/*******************************************************************************
* Copyright (c) 2009 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
* Zend Technologies
*******************************************************************************/
package org.eclipse.php.internal.debug.ui.launching;
import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IResource;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerSorter;
/**
* Sorter for viewers that display items of type <code>IResource</code>. The
* sorter supports two sort criteria:
* <p>
* <code>NAME</code>: Folders are given order precedence, followed by files.
* Within these two groups resources are ordered by name. All name comparisons
* are case-insensitive.
* </p>
* <p>
* <code>TYPE</code>: Folders are given order precedence, followed by files.
* Within these two groups resources are ordered by extension. All extension
* comparisons are case-insensitive.
* </p>
* <p>
* This class may be instantiated; it is not intended to be subclassed.
* </p>
*/
public class ResourceSorter extends ViewerSorter {
/**
* Constructor argument value that indicates to sort items by name.
*/
public final static int NAME = 1;
/**
* Constructor argument value that indicates to sort items by extension.
*/
public final static int TYPE = 2;
private int criteria;
/**
* Creates a resource sorter that will use the given sort criteria.
*
* @param criteria
* the sort criterion to use: one of <code>NAME</code> or
* <code>TYPE</code>
*/
public ResourceSorter(int criteria) {
super();
this.criteria = criteria;
}
/**
* Returns an integer value representing the relative sort priority of the
* given element based on its class.
* <p>
* <ul>
* <li>resources (<code>IResource</code>) - 2</li>
* <li>project references (<code>ProjectReference</code>) - 1</li>
* <li>everything else - 0</li>
* </ul>
* </p>
*
* @param element
* the element
* @return the sort priority (larger numbers means more important)
*/
protected int classComparison(Object element) {
if (element instanceof IResource) {
return 2;
}
return 0;
}
/*
* (non-Javadoc) Method declared on ViewerSorter.
*/
public int compare(Viewer viewer, Object o1, Object o2) {
// have to deal with non-resources in navigator
// if one or both objects are not resources, returned a comparison
// based on class.
if (!(o1 instanceof IResource && o2 instanceof IResource)) {
return compareClass(o1, o2);
}
IResource r1 = (IResource) o1;
IResource r2 = (IResource) o2;
if (r1 instanceof IContainer && r2 instanceof IContainer) {
return compareNames(r1, r2);
} else if (r1 instanceof IContainer) {
return -1;
} else if (r2 instanceof IContainer) {
return 1;
} else if (criteria == NAME) {
return compareNames(r1, r2);
} else if (criteria == TYPE) {
return compareTypes(r1, r2);
} else {
return 0;
}
}
/**
* Returns a number reflecting the collation order of the given elements
* based on their class.
*
* @param element1
* the first element to be ordered
* @param element2
* the second element to be ordered
* @return a negative number if the first element is less than the second
* element; the value <code>0</code> if the first element is equal
* to the second element; and a positive number if the first element
* is greater than the second element
*/
protected int compareClass(Object element1, Object element2) {
return classComparison(element1) - classComparison(element2);
}
/**
* Returns a number reflecting the collation order of the given resources
* based on their resource names.
*
* @param resource1
* the first resource element to be ordered
* @param resource2
* the second resource element to be ordered
* @return a negative number if the first element is less than the second
* element; the value <code>0</code> if the first element is equal
* to the second element; and a positive number if the first element
* is greater than the second element
*/
protected int compareNames(IResource resource1, IResource resource2) {
return getComparator().compare(resource1.getName(), resource2.getName());
}
/**
* Returns a number reflecting the collation order of the given resources
* based on their respective file extensions. Resources with the same file
* extension will be collated based on their names.
*
* @param resource1
* the first resource element to be ordered
* @param resource2
* the second resource element to be ordered
* @return a negative number if the first element is less than the second
* element; the value <code>0</code> if the first element is equal
* to the second element; and a positive number if the first element
* is greater than the second element
*/
protected int compareTypes(IResource resource1, IResource resource2) {
String ext1 = getExtensionFor(resource1);
String ext2 = getExtensionFor(resource2);
// Compare extensions. If they're different then return a value that
// indicates correct extension ordering. If they're the same then
// return a value that indicates the correct NAME ordering.
int result = getComparator().compare(ext1, ext2);
if (result != 0) {
return result;
}
return compareNames(resource1, resource2);
}
/**
* Returns the sort criteria of this this sorter.
*
* @return the sort criterion: one of <code>NAME</code> or <code>TYPE</code>
*/
public int getCriteria() {
return criteria;
}
/**
* Returns the extension portion of the given resource.
*
* @param resource
* the resource
* @return the file extension, possibily the empty string
*/
private String getExtensionFor(IResource resource) {
String ext = resource.getFileExtension();
return ext == null ? "" : ext; //$NON-NLS-1$
}
}