//**********************************************************************
//
//<copyright>
//
//BBN Technologies
//10 Moulton Street
//Cambridge, MA 02138
//(617) 873-8000
//
//Copyright (C) BBNT Solutions LLC. All rights reserved.
//
//</copyright>
//**********************************************************************
//
//$Source: /cvs/distapps/openmap/src/openmap/com/bbn/openmap/tools/dnd/DefaultDnDCatcher.java,v $
//$RCSfile: DefaultDnDCatcher.java,v $
//$Revision: 1.6 $
//$Date: 2005/08/09 20:45:09 $
//$Author: dietrick $
//
//**********************************************************************
package com.bbn.openmap.tools.dnd;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
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.DragSourceListener;
import java.awt.dnd.DropTarget;
import java.awt.dnd.DropTargetDropEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.beans.PropertyVetoException;
import java.beans.VetoableChangeListener;
import java.beans.beancontext.BeanContext;
import java.beans.beancontext.BeanContextChild;
import java.beans.beancontext.BeanContextChildSupport;
import java.beans.beancontext.BeanContextMembershipEvent;
import java.beans.beancontext.BeanContextMembershipListener;
import java.io.Serializable;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Iterator;
import javax.swing.BorderFactory;
import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;
import javax.swing.SwingConstants;
import javax.swing.border.Border;
import javax.swing.border.TitledBorder;
import com.bbn.openmap.Layer;
import com.bbn.openmap.LayerHandler;
import com.bbn.openmap.MapBean;
import com.bbn.openmap.MouseDelegator;
import com.bbn.openmap.event.LayerEvent;
import com.bbn.openmap.event.LayerListener;
import com.bbn.openmap.event.ProjectionEvent;
import com.bbn.openmap.event.ProjectionListener;
import com.bbn.openmap.event.SelectMouseMode;
import com.bbn.openmap.layer.OMGraphicHandlerLayer;
import com.bbn.openmap.layer.location.Location;
import com.bbn.openmap.omGraphics.OMAction;
import com.bbn.openmap.omGraphics.OMGraphic;
import com.bbn.openmap.omGraphics.SinkGraphic;
import com.bbn.openmap.proj.Projection;
import com.bbn.openmap.util.Debug;
/**
* DefaultDnDCatcher manages Drag and Drop events on the map.
*
* Drag: When a mouseDragged event occurs, DropListenerSupport forwards it to
* the DefaultDnDCatcher (consume() method). If it's the first mouseDragged
* event, dragGestureRecognized is fired and drag starts.
*
* Drop: Each layer in the LayerHandler listens to the drop events. When a drop
* occurs, a list of potential targets (layers) is shown in the popup menu.
*
* DefaultDnDCatcher recognizes Location as the droppable object.
*
* DefaultDnDCatcher recognizes OMGraphicHandlerLayer layers as potential drop
* targets.
*/
public class DefaultDnDCatcher extends DnDListener implements BeanContextChild,
BeanContextMembershipListener, PropertyChangeListener, Serializable,
ProjectionListener, LayerListener, ActionListener {
/**
* PropertyChangeSupport for handling listeners.
*/
protected PropertyChangeSupport pcSupport = new PropertyChangeSupport(this);
/**
* BeanContextChildSupport object provides helper functions for
* BeanContextChild interface.
*/
protected BeanContextChildSupport beanContextChildSupport = new BeanContextChildSupport();
/**
* Hashtable for keeping references to potential drop targets
*/
protected Hashtable layers = new Hashtable();
// a reference to the MouseDelegator object in the MapHandler
protected transient MouseDelegator md;
// a copy of current projection
protected transient Projection proj;
// object that is being passed in transferable
protected Object transferData;
protected Point dropLocation;
/**
* Constructs a new DefaultDnDCatcher.
*/
public DefaultDnDCatcher() {
this(new DragSource());
}
/**
* Constructs a new DefaultDnDCatcher given the DragSource for the
* Component.
*
* @param ds the DragSource for the Component
*/
public DefaultDnDCatcher(DragSource ds) {
this(ds, null);
}
/**
* Construct a new DefaultDnDCatcher given the DragSource for the Component
* c, and the Component to observe.
*
* @param ds the DragSource for the Component c
* @param c the Component to observe
*/
public DefaultDnDCatcher(DragSource ds, Component c) {
this(ds, c, DnDConstants.ACTION_NONE);
}
public DefaultDnDCatcher(DragSource ds, Component c, int act) {
this(ds, c, act, null);
}
public DefaultDnDCatcher(DragSource ds, Component c, int act,
DragGestureListener dgl) {
super(ds, c, act, dgl);
dragSource = getDragSource();
dragGestureListener = new ComponentDragGestureListener(this, this);
setSourceActions(DnDConstants.ACTION_MOVE);
}
/**
* Invoked when an action from the popup menu occurs.
