/*
* @(#)KeyStroke.java 1.49 04/05/18
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
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, 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
*
* @version 1.49, 05/18/04
* @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 KeyStroke, given a 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:<ul>
* <li>java.awt.event.InputEvent.SHIFT_MASK (1)
* <li>java.awt.event.InputEvent.CTRL_MASK (2)
* <li>java.awt.event.InputEvent.META_MASK (4)
* <li>java.awt.event.InputEvent.ALT_MASK (8)
* </ul>
* 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>
* The modifiers consist of any combination of:<ul>
* <li>java.awt.event.InputEvent.SHIFT_MASK (1)
* <li>java.awt.event.InputEvent.CTRL_MASK (2)
* <li>java.awt.event.InputEvent.META_MASK (4)
* <li>java.awt.event.InputEvent.ALT_MASK (8)
* </ul>
* 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>
* The modifiers consist of any combination of:<ul>
* <li>java.awt.event.InputEvent.SHIFT_MASK (1)
* <li>java.awt.event.InputEvent.CTRL_MASK (2)
* <li>java.awt.event.InputEvent.META_MASK (4)
* <li>java.awt.event.InputEvent.ALT_MASK (8)
* </ul>
* 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>
* <modifiers>* (<typedID> | <pressedReleasedID>)
*
* modifiers := shift | control | ctrl | meta | alt | altGraph
* typedID := typed <typedKey>
* 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
*/
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;
}
}
}
}
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