/*******************************************************************************
* Copyright (c) 2005, 2006 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
*******************************************************************************/
package org.eclipse.core.internal.resources.mapping;
import java.util.*;
import org.eclipse.core.expressions.*;
import org.eclipse.core.internal.resources.ResourceException;
import org.eclipse.core.internal.utils.Messages;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.resources.mapping.*;
import org.eclipse.core.runtime.*;
import org.eclipse.osgi.util.NLS;
public class ModelProviderDescriptor implements IModelProviderDescriptor {
private String id;
private String[] extendedModels;
private String label;
private ModelProvider provider;
private Expression enablementRule;
private static EvaluationContext createEvaluationContext(Object element) {
EvaluationContext result= new EvaluationContext(null, element);
return result;
}
public ModelProviderDescriptor(IExtension extension) throws CoreException {
readExtension(extension);
}
private boolean convert(EvaluationResult eval) {
if (eval == EvaluationResult.FALSE)
return false;
return true;
}
protected void fail(String reason) throws CoreException {
throw new ResourceException(new Status(IStatus.ERROR, ResourcesPlugin.PI_RESOURCES, 1, reason, null));
}
public String[] getExtendedModels() {
return extendedModels;
}
public String getId() {
return id;
}
public String getLabel() {
return label;
}
public IResource[] getMatchingResources(IResource[] resources) throws CoreException {
Set result= new HashSet();
for (int i= 0; i < resources.length; i++) {
IResource resource= resources[i];
EvaluationContext evalContext= createEvaluationContext(resource);
if (matches(evalContext)) {
result.add(resource);
}
}
return (IResource[])result.toArray(new IResource[result.size()]);
}
public synchronized ModelProvider getModelProvider() throws CoreException {
if (provider == null) {
IExtension extension= Platform.getExtensionRegistry().getExtension(ResourcesPlugin.PI_RESOURCES, ResourcesPlugin.PT_MODEL_PROVIDERS, id);
IConfigurationElement[] elements= extension.getConfigurationElements();
for (int i= 0; i < elements.length; i++) {
IConfigurationElement element= elements[i];
if (element.getName().equalsIgnoreCase("modelProvider")) { //$NON-NLS-1$
try {
provider= (ModelProvider)element.createExecutableExtension("class"); //$NON-NLS-1$
provider.init(this);
} catch (ClassCastException e) {
String message= NLS.bind(Messages.mapping_wrongType, id);
throw new CoreException(new Status(IStatus.ERROR, ResourcesPlugin.PI_RESOURCES, Platform.PLUGIN_ERROR, message, e));
}
}
}
}
return provider;
}
public boolean matches(IEvaluationContext context) throws CoreException {
if (enablementRule == null)
return false;
return convert(enablementRule.evaluate(context));
}
/**
* Initialize this descriptor based on the provided extension point.
*/
protected void readExtension(IExtension extension) throws CoreException {
//read the extension
id= extension.getUniqueIdentifier();
if (id == null)
fail(Messages.mapping_noIdentifier);
label= extension.getLabel();
IConfigurationElement[] elements= extension.getConfigurationElements();
int count= elements.length;
ArrayList extendsList= new ArrayList(count);
for (int i= 0; i < count; i++) {
IConfigurationElement element= elements[i];
String name= element.getName();
if (name.equalsIgnoreCase("extends-model")) { //$NON-NLS-1$
String attribute= element.getAttribute("id"); //$NON-NLS-1$
if (attribute == null)
fail(NLS.bind(Messages.mapping_invalidDef, id));
extendsList.add(attribute);
} else if (name.equalsIgnoreCase(ExpressionTagNames.ENABLEMENT)) {
enablementRule= ExpressionConverter.getDefault().perform(element);
}
}
extendedModels= (String[])extendsList.toArray(new String[extendsList.size()]);
}
public ResourceTraversal[] getMatchingTraversals(ResourceTraversal[] traversals) throws CoreException {
List result= new ArrayList();
for (int i= 0; i < traversals.length; i++) {
ResourceTraversal traversal= traversals[i];
if (getMatchingResources(traversal.getResources()).length > 0) {
result.add(traversal);
}
}
return (ResourceTraversal[])result.toArray(new ResourceTraversal[result.size()]);
}
}