| /******************************************************************************* |
| * Copyright (c) 2000, 2011 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.compare; |
| |
| import org.eclipse.core.runtime.Adapters; |
| |
| /** |
| * Supports cross-pane navigation through the differences of a compare container. |
| * <p> |
| * Clients may subclass this class. |
| * </p> |
| * @see INavigatable |
| * @since 3.3 |
| */ |
| public abstract class CompareNavigator implements ICompareNavigator { |
| @Override |
| public boolean selectChange(boolean next) { |
| // find most down stream CompareViewerPane |
| INavigatable[] navigators= getNavigatables(); |
| Object downStreamInput = null; |
| for (int i = navigators.length - 1; i >=0; i--) { |
| INavigatable navigatable = navigators[i]; |
| if (navigatable.getInput() == downStreamInput) { |
| // Skip to up stream pane if it has the same input |
| continue; |
| } |
| if (navigatable.selectChange(next ? INavigatable.NEXT_CHANGE : INavigatable.PREVIOUS_CHANGE)) { |
| // at end of this navigator |
| downStreamInput = navigatable.getInput(); |
| continue; |
| } |
| // not at end |
| if (i + 1 < navigators.length && navigators[i + 1] != null |
| && navigators[i + 1].getInput() != downStreamInput) { |
| // The navigation has invoked a change in a downstream pane. |
| // Set the selected change depending on the direction we are navigating |
| navigators[i+1].selectChange(next ? INavigatable.FIRST_CHANGE : INavigatable.LAST_CHANGE); |
| } |
| return false; |
| } |
| |
| return true; |
| } |
| |
| protected abstract INavigatable[] getNavigatables(); |
| |
| /** |
| * Returns the {@link INavigatable} for the given object if the object |
| * adapts to {@link INavigatable}. |
| * |
| * @param object the object |
| * @return the {@link INavigatable} for the given object or {@code null} |
| */ |
| protected final INavigatable getNavigator(Object object) { |
| if (object == null) |
| return null; |
| return Adapters.adapt(object, INavigatable.class); |
| } |
| |
| /** |
| * Returns whether a call to {@link ICompareNavigator#selectChange(boolean)} |
| * with the same parameter would succeed. |
| * |
| * @param next if <code>true</code> the next change is selected, otherwise |
| * the previous change |
| * @return whether a call to {@link ICompareNavigator#selectChange(boolean)} |
| * with the same parameter would succeed. |
| * @since 3.3 |
| */ |
| public boolean hasChange(boolean next) { |
| INavigatable[] navigators= getNavigatables(); |
| Object downStreamInput = null; |
| for (int i = navigators.length; --i >= 0;) { |
| INavigatable navigatable = navigators[i]; |
| if (navigatable.getInput() == downStreamInput) { |
| // Skip to up stream pane if it has the same input |
| continue; |
| } |
| if (navigatable.hasChange(next ? INavigatable.NEXT_CHANGE : INavigatable.PREVIOUS_CHANGE)) { |
| return true; |
| } |
| // at end of this navigator |
| downStreamInput = navigatable.getInput(); |
| } |
| return false; |
| } |
| } |