*/
public void actionPerformed(java.awt.event.ActionEvent e) {
Object source = e.getSource();
if (!(source instanceof JMenuItem))
return;
JMenuItem mi = (JMenuItem) source;
String name = mi.getText();
OMGraphicHandlerLayer targetLayer = (OMGraphicHandlerLayer) layers.get(name);
if (targetLayer == null) {
Debug.message("defaultdndcatcher",
"ERROR> DefaultDnDCatcher::actionPerformed: "
+ "no layer found with name " + name);
return;
}
targetLayer.doAction((OMGraphic) transferData,
new OMAction(OMAction.UPDATE_GRAPHIC_MASK));
}
public void addPropertyChangeListener(PropertyChangeListener listener) {
pcSupport.addPropertyChangeListener(listener);
}
/** Method for BeanContextChild interface. */
public void addPropertyChangeListener(String propertyName,
PropertyChangeListener in_pcl) {
pcSupport.addPropertyChangeListener(propertyName, in_pcl);
}
/** Method for BeanContextChild interface. */
public void addVetoableChangeListener(String propertyName,
VetoableChangeListener in_vcl) {
beanContextChildSupport.addVetoableChangeListener(propertyName, in_vcl);
}
/**
* BeanContextMembershipListener method. Called when new objects are added
* to the parent BeanContext.
*
* @param bcme event that contains an iterator that can be used to go
* through the new objects.
*/
public void childrenAdded(BeanContextMembershipEvent bcme) {
findAndInit(bcme.iterator());
}
/**
* BeanContextMembershipListener method. Called when objects have been
* removed from the parent BeanContext. The DefaultDnDCatcher looks for the
* MapBean it is managing DnD and MouseEvents for, and any layers that may
* be removed.
*
* @param bcme event that contains an iterator that can be used to go
* through the removed objects.
*/
public void childrenRemoved(BeanContextMembershipEvent bcme) {
Iterator it = bcme.iterator();
while (it.hasNext()) {
findAndUndo(it.next());
}
}
/**
* The method is invoked on mousePressed, mouseReleased, and mouseDragged
* events that come from the MapBean through DropListenerSupport.
*
* @return boolean
* @param e java.awt.event.MouseEvent
*/
public boolean consume(MouseEvent e) {
if (e.getID() == MouseEvent.MOUSE_PRESSED) {
mousePressed(e);
} else if (e.getID() == MouseEvent.MOUSE_RELEASED) {
mouseReleased(e);
} else if (e.getID() == MouseEvent.MOUSE_DRAGGED) {
mouseDragged(e);
}
return false;
}
/**
* The drag operation has terminated with a drop on this
* <code>DropTarget</code>. This method is responsible for undertaking the
* transfer of the data associated with the gesture. The
* <code>DropTargetDropEvent</code> provides a means to obtain a
* <code>Transferable</code> object that represents the data object(s) to be
* transfered.
* <P>
* From this method, the <code>DropTargetListener</code> shall accept or
* reject the drop via the acceptDrop(int dropAction) or rejectDrop()
* methods of the <code>DropTargetDropEvent</code> parameter.
* <P>
* Subsequent to acceptDrop(), but not before,
* <code>DropTargetDropEvent</code>'s getTransferable() method may be
* invoked, and data transfer may be performed via the returned
* <code>Transferable</code>'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
* <code>boolean</code> to the <code>DropTargetDropEvent</code>'s
* dropComplete(boolean success) method.
* <P>
* Note: The actual processing of the data transfer is not required to
* finish before this method returns. It may be deferred until later.
* <P>
*
* @param dtde the <code>DropTargetDropEvent</code>
*/
public void drop(java.awt.dnd.DropTargetDropEvent dtde) {
//
// Accept the drop and get transferable object.
//
dtde.acceptDrop(DnDConstants.ACTION_MOVE);
transferData = extractTransferData(dtde);
dropLocation = extractDropLocation(dtde);
dtde.dropComplete(true);
if (transferData == null || dropLocation == null)
return;
JPopupMenu popup = new JPopupMenu();
TitledBorder titledBorder = BorderFactory.createTitledBorder(BorderFactory.createEmptyBorder(),
"Available Drop Targets:");
titledBorder.setTitleColor(Color.gray);
popup.setBorder(titledBorder);
Border compoundborder = BorderFactory.createCompoundBorder(BorderFactory.createEtchedBorder(),
BorderFactory.createEmptyBorder(2, 2, 2, 2));
//
// Check whether the dropped object is of type Location
// (has exact x and y coordinates).
