| /****************************************************************************** |
| * Copyright (c) 2002, 2010 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.gmf.runtime.common.ui.services.dnd.drag; |
| |
| import java.lang.ref.WeakReference; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.eclipse.swt.dnd.DragSourceEvent; |
| |
| /** |
| * Abstract parent of all the drag source listeners |
| * |
| * @author Vishy Ramaswamy |
| */ |
| public abstract class AbstractDragSourceListener |
| implements IDragSourceListener { |
| |
| /** |
| * Attribute for the drag source context. |
| */ |
| private WeakReference<IDragSourceContext> context = null; |
| |
| /** |
| * Attribute for the supporting transfer ids. |
| */ |
| private final String[] transferIds; |
| |
| /** |
| * Constructor for AbstractDragSourceListener. |
| * |
| * @param transferIdArray |
| * The transfer agent ids |
| */ |
| public AbstractDragSourceListener(String[] transferIdArray) { |
| super(); |
| |
| assert null != transferIdArray : "transferIdArray cannot be null"; //$NON-NLS-1$ |
| assert transferIdArray.length > 0 : "transferIdArray cannot be empty"; //$NON-NLS-1$ |
| |
| this.transferIds = transferIdArray; |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.eclipse.gmf.runtime.common.ui.services.dnd.drag.IDragSourceListener#isDraggable(org.eclipse.gmf.runtime.common.ui.services.dnd.drag.IDragSourceContext) |
| */ |
| public final boolean isDraggable(IDragSourceContext cntxt) { |
| /* Set the context */ |
| this.context = new WeakReference<IDragSourceContext>(cntxt); |
| |
| /* Check if draggable */ |
| return isDraggable(); |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.eclipse.gmf.runtime.common.ui.services.dnd.drag.IDragSourceListener#getSupportingTransferIds() |
| */ |
| public final String[] getSupportingTransferIds() { |
| return transferIds; |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.eclipse.swt.dnd.DragSourceListener#dragStart(org.eclipse.swt.dnd.DragSourceEvent) |
| */ |
| public final void dragStart(DragSourceEvent event) { |
| event.doit = true; |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.eclipse.swt.dnd.DragSourceListener#dragSetData(org.eclipse.swt.dnd.DragSourceEvent) |
| */ |
| public void dragSetData(DragSourceEvent event) { |
| /* method not implemented */ |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.eclipse.swt.dnd.DragSourceListener#dragFinished(org.eclipse.swt.dnd.DragSourceEvent) |
| */ |
| public void dragFinished(DragSourceEvent event) { |
| /* method not implemented */ |
| } |
| |
| /** |
| * Returns the context. |
| * |
| * @return IDragSourceContext |
| */ |
| protected final IDragSourceContext getContext() { |
| if (context == null) return null; |
| return context.get(); |
| } |
| |
| /** |
| * Checks if the selection contained in the context is draggable. Derived |
| * classes can get context using the <code>getContext()</code> method. |
| * |
| * @return true if draggable, false otherwise |
| */ |
| protected abstract boolean isDraggable(); |
| |
| /** |
| * Combines the arrays in the passed list into one array. |
| * |
| * @param list |
| * The List of arrays to combine together |
| * @param resultingArrayType |
| * the Object[] used to define the type of the combined array |
| * |
| * @return Object[] the combined array of the proper type |
| */ |
| protected final Object[] combineArraysInList(List list, |
| Object[] resultingArrayType) { |
| List listEntry = null; |
| Iterator it = list.iterator(); |
| ArrayList results = new ArrayList(); |
| while (it.hasNext()) { |
| listEntry = Arrays.asList((Object[]) it.next()); |
| results.addAll(listEntry); |
| } |
| |
| return results.toArray(resultingArrayType); |
| } |
| } |