/*
* This file is part of WebLookAndFeel library.
*
* WebLookAndFeel library is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* WebLookAndFeel 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with WebLookAndFeel library. If not, see <http://www.gnu.org/licenses/>.
*/
package com.alee.managers.drag;
import com.alee.managers.glasspane.GlassPaneManager;
import com.alee.managers.glasspane.WebGlassPane;
import com.alee.managers.log.Log;
import com.alee.utils.SwingUtils;
import java.awt.*;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.dnd.*;
import java.awt.image.BufferedImage;
import java.util.HashMap;
import java.util.Map;
/**
* This manager simplifies dragged items visual representation creation.
* You can add customized representation support for DataFlavor by registering new DragViewHandler.
* So far custom DataFlavor view will be displayed only within application window bounds.
*
* @author Mikle Garin
*/
public class DragManager
{
/**
* todo 1. Move dragged object display to a separate transparent non-focusable window
*/
/**
* Drag view handlers map.
*/
protected static Map<DataFlavor, DragViewHandler> viewHandlers;
/**
* Dragged object representation variables.
*/
protected static WebGlassPane glassPane;
protected static Object data;
protected static BufferedImage view;
protected static Component dropLocation;
protected static DragViewHandler dragViewHandler;
/**
* Whether manager is initialized or not.
*/
protected static boolean initialized = false;
/**
* Initializes manager if it wasn't already initialized.
*/
public static synchronized void initialize ()
{
// To avoid more than one initialization
if ( !initialized )
{
// Remember that initialization happened
initialized = true;
// View handlers map
viewHandlers = new HashMap<DataFlavor, DragViewHandler> ();
final DragSourceAdapter dsa = new DragSourceAdapter ()
{
@Override
public void dragEnter ( final DragSourceDragEvent dsde )
{
actualDragEnter ( dsde );
}
protected void actualDragEnter ( final DragSourceDragEvent dsde )
{
// todo Do not recreate view few times while dragging
// Save drop location component
final DragSourceContext dsc = dsde.getDragSourceContext ();
dropLocation = dsc.getComponent ();
// Deciding on enter what to display for this kind of data
final Transferable transferable = dsc.getTransferable ();
final DataFlavor[] flavors = transferable.getTransferDataFlavors ();
for ( final DataFlavor flavor : flavors )
{
if ( viewHandlers.containsKey ( flavor ) )
{
try
{
data = transferable.getTransferData ( flavor );
dragViewHandler = viewHandlers.get ( flavor );
view = dragViewHandler.getView ( data, dsde );
glassPane = GlassPaneManager.getGlassPane ( dsc.getComponent () );
glassPane.setPaintedImage ( view, getLocation ( glassPane, dsde ) );
break;
}
catch ( final Throwable e )
{
Log.error ( DragManager.class, e );
}
}
}
}
@Override
public void dragMouseMoved ( final DragSourceDragEvent dsde )
{
final DragSourceContext dsc = dsde.getDragSourceContext ();
if ( dsc.getComponent () != dropLocation )
{
actualDragEnter ( dsde );
}
// Move displayed data
if ( view != null )
{
final WebGlassPane gp = GlassPaneManager.getGlassPane ( dsde.getDragSourceContext ().getComponent () );
if ( gp != glassPane )
{
glassPane.clearPaintedImage ();
glassPane = gp;
}
glassPane.setPaintedImage ( view, getLocation ( glassPane, dsde ) );
}
}
public Point getLocation ( final WebGlassPane gp, final DragSourceDragEvent dsde )
{
final Point mp = SwingUtils.getMousePoint ( gp );
final Point vp = dragViewHandler.getViewRelativeLocation ( data, dsde );
return new Point ( mp.x + vp.x, mp.y + vp.y );
}
@Override
public void dragDropEnd ( final DragSourceDropEvent dsde )
{
// Cleanup drop location component
dropLocation = null;
// Cleanup displayed data
if ( view != null )
{
dragViewHandler.dragEnded ( data, dsde );
glassPane.clearPaintedImage ();
glassPane = null;
data = null;
view = null;
dragViewHandler = null;
}
}
};
DragSource.getDefaultDragSource ().addDragSourceListener ( dsa );
DragSource.getDefaultDragSource ().addDragSourceMotionListener ( dsa );
}
}
/**
* Registers new DragViewHandler.
*
* @param dragViewHandler DragViewHandler to register
*/
public static void registerViewHandler ( final DragViewHandler dragViewHandler )
{
viewHandlers.put ( dragViewHandler.getObjectFlavor (), dragViewHandler );
}
/**
* Unregisters new DragViewHandler.
*
* @param dragViewHandler DragViewHandler to unregister
*/
public static void unregisterViewHandler ( final DragViewHandler dragViewHandler )
{
viewHandlers.remove ( dragViewHandler.getObjectFlavor () );
}
}