| /******************************************************************************* |
| * Copyright (c) 2006, 2007 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.ui.navigator; |
| |
| import java.util.HashMap; |
| import java.util.LinkedHashSet; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.eclipse.jface.viewers.AbstractTreeViewer; |
| |
| /** |
| * |
| * A pipelined viewer update should map requests to refresh or update elements |
| * in the viewer to their correct, modified structure. Clients use |
| * {@link PipelinedViewerUpdate} as the input and return type from intercept |
| * methods on {@link IPipelinedTreeContentProvider}. |
| * |
| * <p> |
| * Clients should use the viewer update to describe how the request from the |
| * upstream extension (see {@link IPipelinedTreeContentProvider} for more |
| * information on <i>upstream</i> extensions) should be reshaped when applied |
| * to the tree. A request from an upstream extension to refresh a given element |
| * could result in multiple refresh requests from downstream extensions. |
| * Therefore, the refresh targets are modeled as a set. |
| * </p> |
| * <p> |
| * Initially, this set will contain the original element that was passed to the |
| * refresh requests. Clients may squash the refresh by clearing the set, change |
| * the original target by removing the current element and adding a new target, |
| * or expand the refresh by adding more elements to the set. |
| * </p> |
| * <p> |
| * A pipelined extension may receive a {@link PipelinedViewerUpdate} as the |
| * result of a call to {@link AbstractTreeViewer#refresh()}-methods or |
| * {@link AbstractTreeViewer#update(Object, String[])}-methods. The |
| * <code>properties</code> field is only applicable for <code>update()</code> |
| * calls and the <code>updateLabels</code> field is only applicable for |
| * <code>refresh()</code> calls. |
| * </p> |
| * |
| * @since 3.2 |
| * |
| */ |
| public final class PipelinedViewerUpdate { |
| |
| private static final String[] NO_PROPERTIES = new String[0]; |
| |
| private final Set refreshTargets = new LinkedHashSet(); |
| |
| private boolean updateLabels = false; |
| |
| private Map properties; |
| |
| /** |
| * Properties allow optimization for <code>update</code> calls. |
| * |
| * @param aTarget |
| * The target which may have specific properties associated with |
| * it for an optimized refresh. |
| * |
| * @return Returns the properties for the given target. If no properties are |
| * specified, then an empty array is returned. <b>null</b> will |
| * never be returned. |
| */ |
| public final String[] getProperties(Object aTarget) { |
| if (properties != null && properties.containsKey(aTarget)) { |
| String[] props = (String[]) properties.get(aTarget); |
| return props != null ? props : NO_PROPERTIES; |
| } |
| return NO_PROPERTIES; |
| } |
| |
| /** |
| * |
| * Properties allow optimization for <code>update</code> calls. |
| * |
| * @param aTarget |
| * The target of the properties. |
| * @param theProperties |
| * The properties to pass along to the <code>update</code> |
| * call. |
| * @see AbstractTreeViewer#update(Object, String[]) |
| */ |
| public final void setProperties(Object aTarget, String[] theProperties) { |
| if (theProperties != null && theProperties.length > 0) { |
| if (properties == null) { |
| properties = new HashMap(); |
| } |
| properties.put(aTarget, theProperties); |
| |
| } else { |
| properties.remove(aTarget); |
| } |
| |
| if (properties.size() == 0) { |
| properties = null; |
| } |
| |
| } |
| |
| /** |
| * @return Returns the current set of refresh targets. Clients may add or |
| * remove directly to or from this set. |
| */ |
| public final Set getRefreshTargets() { |
| return refreshTargets; |
| } |
| |
| /** |
| * @return Returns the true if the labels should also be updated during the |
| * <code>refresh</code>. |
| */ |
| public final boolean isUpdateLabels() { |
| return updateLabels; |
| } |
| |
| /** |
| * @param toUpdateLabels |
| * True indicates that calls to <code>refresh</code> should |
| * force the update of the labels in addition to refreshing the |
| * structure. |
| */ |
| public final void setUpdateLabels(boolean toUpdateLabels) { |
| updateLabels = toUpdateLabels; |
| } |
| |
| } |