bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/PopupMenuExtender.java

/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Dan Rubel (dan_rubel@instantiations.com) - accessor to get menu id
 *******************************************************************************/
package org.eclipse.ui.internal;


import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import org.eclipse.jface.action.IContributionItem;
import org.eclipse.jface.action.IMenuListener;
import org.eclipse.jface.action.IMenuManager;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.action.Separator;
import org.eclipse.jface.action.SubMenuManager;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.ui.IWorkbenchActionConstants;
import org.eclipse.ui.IWorkbenchPart;

/**
 * This class extends a single popup menu
 */
public class PopupMenuExtender implements IMenuListener {
	
	//for dynamic UI
	public static final class PopupMenuExtenderManager {
		
		private Set extenders = new HashSet();
		
		public void clearCaches() {
			for (Iterator i = extenders.iterator(); i.hasNext();) {
				PopupMenuExtender extender = (PopupMenuExtender) i.next();
				extender.readStaticActions();
			}
		}
		
		private void addExtender(PopupMenuExtender extender) {
			extenders.add(extender);
		}
		
		private void removeExtender(PopupMenuExtender extender) {
			extenders.remove(extender);
		}
	}
	
	private static final PopupMenuExtenderManager manager = new PopupMenuExtenderManager();
	
	public static final PopupMenuExtenderManager getManager() {
		return manager;
	}
	
	private String menuID;
	private MenuManager menu;
	private SubMenuManager menuWrapper;
	private ISelectionProvider selProvider;
	private IWorkbenchPart part;
	private ViewerActionBuilder staticActionBuilder;

	/**
	 * Construct a new menu extender.
	 */
	public PopupMenuExtender(String id, MenuManager menu, ISelectionProvider prov, IWorkbenchPart part) {
		super();
		this.menuID = id;
		this.menu = menu;
		this.selProvider = prov;
		this.part = part;
		menu.addMenuListener(this);
		if (!menu.getRemoveAllWhenShown()) {
			menuWrapper = new SubMenuManager(menu);
			menuWrapper.setVisible(true);
		}
		getManager().addExtender(this);
		readStaticActions();
	}
	// getMenuId() added by Dan Rubel (dan_rubel@instantiations.com)
	/**
	 * Return the menu identifier
	 */
	public String getMenuId() {
		return menuID;
	}
	/**
	 * Contributes items registered for the object type(s) in
	 * the current selection.
	 */
	private void addObjectActions(IMenuManager mgr) {
		if (selProvider != null) {
			if (ObjectActionContributorManager.getManager().contributeObjectActions(part, mgr, selProvider)) {
				mgr.add(new Separator());
			}
		}
	}
	/**
	 * Adds static items to the context menu.
	 */
	private void addStaticActions(IMenuManager mgr) {
		if (staticActionBuilder != null)
			staticActionBuilder.contribute(mgr, null, true);
	}
	/**
	 * Notifies the listener that the menu is about to be shown.
	 */
	public void menuAboutToShow(IMenuManager mgr) {
		testForAdditions();
		if (menuWrapper != null) {
			mgr = menuWrapper;
			menuWrapper.removeAll();
		}
		addObjectActions(mgr);
		addStaticActions(mgr);
	}
	/**
	 * Read static items for the context menu.
	 */
	private void readStaticActions() {
		// If no menu id provided, then there is no contributions
		// to add. Fix for bug #33140.
		if (menuID != null && menuID.length() > 0) {
			staticActionBuilder = new ViewerActionBuilder();
			if (!staticActionBuilder.readViewerContributions(menuID, selProvider, part))
				staticActionBuilder = null;
		}
	}
	/**
	 * Checks for the existance of an MB_ADDITIONS group.
	 */
	private void testForAdditions() {
		IContributionItem item = menu.find(IWorkbenchActionConstants.MB_ADDITIONS);
		if (item == null) {
			WorkbenchPlugin.log("Context menu missing standard group 'org.eclipse.ui.IWorkbenchActionConstants.MB_ADDITIONS'. (menu id = " //$NON-NLS-1$
			+ (menuID == null ? "???" : menuID) //$NON-NLS-1$
			+")  part id = " //$NON-NLS-1$
			+ (part == null ? "???" : part.getSite().getId()) //$NON-NLS-1$
			+")"); //$NON-NLS-1$
		}
	}
	/**
	 * Dispose of the menu extender. Should only be called when the part
	 * is disposed.
	 */
	public void dispose() {
		if (staticActionBuilder != null) {
			staticActionBuilder.dispose();
		}
		getManager().removeExtender(this);
	}
}