以下是NASA WorldWind项目的一个例子：
/*
* Copyright (C) 2012 United States Government as represented by the Administrator of the
* National Aeronautics and Space Administration.
* All Rights Reserved.
*/
package gov.nasa.worldwindx.examples;
import gov.nasa.worldwind.WorldWind;
import gov.nasa.worldwind.avlist.*;
import gov.nasa.worldwind.event.*;
import gov.nasa.worldwind.geom.Position;
import gov.nasa.worldwind.layers.RenderableLayer;
import gov.nasa.worldwind.render.*;
import gov.nasa.worldwindx.applications.worldwindow.util.Util;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
/**
* Illustrates how to attach context (popup) menus to shapes. The example creates several <code>{@link
* PointPlacemark}s</code> and assigns each of them a context-menu definition. When the user presses the right mouse
* button while the cursor is on a placemark, the placemark's context menu is shown and the user may select an item in
* it.
*
* @author tag
* @version $Id$
*/
public class ContextMenusOnShapes extends ApplicationTemplate
{
/** The Controller listens for selection events and either highlights a selected item or shows its context menu. */
protected static class ContextMenuController implements SelectListener
{
protected PointPlacemark lastPickedPlacemark = null;
public void selected(SelectEvent event)
{
try
{
if (event.getEventAction().equals(SelectEvent.ROLLOVER))
highlight(event, event.getTopObject());
else if (event.getEventAction().equals(SelectEvent.RIGHT_PRESS)) // Could do RIGHT_CLICK instead
showContextMenu(event);
}
catch (Exception e)
{
Util.getLogger().warning(e.getMessage() != null ? e.getMessage() : e.toString());
}
}
@SuppressWarnings( {"UnusedDeclaration"})
protected void highlight(SelectEvent event, Object o)
{
if (this.lastPickedPlacemark == o)
return; // same thing selected
// Turn off highlight if on.
if (this.lastPickedPlacemark != null)
{
this.lastPickedPlacemark.setHighlighted(false);
this.lastPickedPlacemark = null;
}
// Turn on highlight if object selected.
if (o != null && o instanceof PointPlacemark)
{
this.lastPickedPlacemark = (PointPlacemark) o;
this.lastPickedPlacemark.setHighlighted(true);
}
}
protected void showContextMenu(SelectEvent event)
{
if (!(event.getTopObject() instanceof PointPlacemark))
return;
// See if the top picked object has context-menu info defined. Show the menu if it does.
Object o = event.getTopObject();
if (o instanceof AVList) // Uses an AVList in order to be applicable to all shapes.
{
AVList params = (AVList) o;
ContextMenuInfo menuInfo = (ContextMenuInfo) params.getValue(ContextMenu.CONTEXT_MENU_INFO);
if (menuInfo == null)
return;
if (!(event.getSource() instanceof Component))
return;
ContextMenu menu = new ContextMenu((Component) event.getSource(), menuInfo);
menu.show(event.getMouseEvent());
}
}
}
/** The ContextMenu class implements the context menu. */
protected static class ContextMenu
{
public static final String CONTEXT_MENU_INFO = "ContextMenuInfo";
protected ContextMenuInfo ctxMenuInfo;
protected Component sourceComponent;
protected JMenuItem menuTitleItem;
protected ArrayList<JMenuItem> menuItems = new ArrayList<JMenuItem>();
public ContextMenu(Component sourceComponent, ContextMenuInfo contextMenuInfo)
{
this.sourceComponent = sourceComponent;
this.ctxMenuInfo = contextMenuInfo;
this.makeMenuTitle();
this.makeMenuItems();
}
protected void makeMenuTitle()
{
this.menuTitleItem = new JMenuItem(this.ctxMenuInfo.menuTitle);
}
protected void makeMenuItems()
{
for (ContextMenuItemInfo itemInfo : this.ctxMenuInfo.menuItems)
{
this.menuItems.add(new JMenuItem(new ContextMenuItemAction(itemInfo)));
}
}
public void show(final MouseEvent event)
{
JPopupMenu popup = new JPopupMenu();
popup.add(this.menuTitleItem);
popup.addSeparator();
for (JMenuItem subMenu : this.menuItems)
{
popup.add(subMenu);
}
popup.show(sourceComponent, event.getX(), event.getY());
}
}
/** The ContextMenuInfo class specifies the contents of the context menu. */
protected static class ContextMenuInfo
{
protected String menuTitle;
protected ContextMenuItemInfo[] menuItems;
public ContextMenuInfo(String title, ContextMenuItemInfo[] menuItems)
{
this.menuTitle = title;
this.menuItems = menuItems;
}
}
/** The ContextMenuItemInfo class specifies the contents of one entry in the context menu. */
protected static class ContextMenuItemInfo
{
protected String displayString;
public ContextMenuItemInfo(String displayString)
{
this.displayString = displayString;
}
}
/** The ContextMenuItemAction responds to user selection of a context menu item. */
public static class ContextMenuItemAction extends AbstractAction
{
protected ContextMenuItemInfo itemInfo;
public ContextMenuItemAction(ContextMenuItemInfo itemInfo)
{
super(itemInfo.displayString);
this.itemInfo = itemInfo;
}
public void actionPerformed(ActionEvent event)
{
System.out.println(this.itemInfo.displayString); // Replace with application's menu-item response.