//
if (transferData instanceof Location) {
((Location) transferData).setLocation(dropLocation.x,
dropLocation.y,
proj);
OMGraphicHandlerLayer omlayer = null;
String layer_name;
Enumeration keys = layers.keys();
while (keys.hasMoreElements()) {
layer_name = keys.nextElement().toString();
omlayer = (OMGraphicHandlerLayer) layers.get(layer_name);
if (omlayer.isVisible()) {
JMenuItem menuItem = new JMenuItem(layer_name);
menuItem.setHorizontalTextPosition(SwingConstants.CENTER);
menuItem.setBorder(compoundborder);
menuItem.addActionListener(this);
popup.add(menuItem);
}
}
popup.addSeparator();
}
JMenuItem menuItem = new JMenuItem("CANCEL");
menuItem.setForeground(Color.red);
menuItem.setHorizontalTextPosition(SwingConstants.CENTER);
menuItem.setBorder(compoundborder);
popup.add(menuItem);
popup.setPreferredSize(new Dimension(150, (popup.getComponentCount() + 1) * 25));
//
// Show a popup menu of available drop targets.
//
popup.show(((DropTarget) dtde.getSource()).getComponent(),
dropLocation.x,
dropLocation.y);
}
/**
* Gets the location where the drop action occurred.
*/
private Point extractDropLocation(DropTargetDropEvent dtde) {
if (dtde == null) {
Debug.message("defaultdndcatcher",
"ERROR> BDnDC::getTransferData(): dropEvent is null");
return null;
}
return dtde.getLocation();
}
/**
* Gets the object that is passed in transferable in DropTargetDropEvent.
*/
private Object extractTransferData(DropTargetDropEvent dtde) {
if (dtde == null) {
Debug.message("defaultdndcatcher",
"ERROR> DefaultDnDCatcher::getTransferData(): dropEvent is null");
return null;
}
Transferable tr = dtde.getTransferable();
try {
return tr.getTransferData(DefaultTransferableObject.OBJECT_FLAVOR);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* Called when an object should be evaluated by the DefaultDnDCatcher to see
* if it is needed.
*/
public void findAndInit(Object someObj) {
if (someObj instanceof MouseDelegator)
md = (MouseDelegator) someObj;
if (someObj instanceof MapBean) {
((MapBean) someObj).addProjectionListener(this);
setProjection(((MapBean) someObj).getProjection().makeClone());
}
if (someObj instanceof LayerHandler) {
LayerHandler lh = (LayerHandler) someObj;
lh.addLayerListener(this);
setLayers(lh.getLayers());
}
}
/**
* Eventually gets called when the DefaultDnDCatcher is added to the
* BeanContext, and when other objects are added to the BeanContext anytime
* after that. The DefaultDnDCatcher looks for LayerHandler to get
* OMGraphicHandlerLayer layers to manage Drag and Drop events for. If a
* MapBean is added to the BeanContext while another already is in use, the
* second MapBean will take the place of the first.
*
* @param it iterator to use to go through the new objects in the
* BeanContext.
*/
public void findAndInit(Iterator it) {
while (it.hasNext()) {
findAndInit(it.next());
}
}
/**
* Called by childrenRemoved.
*/
public void findAndUndo(Object someObj) {
if (someObj == md) {
md = null;
}
if (someObj instanceof MapBean) {
((MapBean) someObj).removeProjectionListener(this);
setProjection((Projection) null);
}
if (someObj instanceof LayerHandler) {
LayerHandler lh = (LayerHandler) someObj;
lh.removeLayerListener(this);
setLayers((Layer[]) null);
}
}
public void firePropertyChange(String property, Object oldObj, Object newObj) {
pcSupport.firePropertyChange(property, oldObj, newObj);
}
/**
* Report a vetoable property update to any registered listeners. If anyone
* vetos the change, then fire a new event reverting everyone to the old
* value and then rethrow the PropertyVetoException.
* <P>
*
* No event is fired if old and new are equal and non-null.
* <P>
*
* @param name The programmatic name of the property that is about to change
*
* @param oldValue The old value of the property
* @param newValue - The new value of the property
*
* @throws PropertyVetoException if the recipient wishes the property change
* to be rolled back.
*/
public void fireVetoableChange(String name, Object oldValue, Object newValue)
throws PropertyVetoException {
beanContextChildSupport.fireVetoableChange(name, oldValue, newValue);
}
/**
* @return the current BeanContext associated with the JavaBean
*/
public java.beans.beancontext.BeanContext getBeanContext() {
return beanContextChildSupport.getBeanContext();
}
/**
* Gets current projection.
