Java tutorial
/* ======================================================================== * JCommon : a free general purpose class library for the Java(tm) platform * ======================================================================== * * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jcommon/index.html * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. * * [Java is a trademark or registered trademark of Sun Microsystems, Inc. * in the United States and other countries.] * * ------------------- * ActionMenuItem.java * ------------------- * (C)opyright 2002-2004, by Thomas Morgner and Contributors. * * Original Author: Thomas Morgner; * Contributor(s): David Gilbert (for Object Refinery Limited); * * $Id: ActionMenuItem.java,v 1.5 2007/11/02 17:50:36 taqua Exp $ * * ChangeLog * --------- * 30-Aug-2002 : Initial version * 01-Aug-2002 : Documentation * 10-Dec-2002 : Minor Javadoc updates (DG); * */ package org.jfree.ui.action; import java.awt.event.KeyEvent; import java.beans.PropertyChangeEvent; import java.beans.PropertyChangeListener; import javax.swing.Action; import javax.swing.Icon; import javax.swing.JMenuItem; import javax.swing.KeyStroke; import org.jfree.util.Log; /** * The ActionMenuItem is used to connect an Action and its properties to an * MenuItem. * <p/> * This functionality is already implemented in JDK 1.3 but needed for JDK 1.2.2 * compatibility. * * @author Thomas Morgner */ public class ActionMenuItem extends JMenuItem { /** The action. */ private Action action; /** The property change handler. */ private ActionEnablePropertyChangeHandler propertyChangeHandler; /** * Helperclass to handle the property change event raised by the action. * Changed properties in the action will affect the button. */ private class ActionEnablePropertyChangeHandler implements PropertyChangeListener { public ActionEnablePropertyChangeHandler() { } /** * Receives notification of a property change event. * * @param event the property change event. */ public void propertyChange(final PropertyChangeEvent event) { try { if (event.getPropertyName().equals("enabled")) { setEnabled(getAction().isEnabled()); } else if (event.getPropertyName().equals(Action.SMALL_ICON)) { setIcon((Icon) getAction().getValue(Action.SMALL_ICON)); } else if (event.getPropertyName().equals(Action.NAME)) { setText((String) getAction().getValue(Action.NAME)); } else if (event.getPropertyName().equals(Action.SHORT_DESCRIPTION)) { ActionMenuItem.this.setToolTipText((String) getAction().getValue(Action.SHORT_DESCRIPTION)); } final Action ac = getAction(); if (event.getPropertyName().equals(ActionDowngrade.ACCELERATOR_KEY)) { setAccelerator((KeyStroke) ac.getValue(ActionDowngrade.ACCELERATOR_KEY)); } else if (event.getPropertyName().equals(ActionDowngrade.MNEMONIC_KEY)) { final Object o = ac.getValue(ActionDowngrade.MNEMONIC_KEY); if (o != null) { if (o instanceof Character) { final Character c = (Character) o; setMnemonic(c.charValue()); } else if (o instanceof Integer) { final Integer c = (Integer) o; setMnemonic(c.intValue()); } } else { setMnemonic(KeyEvent.VK_UNDEFINED); } } } catch (Exception e) { Log.warn("Error on PropertyChange in ActionButton: ", e); } } } /** Default constructor. */ public ActionMenuItem() { // nothing required } /** * Creates a menu item with the specified icon. * * @param icon the icon. */ public ActionMenuItem(final Icon icon) { super(icon); } /** * Creates a menu item with the specified label. * * @param text the label. */ public ActionMenuItem(final String text) { super(text); } /** * Creates a menu item with the specified label and icon. * * @param text the label. * @param icon the icon. */ public ActionMenuItem(final String text, final Icon icon) { super(text, icon); } /** * Creates a new menu item with the specified label and mnemonic. * * @param text the label. * @param i the mnemonic. */ public ActionMenuItem(final String text, final int i) { super(text, i); } /** * Creates a new menu item based on the specified action. * * @param action the action. */ public ActionMenuItem(final Action action) { setAction(action); } /** * Returns the assigned action or null if no action has been assigned. * * @return the action. */ public Action getAction() { return this.action; } /** * Returns and initializes the PropertyChangehandler for this ActionMenuItem. * The PropertyChangeHandler monitors the action and updates the menuitem if * necessary. * * @return the property change handler. */ private ActionEnablePropertyChangeHandler getPropertyChangeHandler() { if (this.propertyChangeHandler == null) { this.propertyChangeHandler = new ActionEnablePropertyChangeHandler(); } return this.propertyChangeHandler; } /** * Enables and disables this button and if an action is assigned to this * menuitem the propertychange is forwarded to the assigned action. * * @param b the new enable-state of this menuitem */ public void setEnabled(final boolean b) { super.setEnabled(b); if (getAction() != null) { getAction().setEnabled(b); } } /** * Assigns the given action to this menuitem. The properties of the action * will be assigned to the menuitem. If an previous action was set, the old * action is unregistered. * <p/> * <ul> <li>NAME - specifies the menuitem text <li>SMALL_ICON - specifies the * menuitems icon <li>MNEMONIC_KEY - specifies the menuitems mnemonic key * <li>ACCELERATOR_KEY - specifies the menuitems accelerator </ul> * * @param newAction the new action */ public void setAction(final Action newAction) { final Action oldAction = getAction(); if (oldAction != null) { removeActionListener(oldAction); oldAction.removePropertyChangeListener(getPropertyChangeHandler()); setAccelerator(null); } this.action = newAction; if (this.action != null) { addActionListener(newAction); newAction.addPropertyChangeListener(getPropertyChangeHandler()); setText((String) (newAction.getValue(Action.NAME))); setToolTipText((String) (newAction.getValue(Action.SHORT_DESCRIPTION))); setIcon((Icon) newAction.getValue(Action.SMALL_ICON)); setEnabled(this.action.isEnabled()); Object o = newAction.getValue(ActionDowngrade.MNEMONIC_KEY); if (o != null) { if (o instanceof Character) { final Character c = (Character) o; setMnemonic(c.charValue()); } else if (o instanceof Integer) { final Integer c = (Integer) o; setMnemonic(c.intValue()); } } else { setMnemonic(KeyEvent.VK_UNDEFINED); } o = newAction.getValue(ActionDowngrade.ACCELERATOR_KEY); if (o instanceof KeyStroke) { setAccelerator((KeyStroke) o); } } } }