	}


 	String getSettingsGroupId() {
 		return this.qualifier;
 	}

 	StringSetPref getPrefDefaultDisabledCategoryIds() {
 		return this.prefDisabledCategoryIds;
 	}

 	StringArrayPref getPrefCirclingOrderedCategoryIds() {
 		return this.prefOrderedCategoryIds;
 	}

 	@Override
 	public void beforeSettingsChangeNotification(final Set<String> groupIds) {
 		if (this.qualifier != null && groupIds.contains(this.qualifier)) {
 			synchronized (this) {
 				if (this.categories != null) {
 					this.categories= ImCollections.toList(
 							applyPreferences(PreferenceUtils.getInstancePrefs(), this.categories) );
 				}
 			}
 		}
 	}

 	@Override
 	public void afterSettingsChangeNotification(final Set<String> groupIds) {
 	}

 	private void loadExtensions() {
 		final ArrayList<IConfigurationElement> categoryConfigs= new ArrayList<>(); // categories of all content types!
 		final List<ComputerDescriptor> allComputers= new ArrayList<>();
 		final Map<String, List<ComputerDescriptor>> computersByCategoryId= new HashMap<>();

 		final IExtensionRegistry extensionRegistry= Platform.getExtensionRegistry();

 		final IConfigurationElement[] elements= extensionRegistry.getConfigurationElementsFor(
 				AdvancedExtensionsInternal.CONTENTASSIST_EXTENSIONPOINT_ID);
 		for (final IConfigurationElement element : elements) {
 			if (element.getName().equals(AdvancedExtensionsInternal.CONFIG_CATEGORY_ELEMENT_NAME)) {
 				categoryConfigs.add(element);
 				continue;
 			}
 			if (element.getName().equals(AdvancedExtensionsInternal.CONFIG_COMPUTER_ELEMENT_NAME)) {
 				// Create computer descriptor
 				String id= null;
 				try {
 					final String contentTypeId= AdvancedExtensionsInternal.getCheckedString(element, AdvancedExtensionsInternal.CONFIG_CONTENT_TYPE_ID_ATTRIBUTE_NAME);
 					if (!this.contentTypeId.equals(contentTypeId)) {
 						continue;
 					}
 					id= AdvancedExtensionsInternal.getCheckedString(element, AdvancedExtensionsInternal.CONFIG_ID_ATTRIBUTE_NAME).intern();
 					final String categoryId= AdvancedExtensionsInternal.getCheckedString(element, AdvancedExtensionsInternal.CONFIG_CATEGORY_ID_ATTRIBUTE_NAME);
 					final Set<String> partitions= new HashSet<>();
 					final IConfigurationElement[] partitionConfigs= element.getChildren(AdvancedExtensionsInternal.CONFIG_PARTITION_ELEMENT_NAME);
 					for (final IConfigurationElement partitionConfig : partitionConfigs) {
 						partitions.add(AdvancedExtensionsInternal.getCheckedString(partitionConfig, AdvancedExtensionsInternal.CONFIG_CONTENTTYPE_ID_ELEMENT_NAME).intern());
 					}
 					checkPartitions(partitions);

 					final ComputerDescriptor computer= new ComputerDescriptor(id, partitions, element);
 					allComputers.add(computer);

 					List<ComputerDescriptor> list= computersByCategoryId.get(categoryId);
 					if (list == null) {
 						list= new ArrayList<>(4);
 						computersByCategoryId.put(categoryId, list);
 					}
 					list.add(computer);
 				}
 				catch (final CoreException e) {
 					StatusManager.getManager().handle(new Status(IStatus.ERROR, SharedUIResources.BUNDLE_ID, 0,
 							NLS.bind("Loading Completion Proposal Computer ''{0}'' failed (contributed by= ''{1}'')", //$NON-NLS-1$
 									(id != null) ? id : "", element.getDeclaringExtension().getContributor().getName() ), //$NON-NLS-1$
 							e ));
 				}
 			}
 		}

