java.awt

Class MenuShortcut

Implemented Interfaces:
Serializable

public class MenuShortcut
extends Object
implements Serializable

This class implements a keyboard accelerator for a menu item.
See Also:
Serialized Form

Constructor Summary

MenuShortcut(int key)
Initializes a new instance of MenuShortcut with the specified virtual key value.
MenuShortcut(int key, boolean usesShift)
Initializes a new instance of MenuShortcut with the specified virtual key value and shift setting.

Method Summary

boolean
equals(MenuShortcut obj)
Tests this object for equality against the specified object.
boolean
equals(Object obj)
Determine whether this Object is semantically equal to another Object.
int
getKey()
Returns the virtual keycode for this shortcut.
int
hashCode()
Get a value that represents this Object, as uniquely as possible within the confines of an int.
protected String
paramString()
Returns a debugging string for this object.
String
toString()
Returns a string representation of this shortcut.
boolean
usesShiftModifier()
Returns the shift setting for this shortcut.

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

MenuShortcut

public MenuShortcut(int key)
Initializes a new instance of MenuShortcut with the specified virtual key value.
Parameters:
key - The virtual keycode for the shortcut.

MenuShortcut

public MenuShortcut(int key,
                    boolean usesShift)
Initializes a new instance of MenuShortcut with the specified virtual key value and shift setting.
Parameters:
key - The virtual keycode for the shortcut.
usesShift - true if the shift key was pressed, false otherwise.

Method Details

equals

public boolean equals(MenuShortcut obj)
Tests this object for equality against the specified object. The two objects will be considered equal if and only if the specified object is an instance of MenuShortcut and has the same key value and shift setting as this object.
Parameters:
obj - The object to test for equality against.
Returns:
true if the two objects are equal, false otherwise.

equals

public boolean equals(Object obj)
Determine whether this Object is semantically equal to another Object.

There are some fairly strict requirements on this method which subclasses must follow:

  • It must be transitive. If a.equals(b) and b.equals(c), then a.equals(c) must be true as well.
  • It must be symmetric. a.equals(b) and b.equals(a) must have the same value.
  • It must be reflexive. a.equals(a) must always be true.
  • It must be consistent. Whichever value a.equals(b) returns on the first invocation must be the value returned on all later invocations.
  • a.equals(null) must be false.
  • It must be consistent with hashCode(). That is, a.equals(b) must imply a.hashCode() == b.hashCode(). The reverse is not true; two objects that are not equal may have the same hashcode, but that has the potential to harm hashing performance.

This is typically overridden to throw a ClassCastException if the argument is not comparable to the class performing the comparison, but that is not a requirement. It is legal for a.equals(b) to be true even though a.getClass() != b.getClass(). Also, it is typical to never cause a NullPointerException.

In general, the Collections API (java.util) use the equals method rather than the == operator to compare objects. However, IdentityHashMap is an exception to this rule, for its own good reasons.

The default implementation returns this == o.

Overrides:
equals in interface Object
Parameters:
obj - the Object to compare to
Returns:
whether this Object is semantically equal to another

getKey

public int getKey()
Returns the virtual keycode for this shortcut.
Returns:
The virtual keycode for this shortcut.

hashCode

public int hashCode()
Get a value that represents this Object, as uniquely as possible within the confines of an int.

There are some requirements on this method which subclasses must follow:

  • Semantic equality implies identical hashcodes. In other words, if a.equals(b) is true, then a.hashCode() == b.hashCode() must be as well. However, the reverse is not necessarily true, and two objects may have the same hashcode without being equal.
  • It must be consistent. Whichever value o.hashCode() returns on the first invocation must be the value returned on all later invocations as long as the object exists. Notice, however, that the result of hashCode may change between separate executions of a Virtual Machine, because it is not invoked on the same object.

Notice that since hashCode is used in Hashtable and other hashing classes, a poor implementation will degrade the performance of hashing (so don't blindly implement it as returning a constant!). Also, if calculating the hash is time-consuming, a class may consider caching the results.

The default implementation returns System.identityHashCode(this)

Overrides:
hashCode in interface Object
Returns:
the hash code for this Object

paramString

protected String paramString()
Returns a debugging string for this object.
Returns:
A debugging string for this object.

toString

public String toString()
Returns a string representation of this shortcut.
Overrides:
toString in interface Object
Returns:
A string representation of this shortcut.

usesShiftModifier

public boolean usesShiftModifier()
Returns the shift setting for this shortcut.
Returns:
true if the shift key was pressed, false otherwise.

MenuShortcut.java -- A class for menu accelerators Copyright (C) 1999, 2002 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath 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 for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.