Module java.desktop
Package java.awt

Class AWTKeyStroke

java.lang.Object
java.awt.AWTKeyStroke
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
KeyStroke
public class AWTKeyStroke extends Object implements Serializable
An AWTKeyStroke represents a key action on the keyboard, or equivalent input device. AWTKeyStrokes 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, AWTKeyStrokes can specify modifiers (alt, shift, control, meta, altGraph, or a combination thereof) which must be present during the action for an exact match.

AWTKeyStrokes are immutable, and are intended to be unique. Client code should never create an AWTKeyStroke on its own, but should instead use a variant of getAWTKeyStroke. Client use of these factory methods allows the AWTKeyStroke implementation to cache and share instances efficiently.

Since:
1.4
See Also:

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    AWTKeyStroke()
    Constructs an AWTKeyStroke with default values.
    protected
    AWTKeyStroke(char keyChar, int keyCode, int modifiers, boolean onKeyRelease)
    Constructs an AWTKeyStroke with the specified values.

  • Method Summary

    Modifier and Type
    Method
    Description
    final boolean
    equals(Object anObject)
    Returns true if this object is identical to the specified object.
    static AWTKeyStroke
    getAWTKeyStroke(char keyChar)
    Returns a shared instance of an AWTKeyStroke that represents a KEY_TYPED event for the specified character.
    static AWTKeyStroke
    getAWTKeyStroke(int keyCode, int modifiers)
    Returns a shared instance of an AWTKeyStroke, given a numeric key code and a set of modifiers.
    static AWTKeyStroke
    getAWTKeyStroke(int keyCode, int modifiers, boolean onKeyRelease)
    Returns a shared instance of an AWTKeyStroke, given a numeric key code and a set of modifiers, specifying whether the key is activated when it is pressed or released.
    static AWTKeyStroke
    getAWTKeyStroke(Character keyChar, int modifiers)
    Returns a shared instance of an AWTKeyStroke that represents a KEY_TYPED event for the specified Character object and a set of modifiers.
    static AWTKeyStroke
    getAWTKeyStroke(String s)
    Parses a string and returns an AWTKeyStroke.
    static AWTKeyStroke
    getAWTKeyStrokeForEvent(KeyEvent anEvent)
    Returns an AWTKeyStroke which represents the stroke which generated a given KeyEvent.
    final char
    getKeyChar()
    Returns the character for this AWTKeyStroke.
    final int
    getKeyCode()
    Returns the numeric key code for this AWTKeyStroke.
    final int
    getKeyEventType()
    Returns the type of KeyEvent which corresponds to this AWTKeyStroke.
    final int
    getModifiers()
    Returns the modifier keys for this AWTKeyStroke.
    int
    hashCode()
    Returns a numeric value for this object that is likely to be unique, making it a good choice as the index value in a hash table.
    final boolean
    isOnKeyRelease()
    Returns whether this AWTKeyStroke represents a key release.
    protected Object
    readResolve()
    Returns a cached instance of AWTKeyStroke (or a subclass of AWTKeyStroke) which is equal to this instance.
    protected static void
    registerSubclass(Class<?> subclass)
    Deprecated. 
    String
    toString()
    Returns a string that displays and identifies this object's properties.

    Methods declared in class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • AWTKeyStroke

      protected AWTKeyStroke()
      Constructs an AWTKeyStroke with default values. The default values used are:
      AWTKeyStroke default values
      Property Default Value
      Key Char KeyEvent.CHAR_UNDEFINED
      Key Code KeyEvent.VK_UNDEFINED
      Modifiers none
      On key release? false
      AWTKeyStrokes should not be constructed by client code. Use a variant of getAWTKeyStroke instead.
      See Also:

    • AWTKeyStroke

      protected AWTKeyStroke(char keyChar, int keyCode, int modifiers, boolean onKeyRelease)
      Constructs an AWTKeyStroke with the specified values. AWTKeyStrokes should not be constructed by client code. Use a variant of getAWTKeyStroke instead.
      Parameters:
      keyChar - the character value for a keyboard key
      keyCode - the key code for this AWTKeyStroke
      modifiers - a bitwise-ored combination of any modifiers
      onKeyRelease - true if this AWTKeyStroke corresponds to a key release; false otherwise
      See Also:

