TreeDropTarget.java

/****************************************************************************
 * Copyright (c) 2004, 2007 Composent, Inc. 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:
 *    Composent, Inc. - initial API and implementation
 *****************************************************************************/

package org.eclipse.ecf.internal.example.collab.ui;

import org.eclipse.ecf.core.user.IUser;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Widget;

class TreeDropTarget extends ChatDropTarget {
	public TreeDropTarget(LineChatClientView view, Control control,
			ChatComposite comp) {
		super(view, control, comp);
	}

	protected Object getData(DropTargetEvent event) {
		Widget item = event.item;
		if (item != null) {
			return item.getData();
		} else {
			return null;
		}
	}

	public void dragEnter(DropTargetEvent event) {
		if (event.detail == DND.DROP_DEFAULT) {
			if ((event.operations & DND.DROP_COPY) != 0) {
				event.detail = DND.DROP_COPY;
			} else {
				event.detail = DND.DROP_NONE;
			}
		}
		Object item = getData(event);
		if (item == null) {
			event.detail = DND.DROP_NONE;
			return;
		} else {
			if (item instanceof IUser) {
				selectedUser = (IUser) item;
			} else {
				event.detail = DND.DROP_NONE;
				return;
			}
		}
		// will accept text but prefer to have files dropped
		for (int i = 0; i < event.dataTypes.length; i++) {
			if (fileTransfer.isSupportedType(event.dataTypes[i])) {
				event.currentDataType = event.dataTypes[i];
				// files should only be copied
				if (event.detail != DND.DROP_COPY) {
					event.detail = DND.DROP_NONE;
					selectedUser = null;
				}
				break;
			}
		}
	}

	public void dragOver(DropTargetEvent event) {
		if ((event.operations & DND.DROP_COPY) != 0) {
			event.detail = DND.DROP_COPY;
		} else {
			event.detail = DND.DROP_NONE;
		}
		Object item = getData(event);
		if (item == null) {
			event.detail = DND.DROP_NONE;
		} else {
			if (item instanceof IUser) {
				selectedUser = (IUser) item;
			} else {
				event.detail = DND.DROP_NONE;
			}
		}
	}
}