Java tutorial
/* * Copyright (c) 1996, 2009, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.awt; import java.awt.event.InputEvent; import java.awt.event.KeyEvent; /** * The {@code MenuShortcut} class represents a keyboard accelerator * for a MenuItem. * <p> * Menu shortcuts are created using virtual keycodes, not characters. * For example, a menu shortcut for Ctrl-a (assuming that Control is * the accelerator key) would be created with code like the following: * <p> * {@code MenuShortcut ms = new MenuShortcut(KeyEvent.VK_A, false);} * <p> or alternatively * <p> * {@code MenuShortcut ms = new MenuShortcut(KeyEvent.getExtendedKeyCodeForChar('A'), false);} * <p> * Menu shortcuts may also be constructed for a wider set of keycodes * using the {@code java.awt.event.KeyEvent.getExtendedKeyCodeForChar} call. * For example, a menu shortcut for "Ctrl+cyrillic ef" is created by * <p> * <code>MenuShortcut ms = new MenuShortcut(KeyEvent.getExtendedKeyCodeForChar('\u0444'), false);</code> * <p> * Note that shortcuts created with a keycode or an extended keycode defined as a constant in {@code KeyEvent} * work regardless of the current keyboard layout. However, a shortcut made of * an extended keycode not listed in {@code KeyEvent} * only work if the current keyboard layout produces a corresponding letter. * <p> * The accelerator key is platform-dependent and may be obtained * via {@link Toolkit#getMenuShortcutKeyMaskEx()}. * * @author Thomas Ball * @since 1.1 */ public class MenuShortcut implements java.io.Serializable { /** * The virtual keycode for the menu shortcut. * This is the keycode with which the menu shortcut will be created. * Note that it is a virtual keycode, not a character, * e.g. KeyEvent.VK_A, not 'a'. * Note: in 1.1.x you must use setActionCommand() on a menu item * in order for its shortcut to work, otherwise it will fire a null * action command. * * @serial * @see #getKey() * @see #usesShiftModifier() * @see java.awt.event.KeyEvent * @since 1.1 */ int key; /** * Indicates whether the shift key was pressed. * If true, the shift key was pressed. * If false, the shift key was not pressed * * @serial * @see #usesShiftModifier() * @since 1.1 */ boolean usesShift; /* * JDK 1.1 serialVersionUID */ private static final long serialVersionUID = 143448358473180225L; /** * Constructs a new MenuShortcut for the specified virtual keycode. * @param key the raw keycode for this MenuShortcut, as would be returned * in the keyCode field of a {@link java.awt.event.KeyEvent KeyEvent} if * this key were pressed. * @see java.awt.event.KeyEvent **/ public MenuShortcut(int key) { this(key, false); } /** * Constructs a new MenuShortcut for the specified virtual keycode. * @param key the raw keycode for this MenuShortcut, as would be returned * in the keyCode field of a {@link java.awt.event.KeyEvent KeyEvent} if * this key were pressed. * @param useShiftModifier indicates whether this MenuShortcut is invoked * with the SHIFT key down. * @see java.awt.event.KeyEvent **/ public MenuShortcut(int key, boolean useShiftModifier) { this.key = key; this.usesShift = useShiftModifier; } /** * Returns the raw keycode of this MenuShortcut. * @return the raw keycode of this MenuShortcut. * @see java.awt.event.KeyEvent * @since 1.1 */ public int getKey() { return key; } /** * Returns whether this MenuShortcut must be invoked using the SHIFT key. * @return {@code true} if this MenuShortcut must be invoked using the * SHIFT key, {@code false} otherwise. * @since 1.1 */ public boolean usesShiftModifier() { return usesShift; } /** * Returns whether this MenuShortcut is the same as another: * equality is defined to mean that both MenuShortcuts use the same key * and both either use or don't use the SHIFT key. * @param s the MenuShortcut to compare with this. * @return {@code true} if this MenuShortcut is the same as another, * {@code false} otherwise. * @since 1.1 */ public boolean equals(MenuShortcut s) { return (s != null && (s.getKey() == key) && (s.usesShiftModifier() == usesShift)); } /** * Returns whether this MenuShortcut is the same as another: * equality is defined to mean that both MenuShortcuts use the same key * and both either use or don't use the SHIFT key. * @param obj the Object to compare with this. * @return {@code true} if this MenuShortcut is the same as another, * {@code false} otherwise. * @since 1.2 */ public boolean equals(Object obj) { if (obj instanceof MenuShortcut) { return equals((MenuShortcut) obj); } return false; } /** * Returns the hashcode for this MenuShortcut. * @return the hashcode for this MenuShortcut. * @since 1.2 */ public int hashCode() { return (usesShift) ? (~key) : key; } /** * Returns an internationalized description of the MenuShortcut. * @return a string representation of this MenuShortcut. * @since 1.1 */ public String toString() { int modifiers = 0; if (!GraphicsEnvironment.isHeadless()) { modifiers = Toolkit.getDefaultToolkit().getMenuShortcutKeyMaskEx(); } if (usesShiftModifier()) { modifiers |= InputEvent.SHIFT_DOWN_MASK; } return InputEvent.getModifiersExText(modifiers) + "+" + KeyEvent.getKeyText(key); } /** * Returns the parameter string representing the state of this * MenuShortcut. This string is useful for debugging. * @return the parameter string of this MenuShortcut. * @since 1.1 */ protected String paramString() { String str = "key=" + key; if (usesShiftModifier()) { str += ",usesShiftModifier"; } return str; } }