  • Method Details

    • registerSubclass

      @Deprecated protected static void registerSubclass(Class<?> subclass)
      Deprecated.
      The method has no effect and is only left present to avoid introducing a binary incompatibility.
      Parameters:
      subclass - the new Class of which the factory methods should create instances

    • getAWTKeyStroke

      public static AWTKeyStroke getAWTKeyStroke(char keyChar)
      Returns a shared instance of an AWTKeyStroke that represents a KEY_TYPED event for the specified character.
      Parameters:
      keyChar - the character value for a keyboard key
      Returns:
      an AWTKeyStroke object for that key

    • getAWTKeyStroke

      public static AWTKeyStroke getAWTKeyStroke(Character keyChar, int modifiers)
      Returns a shared instance of an AWTKeyStroke that represents a 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 getAWTKeyStroke(int keyCode, int modifiers). The modifiers consist of any combination of following:
      • java.awt.event.InputEvent.SHIFT_DOWN_MASK
      • java.awt.event.InputEvent.CTRL_DOWN_MASK
      • java.awt.event.InputEvent.META_DOWN_MASK
      • java.awt.event.InputEvent.ALT_DOWN_MASK
      • java.awt.event.InputEvent.ALT_GRAPH_DOWN_MASK
      The old modifiers listed below also can be used, but they are mapped to _DOWN_ modifiers.
      • java.awt.event.InputEvent.SHIFT_MASK
      • java.awt.event.InputEvent.CTRL_MASK
      • java.awt.event.InputEvent.META_MASK
      • java.awt.event.InputEvent.ALT_MASK
      • java.awt.event.InputEvent.ALT_GRAPH_MASK
      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.
      Parameters:
      keyChar - the Character object for a keyboard character
      modifiers - a bitwise-ored combination of any modifiers
      Returns:
      an AWTKeyStroke object for that key
      Throws:
      IllegalArgumentException - if keyChar is null
      See Also:

    • getAWTKeyStroke

      public static AWTKeyStroke getAWTKeyStroke(int keyCode, int modifiers, boolean onKeyRelease)
      Returns a shared instance of an AWTKeyStroke, given a numeric key code and a set of modifiers, specifying whether the key is activated when it is pressed or released.

      The "virtual key" constants defined in java.awt.event.KeyEvent can be used to specify the key code. For example:

      • java.awt.event.KeyEvent.VK_ENTER
      • java.awt.event.KeyEvent.VK_TAB
      • java.awt.event.KeyEvent.VK_SPACE
      Alternatively, the key code may be obtained by calling java.awt.event.KeyEvent.getExtendedKeyCodeForChar. The modifiers consist of any combination of:
      • java.awt.event.InputEvent.SHIFT_DOWN_MASK
      • java.awt.event.InputEvent.CTRL_DOWN_MASK
      • java.awt.event.InputEvent.META_DOWN_MASK
      • java.awt.event.InputEvent.ALT_DOWN_MASK
      • java.awt.event.InputEvent.ALT_GRAPH_DOWN_MASK
      The old modifiers
      • java.awt.event.InputEvent.SHIFT_MASK
      • java.awt.event.InputEvent.CTRL_MASK
      • java.awt.event.InputEvent.META_MASK
      • java.awt.event.InputEvent.ALT_MASK
      • java.awt.event.InputEvent.ALT_GRAPH_MASK
      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.
      Parameters:
      keyCode - an int specifying the numeric code for a keyboard key
      modifiers - a bitwise-ored combination of any modifiers
      onKeyRelease - true if the AWTKeyStroke should represent a key release; false otherwise
      Returns:
      an AWTKeyStroke object for that key
      See Also:

    • getAWTKeyStroke

      public static AWTKeyStroke getAWTKeyStroke(int keyCode, int modifiers)
      Returns a shared instance of an AWTKeyStroke, given a numeric key code and a set of modifiers. The returned AWTKeyStroke will correspond to a key press.

