/* * Copyright (c) 1997, 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 javax.swing; import java.awt.AWTKeyStroke;import java.awt.event.KeyEvent; /** * A KeyStroke represents a key action on the keyboard, or equivalent input * device. KeyStrokes can correspond to only a press or release of a particular * key, just as KEY_PRESSED and KEY_RELEASED KeyEvents do; alternately, they * can correspond to typing a specific Java character, just as KEY_TYPED * KeyEvents do. In all cases, KeyStrokes can specify modifiers (alt, shift, * control, meta, altGraph, or a combination thereof) which must be present during the * action for an exact match. * <p> * KeyStrokes are used to define high-level (semantic) action events. Instead * of trapping every keystroke and throwing away the ones you are not * interested in, those keystrokes you care about automatically initiate * actions on the Components with which they are registered. * <p> * KeyStrokes are immutable, and are intended to be unique. Client code cannot * create a KeyStroke; a variant of <code>getKeyStroke</code> must be used * instead. These factory methods allow the KeyStroke implementation to cache * and share instances efficiently. * <p> * <strong>Warning:</strong> * Serialized objects of this class will not be compatible with * future Swing releases. The current serialization support is * appropriate for short term storage or RMI between applications running * the same version of Swing.  As of 1.4, support for long term storage * of all JavaBeans<sup><font size="-2">TM</font></sup> * has been added to the <code>java.beans</code> package. * Please see {@link java.beans.XMLEncoder}. * * @see javax.swing.text.Keymap * @see #getKeyStroke * * @author Arnaud Weber * @author David Mendenhall */public class KeyStroke extends AWTKeyStroke {     /**     * Serial Version ID.     */    private static final long serialVersionUID = -9060180771037902530L;     private KeyStroke() {    }    private KeyStroke(char keyChar, int keyCode, int modifiers,                      boolean onKeyRelease) {        super(keyChar, keyCode, modifiers, onKeyRelease);    }     /**     * Returns a shared instance of a <code>KeyStroke</code>     * that represents a <code>KEY_TYPED</code> event for the     * specified character.     *     * @param keyChar the character value for a keyboard key     * @return a KeyStroke object for that key     */    public static KeyStroke getKeyStroke(char keyChar) {        synchronized (AWTKeyStroke.class) {            registerSubclass(KeyStroke.class);            return (KeyStroke)getAWTKeyStroke(keyChar);        }    }     /**     * Returns an instance of a KeyStroke, specifying whether the key is     * considered to be activated when it is pressed or released. Unlike all     * other factory methods in this class, the instances returned by this     * method are not necessarily cached or shared.     *     * @param keyChar the character value for a keyboard key     * @param onKeyRelease <code>true</code> if this KeyStroke corresponds to a     *        key release; <code>false</code> otherwise.     * @return a KeyStroke object for that key     * @deprecated use getKeyStroke(char)     */    @Deprecated    public static KeyStroke getKeyStroke(char keyChar, boolean onKeyRelease) {        return new KeyStroke(keyChar, KeyEvent.VK_UNDEFINED, 0, onKeyRelease);    }     /**     * Returns a shared instance of a {@code KeyStroke}     * that represents a {@code KEY_TYPED} event for the     * specified Character object and a      * set of modifiers. Note that the first parameter is of type Character     * rather than char. This is to avoid inadvertent clashes with calls to     * <code>getKeyStroke(int keyCode, int modifiers)</code>.     *     * The modifiers consist of any combination of following:<ul>     * <li>java.awt.event.InputEvent.SHIFT_DOWN_MASK     * <li>java.awt.event.InputEvent.CTRL_DOWN_MASK     * <li>java.awt.event.InputEvent.META_DOWN_MASK     * <li>java.awt.event.InputEvent.ALT_DOWN_MASK     * <li>java.awt.event.InputEvent.ALT_GRAPH_DOWN_MASK     * </ul>     * The old modifiers listed below also can be used, but they are     * mapped to _DOWN_ modifiers. <ul>     * <li>java.awt.event.InputEvent.SHIFT_MASK     * <li>java.awt.event.InputEvent.CTRL_MASK     * <li>java.awt.event.InputEvent.META_MASK     * <li>java.awt.event.InputEvent.ALT_MASK     * <li>java.awt.event.InputEvent.ALT_GRAPH_MASK     * </ul>     * also can be used, but they are mapped to _DOWN_ modifiers.     *     * Since these numbers are all different powers of two, any combination of     * them is an integer in which each bit represents a different modifier     * key. Use 0 to specify no modifiers.     *     * @param keyChar the Character object for a keyboard character     * @param modifiers a bitwise-ored combination of any modifiers     * @return an KeyStroke object for that key     * @throws IllegalArgumentException if keyChar is null     *     * @see java.awt.event.InputEvent     * @since 1.3     */    public static KeyStroke getKeyStroke(Character keyChar, int modifiers) {        synchronized (AWTKeyStroke.class) {            registerSubclass(KeyStroke.class);            return (KeyStroke)getAWTKeyStroke(keyChar, modifiers);        }    }     /**     * Returns a shared instance of a KeyStroke, given a numeric key code and a     * set of modifiers, specifying whether the key is activated when it is     * pressed or released.     * <p>     * The "virtual key" constants defined in java.awt.event.KeyEvent can be     * used to specify the key code. For example:<ul>     * <li>java.awt.event.KeyEvent.VK_ENTER     * <li>java.awt.event.KeyEvent.VK_TAB     * <li>java.awt.event.KeyEvent.VK_SPACE     * </ul>     * Alternatively, the key code may be obtained by calling     * <code>java.awt.event.KeyEvent.getExtendedKeyCodeForChar</code>.     *     * The modifiers consist of any combination of:<ul>     * <li>java.awt.event.InputEvent.SHIFT_DOWN_MASK     * <li>java.awt.event.InputEvent.CTRL_DOWN_MASK     * <li>java.awt.event.InputEvent.META_DOWN_MASK     * <li>java.awt.event.InputEvent.ALT_DOWN_MASK     * <li>java.awt.event.InputEvent.ALT_GRAPH_DOWN_MASK     * </ul>     * The old modifiers <ul>     * <li>java.awt.event.InputEvent.SHIFT_MASK     * <li>java.awt.event.InputEvent.CTRL_MASK     * <li>java.awt.event.InputEvent.META_MASK     * <li>java.awt.event.InputEvent.ALT_MASK     * <li>java.awt.event.InputEvent.ALT_GRAPH_MASK     * </ul>     * also can be used, but they are mapped to _DOWN_ modifiers.     *     * Since these numbers are all different powers of two, any combination of     * them is an integer in which each bit represents a different modifier     * key. Use 0 to specify no modifiers.     *     * @param keyCode an int specifying the numeric code for a keyboard key     * @param modifiers a bitwise-ored combination of any modifiers     * @param onKeyRelease <code>true</code> if the KeyStroke should represent     *        a key release; <code>false</code> otherwise.     * @return a KeyStroke object for that key     *     * @see java.awt.event.KeyEvent     * @see java.awt.event.InputEvent     */    public static KeyStroke getKeyStroke(int keyCode, int modifiers,                                         boolean onKeyRelease) {        synchronized (AWTKeyStroke.class) {            registerSubclass(KeyStroke.class);            return (KeyStroke)getAWTKeyStroke(keyCode, modifiers,                                              onKeyRelease);        }    }     /**     * Returns a shared instance of a KeyStroke, given a numeric key code and a     * set of modifiers. The returned KeyStroke will correspond to a key press.     * <p>     * The "virtual key" constants defined in java.awt.event.KeyEvent can be     * used to specify the key code. For example:<ul>     * <li>java.awt.event.KeyEvent.VK_ENTER     * <li>java.awt.event.KeyEvent.VK_TAB     * <li>java.awt.event.KeyEvent.VK_SPACE     * </ul>     * Alternatively, the key code may be obtained by calling     * <code>java.awt.event.KeyEvent.getExtendedKeyCodeForChar</code>.     *     * The modifiers consist of any combination of:<ul>     * <li>java.awt.event.InputEvent.SHIFT_DOWN_MASK     * <li>java.awt.event.InputEvent.CTRL_DOWN_MASK     * <li>java.awt.event.InputEvent.META_DOWN_MASK     * <li>java.awt.event.InputEvent.ALT_DOWN_MASK     * <li>java.awt.event.InputEvent.ALT_GRAPH_DOWN_MASK     * </ul>     * The old modifiers <ul>     * <li>java.awt.event.InputEvent.SHIFT_MASK     * <li>java.awt.event.InputEvent.CTRL_MASK     * <li>java.awt.event.InputEvent.META_MASK     * <li>java.awt.event.InputEvent.ALT_MASK     * <li>java.awt.event.InputEvent.ALT_GRAPH_MASK     * </ul>     * also can be used, but they are mapped to _DOWN_ modifiers.     *     * Since these numbers are all different powers of two, any combination of     * them is an integer in which each bit represents a different modifier     * key. Use 0 to specify no modifiers.     *     * @param keyCode an int specifying the numeric code for a keyboard key     * @param modifiers a bitwise-ored combination of any modifiers     * @return a KeyStroke object for that key     *     * @see java.awt.event.KeyEvent     * @see java.awt.event.InputEvent     */    public static KeyStroke getKeyStroke(int keyCode, int modifiers) {        synchronized (AWTKeyStroke.class) {            registerSubclass(KeyStroke.class);            return (KeyStroke)getAWTKeyStroke(keyCode, modifiers);        }    }     /**     * Returns a KeyStroke which represents the stroke which generated a given     * KeyEvent.     * <p>     * This method obtains the keyChar from a KeyTyped event, and the keyCode     * from a KeyPressed or KeyReleased event. The KeyEvent modifiers are     * obtained for all three types of KeyEvent.     *     * @param anEvent the KeyEvent from which to obtain the KeyStroke     * @throws NullPointerException if <code>anEvent</code> is null     * @return the KeyStroke that precipitated the event     */    public static KeyStroke getKeyStrokeForEvent(KeyEvent anEvent) {        synchronized (AWTKeyStroke.class) {            registerSubclass(KeyStroke.class);            return (KeyStroke)getAWTKeyStrokeForEvent(anEvent);        }    }     /**     * Parses a string and returns a <code>KeyStroke</code>.     * The string must have the following syntax:     * <pre>     *    &lt;modifiers&gt;* (&lt;typedID&gt; | &lt;pressedReleasedID&gt;)     *     *    modifiers := shift | control | ctrl | meta | alt | altGraph     *    typedID := typed &lt;typedKey&gt;     *    typedKey := string of length 1 giving Unicode character.     *    pressedReleasedID := (pressed | released) key     *    key := KeyEvent key code name, i.e. the name following "VK_".     * </pre>     * If typed, pressed or released is not specified, pressed is assumed. Here     * are some examples:     * <pre>     *     "INSERT" => getKeyStroke(KeyEvent.VK_INSERT, 0);     *     "control DELETE" => getKeyStroke(KeyEvent.VK_DELETE, InputEvent.CTRL_MASK);     *     "alt shift X" => getKeyStroke(KeyEvent.VK_X, InputEvent.ALT_MASK | InputEvent.SHIFT_MASK);     *     "alt shift released X" => getKeyStroke(KeyEvent.VK_X, InputEvent.ALT_MASK | InputEvent.SHIFT_MASK, true);     *     "typed a" => getKeyStroke('a');     * </pre>     *     * In order to maintain backward-compatibility, specifying a null String,     * or a String which is formatted incorrectly, returns null.     *     * @param s a String formatted as described above     * @return a KeyStroke object for that String, or null if the specified     *         String is null, or is formatted incorrectly     *     * @see java.awt.event.KeyEvent     */    public static KeyStroke getKeyStroke(String s) {        if (s == null || s.length() == 0) {            return null;        }        synchronized (AWTKeyStroke.class) {            registerSubclass(KeyStroke.class);            try {                return (KeyStroke)getAWTKeyStroke(s);            } catch (IllegalArgumentException e) {                return null;            }        }    }}