 		final ArrayList<ContentAssistCategory> categories= new ArrayList<>(8);
 		for (final IConfigurationElement catConfig : categoryConfigs) {
 			// Create category descriptor
 			String id= null;
 			try {
 				id= AdvancedExtensionsInternal.getCheckedString(catConfig, AdvancedExtensionsInternal.CONFIG_ID_ATTRIBUTE_NAME);
 				final List<ComputerDescriptor> descriptors= computersByCategoryId.get(id);
 				if (descriptors != null) {
 					final ImageDescriptor icon= AdvancedExtensionsInternal.getImageDescriptor(catConfig, AdvancedExtensionsInternal.CONFIG_ICON_ATTRIBUTE_NAME);
 					final String name= AdvancedExtensionsInternal.getCheckedString(catConfig, AdvancedExtensionsInternal.CONFIG_NAME_ATTRIBUTE_NAME);
 					final ContentAssistCategory cat= new ContentAssistCategory(id, name, icon, descriptors);
 					categories.add(cat);
 				}
 			}
 			catch (final CoreException e) {
 				StatusManager.getManager().handle(new Status(IStatus.ERROR, SharedUIResources.BUNDLE_ID, 0,
 						NLS.bind("Loading Completion Proposal Category ''{0}'' failed (contributed by= ''{1}'')", //$NON-NLS-1$
 								(id != null) ? id : "", catConfig.getDeclaringExtension().getContributor().getName() ), //$NON-NLS-1$
 						e ));
 			}
 		}
 		this.computers= ImCollections.toList(allComputers);
 		this.categories= ImCollections.toList(
 				applyPreferences(PreferenceUtils.getInstancePrefs(), categories) );
 	}

 	List<ContentAssistCategory> applyPreferences(final PreferenceAccess prefAccess,
 			final List<ContentAssistCategory> categories) {
 		final Set<String> disabledIds= prefAccess.getPreferenceValue(getPrefDefaultDisabledCategoryIds());
 		for (final ContentAssistCategory category : categories) {
 			final boolean enabled= disabledIds == null || !disabledIds.contains(category.getId());
 			category.isIncludedInDefault= enabled;
 		}

 		final Map<String, ContentAssistCategory> map= createCategoryByIdMap(categories);
 		final String[] orderPref= prefAccess.getPreferenceValue(getPrefCirclingOrderedCategoryIds());
 		final List<ContentAssistCategory> ordered= new ArrayList<>(categories.size());
 		for (final String value : orderPref) {
 			final String id;
 			final boolean enabled;
 			final int idx= value.lastIndexOf(':');
 			if (idx > 0) {
 				id= value.substring(0, idx);
 				enabled= Boolean.parseBoolean(value.substring(idx+1));
 			}
 			else { // fallback
 				id= value;
 				enabled= false;
 			}
 			final ContentAssistCategory category= map.remove(id);
 			if (category != null) {
 				ordered.add(category);
 				category.isEnabledAsSeparate= enabled;
 			}
 		}
 		for (final ContentAssistCategory category : map.values()) {
 			ordered.add(category);
 			category.isEnabledAsSeparate= false;
 		}

 		return ordered;
 	}

 	Map<Preference<?>, Object> createPreferences(final List<ContentAssistCategory> orderedCategories) {
 		final Set<String> disabledIds= new HashSet<>();
 		final String[] orderedPref= new @NonNull String[orderedCategories.size()];

 		for (int i= 0; i < orderedCategories.size(); i++) {
 			final ContentAssistCategory category= orderedCategories.get(i);
 			if (!category.isIncludedInDefault) {
 				disabledIds.add(category.getId());
 			}
 			orderedPref[i]= category.getId() +
 					(category.isEnabledAsSeparate ? ":true" : ":false"); //$NON-NLS-1$ //$NON-NLS-2$
 		}

 		final Map<Preference<?>, Object> prefMap= new HashMap<>();
 		prefMap.put(getPrefDefaultDisabledCategoryIds(), disabledIds);
 		prefMap.put(getPrefCirclingOrderedCategoryIds(), orderedPref);
 		return prefMap;
 	}


 	protected void checkPartitions(final Set<String> partitions) {
 	}


 	@SuppressWarnings("null")
 	public synchronized ImList<ContentAssistCategory> getCategories() {
 		ImList<ContentAssistCategory> categories= this.categories;
 		if (categories == null) {
 			loadExtensions();
 			categories= this.categories;
 		}
 		return categories;
 	}

 	public List<ContentAssistCategory> getCopyOfCategories() {
 		final ImList<ContentAssistCategory> categories= getCategories();
 		final List<ContentAssistCategory> copies= new ArrayList<>(categories.size());
 		for (final ContentAssistCategory category : categories) {
 			copies.add(new ContentAssistCategory(category));
 		}
 		return copies;
 	}

 	public ImList<ContentAssistCategory> getCategory(final String categoryId) {
 		final ImList<ContentAssistCategory> categories= getCategories();
 		for (final ContentAssistCategory category : categories) {
 			if (category.getId().equals(categoryId)) {
 				final ContentAssistCategory copy= new ContentAssistCategory(category);
 				copy.isIncludedInDefault= true;
 				return ImCollections.newList(copy);
 			}
 		}
 		return ImCollections.emptyList();
 	}

