/*******************************************************************************
* Copyright (c) 2009, 2010 Wind River Systems, Inc. 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:
* Wind River Systems - initial API and implementation
*******************************************************************************/
package org.eclipse.tm.tcf.extensions;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
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.osgi.util.NLS;
import org.eclipse.tm.tcf.Activator;
import org.eclipse.tm.tcf.internal.nls.TcfPluginMessages;
/**
* Abstract extension point manager base implementation.
*/
public abstract class TcfAbstractExtensionPointManager<V> {
// Flag to mark the extension point manager initialized (extensions loaded).
private boolean fInitialized = false;
// The map of loaded extension listed by their unique ids
private Map<String, TcfExtensionProxy<V>> fExtensions = new LinkedHashMap<String, TcfExtensionProxy<V>>();
// The extension point comparator
private TcfExtensionPointComparator fComparator = null;
/**
* Constructor.
*/
public TcfAbstractExtensionPointManager() {
}
/**
* Returns if or if not the service provider extension point manager
* got initialized. Initialized means that the manager read the
* contributions for the managed extension point.
*
* @return <code>True</code> if already initialized, <code>false</code> otherwise.
*/
protected boolean isInitialized() {
return fInitialized;
}
/**
* Sets if or if not the service provider extension point manager
* is initialized. Initialized means that the manager has read
* the contributions for the managed extension point.
*
* @return <code>True</code> to set the extension point manager is initialized, <code>false</code> otherwise.
*/
protected void setInitialized(boolean initialized) {
fInitialized = initialized;
}
/**
* Returns the map of managed extensions. If not loaded before,
* this methods trigger the loading of the extensions to the managed
* extension point.
*
* @return The map of contributions.
*/
protected Map<String, TcfExtensionProxy<V>> getExtensions() {
if (!isInitialized()) { loadExtensions(); setInitialized(true); }
return fExtensions;
}
/**
* Returns the extensions of the specified extension point sorted.
* For the order of the extensions, see {@link WRLaunchExtensionPointComparator}.
*
* @param point The extension point. Must be not <code>null</code>.
* @return The extensions in sorted order or an empty array if the extension point has no extensions.
*/
protected IExtension[] getExtensionsSorted(IExtensionPoint point) {
assert point != null;
List<IExtension> extensions = new ArrayList<IExtension>(Arrays.asList(point.getExtensions()));
if (extensions.size() > 0) {
Collections.sort(extensions, getExtensionPointComparator());
}
return extensions.toArray(new IExtension[extensions.size()]);
}
/**
* Returns the extension point comparator instance. If not available,
* {@link #doCreateExtensionPointComparator()} is called to create a new instance.
*
* @return The extension point comparator or <code>null</code> if the instance creation fails.
*/
protected final TcfExtensionPointComparator getExtensionPointComparator() {
if (fComparator == null) {
fComparator = doCreateExtensionPointComparator();
}
return fComparator;
}
/**
* Creates a new extension point comparator instance.
*
* @return The extension point comparator instance. Must never be <code>null</code>.
*/
protected TcfExtensionPointComparator doCreateExtensionPointComparator() {
return new TcfExtensionPointComparator();
}
/**
* Returns the extension point id to read. The method
* must return never <code>null</code>.
*
* @return The extension point id.
*/
protected abstract String getExtensionPointId();
/**
* Returns the configuration element name. The method
* must return never <code>null</code>.
*
* @return The configuration element name.
*/
protected abstract String getConfigurationElementName();
/**
* Creates the extension proxy instance.
*
* @param element The configuration element of the extension. Must be not <code>null</code>.
* @return The extension proxy instance.
*
* @throws CoreException If the extension proxy instantiation failed.
*/
protected TcfExtensionProxy<V> doCreateExtensionProxy(IConfigurationElement element) throws CoreException {
assert element != null;
return new TcfExtensionProxy<V>(element);
}
/**
* Loads the extensions for the managed extenions point.
*/
protected void loadExtensions() {
// If already initialized, this method will do nothing.
if (isInitialized()) return;
IExtensionRegistry registry = Platform.getExtensionRegistry();
IExtensionPoint point = registry.getExtensionPoint(getExtensionPointId());
if (point != null) {
IExtension[] extensions = getExtensionsSorted(point);
for (IExtension extension : extensions) {
IConfigurationElement[] elements = extension.getConfigurationElements();
for (IConfigurationElement element : elements) {
if (getConfigurationElementName().equals(element.getName())) {
try {
TcfExtensionProxy<V> candidate = doCreateExtensionProxy(element);
if (candidate.getId() != null) {
// If no contribution with this id had been registered before, register now.
if (!fExtensions.containsKey(candidate.getId())) {
fExtensions.put(candidate.getId(), candidate);
}
else {
throw new CoreException(new Status(IStatus.ERROR,
Activator.PLUGIN_ID,
0,
NLS.bind(TcfPluginMessages.Extension_error_duplicateExtension, candidate.getId(), element.getContributor().getName()),
null));
}
}
else {
throw new CoreException(new Status(IStatus.ERROR,
Activator.PLUGIN_ID,
0,
NLS.bind(TcfPluginMessages.Extension_error_missingRequiredAttribute, "id", element.getAttribute("label")), //$NON-NLS-1$ //$NON-NLS-2$
null));
}
}
catch (CoreException e) {
IStatus status = new Status(IStatus.ERROR, Activator.PLUGIN_ID,
NLS.bind(TcfPluginMessages.Extension_error_invalidExtensionPoint, element.getDeclaringExtension().getUniqueIdentifier()),
e);
Activator.getDefault().getLog().log(status);
}
}
}
}
}
}
}