Module java.desktop
Package java.awt

Class 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:
    getAWTKeyStroke(char), Serialized Form
    • 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.
    • Constructor Detail

      • 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:
        getAWTKeyStroke(char)
      • 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:
        getAWTKeyStroke(char)
    • Method Detail

      • 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:
        InputEvent
      • 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:
        KeyEvent, InputEvent
      • 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:
        KeyEvent, InputEvent
      • 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
      • getModifiers

        public final int getModifiers()
        Returns the modifier keys for this AWTKeyStroke.
        Returns:
        an int containing the modifiers
        See Also:
        getAWTKeyStroke(int,int)
      • 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:
        getAWTKeyStroke(int,int,boolean)
      • 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:
        KeyEvent
      • 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:
        Object.hashCode(), HashMap
      • 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:
        getAWTKeyStroke(String)
      • 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