/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.swing.control;
import java.awt.datatransfer.Transferable;
import java.awt.dnd.DnDConstants;
import java.awt.dnd.DragGestureEvent;
import java.awt.dnd.DragGestureListener;
import java.awt.dnd.DragSource;
import java.awt.dnd.DragSourceDragEvent;
import java.awt.dnd.DragSourceDropEvent;
import java.awt.dnd.DragSourceEvent;
import java.awt.dnd.DragSourceListener;
import java.awt.dnd.DropTarget;
import java.awt.dnd.DropTargetDragEvent;
import java.awt.dnd.DropTargetDropEvent;
import java.awt.dnd.DropTargetEvent;
import java.awt.dnd.DropTargetListener;
import java.util.List;
import javax.swing.JList;
/**
* A sub-class of JList that supports drag and drop to reorder items within a single list
* and to copy or move items between lists. It is used by the
* {@linkplain org.geotools.swing.MapLayerTable} widget but has been written
* in a general fashion so that it may be used for other pusposes.
*
* @see DnDListModel
*
* @author Michael Bedward
* @since 2.6
*
*
*
* @source $URL$
* @version $Id$
*/
public class DnDList<T> extends JList implements DragGestureListener, DragSourceListener, DropTargetListener {
private static final long serialVersionUID = 3310751294076288683L;
private DragSource src;
@SuppressWarnings("unused")
private DropTarget tgt; // this is not used? what is it for
private boolean movingItems;
private int overIndex;
private int[] dragIndices;
/**
* Default constructor. An DnDListModel object will be created
* for the list.
*/
public DnDList() {
this(new DnDListModel<T>());
}
/**
* Constructor allowing the list model to be specified
* @param model an instance of DnDListModel
* @throws IllegalArgumentException if model is null
*/
public DnDList(DnDListModel<T> model) {
super( model );
if (model == null) {
throw new IllegalArgumentException("model must not be null");
}
//this.setModel(model);
src = new DragSource();
src.createDefaultDragGestureRecognizer(this, DnDConstants.ACTION_MOVE, this);
tgt = new DropTarget(this, this);
movingItems = false;
overIndex = -1;
}
@SuppressWarnings("unchecked")
@Override
public DnDListModel<T> getModel() {
return (DnDListModel<T>) super.getModel();
}
/**
* Called by the system when a drag gesture starts
*/
@Override
public void dragGestureRecognized(DragGestureEvent dge) {
dragIndices = getSelectedIndices();
if (dragIndices.length > 0) {
List<T> items = getModel().getElementsAt(dragIndices);
Transferable stuff = new DnDListItemsTransferable<T>(items);
movingItems = true;
src.startDrag(dge, DragSource.DefaultMoveDrop, stuff, this);
}
}
/**
* DragSourceListener method - presently ignored
* <p>
* Description copied from interface:<br>
* Called as the cursor's hotspot enters a platform-dependent drop site.
* This method is invoked when all the following conditions are true:
* <ul>
* <li> The cursor's hotspot enters the operable part of a platform- dependent drop site.
* <li> The drop site is active.
* <li> The drop site accepts the drag.
* </ul>
*/
@Override
public void dragEnter(DragSourceDragEvent dsde) {
// do nothing
}
/**
* DragSourceListener method - presently ignored
* <p>
* Description copied from interface:<br>
* Called as the cursor's hotspot moves over a platform-dependent drop site.
* This method is invoked when all the following conditions are true:
* <ul>
* <li> The cursor's hotspot has moved, but still intersects the operable part
* of the drop site associated with the previous dragEnter() invocation.
* <li> The drop site is still active.
* <li> The drop site accepts the drag.
* </ul>
*/
@Override
public void dragOver(DragSourceDragEvent dsde) {
// do nothing
}
/**
* DragSourceListener method - presently ignored
* <p>
* Description copied from interface:<br>
* Called when the user has modified the drop gesture. This method is invoked when
* the state of the input device(s) that the user is interacting with changes.
* Such devices are typically the mouse buttons or keyboard modifiers that the
* user is interacting with.
*/
@Override
public void dropActionChanged(DragSourceDragEvent dsde) {
// do nothing
}
/**
* DragSourceListener method - presently ignored
* <p>
* Description copied from interface:<br>
* Called as the cursor's hotspot exits a platform-dependent drop site.