 	@SuppressWarnings("null")
 	private synchronized ImList<ComputerDescriptor> getComputers() {
 		ImList<ComputerDescriptor> computers= this.computers;
 		if (computers == null) {
 			loadExtensions();
 			computers= this.computers;
 		}
 		return computers;
 	}

 	public @Nullable ContentAssistComputer getComputer(final String id) {
 		final ImList<ComputerDescriptor> computers= getComputers();
 		for (final ComputerDescriptor descr : computers) {
 			if (descr.getId().equals(id)) {
 				return descr.getComputer();
 			}
 		}
 		return null;
 	}

 }
	/*=============================================================================#
	# Copyright (c) 2008, 2020 Stephan Wahlbrink and others.
	#
	# This program and the accompanying materials are made available under the
	# terms of the Eclipse Public License 2.0 which is available at
	# https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
	# which is available at https://www.apache.org/licenses/LICENSE-2.0.
	#
	# SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
	#
	# Contributors:
	# Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
	#=============================================================================*/

	package org.eclipse.statet.ltk.ui.sourceediting.assist;

	import static org.eclipse.statet.jcommons.lang.ObjectUtils.nonNullAssert;

	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	import org.osgi.framework.Bundle;

	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtensionRegistry;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.jface.resource.ImageDescriptor;
	import org.eclipse.osgi.util.NLS;
	import org.eclipse.ui.statushandlers.StatusManager;

	import org.eclipse.statet.jcommons.collections.ImCollections;
	import org.eclipse.statet.jcommons.collections.ImList;
	import org.eclipse.statet.jcommons.lang.Disposable;
	import org.eclipse.statet.jcommons.lang.NonNull;
	import org.eclipse.statet.jcommons.lang.NonNullByDefault;
	import org.eclipse.statet.jcommons.lang.Nullable;

	import org.eclipse.statet.ecommons.preferences.PreferencesUtil;
	import org.eclipse.statet.ecommons.preferences.SettingsChangeNotifier;
	import org.eclipse.statet.ecommons.preferences.SettingsChangeNotifier.ManageListener;
	import org.eclipse.statet.ecommons.preferences.core.Preference;
	import org.eclipse.statet.ecommons.preferences.core.Preference.StringArrayPref;
	import org.eclipse.statet.ecommons.preferences.core.Preference.StringSetPref;
	import org.eclipse.statet.ecommons.preferences.core.PreferenceAccess;
	import org.eclipse.statet.ecommons.preferences.core.util.PreferenceUtils;
	import org.eclipse.statet.ecommons.ui.SharedUIResources;

	import org.eclipse.statet.internal.ltk.ui.AdvancedExtensionsInternal;


	/**
	* Registry of contributions for {@link ContentAssistProcessor}s for a single content type.
	*/
	@NonNullByDefault
	public class ContentAssistComputerRegistry implements ManageListener, Disposable {


	public static String DEFAULT_DISABLED= "assist.default.disabled_categories.ids"; //$NON-NLS-1$
	public static String CIRCLING_ORDERED= "assist.circling.ordered_categories.ids:enabled"; //$NON-NLS-1$


	public static final Bundle getBundle(final IConfigurationElement element) {
	final String namespace= element.getDeclaringExtension().getContributor().getName();
	final Bundle bundle= Platform.getBundle(namespace);
	return nonNullAssert(bundle);
	}

	protected static final Map<String, ContentAssistCategory> createCategoryByIdMap(final List<ContentAssistCategory> categories) {
	final Map<String, ContentAssistCategory> map= new HashMap<>();
	for (final ContentAssistCategory category : categories) {
	map.put(category.getId(), category);
	}
	return map;
	}


