MenuFactory.java

/*******************************************************************************
 * Copyright (c) 2012-2013 RelationWare, Benno Luthiger
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 * RelationWare, Benno Luthiger
 ******************************************************************************/
package org.ripla.web.internal.menu;

import java.util.List;
import java.util.Map;

import org.osgi.service.useradmin.Authorization;
import org.ripla.interfaces.IMenuCommand;
import org.ripla.interfaces.IMenuItem;

import com.vaadin.server.Resource;
import com.vaadin.ui.MenuBar;
import com.vaadin.ui.MenuBar.Command;
import com.vaadin.ui.MenuBar.MenuItem;

/**
 * Helper class for creating the main menu's pulldown menu entries.
 * 
 * @author Luthiger
 */
public class MenuFactory implements Comparable<MenuFactory> {
	private final transient IMenuItem menu;

	/**
	 * Constructor
	 * 
	 * @param inMenu
	 *            {@link IVIFMenuItem} the main menu item to process.
	 */
	public MenuFactory(final IMenuItem inMenu) {
		menu = inMenu;
	}

	/**
	 * Creates the menu for the use case and adds it to the specified menu bar.
	 * 
	 * @param inMenuBar
	 *            {@link MenuBar}
	 * @param inIcon
	 *            {@link Resource} the resource for the icon to indicate a
	 *            submenu, may be <code>null</code>
	 * @param inMap
	 *            Map<Integer, IMenuCommand> the map to register the menu's
	 *            command
	 * @param inCommand
	 *            {@link Command} the Vaadin menu bar command
	 * @param inAuthorization
	 *            {@link Authorization} the authorization object
	 * @param inMenuTagFilter
	 *            String a filter expression for the application's menu, e.g.
	 *            <code>demo.*</code>.
	 * @return MenuItem the Vaadin menu item
	 */
	public MenuItem createMenu(final MenuBar inMenuBar, final Resource inIcon,
			final Map<Integer, IMenuCommand> inMap, final Command inCommand,
			final Authorization inAuthorization, final String inMenuTagFilter) {
		if (!checkPermissions(menu.getPermission(), inAuthorization)) {
			return null;
		}

		if (!MenuFilter.checkTagFilter(inMenuTagFilter, menu.getTag())) {
			return null;
		}

		final MenuItem outItem = inMenuBar.addItem(menu.getLabel(), null,
				inCommand);
		outItem.setStyleName("ripla-menu-item"); //$NON-NLS-1$
		outItem.setIcon(inIcon);
		addCommand(inMap, outItem, menu);

		final List<IMenuItem> lSubMenu = menu.getSubMenu();
		if (!lSubMenu.isEmpty()) {
			createSubMenu(lSubMenu, outItem, inMap, inCommand, inAuthorization);
		}

		return outItem;
	}

	/**
	 * Check permission.
	 * 
	 * @param inMenuPermission
	 *            String the permission, may be an empty string
	 * @param inAuthorization
	 *            {@link Authorization} the parameter object containing the
	 *            permissions the user has
	 * @return boolean <code>true</code> if the user has sufficient permissions
	 *         for the command handled by the menu item
	 */
	protected boolean checkPermissions(final String inMenuPermission,
			final Authorization inAuthorization) {
		if (inAuthorization == null) {
			return true;
		}
		if (!inMenuPermission.isEmpty()
				&& !inAuthorization.hasRole(inMenuPermission)) {
			return false;
		}
		return true;
	}

	protected void addCommand(final Map<Integer, IMenuCommand> inMap,
			final MenuItem inItem, final IMenuItem inMenuItem) {
		addCommand(inMap, inItem,
				createMenuCommand(inMenuItem.getControllerName()));
	}

	protected void addCommand(final Map<Integer, IMenuCommand> inMap,
			final MenuItem inItem, final IMenuCommand inCommand) {
		if (inCommand != null) {
			inMap.put(inItem.getId(), inCommand);
		}
	}

	protected IMenuCommand createMenuCommand(final String inControllerName) {
		return new IMenuCommand() {
			@Override
			public String getControllerName() {
				return inControllerName;
			}
		};
	}

	/**
	 * Recurse structure to create the menu's pulldown entries.
	 * 
	 * @param inSubItems
	 * @param inItem
	 * @param inMap
	 * @param inAuthorization
	 * @param inComman
	 */
	protected void createSubMenu(final List<IMenuItem> inSubItems,
			final MenuItem inItem, final Map<Integer, IMenuCommand> inMap,
			final Command inCommand, final Authorization inAuthorization) {
		for (final IMenuItem lItem : inSubItems) {
			if (!checkPermissions(lItem.getPermission(), inAuthorization)) {
				continue;
			}
			final MenuItem lMenuItem = inItem.addItem(lItem.getLabel(), null,
					inCommand);
			lMenuItem.setStyleName("ripla-menu-item");
			addCommand(inMap, lMenuItem, lItem);
			final List<IMenuItem> lSubMenu = lItem.getSubMenu();
			if (!lSubMenu.isEmpty()) {
				createSubMenu(lSubMenu, lMenuItem, inMap, inCommand,
						inAuthorization);
			}
		}
	}

	/**
	 * This menu's position compared to other menu entry's position. Higher
	 * position values are displayed more to the right.
	 * 
	 * @return int the position
	 */
	public int getPosition() {
		return menu.getPosition();
	}

	@Override
	public int compareTo(final MenuFactory inCompare) {
		return getPosition() - inCompare.getPosition();
	}

	/**
	 * @return String the symbolic name of the bundle providing this menu, may
	 *         be <code>null</code>
	 */
	public String getProviderSymbolicName() {
		return menu.getControllerName().split("/")[0]; //$NON-NLS-1$
	}

}