listmenudisplayer.java

Struts Menu这是为基于JSP和Struts的应用程序提供的Web菜单框架。菜单可以在一个XML文件中定义

/*
 * ListMenuDisplayer.java
 *
 * Created on December 7, 2002, 12:35 AM
 */
package net.sf.navigator.displayer;

import net.sf.navigator.menu.MenuComponent;

import org.apache.commons.lang.StringUtils;

import java.io.IOException;

import java.util.HashMap;
import java.util.Map;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;


/**
 *
 * @author  <a href="mailto:[e-mail]">Matt Raible</a>
 * @version 1.0
 */
public class ListMenuDisplayer extends MessageResourcesMenuDisplayer {
    //~ Instance fields ========================================================

    // Is this class thread safe?  I'm doubting it - therefore, this
    // probably shouldn't be here
    private Map jsMap;

    //~ Methods ================================================================

    public void init(PageContext pageContext, MenuDisplayerMapping mapping) {
        super.init(pageContext, mapping);
        jsMap = new HashMap();

        try {
            out.println(displayStrings.getMessage("lmd.begin"));
        } catch (Exception e) {}
    }

    public void display(MenuComponent menu) throws JspException, IOException {
        if (isAllowed(menu)) {
            out.println(displayStrings.getMessage("lmd.menu.top"));
            displayComponents(menu, 0);
            out.println(displayStrings.getMessage("lmd.menu.bottom"));
        }
    }

    protected void displayComponents(MenuComponent menu, int level)
    throws JspException, IOException {
        String title = super.getMessage(menu.getTitle());
        MenuComponent[] components = menu.getMenuComponents();

        if (components.length > 0) {
            // eliminate spaces in string used for Id
            String domId =
                StringUtils.deleteWhitespace(getMessage(menu.getTitle()));

            // check to see if this name has already been used
            if (jsMap.containsKey(domId + "Menu")) {
                domId = domId + Math.round((Math.random() * 100)); // use a random number for uniqueness
            }

            String menuClass = "menu";

            if (level >= 1) {
                menuClass = "submenu";
            }

            out.println(displayStrings.getMessage("lmd.menu.actuator.top",
                                                  domId,
                                                  getMessage(menu.getTitle()),
                                                  menuClass));

            jsMap.put(domId + "Menu", domId + "Actuator");

            for (int i = 0; i < components.length; i++) {
                // check the permissions on this component
                if (isAllowed(components[i])) {
                    if (components[i].getMenuComponents().length > 0) {
                        out.println("<li>");

                        displayComponents(components[i], level + 1);

                        out.println(displayStrings.getMessage("lmd.menu.actuator.bottom"));

                        if (i == (components[i].getMenuComponents().length - 1)) { // last one
                            out.println("</li>");
                        }
                    } else {
                        out.println(displayStrings.getMessage("lmd.menu.item",
                                                              components[i].getUrl(),
                                                              super.getMenuToolTip(components[i]),
                                                              this.getMessage(components[i].getTitle())));
                    }
                }
            }

            // close the </ul> for the top menu
            if (menuClass.equals("menu")) {
                out.println("</ul>");
            }
        } else {
            if (menu.getParent() == null) {
                out.println(displayStrings.getMessage("lmd.menu.standalone",
                                                      menu.getUrl(),
                                                      super.getMenuToolTip(menu),
                                                      getMessage(menu.getTitle())));
            } else {
                out.println(displayStrings.getMessage("lmd.menu.item",
                                                      menu.getUrl(),
                                                      super.getMenuToolTip(menu),
                                                      getMessage(menu.getTitle())));
            }
        }
    }

    /**
     * This will output the ending HTML code to close tags from the beginning
     * @param context the current pageContext
     */
    public void end(PageContext context) {
        try {
            out.print(displayStrings.getMessage("lmd.end"));

            /*
               // MR: Refactored to put initialization login into menuExpandable.js
               out.print(displayStrings.getMessage("lmd.js.start"));
               Set menus = jsMap.keySet();
               // loop through each menu and initialize it
               for (Iterator name = menus.iterator(); name.hasNext();) {
                   String id = name.next().toString();
                   out.print(displayStrings.getMessage("lmd.js", id, jsMap.get(id)));
               }
               out.print(displayStrings.getMessage("lmd.js.expand"));
               out.print(displayStrings.getMessage("lmd.js.stop"));
             */
        } catch (Exception e) {}
    }
}