beanboxdndcatcher.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

        }

        selectedBeanBox.showUnCut(selectedBean);

        clearSelection();

        if (Debug.debugging("beanbox"))
            Debug.output("Exit> unCutSelectedBean");
    }

    private void clearSelection() {
        cutBean = null;
        selectedBean = null;
        selectedBeanLocation = null;
        selectedBeanBox = null;
        selectedBeanLayer = null;
        serBean = null;
    }

    /**
     * This method is called when the user chooses to delete a bean by
     * some means such by by pressing DEL. This method removes the
     * selected bean from its beanbox. If no bean is selected this
     * method is a no-op.
     */
    protected void deleteSelectedBean() {
        if (Debug.debugging("beanbox"))
            Debug.output("Enter> deleteSelectedBean");

        if (selectedBean == null || selectedBeanLocation == null) {
            if (Debug.debugging("beanbox"))
                Debug.output("selectedBean=" + selectedBean);
            if (Debug.debugging("beanbox"))
                Debug.output("selectedBeanLocation=" + selectedBeanLocation);
            return;
        }

        selectedBeanBox.removeBean(selectedBean);
        cutBean = null;

        if (Debug.debugging("beanbox"))
            Debug.output("Exit> deleteSelectedBean");
    }

    /**
     * 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>
     * <P>
     * 
     * @param dtde the <code>DropTargetDropEvent</code>
     */
    public void drop(DropTargetDropEvent dtde) {
        if (Debug.debugging("beanbox"))
            Debug.output("Enter> drop");

        dtde.acceptDrop(DnDConstants.ACTION_MOVE);
        extractTransferData(dtde);
        extractDropLocation(dtde);

        if (transferData == null || dropLocation == null)
            return;

        Component parent = ((DropTarget) dtde.getSource()).getComponent();

        dtde.dropComplete(true);

        showPopUp(parent);
        if (Debug.debugging("beanbox"))
            Debug.output("Exit> drop");
    }

    private void showPopUp(Component parent) {
        if (Debug.debugging("beanbox"))
            Debug.output("Enter> showPopUp");
        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));

        Enumeration keys = layers.keys();
        while (keys.hasMoreElements()) {
            String layerName = keys.nextElement().toString();
            Layer omlayer = (Layer) layers.get(layerName);

            if (omlayer.isVisible()) {
                JMenuItem menuItem = new JMenuItem(layerName);
                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));

        if (Debug.debugging("beanbox"))
            Debug.output("showing popup");

        popup.show(parent, dropLocation.x, dropLocation.y);
        if (Debug.debugging("beanbox"))
            Debug.output("Exit> showPopUp");
    }

    /**
     * Displays a
     * {@link com.bbn.openmap.tools.beanbox.GenericPropertySheet}if
     * mouse click is on a bean in some layer. In case of overlapping
     * beans, chooses the first bean found to be under the mouse,
     * which is usually a bean in the top most visible layer.
     */
    public void mouseClicked(MouseEvent evt) {
        if (Debug.debugging("beanbox"))
            Debug.output("Enter> mouseClicked");

        Point srcLocation = evt.getPoint();

        Enumeration keys = layers.keys();
        while (keys.hasMoreElements()) {
            String layerName = keys.nextElement().toString();
            selectedBeanLayer = (Layer) layers.get(layerName);
            if (!selectedBeanLayer.isVisible())
                continue;
            selectedBeanBox = ((BeanBoxHandler) selectedBeanLayer).getBeanBox();
            if (selectedBeanBox == null)
                continue;
            selectedBean = selectedBeanBox.getBeanAtLocation(srcLocation);
            if (selectedBean != null) {
                break;
            }
        }

        if (selectedBean == null) {
            clearSelection();
            return;
        }

        selectedBeanLocation = srcLocation;

        selectedBeanBox.showSelected(selectedBean);

        if (Debug.debugging("beanbox"))
            Debug.output("selectedBean=" + selectedBean);

        if (evt.getModifiers() != InputEvent.BUTTON1_MASK) {
            GenericPropertySheet propertySheet = new GenericPropertySheet(selectedBean, 575, 20, null, selectedBeanBox);
            propertySheet.setVisible(true);
        }

        if (Debug.debugging("beanbox"))
            Debug.output("Exit> mouseClicked");
    }

    /**
     * This method is called whenever the user choose a layer to drop
     * or move a bean to. This method adds the bean to the layer or
     * moves the beans to or within the selected layer.
     */
    public void actionPerformed(ActionEvent evt) {

        if (Debug.debugging("beanbox"))
            Debug.output("Enter> actionPerformed");
        Object source = evt.getSource();
        if (!(source instanceof JMenuItem))
            return;

        JMenuItem mi = (JMenuItem) source;
        String name = mi.getText();
        Layer targetLayer = (Layer) layers.get(name);

        if (targetLayer == null) {
            System.out.println("ERROR> BBDnDC::actionPerformed: "
                    + "no layer found with name " + name);
            return;
        }