*/
public Projection getProjection() {
return proj;
}
/**
* The mouseDragged event gets interpreted as DragGestureRecognized when
* startDrag boolean is true. After the first mouseDragged event, set
* startDrag to false.
*
*/
public void mouseDragged(MouseEvent e) {
Debug.message("defaultdndcatcher", "mouseDragged, startDrag="
+ startDrag);
if (startDrag) {
startDrag = false;
if (md.getActiveMouseMode() instanceof SelectMouseMode) {
appendEvent(e);
setComponent((Component) e.getSource());
fireDragGestureRecognized(DnDConstants.ACTION_MOVE,
((MouseEvent) getTriggerEvent()).getPoint());
}
}
}
/**
* On mouseReleased, set startDrag to true in order to enable dragging.
*/
public void mouseReleased(MouseEvent e) {
startDrag = true;
}
/**
* Invoked when there has been a fundamental change to the Map.
* <p>
* Layers are expected to recompute their graphics (if this makes sense),
* and then <code>repaint()</code> themselves.
*
* @param e ProjectionEvent
*/
public void projectionChanged(ProjectionEvent e) {
setProjection(e);
}
/**
* This method gets called when a bound property is changed.
*
* @param evt A PropertyChangeEvent object describing the event source and
* the property that has changed.
*/
public void propertyChange(java.beans.PropertyChangeEvent evt) {}
/**
* remove a property change listener to this bean child
*/
public void removePropertyChangeListener(
String name,
java.beans.PropertyChangeListener pcl) {}
/**
* remove a vetoable change listener to this child
*/
public void removeVetoableChangeListener(
String name,
java.beans.VetoableChangeListener vcl) {}
/**
* A change in the value of the nesting BeanContext property of this
* BeanContextChild may be vetoed by throwing the appropriate exception.
*
* @param in_bc the new BeanContext for this object
*/
public void setBeanContext(BeanContext in_bc) throws PropertyVetoException {
if (in_bc != null) {
in_bc.addBeanContextMembershipListener(this);
beanContextChildSupport.setBeanContext(in_bc);
findAndInit(in_bc.iterator());
}
}
/**
* DefaultDnDCatcher adds itself to each layer as the DropTargetListener.
* This is needed in order to capture drop events from any layer on the map,
* and then apply the events to the applicable layers.
*/
public void setLayers(Layer[] allLayers) {
// remove old layers list
layers.clear();
if (allLayers != null) {
for (int i = 0; i < allLayers.length; i++) {
// create a new drop target
/* dropTarget = */new DropTarget(allLayers[i], DnDConstants.ACTION_MOVE, this);
if (allLayers[i] instanceof OMGraphicHandlerLayer) {
Debug.message("DnDCatcher", "Layers changed");
// keep a reference to potential drop target
layers.put(allLayers[i].getName(), allLayers[i]);
}
}
}
}
/**
* The method is invoked when there is a change in layers property in the
* LayerHandler.
*/
public void setLayers(LayerEvent evt) {
if (evt.getType() == LayerEvent.ALL) {
setLayers(evt.getLayers());
}
}
/**
* This method lets you take the ProjectionEvent received from the MapBean,
* and lets you know if you should do something with it. MUST to be called
* in the projectionChanged() method of your layer, if you want to refer to
* the projection later. If this methods returns null, you probably just
* want to call repaint() if your layer.paint() method is ready to paint
* what it should.
*
* @param projEvent the ProjectionEvent from the ProjectionListener method.
* @return The new Projection if it is different from the one we already
* have, null if is the same as the current one.
*/
public Projection setProjection(ProjectionEvent projEvent) {
Projection newProjection = projEvent.getProjection();
if (!newProjection.equals(getProjection())) {
Projection clone = newProjection.makeClone();
setProjection(clone);
return clone;
} else {
return null;
}
}
/**
* Sets the current projection.
*/
public void setProjection(Projection projection) {
proj = projection;
}
/**
* Invoked on dragGestureRecognized in the ComponentDragGestureListener
* class.
*
*/
public void startDragAction(DragGestureEvent dge, DragSourceListener dsl) {
// create a Transferable object here.
// Create a location object that can be dropped on a layer.
// dragSource.startDrag(dge,
// getCursor(DragSource.DefaultMoveDrop), new
// DefaultTransferableObject(new BasicLocation()), dsl);
// SinkGraphic is a singleton object used as sample. No action
// on a layer will be done at drop.
dragSource.startDrag(dge,
getCursor(DragSource.DefaultMoveDrop),
new DefaultTransferableObject(SinkGraphic.getSharedInstance()),
dsl);
}
}