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.
KeyStrokes are immutable, and are intended to be unique. Client code cannot
create a KeyStroke; a variant of getKeyStroke must be used
instead. These factory methods allow the KeyStroke implementation to cache
and share instances efficiently.
Warning:
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 JavaBeansTM
has been added to the java.beans package.
Please see java.beans.XMLEncoder
.
AWTKeyStroke
that represents a KEY_TYPED event for the
specified character.AWTKeyStroke,
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 getAWTKeyStroke(int keyCode, int modifiers).
The modifiers consist of any combination of: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
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
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');
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.
AWTKeyStroke.AWTKeyStroke.KeyEvent which corresponds to
this AWTKeyStroke.KeyStroke
that represents a KEY_TYPED event for the
specified character.getKeyStroke(int keyCode, int modifiers).
The modifiers consist of any combination of:The "virtual key" constants defined in java.awt.event.KeyEvent can be used to specify the key code. For example:
The "virtual key" constants defined in java.awt.event.KeyEvent can be used to specify the key code. For example:
KeyStroke.
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" => 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');
In order to maintain backward-compatibility, specifying a null String,
or a String which is formatted incorrectly, returns null.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.
AWTKeyStroke.AWTKeyStroke represents a key release.wait methods.
The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:
synchronized statement
that synchronizes on the object.
Class, by executing a
synchronized static method of that class.
Only one thread at a time can own an object's monitor.
wait methods.
The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
String returned by this method can be passed
as a parameter to getAWTKeyStroke(String) to produce
a key stroke equal to this key stroke.
The current thread must own this object's monitor. The thread
releases ownership of this monitor and waits until another thread
notifies threads waiting on this object's monitor to wake up
either through a call to the notify method or the
notifyAll method. The thread then waits until it can
re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait();
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.The current thread must own this object's monitor.
This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:
A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout);
... // Perform action appropriate to condition
}
(For more information on this topic, see Section 3.2.3 in Doug Lea's
"Concurrent Programming in Java (Second Edition)" (Addison-Wesley,
2000), or Item 50 in Joshua Bloch's "Effective Java Programming
Language Guide" (Addison-Wesley, 2001).
If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.
Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
This method is similar to the wait method of one
argument, but it allows finer control over the amount of time to
wait for a notification before giving up. The amount of real time,
measured in nanoseconds, is given by:
1000000*timeout+nanos
In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).
The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:
notify method
or the notifyAll method.
timeout
milliseconds plus nanos nanoseconds arguments, has
elapsed.
The thread then waits until it can re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout, nanos);
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.