| /******************************************************************************* |
| * 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 org.eclipse.core.expressions.EvaluationContext; |
| import org.eclipse.core.expressions.EvaluationResult; |
| import org.eclipse.core.expressions.Expression; |
| import org.eclipse.core.runtime.CoreException; |
| import org.eclipse.core.runtime.IConfigurationElement; |
| import org.eclipse.jface.viewers.IStructuredSelection; |
| import org.eclipse.ui.internal.navigator.CustomAndExpression; |
| import org.eclipse.ui.internal.navigator.NavigatorPlugin; |
| import org.eclipse.ui.internal.navigator.extensions.INavigatorContentExtPtConstants; |
| import org.eclipse.ui.navigator.CommonDropAdapterAssistant; |
| import org.eclipse.ui.navigator.INavigatorContentDescriptor; |
| |
| /** |
| * @since 3.2 |
| * |
| */ |
| public final class CommonDropAdapterDescriptor implements |
| INavigatorContentExtPtConstants { |
| |
| private final IConfigurationElement element; |
| |
| private final INavigatorContentDescriptor contentDescriptor; |
| |
| private Expression dropExpr; |
| |
| /* package */CommonDropAdapterDescriptor( |
| IConfigurationElement aConfigElement, |
| INavigatorContentDescriptor aContentDescriptor) { |
| element = aConfigElement; |
| contentDescriptor = aContentDescriptor; |
| init(); |
| } |
| |
| private void init() { |
| IConfigurationElement[] children = element.getChildren(TAG_POSSIBLE_DROP_TARGETS); |
| if (children.length == 1) { |
| dropExpr = new CustomAndExpression(children[0]); |
| } |
| } |
| |
| /** |
| * |
| * @param anElement |
| * The element from the set of elements being dragged. |
| * @return True if the element matches the drag expression from the |
| * extension. |
| */ |
| public boolean isDragElementSupported(Object anElement) { |
| return contentDescriptor.isPossibleChild(anElement); |
| } |
| |
| /** |
| * |
| * @param aSelection |
| * The set of elements being dragged. |
| * @return True if the element matches the drag expression from the |
| * extension. |
| */ |
| public boolean areDragElementsSupported(IStructuredSelection aSelection) { |
| if (aSelection.isEmpty()) { |
| return false; |
| } |
| return contentDescriptor.arePossibleChildren(aSelection); |
| } |
| |
| /** |
| * |
| * @param anElement |
| * The element from the set of elements benig dropped. |
| * @return True if the element matches the drop expression from the |
| * extension. |
| */ |
| public boolean isDropElementSupported(Object anElement) { |
| if (dropExpr != null && anElement != null) { |
| try { |
| EvaluationContext context = new EvaluationContext(null, anElement); |
| context.setAllowPluginActivation(true); |
| return dropExpr |
| .evaluate(context) == EvaluationResult.TRUE; |
| } catch (CoreException e) { |
| NavigatorPlugin.logError(0, e.getMessage(), e); |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * |
| * @return An instance of {@link CommonDropAdapterAssistant} from the |
| * descriptor or {@link SkeletonCommonDropAssistant}. |
| */ |
| public CommonDropAdapterAssistant createDropAssistant() { |
| |
| try { |
| return (CommonDropAdapterAssistant) element |
| .createExecutableExtension(ATT_CLASS); |
| } catch (CoreException e) { |
| NavigatorPlugin.logError(0, e.getMessage(), e); |
| } catch (RuntimeException re) { |
| NavigatorPlugin.logError(0, re.getMessage(), re); |
| } |
| return SkeletonCommonDropAssistant.INSTANCE; |
| } |
| |
| /** |
| * |
| * @return The content descriptor that contains this drop descriptor. |
| */ |
| public INavigatorContentDescriptor getContentDescriptor() { |
| return contentDescriptor; |
| } |
| |
| } |