vaadin-framework/src/com/itmill/toolkit/terminal/gwt/client/ui/ContextMenu.java

package com.itmill.toolkit.terminal.gwt.client.ui;

import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.MenuBar;
import com.google.gwt.user.client.ui.MenuItem;
import com.google.gwt.user.client.ui.PopupPanel;

public class ContextMenu extends PopupPanel {

	private ActionOwner actionOwner;

	private CMenuBar menu = new CMenuBar();

	/**
	 * This method should be used only by Client object as only one per client
	 * should exists. Request an instance via client.getContextMenu();
	 * 
	 * @param cli
	 *            to be set as an owner of menu
	 */
	public ContextMenu() {
		super(true);
		setWidget(menu);
		setStyleName("i-contextmenu");
	}

	/**
	 * Sets the element from which to build menu
	 * 
	 * @param ao
	 */
	public void setActionOwner(ActionOwner ao) {
		this.actionOwner = ao;
	}

	/**
	 * Shows context menu at given location.
	 * 
	 * @param left
	 * @param top
	 */
	public void showAt(int left, int top) {
		menu.clearItems();
		Action[] actions = actionOwner.getActions();
		for (int i = 0; i < actions.length; i++) {
			Action a = actions[i];
			menu.addItem(new MenuItem(a.getHTML(), true, a));
		}

		setPopupPosition(left, top);
		show();
		// fix position if "outside" screen
		if (DOM.getElementPropertyInt(getElement(), "offsetWidth") + left > Window
				.getClientWidth()) {
			left = Window.getClientWidth()
					- DOM.getElementPropertyInt(getElement(), "offsetWidth");
			setPopupPosition(left, top);
		}
	}

	public void showAt(ActionOwner ao, int left, int top) {
		setActionOwner(ao);
		showAt(left, top);
	}

	/**
	 * Extend standard Gwt MenuBar to set proper settings and to override
	 * onPopupClosed method so that PopupPanel gets closed.
	 */
	class CMenuBar extends MenuBar {
		public CMenuBar() {
			super(true);
		}

		public void onPopupClosed(PopupPanel sender, boolean autoClosed) {
			super.onPopupClosed(sender, autoClosed);
			ContextMenu.this.hide();
		}
	}
}