* This method is invoked when <b>any</b> of the following conditions are true:
* <ul>
* <li> The cursor's hotspot no longer intersects the operable part of the
* drop site associated with the previous dragEnter() invocation.
* <li> The drop site associated with the previous dragEnter() invocation is
* no longer active.
* <li> The drop site associated with the previous dragEnter() invocation
* has rejected the drag.
* </ul>
*/
@Override
public void dragExit(DragSourceEvent dse) {
// do nothing
}
/**
* Description copied from interface:<br>
* This method is invoked to signify that the Drag and Drop operation is
* complete. The getDropSuccess() method of the DragSourceDropEvent can be
* used to determine the termination state. The getDropAction() method returns
* the operation that the drop site selected to apply to the Drop operation.
* Once this method is complete, the current DragSourceContext and associated
* resources become invalid.
*/
@Override
public void dragDropEnd(DragSourceDropEvent dsde) {
movingItems = false;
overIndex = -1;
}
/**
* Records the index of the list item (if any) pointed to by the mouse cursor
* <p>
* Description copied from interface:<br>
* Called while a drag operation is ongoing, when the mouse pointer enters
* the operable part of the drop site for the DropTarget registered with
* this listener.
*/
@Override
public void dragEnter(DropTargetDragEvent dtde) {
overIndex = this.locationToIndex(dtde.getLocation());
setSelectedIndex(overIndex);
}
/**
* Records the index of the list item (if any) pointed to by the mouse cursor
* <p>
* Description copied from interface:<br>
* Called when a drag operation is ongoing, while the mouse pointer is still
* over the operable part of the drop site for the DropTarget registered with
* this listener.
*/
@Override
public void dragOver(DropTargetDragEvent dtde) {
int index = this.locationToIndex(dtde.getLocation());
if (index >= 0 && index != overIndex) {
overIndex = index;
setSelectedIndex(overIndex);
}
}
/**
* DropTargetListener method - presently ignored
* <p>
* Description copied from interface:<br>
* Called if the user has modified the current drop gesture.
*/
@Override
public void dropActionChanged(DropTargetDragEvent dtde) {
// do nothing
}
/**
* Description copied from interface:<br>
* Called while a drag operation is ongoing, when the mouse pointer has exited
* the operable part of the drop site for the DropTarget registered with this
* listener.
*/
@Override
public void dragExit(DropTargetEvent dte) {
overIndex = -1;
}
/**
* Handles the moving (for drag and drop actions within this list) or transfer
* (for actions between lists) of list items.
* Description copied from interface:<br>
* Called when the drag operation has terminated with a drop on the operable part
* of the drop site for the DropTarget registered with this listener.
* <p>
* This method is responsible for undertaking the transfer of the data associated
* with the gesture. The DropTargetDropEvent provides a means to obtain a Transferable
* object that represents the data object(s) to be transfered.
* <p>
* From this method, the DropTargetListener shall accept or reject the drop via
* the acceptDrop(int dropAction) or rejectDrop() methods of the DropTargetDropEvent
* parameter.
* <p>
* Subsequent to acceptDrop(), but not before, DropTargetDropEvent's getTransferable()
* method may be invoked, and data transfer may be performed via the returned
* Transferable's getTransferData() method.
* <p>
* At the completion of a drop, an implementation of this method is required to
* signal the success/failure of the drop by passing an appropriate boolean to the
* DropTargetDropEvent's dropComplete(boolean success) method.
* <p>
* Note: The data transfer should be completed before the call to the
* DropTargetDropEvent's dropComplete(boolean success) method. After that, a call
* to the getTransferData() method of the Transferable returned by
* DropTargetDropEvent.getTransferable() is guaranteed to succeed only if the data
* transfer is local; that is, only if DropTargetDropEvent.isLocalTransfer()
* returns true. Otherwise, the behavior of the call is implementation-dependent.
*/
@Override
public void drop(DropTargetDropEvent dtde) {
//Transferable stuff = dtde.getTransferable();
/*
* @todo check DataFlavor of stuff
*/
dtde.acceptDrop(DnDConstants.ACTION_MOVE);
if (movingItems) {
/*
* This is a local drag and drop to reorder items
*/
DnDListModel<T> model = getModel();
model.moveItems(overIndex, dragIndices);
} else {
// @todo stuff dragged from other list
}
overIndex = -1;
movingItems = false;
dtde.getDropTargetContext().dropComplete(true);
}
}