}
}
// The code below makes and displays some placemarks. The context menu info for each placemark is also specified.
public static class AppFrame extends ApplicationTemplate.AppFrame
{
public AppFrame()
{
RenderableLayer layer = new RenderableLayer();
// Create and set an attribute bundle.
PointPlacemarkAttributes attrs = new PointPlacemarkAttributes();
attrs.setAntiAliasHint(Polyline.ANTIALIAS_FASTEST);
attrs.setLineMaterial(Material.WHITE);
attrs.setLineWidth(2d);
attrs.setImageAddress("images/pushpins/push-pin-yellow.png");
attrs.setScale(0.6);
attrs.setImageOffset(new Offset(19d, 11d, AVKey.PIXELS, AVKey.PIXELS));
PointPlacemarkAttributes highlightAttrs = new PointPlacemarkAttributes(attrs);
highlightAttrs.setScale(0.7);
ContextMenuItemInfo[] itemActionNames = new ContextMenuItemInfo[]
{
new ContextMenuItemInfo("Do This"),
new ContextMenuItemInfo("Do That"),
new ContextMenuItemInfo("Do the Other Thing"),
};
PointPlacemark pp = new PointPlacemark(Position.fromDegrees(28, -102, 1e4));
pp.setAttributes(attrs);
pp.setHighlightAttributes(highlightAttrs);
pp.setAltitudeMode(WorldWind.CLAMP_TO_GROUND);
pp.setValue(ContextMenu.CONTEXT_MENU_INFO, new ContextMenuInfo("Placemark A", itemActionNames));
layer.addRenderable(pp);
pp = new PointPlacemark(Position.fromDegrees(29, -104, 2e4));
pp.setAttributes(attrs);
pp.setHighlightAttributes(highlightAttrs);
pp.setAltitudeMode(WorldWind.RELATIVE_TO_GROUND);
pp.setValue(ContextMenu.CONTEXT_MENU_INFO, new ContextMenuInfo("Placemark B", itemActionNames));
layer.addRenderable(pp);
pp = new PointPlacemark(Position.fromDegrees(30, -104.5, 2e4));
pp.setAttributes(attrs);
pp.setHighlightAttributes(highlightAttrs);
pp.setAltitudeMode(WorldWind.RELATIVE_TO_GROUND);
pp.setValue(ContextMenu.CONTEXT_MENU_INFO, new ContextMenuInfo("Placemark C", itemActionNames));
layer.addRenderable(pp);
pp = new PointPlacemark(Position.fromDegrees(28, -104.5, 2e4));
pp.setAttributes(attrs);
pp.setHighlightAttributes(highlightAttrs);
pp.setAltitudeMode(WorldWind.RELATIVE_TO_GROUND);
pp.setValue(ContextMenu.CONTEXT_MENU_INFO, new ContextMenuInfo("Placemark D", itemActionNames));
layer.addRenderable(pp);
// Create a placemark that uses all default values.
pp = new PointPlacemark(Position.fromDegrees(30, -103.5, 2e3));
pp.setValue(ContextMenu.CONTEXT_MENU_INFO, new ContextMenuInfo("Placemark E", itemActionNames));
layer.addRenderable(pp);
// Add the layer to the model.
insertBeforeCompass(getWwd(), layer);
// Set up the context menu
ContextMenuController contextMenuController = new ContextMenuController();
getWwd().addSelectListener(contextMenuController);
}
}
public static void main(String[] args)
{
ApplicationTemplate.start("World Wind Context Menus on Shapes", AppFrame.class);
}
}
我正在尝试重构ContextMenu代码以支持ContextMenuItemAction的任意操作。我希望能够使用一个匿名类，类似于ActionListener，通常在Swing代码中使用。这段代码可以轻松地重构以支持吗？目的是避免为菜单中的每个操作创建完整的类。
答案 0 :(得分：0)
我相信你只想创建一个可以用作匿名内联类的抽象类：
package gov.nasa.worldwindx.examples;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import gov.nasa.worldwindx.examples.ContextMenusOnShapes.ContextMenuItemInfo;
public abstract class ContextMenuItemAction extends AbstractAction
{
protected ContextMenuItemInfo itemInfo;
public ContextMenuItemAction(ContextMenuItemInfo itemInfo)
{
super(itemInfo.displayString);
this.itemInfo = itemInfo;
}
public abstract void actionPerformed(ActionEvent event);
}
用法：
new ContextMenuItemAction(itemInfo) {
@Override
public void actionPerformed(ActionEvent event) {
// TODO Add Action Here!!
}
}));