      The "virtual key" constants defined in java.awt.event.KeyEvent can be used to specify the key code. For example:

      • java.awt.event.KeyEvent.VK_ENTER
      • java.awt.event.KeyEvent.VK_TAB
      • java.awt.event.KeyEvent.VK_SPACE
      The modifiers consist of any combination of:
      • java.awt.event.InputEvent.SHIFT_DOWN_MASK
      • java.awt.event.InputEvent.CTRL_DOWN_MASK
      • java.awt.event.InputEvent.META_DOWN_MASK
      • java.awt.event.InputEvent.ALT_DOWN_MASK
      • java.awt.event.InputEvent.ALT_GRAPH_DOWN_MASK
      The old modifiers
      • java.awt.event.InputEvent.SHIFT_MASK
      • java.awt.event.InputEvent.CTRL_MASK
      • java.awt.event.InputEvent.META_MASK
      • java.awt.event.InputEvent.ALT_MASK
      • java.awt.event.InputEvent.ALT_GRAPH_MASK
      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.
      Parameters:
      keyCode - an int specifying the numeric code for a keyboard key
      modifiers - a bitwise-ored combination of any modifiers
      Returns:
      an AWTKeyStroke object for that key
      See Also:

    • getAWTKeyStrokeForEvent

      public static AWTKeyStroke getAWTKeyStrokeForEvent(KeyEvent anEvent)
      Returns an AWTKeyStroke which represents the stroke which generated a given KeyEvent.

      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.

      Parameters:
      anEvent - the KeyEvent from which to obtain the AWTKeyStroke
      Returns:
      the AWTKeyStroke that precipitated the event
      Throws:
      NullPointerException - if anEvent is null

    • getAWTKeyStroke

      public static AWTKeyStroke getAWTKeyStroke(String s)
      Parses a string and returns an AWTKeyStroke. The string must have the following syntax: 
          <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_".
      If typed, pressed or released is not specified, pressed is assumed. Here are some examples: 
           "INSERT" => getAWTKeyStroke(KeyEvent.VK_INSERT, 0);
     "control DELETE" => getAWTKeyStroke(KeyEvent.VK_DELETE, InputEvent.CTRL_MASK);
     "alt shift X" => getAWTKeyStroke(KeyEvent.VK_X, InputEvent.ALT_MASK | InputEvent.SHIFT_MASK);
     "alt shift released X" => getAWTKeyStroke(KeyEvent.VK_X, InputEvent.ALT_MASK | InputEvent.SHIFT_MASK, true);
     "typed a" => getAWTKeyStroke('a');
      Parameters:
      s - a String formatted as described above
      Returns:
      an AWTKeyStroke object for that String
      Throws:
      IllegalArgumentException - if s is null, or is formatted incorrectly

    • getKeyChar

      public final char getKeyChar()
      Returns the character for this AWTKeyStroke.
      Returns:
      a char value
      See Also:

    • getKeyCode

      public final int getKeyCode()
      Returns the numeric key code for this AWTKeyStroke.
      Returns:
      an int containing the key code value
      See Also:

    • getModifiers

      public final int getModifiers()
      Returns the modifier keys for this AWTKeyStroke.
      Returns:
      an int containing the modifiers
      See Also:

    • isOnKeyRelease

      public final boolean isOnKeyRelease()
      Returns whether this AWTKeyStroke represents a key release.
      Returns:
      true if this AWTKeyStroke represents a key release; false otherwise
      See Also:

    • getKeyEventType

      public final int getKeyEventType()
      Returns the type of KeyEvent which corresponds to this AWTKeyStroke.
      Returns:
      KeyEvent.KEY_PRESSED, KeyEvent.KEY_TYPED, or KeyEvent.KEY_RELEASED
      See Also:

    • hashCode

      public int hashCode()
      Returns a numeric value for this object that is likely to be unique, making it a good choice as the index value in a hash table.
      Overrides:
      hashCode in class Object
      Returns:
      an int that represents this object
      See Also:

    • equals

      public final boolean equals(Object anObject)
      Returns true if this object is identical to the specified object.
      Overrides:
      equals in class Object
      Parameters:
      anObject - the Object to compare this object to
      Returns:
      true if the objects are identical
      See Also:

    • toString

      public String toString()
      Returns a string that displays and identifies this object's properties. The String returned by this method can be passed as a parameter to getAWTKeyStroke(String) to produce a key stroke equal to this key stroke.
      Overrides:
      toString in class Object
      Returns:
      a String representation of this object
      See Also:

    • readResolve

      protected Object readResolve() throws ObjectStreamException
      Returns a cached instance of AWTKeyStroke (or a subclass of AWTKeyStroke) which is equal to this instance.
      Returns:
      a cached instance which is equal to this instance
      Throws:
      ObjectStreamException - if a serialization problem occurs