	/**
	* The description of an {@link ContentAssistComputer}
	*/
	final class ComputerDescriptor {


	/** The identifier of the extension. */
	private final String id;

	private final Set<String> partitions;

	/** The configuration element of this extension. */
	private final IConfigurationElement configurationElement;

	/** The computer, if instantiated, <code>null</code> otherwise. */
	private @Nullable ContentAssistComputer computer;

	/** Tells whether we tried to load the computer. */
	private boolean triedLoadingComputer= false;


	/**
	* Creates a new descriptor with lazy loaded computer
	*/
	ComputerDescriptor(final String id, final Set<String> partitions, final IConfigurationElement configurationElement) {
	this.id= id;
	this.partitions= partitions;
	this.configurationElement= configurationElement;
	}


	/**
	* Returns the identifier of the described extension.
	*
	* @return Returns the id
	*/
	public String getId() {
	return this.id;
	}

	/**
	* Returns the partition types of the described extension.
	*
	* @return the set of partition types (element type: {@link String})
	*/
	public Set<String> getPartitions() {
	return this.partitions;
	}

	/**
	* Returns a cached instance of the computer
	*/
	public @Nullable ContentAssistComputer getComputer() {
	if (this.computer == null && !this.triedLoadingComputer && this.configurationElement != null) {
	this.triedLoadingComputer= true;
	try {
	this.computer= (ContentAssistComputer) this.configurationElement.createExecutableExtension(AdvancedExtensionsInternal.CONFIG_CLASS_ATTRIBUTE_NAME);
	}
	catch (final CoreException e) {
	StatusManager.getManager().handle(new Status(IStatus.ERROR, SharedUIResources.BUNDLE_ID, -1,
	NLS.bind("Loading Content Assist Computer ''{0}'' failed (contributed by= '' {1}'').", //$NON-NLS-1$
	this.id, this.configurationElement.getDeclaringExtension().getContributor().getName() ),
	e ));
	}
	}
	return this.computer;
	}

	}

	class CategoryPreferences {

	public final List<ContentAssistCategory> allCategories;
	public final List<ContentAssistCategory> defaultEnabledCategories;
	public final List<ContentAssistCategory> circlingOrderedCategories;
	public final List<ContentAssistCategory> circlingOrderedEnabledCategories;


	public CategoryPreferences(final List<ContentAssistCategory> categories) {
	this.allCategories= categories;
	this.defaultEnabledCategories= new ArrayList<>(categories.size());
	this.circlingOrderedCategories= new ArrayList<>(categories.size());
	this.circlingOrderedEnabledCategories= new ArrayList<>(categories.size());
	}

	}


	private final String contentTypeId;

	private final String qualifier;
	private final StringSetPref prefDisabledCategoryIds;
	private final StringArrayPref prefOrderedCategoryIds;

	private @Nullable ImList<ComputerDescriptor> computers;
	private @Nullable ImList<ContentAssistCategory> categories;


	public ContentAssistComputerRegistry(final String contentTypeId, final String prefQualifier) {
	this.contentTypeId= contentTypeId;
	this.qualifier= prefQualifier;
	this.prefDisabledCategoryIds= new StringSetPref(prefQualifier, DEFAULT_DISABLED);
	this.prefOrderedCategoryIds= new StringArrayPref(prefQualifier, CIRCLING_ORDERED);

	PreferencesUtil.getSettingsChangeNotifier().addManageListener(this);
	}


	@Override
	public void dispose() {
	final SettingsChangeNotifier notifier= PreferencesUtil.getSettingsChangeNotifier();
	if (notifier != null) {
	notifier.removeManageListener(this);
	}
	}


	String getSettingsGroupId() {
	return this.qualifier;
	}

	StringSetPref getPrefDefaultDisabledCategoryIds() {
	return this.prefDisabledCategoryIds;
	}

	StringArrayPref getPrefCirclingOrderedCategoryIds() {
	return this.prefOrderedCategoryIds;
	}

	@Override
	public void beforeSettingsChangeNotification(final Set<String> groupIds) {
	if (this.qualifier != null && groupIds.contains(this.qualifier)) {
	synchronized (this) {
	if (this.categories != null) {
	this.categories= ImCollections.toList(
	applyPreferences(PreferenceUtils.getInstancePrefs(), this.categories) );
	}
	}
	}
	}

