org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/ResourceExtender.java

/*******************************************************************************
 * Copyright (c) 2004 International Business Machines Corp. and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v0.5 
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v05.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 ******************************************************************************/
package org.eclipse.debug.internal.ui;

import org.eclipse.core.expressions.PropertyTester;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.content.IContentDescription;
import org.eclipse.core.runtime.content.IContentType;

/**
 * ResourceExtender provides property testers for the XML expression
 * language evaluation. We provide a copy in Debug so that launch shortcuts
 * can add contextual launch enablement that does not require their plugins
 * to be loaded.
 * Copied from org.eclipse.jdt.internal.corext.refactoring.participants.xml.ResourceExtender
 */
public class ResourceExtender extends PropertyTester {

	private static final String PROPERTY_MATCHES_PATTERN= "matchesPattern";	 //$NON-NLS-1$
	private static final String PROJECT_NATURE = "projectNature";	 //$NON-NLS-1$
	private static final String PROPERTY_MATCHES_CONTENT_TYPE= "matchesContentType"; //$NON-NLS-1$
	
	/* (non-Javadoc)
	 * @see org.eclipse.jdt.internal.corext.refactoring.participants.properties.IPropertyEvaluator#test(java.lang.Object, java.lang.String, java.lang.String)
	 */
	public boolean test(Object receiver, String method, Object[] args, Object expectedValue) {
		IResource resource= (IResource) ((IAdaptable)receiver).getAdapter(IResource.class);
		if (resource != null) {
			if (PROPERTY_MATCHES_PATTERN.equals(method)) { //$NON-NLS-1$
				String fileName= resource.getName();
				StringMatcher matcher= new StringMatcher((String)expectedValue, false, false);
				return matcher.match(fileName);
			} else if (PROJECT_NATURE.equals(method)) {
				try {
					IProject proj = resource.getProject();
					return proj.isAccessible() && proj.hasNature((String)expectedValue);
				} catch (CoreException e) {
					return false;		
				}
			} else if (PROPERTY_MATCHES_CONTENT_TYPE.equals(method)) {
				return matchesContentType(resource, (String) expectedValue);
			}
		}
		return false;
	}
		
	/**
	 * Returns whether or not the given file's content type matches
	 * the specified content type.
	 * 
	 * Content types are looked up in the content type registry.
	 * 
	 * @return whether or not the given resource has the given content type
	 */
	private boolean matchesContentType(IResource resource, String contentType) {
		if (resource == null || !(resource instanceof IFile) || !resource.exists()) {
			return false;
		}
		IFile file= (IFile) resource;
		IContentDescription description;
		try {
			description = file.getContentDescription();
		} catch (CoreException e) {
			return false;
		}
		if (description != null) {
			IContentType type= description.getContentType();
			return type != null && contentType.equals(type.getId());
		}
		return false;
	}
	
}