| /******************************************************************************* |
| * Copyright (c) 2000, 2006 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.ArrayList; |
| |
| /** |
| * A viewer filter is used by a structured viewer to |
| * extract a subset of elements provided by its content provider. |
| * <p> |
| * Subclasses must implement the <code>select</code> method |
| * and may implement the <code>isFilterProperty</code> method. |
| * </p> |
| * @see IStructuredContentProvider |
| * @see StructuredViewer |
| */ |
| public abstract class ViewerFilter { |
| /** |
| * Creates a new viewer filter. |
| */ |
| protected ViewerFilter() { |
| } |
| |
| /** |
| * Filters the given elements for the given viewer. |
| * The input array is not modified. |
| * <p> |
| * The default implementation of this method calls |
| * <code>select</code> on each element in the array, |
| * and returns only those elements for which <code>select</code> |
| * returns <code>true</code>. |
| * </p> |
| * @param viewer the viewer |
| * @param parent the parent element |
| * @param elements the elements to filter |
| * @return the filtered elements |
| */ |
| public Object[] filter(Viewer viewer, Object parent, Object[] elements) { |
| int size = elements.length; |
| ArrayList out = new ArrayList(size); |
| for (int i = 0; i < size; ++i) { |
| Object element = elements[i]; |
| if (select(viewer, parent, element)) { |
| out.add(element); |
| } |
| } |
| return out.toArray(); |
| } |
| |
| /** |
| * Filters the given elements for the given viewer. |
| * The input array is not modified. |
| * <p> |
| * The default implementation of this method calls |
| * {@link #filter(Viewer, Object, Object[])} with the |
| * parent from the path. Subclasses may override |
| * </p> |
| * @param viewer the viewer |
| * @param parentPath the path of the parent element |
| * @param elements the elements to filter |
| * @return the filtered elements |
| * @since 3.2 |
| */ |
| public Object[] filter(Viewer viewer, TreePath parentPath, Object[] elements) { |
| return filter(viewer, parentPath.getLastSegment(), elements); |
| } |
| |
| /** |
| * Returns whether this viewer filter would be affected |
| * by a change to the given property of the given element. |
| * <p> |
| * The default implementation of this method returns <code>false</code>. |
| * Subclasses should reimplement. |
| * </p> |
| * |
| * @param element the element |
| * @param property the property |
| * @return <code>true</code> if the filtering would be affected, |
| * and <code>false</code> if it would be unaffected |
| */ |
| public boolean isFilterProperty(Object element, String property) { |
| return false; |
| } |
| |
| /** |
| * Returns whether the given element makes it through this filter. |
| * |
| * @param viewer the viewer |
| * @param parentElement the parent element |
| * @param element the element |
| * @return <code>true</code> if element is included in the |
| * filtered set, and <code>false</code> if excluded |
| */ |
| public abstract boolean select(Viewer viewer, Object parentElement, |
| Object element); |
| } |