/*
* Copyright (c) 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017 David Berkman
*
* This file is part of the SmallMind Code Project.
*
* The SmallMind Code Project is free software, you can redistribute
* it and/or modify it under either, at your discretion...
*
* 1) The terms of GNU Affero General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at
* your option) any later version.
*
* ...or...
*
* 2) The terms of the Apache License, Version 2.0.
*
* The SmallMind Code Project 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
* General Public License or Apache License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* and the Apache License along with the SmallMind Code Project. If not, see
* <http://www.gnu.org/licenses/> or <http://www.apache.org/licenses/LICENSE-2.0>.
*
* Additional permission under the GNU Affero GPL version 3 section 7
* ------------------------------------------------------------------
* If you modify this Program, or any covered work, by linking or
* combining it with other code, such other code is not for that reason
* alone subject to any of the requirements of the GNU Affero GPL
* version 3.
*/
package org.smallmind.swing.dragndrop;
import java.awt.Component;
import java.awt.Cursor;
import java.awt.Graphics;
import java.awt.Point;
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.DragSourceMotionListener;
import java.awt.image.BufferedImage;
import javax.swing.Icon;
import javax.swing.SwingUtilities;
public abstract class DragHandler implements DragSourceListener, DragSourceMotionListener, DragGestureListener {
private GhostPanel ghostPanel;
private CursorPair cursorPair;
private Component component;
private Point imageOffset = new Point(0, 0);
private Point ghostPoint = new Point(0, 0);
private int actions;
public DragHandler (GhostPanel ghostPanel, Component component, int actions) {
this.ghostPanel = ghostPanel;
this.component = component;
this.actions = actions;
DragSource.getDefaultDragSource().createDefaultDragGestureRecognizer(component, actions, this);
}
public abstract Transferable getTransferable (DragGestureEvent dragGestureEvent);
public abstract Icon getDragIcon (DragGestureEvent dragGestureEvent, Point offset);
public abstract void dragTerminated (int action, boolean success);
private BufferedImage createImageFromIcon (Icon icon) {
BufferedImage image;
Graphics graphics;
image = new BufferedImage(icon.getIconWidth(), icon.getIconHeight(), BufferedImage.TYPE_INT_ARGB_PRE);
graphics = image.getGraphics();
icon.paintIcon(component, graphics, 0, 0);
graphics.dispose();
return image;
}
@Override
public void dragGestureRecognized (DragGestureEvent dragGestureEvent) {
Transferable transferable;
Icon dragIcon;
if (((dragGestureEvent.getDragAction() & actions) != 0) && ((transferable = getTransferable(dragGestureEvent)) != null)) {
cursorPair = new CursorPair(dragGestureEvent.getDragAction());
if (((dragIcon = getDragIcon(dragGestureEvent, imageOffset)) != null) && DragSource.isDragImageSupported()) {
dragGestureEvent.startDrag(cursorPair.getNoDropCursor(), createImageFromIcon(dragIcon), imageOffset, transferable, this);
}
else {
if (dragIcon != null) {
ghostPanel.setImage(createImageFromIcon(dragIcon));
ghostPanel.setLocation(0, 0);
ghostPanel.setCursor(cursorPair.getNoDropCursor());
ghostPanel.setVisible(true);
}
dragGestureEvent.startDrag(cursorPair.getNoDropCursor(), transferable, this);
}
dragGestureEvent.getDragSource().addDragSourceMotionListener(this);
}
}
@Override
public void dragMouseMoved (DragSourceDragEvent dragSourceDragEvent) {
ghostPoint.setLocation(dragSourceDragEvent.getLocation());
SwingUtilities.convertPointFromScreen(ghostPoint, ghostPanel);
ghostPoint.translate((int)imageOffset.getX(), (int)imageOffset.getY());
ghostPanel.setImageLocation(ghostPoint);
ghostPanel.repaint();
}
@Override
public void dragEnter (DragSourceDragEvent dragSourceDragEvent) {
}
@Override
public void dragOver (DragSourceDragEvent dragSourceDragEvent) {
Cursor cursor = (((DropHandler.getCurrentDropActions() & dragSourceDragEvent.getUserAction() & actions) != 0) && DropHandler.hasDropPermission()) ? cursorPair.getDropCursor() : cursorPair.getNoDropCursor();
ghostPanel.setCursor(cursor);
dragSourceDragEvent.getDragSourceContext().setCursor(cursor);
}
@Override
public void dropActionChanged (DragSourceDragEvent dragSourceDragEvent) {
cursorPair.setCursors(dragSourceDragEvent.getUserAction());
}
@Override
public void dragExit (DragSourceEvent dragSourceEvent) {
ghostPanel.setCursor(cursorPair.getNoDropCursor());
dragSourceEvent.getDragSourceContext().setCursor(cursorPair.getNoDropCursor());
}
@Override
public void dragDropEnd (DragSourceDropEvent dragSourceDropEvent) {
try {
dragTerminated(dragSourceDropEvent.getDropAction(), dragSourceDropEvent.getDropSuccess());
}
finally {
ghostPanel.setVisible(false);
ghostPanel.setImage(null);
ghostPanel.setImageLocation(null);
dragSourceDropEvent.getDragSourceContext().getDragSource().removeDragSourceMotionListener(this);
cursorPair = null;
}
}
private class CursorPair {
private Cursor dropCursor;
private Cursor noDropCursor;
public CursorPair (int action) {
setCursors(action);
}
public synchronized void setCursors (int action) {
if ((action & DnDConstants.ACTION_LINK) != 0) {
dropCursor = DragSource.DefaultLinkDrop;
noDropCursor = DragSource.DefaultLinkNoDrop;
}
else if ((action & DnDConstants.ACTION_COPY) != 0) {
dropCursor = DragSource.DefaultCopyDrop;
noDropCursor = DragSource.DefaultCopyNoDrop;
}
else if ((action & DnDConstants.ACTION_MOVE) != 0) {
dropCursor = DragSource.DefaultMoveDrop;
noDropCursor = DragSource.DefaultMoveNoDrop;
}
else {
dropCursor = DragSource.DefaultMoveNoDrop;
noDropCursor = DragSource.DefaultMoveNoDrop;
}
}
public synchronized Cursor getDropCursor () {
return dropCursor;
}
public synchronized Cursor getNoDropCursor () {
return noDropCursor;
}
}
}