	@Override
	public void afterSettingsChangeNotification(final Set<String> groupIds) {
	}

	private void loadExtensions() {
	final ArrayList<IConfigurationElement> categoryConfigs= new ArrayList<>(); // categories of all content types!
	final List<ComputerDescriptor> allComputers= new ArrayList<>();
	final Map<String, List<ComputerDescriptor>> computersByCategoryId= new HashMap<>();

	final IExtensionRegistry extensionRegistry= Platform.getExtensionRegistry();

	final IConfigurationElement[] elements= extensionRegistry.getConfigurationElementsFor(
	AdvancedExtensionsInternal.CONTENTASSIST_EXTENSIONPOINT_ID);
	for (final IConfigurationElement element : elements) {
	if (element.getName().equals(AdvancedExtensionsInternal.CONFIG_CATEGORY_ELEMENT_NAME)) {
	categoryConfigs.add(element);
	continue;
	}
	if (element.getName().equals(AdvancedExtensionsInternal.CONFIG_COMPUTER_ELEMENT_NAME)) {
	// Create computer descriptor
	String id= null;
	try {
	final String contentTypeId= AdvancedExtensionsInternal.getCheckedString(element, AdvancedExtensionsInternal.CONFIG_CONTENT_TYPE_ID_ATTRIBUTE_NAME);
	if (!this.contentTypeId.equals(contentTypeId)) {
	continue;
	}
	id= AdvancedExtensionsInternal.getCheckedString(element, AdvancedExtensionsInternal.CONFIG_ID_ATTRIBUTE_NAME).intern();
	final String categoryId= AdvancedExtensionsInternal.getCheckedString(element, AdvancedExtensionsInternal.CONFIG_CATEGORY_ID_ATTRIBUTE_NAME);
	final Set<String> partitions= new HashSet<>();
	final IConfigurationElement[] partitionConfigs= element.getChildren(AdvancedExtensionsInternal.CONFIG_PARTITION_ELEMENT_NAME);
	for (final IConfigurationElement partitionConfig : partitionConfigs) {
	partitions.add(AdvancedExtensionsInternal.getCheckedString(partitionConfig, AdvancedExtensionsInternal.CONFIG_CONTENTTYPE_ID_ELEMENT_NAME).intern());
	}
	checkPartitions(partitions);

	final ComputerDescriptor computer= new ComputerDescriptor(id, partitions, element);
	allComputers.add(computer);

	List<ComputerDescriptor> list= computersByCategoryId.get(categoryId);
	if (list == null) {
	list= new ArrayList<>(4);
	computersByCategoryId.put(categoryId, list);
	}
	list.add(computer);
	}
	catch (final CoreException e) {
	StatusManager.getManager().handle(new Status(IStatus.ERROR, SharedUIResources.BUNDLE_ID, 0,
	NLS.bind("Loading Completion Proposal Computer ''{0}'' failed (contributed by= ''{1}'')", //$NON-NLS-1$
	(id != null) ? id : "", element.getDeclaringExtension().getContributor().getName() ), //$NON-NLS-1$
	e ));
	}
	}
	}

	final ArrayList<ContentAssistCategory> categories= new ArrayList<>(8);
	for (final IConfigurationElement catConfig : categoryConfigs) {
	// Create category descriptor
	String id= null;
	try {
	id= AdvancedExtensionsInternal.getCheckedString(catConfig, AdvancedExtensionsInternal.CONFIG_ID_ATTRIBUTE_NAME);
	final List<ComputerDescriptor> descriptors= computersByCategoryId.get(id);
	if (descriptors != null) {
	final ImageDescriptor icon= AdvancedExtensionsInternal.getImageDescriptor(catConfig, AdvancedExtensionsInternal.CONFIG_ICON_ATTRIBUTE_NAME);
	final String name= AdvancedExtensionsInternal.getCheckedString(catConfig, AdvancedExtensionsInternal.CONFIG_NAME_ATTRIBUTE_NAME);
	final ContentAssistCategory cat= new ContentAssistCategory(id, name, icon, descriptors);
	categories.add(cat);
	}
	}
	catch (final CoreException e) {
	StatusManager.getManager().handle(new Status(IStatus.ERROR, SharedUIResources.BUNDLE_ID, 0,
	NLS.bind("Loading Completion Proposal Category ''{0}'' failed (contributed by= ''{1}'')", //$NON-NLS-1$
	(id != null) ? id : "", catConfig.getDeclaringExtension().getContributor().getName() ), //$NON-NLS-1$
	e ));
	}
	}
	this.computers= ImCollections.toList(allComputers);
	this.categories= ImCollections.toList(
	applyPreferences(PreferenceUtils.getInstancePrefs(), categories) );
	}