        BeanBox targetBeanBox = ((BeanBoxHandler) targetLayer).getBeanBox();

        Object bean = transferData.get(0);
        BeanInfo beanInfo = (BeanInfo) transferData.get(1);
        Boolean wasBeanMoved = (Boolean) transferData.get(2);

        if (wasBeanMoved.booleanValue()) {

            String sourceLayerName = (String) transferData.get(3);
            if (sourceLayerName.equals(targetLayer.getName())) {
                targetBeanBox.relocateBean(bean, beanInfo, dropLocation);
            } else {
                Layer sourceLayer = (Layer) layers.get(sourceLayerName);
                BeanBox sourceBeanBox = ((BeanBoxHandler) sourceLayer).getBeanBox();
                sourceBeanBox.removeBean(bean);
                Vector object = new Vector();
                object.add(bean);
                object.add(beanInfo);
                object.add(dropLocation);
                targetBeanBox.addBean(object);
            }
        } else {
            Vector object = new Vector();
            object.add(bean);
            object.add(beanInfo);
            object.add(dropLocation);
            targetBeanBox.addBean(object);
        }
    }

    /**
     * Asscoiates a DropTarget with each layer. Also caches all layers
     * that implement the BeanBoxHandler interface.
     */
    public void setLayers(Layer[] allLayers) {
        layers.clear();
        for (int i = 0; i < allLayers.length; i++) {
            new DropTarget(allLayers[i], DnDConstants.ACTION_MOVE, this);
            if (allLayers[i] instanceof BeanBoxHandler) {
                Debug.message("DnDCatcher", "Layers changed");
                layers.put(allLayers[i].getName(), allLayers[i]);
            }
        }
    }

    /**
     * Invoked on dragGestureRecognized
     */
    public void startDragAction(DragGestureEvent dge, DragSourceListener dsl) {
        if (Debug.debugging("beanbox"))
            Debug.output("Enter> startDragAction");

        Object selectedBean = null;
        BeanBox selectedBeanBox = null;
        Layer selectedLayer = null;

        Point srcLocation = dge.getDragOrigin();

        Enumeration keys = layers.keys();
        while (keys.hasMoreElements()) {
            String layerName = keys.nextElement().toString();
            Layer omLayer = (Layer) layers.get(layerName);
            BeanBox beanBox = ((BeanBoxHandler) omLayer).getBeanBox();
            selectedBean = beanBox.getBeanAtLocation(srcLocation);
            if (selectedBean != null) {
                selectedBeanBox = beanBox;
                selectedLayer = omLayer;
                break;
            }
        }

        if (Debug.debugging("beanbox"))
            Debug.output("selectedBean=" + selectedBean);

        if (selectedBean == null) {
            if (Debug.debugging("beanbox"))
                Debug.output("Exit> startDragAction");
            return;
        }

        Image dragImage = selectedBeanBox.getDragImage(selectedBean);

        super.setCursor(dragImage, DragSource.DefaultMoveDrop);

        BeanInfo beanInfo = selectedBeanBox.getBeanInfoForBean(selectedBean.getClass()
                .getName());

        Vector beanTransferData = new Vector();
        beanTransferData.add(selectedBean);
        beanTransferData.add(beanInfo);
        beanTransferData.add(new Boolean(true));
        beanTransferData.add(selectedLayer.getName());

        dragSource.startDrag(dge,
                super.getCursor(DragSource.DefaultMoveDrop),
                new DefaultTransferableObject(beanTransferData),
                dsl);

        if (Debug.debugging("beanbox"))
            Debug.output("Exit> startDragAction");
    }

    private void extractTransferData(DropTargetDropEvent dtde) {
        if (dtde == null) {
            System.out.println("ERROR> BDnDC::getTransferData(): dropEvent is null");
            return;
        }

        Transferable tr = dtde.getTransferable();
        try {
            transferData = (Vector) tr.getTransferData(DefaultTransferableObject.OBJECT_FLAVOR);

            // cache beanInfos
            if (transferData.size() >= 2) {
                Object bean = transferData.get(0);
                BeanInfo beanInfo = (BeanInfo) transferData.get(1);
                beanInfoMap.put(bean.getClass().getName(), beanInfo);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void extractDropLocation(DropTargetDropEvent dtde) {
        if (dtde == null) {
            System.out.println("ERROR> BDnDC::getTransferData(): dropEvent is null");
            return;
        }

        dropLocation = dtde.getLocation();
    }

    private static void setDefaultIcon() {
        if (BeanPanel.defaultBeanIcon == null) {
            URL url = BeanPanel.class.getResource("bluebean.gif");
            if (url != null)
                BeanPanel.defaultBeanIcon = new ImageIcon(url);
        }
    }
}