| /******************************************************************************* |
| * Copyright (c) 2000, 2004 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; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.eclipse.jface.resource.JFaceResources; |
| import org.eclipse.jface.util.Assert; |
| |
| /** |
| * A concrete implementation of the <code>IStructuredSelection</code> interface, |
| * suitable for instantiating. |
| * <p> |
| * This class is not intended to be subclassed. |
| * </p> |
| */ |
| public class StructuredSelection implements IStructuredSelection { |
| |
| /** |
| * The element that make up this structured selection. |
| */ |
| private Object[] elements; |
| |
| /** |
| * The canonical empty selection. This selection should be used instead of |
| * <code>null</code>. |
| */ |
| public static final StructuredSelection EMPTY = new StructuredSelection(); |
| |
| /** |
| * Creates a new empty selection. |
| * See also the static field <code>EMPTY</code> which contains an empty selection singleton. |
| * |
| * @see #EMPTY |
| */ |
| public StructuredSelection() { |
| } |
| |
| /** |
| * Creates a structured selection from the given elements. |
| * |
| * @param elements an array of elements |
| */ |
| public StructuredSelection(Object[] elements) { |
| this.elements = new Object[elements.length]; |
| System.arraycopy(elements, 0, this.elements, 0, elements.length); |
| } |
| |
| /** |
| * Creates a structured selection containing a single object. |
| * The object must not be <code>null</code>. |
| * |
| * @param element the element |
| */ |
| public StructuredSelection(Object element) { |
| Assert.isNotNull(element); |
| elements = new Object[] { element }; |
| } |
| |
| /** |
| * Creates a structured selection from the given <code>List</code>. |
| */ |
| public StructuredSelection(List elements) { |
| Assert.isNotNull(elements); |
| this.elements = elements.toArray(); |
| } |
| |
| /** |
| * Returns whether this structured selection is equal to the given object. |
| * Two structured selections are equal iff they contain the same elements |
| * in the same order. |
| * |
| * @param o the other object |
| * @return <code>true</code> if they are equal, and <code>false</code> otherwise |
| */ |
| public boolean equals(Object o) { |
| if (this == o) { |
| return true; |
| } |
| //null and other classes |
| if (!(o instanceof StructuredSelection)) { |
| return false; |
| } |
| StructuredSelection s2 = (StructuredSelection) o; |
| |
| // either or both empty? |
| if (isEmpty()) { |
| return s2.isEmpty(); |
| } |
| if (s2.isEmpty()) { |
| return false; |
| } |
| |
| //size |
| int myLen = elements.length; |
| if (myLen != s2.elements.length) { |
| return false; |
| } |
| //element comparison |
| for (int i = 0; i < myLen; i++) { |
| if (!elements[i].equals(s2.elements[i])) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /* (non-Javadoc) |
| * Method declared in IStructuredSelection. |
| */ |
| public Object getFirstElement() { |
| return isEmpty() ? null : elements[0]; |
| } |
| |
| /* (non-Javadoc) |
| * Method declared in ISelection. |
| */ |
| public boolean isEmpty() { |
| return elements == null || elements.length == 0; |
| } |
| |
| /* (non-Javadoc) |
| * Method declared in IStructuredSelection. |
| */ |
| public Iterator iterator() { |
| return Arrays.asList(elements == null ? new Object[0] : elements) |
| .iterator(); |
| } |
| |
| /* (non-Javadoc) |
| * Method declared in IStructuredSelection. |
| */ |
| public int size() { |
| return elements == null ? 0 : elements.length; |
| } |
| |
| /* (non-Javadoc) |
| * Method declared in IStructuredSelection. |
| */ |
| public Object[] toArray() { |
| return elements == null ? new Object[0] : (Object[]) elements.clone(); |
| } |
| |
| /* (non-Javadoc) |
| * Method declared in IStructuredSelection. |
| */ |
| public List toList() { |
| return Arrays.asList(elements == null ? new Object[0] : elements); |
| } |
| |
| /** |
| * Internal method which returns a string representation of this |
| * selection suitable for debug purposes only. |
| * |
| * @return debug string |
| */ |
| public String toString() { |
| return isEmpty() ? JFaceResources.getString("<empty_selection>") : toList().toString(); //$NON-NLS-1$ |
| } |
| } |