	List<ContentAssistCategory> applyPreferences(final PreferenceAccess prefAccess,
	final List<ContentAssistCategory> categories) {
	final Set<String> disabledIds= prefAccess.getPreferenceValue(getPrefDefaultDisabledCategoryIds());
	for (final ContentAssistCategory category : categories) {
	final boolean enabled= disabledIds == null \|\| !disabledIds.contains(category.getId());
	category.isIncludedInDefault= enabled;
	}

	final Map<String, ContentAssistCategory> map= createCategoryByIdMap(categories);
	final String[] orderPref= prefAccess.getPreferenceValue(getPrefCirclingOrderedCategoryIds());
	final List<ContentAssistCategory> ordered= new ArrayList<>(categories.size());
	for (final String value : orderPref) {
	final String id;
	final boolean enabled;
	final int idx= value.lastIndexOf(':');
	if (idx > 0) {
	id= value.substring(0, idx);
	enabled= Boolean.parseBoolean(value.substring(idx+1));
	}
	else { // fallback
	id= value;
	enabled= false;
	}
	final ContentAssistCategory category= map.remove(id);
	if (category != null) {
	ordered.add(category);
	category.isEnabledAsSeparate= enabled;
	}
	}
	for (final ContentAssistCategory category : map.values()) {
	ordered.add(category);
	category.isEnabledAsSeparate= false;
	}

	return ordered;
	}

	Map<Preference<?>, Object> createPreferences(final List<ContentAssistCategory> orderedCategories) {
	final Set<String> disabledIds= new HashSet<>();
	final String[] orderedPref= new @NonNull String[orderedCategories.size()];

	for (int i= 0; i < orderedCategories.size(); i++) {
	final ContentAssistCategory category= orderedCategories.get(i);
	if (!category.isIncludedInDefault) {
	disabledIds.add(category.getId());
	}
	orderedPref[i]= category.getId() +
	(category.isEnabledAsSeparate ? ":true" : ":false"); //$NON-NLS-1$ //$NON-NLS-2$
	}

	final Map<Preference<?>, Object> prefMap= new HashMap<>();
	prefMap.put(getPrefDefaultDisabledCategoryIds(), disabledIds);
	prefMap.put(getPrefCirclingOrderedCategoryIds(), orderedPref);
	return prefMap;
	}


	protected void checkPartitions(final Set<String> partitions) {
	}


	@SuppressWarnings("null")
	public synchronized ImList<ContentAssistCategory> getCategories() {
	ImList<ContentAssistCategory> categories= this.categories;
	if (categories == null) {
	loadExtensions();
	categories= this.categories;
	}
	return categories;
	}

	public List<ContentAssistCategory> getCopyOfCategories() {
	final ImList<ContentAssistCategory> categories= getCategories();
	final List<ContentAssistCategory> copies= new ArrayList<>(categories.size());
	for (final ContentAssistCategory category : categories) {
	copies.add(new ContentAssistCategory(category));
	}
	return copies;
	}

	public ImList<ContentAssistCategory> getCategory(final String categoryId) {
	final ImList<ContentAssistCategory> categories= getCategories();
	for (final ContentAssistCategory category : categories) {
	if (category.getId().equals(categoryId)) {
	final ContentAssistCategory copy= new ContentAssistCategory(category);
	copy.isIncludedInDefault= true;
	return ImCollections.newList(copy);
	}
	}
	return ImCollections.emptyList();
	}

	@SuppressWarnings("null")
	private synchronized ImList<ComputerDescriptor> getComputers() {
	ImList<ComputerDescriptor> computers= this.computers;
	if (computers == null) {
	loadExtensions();
	computers= this.computers;
	}
	return computers;
	}

	public @Nullable ContentAssistComputer getComputer(final String id) {
	final ImList<ComputerDescriptor> computers= getComputers();
	for (final ComputerDescriptor descr : computers) {
	if (descr.getId().equals(id)) {
	return descr.getComputer();
	}
	}
	return null;
	}

	}