/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.examples.readmetool;

import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.swt.dnd.*;
import org.eclipse.ui.part.PluginTransfer;
import org.eclipse.ui.part.PluginTransferData;

/**
 * A drag listener for the readme editor's content outline page.
 * Allows dragging of content segments into views that support
 * the <code>TextTransfer</code> or <code>PluginTransfer</code> transfer types.
 */
public class ReadmeContentOutlineDragListener extends DragSourceAdapter {
	private ReadmeContentOutlinePage page;
/**
 * Creates a new drag listener for the given page.
 */
public ReadmeContentOutlineDragListener(ReadmeContentOutlinePage page) {
	this.page = page;
}
/* (non-Javadoc)
 * Method declared on DragSourceListener
 */
public void dragSetData(DragSourceEvent event) {
	if (PluginTransfer.getInstance().isSupportedType(event.dataType)) {
		byte[] segmentData = getSegmentText().getBytes();
		event.data = new PluginTransferData(ReadmeDropActionDelegate.ID, segmentData);
		return;
	}
	if (TextTransfer.getInstance().isSupportedType(event.dataType)) {
		event.data = getSegmentText();
		return;
	}
}
/**
 * Returns the text of the currently selected readme segment.
 */
private String getSegmentText() {
	StringBuffer result = new StringBuffer();
	ISelection selection = page.getSelection();
	if (selection instanceof org.eclipse.jface.viewers.IStructuredSelection) {
		Object[] selected = ((IStructuredSelection) selection).toArray();
		result.append("\n"); //$NON-NLS-1$
		for (int i = 0; i < selected.length; i++) {
			if (selected[i] instanceof MarkElement) {
				result.append(((MarkElement) selected[i]).getLabel(selected[i]));
				result.append("\n"); //$NON-NLS-1$
			}
		}
	}
	return result.toString();
}
}