| /******************************************************************************* |
| * Copyright (c) 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.ui.internal.navigator.dnd; |
| |
| import java.util.ArrayList; |
| import java.util.Iterator; |
| import java.util.LinkedHashSet; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.TreeMap; |
| |
| import org.eclipse.core.runtime.IConfigurationElement; |
| import org.eclipse.ui.internal.navigator.extensions.ExtensionPriorityComparator; |
| import org.eclipse.ui.internal.navigator.extensions.INavigatorContentExtPtConstants; |
| import org.eclipse.ui.internal.navigator.extensions.NavigatorContentRegistryReader; |
| import org.eclipse.ui.navigator.INavigatorContentDescriptor; |
| import org.eclipse.ui.navigator.INavigatorContentService; |
| |
| /** |
| * @since 3.2 |
| * |
| */ |
| public class CommonDropDescriptorManager { |
| |
| private static final CommonDropDescriptorManager INSTANCE = new CommonDropDescriptorManager(); |
| |
| private static final CommonDropAdapterDescriptor[] NO_DESCRIPTORS = new CommonDropAdapterDescriptor[0]; |
| |
| /** |
| * A map of (INavigatorContentDescriptor, |
| * CommonDropAdapterDescriptor)-pairs. |
| */ |
| private final Map dropDescriptors = new TreeMap(ExtensionPriorityComparator.INSTANCE); |
| |
| /** |
| * |
| * @return An initialized singleton instance of the |
| * CommonDropDescriptorManager. |
| */ |
| public static CommonDropDescriptorManager getInstance() { |
| return INSTANCE; |
| } |
| |
| private CommonDropDescriptorManager() { |
| new CommonDropAdapterRegistry().readRegistry(); |
| } |
| |
| /** |
| * |
| * @param aDropTarget |
| * The drop target of the operation |
| * @param aContentService |
| * The associated content service to filter results by. |
| * @return An array of drop descriptors that can handle the given drop |
| * target and are <i>visible</i> and <i>active</i> for the given |
| * service and <i>enabled</i> for the given drop target.. |
| */ |
| public CommonDropAdapterDescriptor[] findCommonDropAdapterAssistants(Object aDropTarget, INavigatorContentService aContentService) { |
| |
| Set foundDescriptors = new LinkedHashSet(); |
| for (Iterator iter = dropDescriptors.keySet().iterator(); iter |
| .hasNext();) { |
| INavigatorContentDescriptor contentDescriptor = (INavigatorContentDescriptor) iter |
| .next(); |
| if (aContentService.isVisible(contentDescriptor.getId()) |
| && aContentService.isActive(contentDescriptor.getId())) { |
| List dropDescriptors = getDropDescriptors(contentDescriptor); |
| for (Iterator iterator = dropDescriptors.iterator(); iterator |
| .hasNext();) { |
| CommonDropAdapterDescriptor dropDescriptor = (CommonDropAdapterDescriptor) iterator |
| .next(); |
| if (dropDescriptor.isDropElementSupported(aDropTarget)) { |
| foundDescriptors.add(dropDescriptor); |
| } |
| } |
| } |
| } |
| |
| if (foundDescriptors.isEmpty()) { |
| return NO_DESCRIPTORS; |
| } |
| return (CommonDropAdapterDescriptor[]) foundDescriptors |
| .toArray(new CommonDropAdapterDescriptor[foundDescriptors |
| .size()]); |
| } |
| |
| private List getDropDescriptors( |
| INavigatorContentDescriptor aContentDescriptor) { |
| List descriptors = (List) dropDescriptors.get(aContentDescriptor); |
| if (descriptors != null) { |
| return descriptors; |
| } |
| synchronized (dropDescriptors) { |
| descriptors = (List) dropDescriptors.get(aContentDescriptor); |
| if (descriptors == null) { |
| dropDescriptors.put(aContentDescriptor, |
| (descriptors = new ArrayList())); |
| } |
| |
| } |
| return descriptors; |
| } |
| |
| /** |
| * @param aContentDescriptor |
| * A non-null content descriptor. |
| * @param aDropDescriptor |
| * A non-null drop descriptor. |
| */ |
| private void addCommonDropAdapter( |
| INavigatorContentDescriptor aContentDescriptor, |
| CommonDropAdapterDescriptor aDropDescriptor) { |
| getDropDescriptors(aContentDescriptor).add(aDropDescriptor); |
| } |
| |
| private class CommonDropAdapterRegistry extends |
| NavigatorContentRegistryReader implements |
| INavigatorContentExtPtConstants { |
| |
| private CommonDropAdapterRegistry() { |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.eclipse.ui.internal.navigator.extensions.RegistryReader#readElement(org.eclipse.core.runtime.IConfigurationElement) |
| */ |
| protected boolean readElement(IConfigurationElement element) { |
| |
| if (TAG_NAVIGATOR_CONTENT.equals(element.getName())) { |
| |
| String id = element.getAttribute(ATT_ID); |
| if (id != null) { |
| INavigatorContentDescriptor contentDescriptor = CONTENT_DESCRIPTOR_MANAGER |
| .getContentDescriptor(id); |
| if (contentDescriptor != null) { |
| |
| IConfigurationElement[] commonDropAdapters = element |
| .getChildren(TAG_COMMON_DROP_ADAPTER); |
| |
| for (int i = 0; i < commonDropAdapters.length; i++) { |
| addCommonDropAdapter(contentDescriptor, |
| new CommonDropAdapterDescriptor(commonDropAdapters[i], contentDescriptor)); |
| } |
| } |
| } |
| |
| } |
| return super.readElement(element); |
| } |
| |
| } |
| |
| } |