/*******************************************************************************
* Copyright (c) 2006, 2015 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.jface.viewers;
import java.util.Arrays;
/**
* A viewer sorter that is provided extra context in the form of the path of the
* parent element of the elements being sorted.
*
* @since 3.2
*/
public class TreePathViewerSorter extends ViewerSorter {
/**
* Provide a category for the given element that will have the given parent
* path when it is added to the viewer. The provided path is relative to the
* viewer input. The parent path will be <code>null</code> when the elements
* are root elements.
* <p>
* By default, the this method calls {@code ViewerSorter#category(Object)}.
* Subclasses may override.
*
* @param parentPath
* the parent path for the element
* @param element
* the element
* @return the category of the element
*/
public int category(TreePath parentPath, Object element) {
return category(element);
}
/**
* Compare the given elements that will have the given parent
* path when they are added to the viewer. The provided path is
* relative to the viewer input. The parent path will
* be <code>null</code> when the elements are root elements.
* <p>
* By default, the this method calls
* {@code ViewerSorter#sort(Viewer, Object[])}. Subclasses may override.
* @param viewer the viewer
* @param parentPath the parent path for the two elements
* @param e1 the first element
* @param e2 the second element
* @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
*/
public int compare(Viewer viewer, TreePath parentPath, Object e1, Object e2) {
return compare(viewer, e1, e2);
}
/**
* Returns whether this viewer sorter would be affected
* by a change to the given property of the given element.
* The provided path is
* relative to the viewer input. The parent path will
* be <code>null</code> when the elements are root elements.
* <p>
* The default implementation of this method calls
* {@code ViewerSorter#isSorterProperty(Object, String)}.
* Subclasses may reimplement.
* @param parentPath the parent path of the element
* @param element the element
* @param property the property
* @return <code>true</code> if the sorting would be affected,
* and <code>false</code> if it would be unaffected
*/
public boolean isSorterProperty(TreePath parentPath, Object element, String property) {
return isSorterProperty(element, property);
}
/**
* Sorts the given elements in-place, modifying the given array.
* The provided path is
* relative to the viewer input. The parent path will
* be <code>null</code> when the elements are root elements.
* <p>
* The default implementation of this method uses the
* java.util.Arrays#sort algorithm on the given array,
* calling {@link #compare(Viewer, TreePath, Object, Object)} to compare elements.
* </p>
* <p>
* Subclasses may reimplement this method to provide a more optimized implementation.
* </p>
*
* @param viewer the viewer
* @param parentPath the parent path of the given elements
* @param elements the elements to sort
*/
public void sort(final Viewer viewer, final TreePath parentPath, Object[] elements) {
Arrays.sort(elements, (a, b) -> TreePathViewerSorter.this.compare(viewer, parentPath, a, b));
}
}