| /******************************************************************************* |
| * Copyright (c) 2008, 2009 Matthew Hall 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: |
| * Matthew Hall - initial API and implementation (bug 226765) |
| * Matthew Hall - bug 230296, 238296 |
| ******************************************************************************/ |
| |
| package org.eclipse.jface.internal.databinding.viewers; |
| |
| import java.util.Iterator; |
| |
| import org.eclipse.jface.databinding.viewers.IViewerUpdater; |
| import org.eclipse.jface.util.Util; |
| import org.eclipse.jface.viewers.IElementComparer; |
| import org.eclipse.jface.viewers.IStructuredSelection; |
| import org.eclipse.jface.viewers.StructuredViewer; |
| |
| /** |
| * NON-API - An interface for updating a viewer's elements. |
| * |
| * @since 1.2 |
| */ |
| public abstract class ViewerUpdater implements IViewerUpdater { |
| private final StructuredViewer viewer; |
| |
| /** |
| * Constructs a ViewerUpdater for updating the specified viewer. |
| * |
| * @param viewer |
| * the viewer which will be updated through this instance. |
| */ |
| protected ViewerUpdater(StructuredViewer viewer) { |
| this.viewer = viewer; |
| } |
| |
| public abstract void insert(Object element, int position); |
| |
| public abstract void remove(Object element, int position); |
| |
| public void replace(Object oldElement, Object newElement, int position) { |
| remove(oldElement, position); |
| insert(newElement, position); |
| } |
| |
| public void move(Object element, int oldPosition, int newPosition) { |
| if (isElementOrderPreserved()) { |
| IStructuredSelection selection = (IStructuredSelection) viewer |
| .getSelection(); |
| |
| remove(element, oldPosition); |
| insert(element, newPosition); |
| |
| // Preserve selection |
| if (selectionContains(selection, element)) { |
| viewer.setSelection(selection); |
| } |
| } |
| } |
| |
| boolean isElementOrderPreserved() { |
| return viewer.getComparator() == null |
| && viewer.getFilters().length == 0; |
| } |
| |
| private boolean selectionContains(IStructuredSelection selection, |
| Object element) { |
| if (!selection.isEmpty()) { |
| IElementComparer comparer = viewer.getComparer(); |
| for (Iterator iter = selection.iterator(); iter.hasNext();) { |
| Object selectionElement = iter.next(); |
| if (comparer == null ? Util.equals(element, selectionElement) |
| : comparer.equals(element, selectionElement)) { |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| public abstract void add(Object[] elements); |
| |
| public abstract void remove(Object[] elements); |
| } |