javax.swing.text

Class SimpleAttributeSet

Implemented Interfaces:
AttributeSet, Cloneable, MutableAttributeSet, Serializable
Known Direct Subclasses:
htmlAttributeSet

public class SimpleAttributeSet
extends Object
implements MutableAttributeSet, Serializable, Cloneable

See Also:
Serialized Form

Field Summary

static AttributeSet
EMPTY

Fields inherited from interface javax.swing.text.AttributeSet

NameAttribute, ResolveAttribute

Constructor Summary

SimpleAttributeSet()
The basic constructor.
SimpleAttributeSet(AttributeSet a)

Method Summary

void
addAttribute(Object name, Object value)
addAttribute
void
addAttributes(AttributeSet attributes)
addAttributes
Object
clone()
This method may be called to create a new copy of the Object.
boolean
containsAttribute(Object name, Object value)
Returns true if the given name and value represent an attribute found either in this AttributeSet or in its resolve parent hierarchy.
boolean
containsAttributes(AttributeSet attributes)
AttributeSet
copyAttributes()
boolean
equals(Object obj)
Determine whether this Object is semantically equal to another Object.
Object
getAttribute(Object name)
int
getAttributeCount()
Enumeration
getAttributeNames()
AttributeSet
getResolveParent()
int
hashCode()
Get a value that represents this Object, as uniquely as possible within the confines of an int.
boolean
isDefined(Object attrName)
boolean
isEmpty()
boolean
isEqual(AttributeSet attr)
Returns true if the given set has the same number of attributes as this set and containsAttributes(attr) returns true.
void
removeAttribute(Object name)
removeAttribute
void
removeAttributes(Enumeration names)
removeAttributes
void
removeAttributes(AttributeSet attributes)
Removes attributes from this set if they are found in the given set.
void
setResolveParent(AttributeSet parent)
setResolveParent
String
toString()
Convert this Object to a human-readable String.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

EMPTY

public static final AttributeSet EMPTY

Constructor Details

SimpleAttributeSet

public SimpleAttributeSet()
The basic constructor. Object is special, because it has no superclass, so there is no call to super().

SimpleAttributeSet

public SimpleAttributeSet(AttributeSet a)

Method Details

addAttribute

public void addAttribute(Object name,
                         Object value)
addAttribute
Specified by:
addAttribute in interface MutableAttributeSet
Parameters:
name - TODO
value - TODO

addAttributes

public void addAttributes(AttributeSet attributes)
addAttributes
Specified by:
addAttributes in interface MutableAttributeSet
Parameters:
attributes - TODO

clone

public Object clone()
This method may be called to create a new copy of the Object. The typical behavior is as follows:
  • o == o.clone() is false
  • o.getClass() == o.clone().getClass() is true
  • o.equals(o) is true

However, these are not strict requirements, and may be violated if necessary. Of the three requirements, the last is the most commonly violated, particularly if the subclass does not override Object.equals(Object).

If the Object you call clone() on does not implement Cloneable (which is a placeholder interface), then a CloneNotSupportedException is thrown. Notice that Object does not implement Cloneable; this method exists as a convenience for subclasses that do.

Object's implementation of clone allocates space for the new Object using the correct class, without calling any constructors, and then fills in all of the new field values with the old field values. Thus, it is a shallow copy. However, subclasses are permitted to make a deep copy.

All array types implement Cloneable, and override this method as follows (it should never fail):

 public Object clone()
 {
   try
     {
       super.clone();
     }
   catch (CloneNotSupportedException e)
     {
       throw new InternalError(e.getMessage());
     }
 }
 
Overrides:
clone in interface Object
Returns:
a copy of the Object
See Also:
Cloneable

containsAttribute

public boolean containsAttribute(Object name,
                                 Object value)
Returns true if the given name and value represent an attribute found either in this AttributeSet or in its resolve parent hierarchy.
Specified by:
containsAttribute in interface AttributeSet
Parameters:
name - the key for the attribute
value - the value for the attribute
Returns:
true if the attribute is found here or in this set's resolve parent hierarchy

containsAttributes

public boolean containsAttributes(AttributeSet attributes)
Specified by:
containsAttributes in interface AttributeSet

copyAttributes

public AttributeSet copyAttributes()
Specified by:
copyAttributes in interface AttributeSet

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

getAttribute

public Object getAttribute(Object name)
Specified by:
getAttribute in interface AttributeSet

getAttributeCount

public int getAttributeCount()
Specified by:
getAttributeCount in interface AttributeSet

getAttributeNames

public Enumeration getAttributeNames()
Specified by:
getAttributeNames in interface AttributeSet

getResolveParent

public AttributeSet getResolveParent()
Specified by:
getResolveParent in interface AttributeSet

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

isDefined

public boolean isDefined(Object attrName)
Specified by:
isDefined in interface AttributeSet

isEmpty

public boolean isEmpty()

isEqual

public boolean isEqual(AttributeSet attr)
Returns true if the given set has the same number of attributes as this set and containsAttributes(attr) returns true.
Specified by:
isEqual in interface AttributeSet

removeAttribute

public void removeAttribute(Object name)
removeAttribute
Specified by:
removeAttribute in interface MutableAttributeSet
Parameters:
name - TODO

removeAttributes

public void removeAttributes(Enumeration names)
removeAttributes
Specified by:
removeAttributes in interface MutableAttributeSet
Parameters:
names - TODO

removeAttributes

public void removeAttributes(AttributeSet attributes)
Removes attributes from this set if they are found in the given set. Only attributes whose key AND value are removed. Removes attributes only from this set, not from the resolving parent.
Specified by:
removeAttributes in interface MutableAttributeSet

setResolveParent

public void setResolveParent(AttributeSet parent)
setResolveParent
Specified by:
setResolveParent in interface MutableAttributeSet
Parameters:
parent - TODO

toString

public String toString()
Convert this Object to a human-readable String. There are no limits placed on how long this String should be or what it should contain. We suggest you make it as intuitive as possible to be able to place it into System.out.println() and such.

It is typical, but not required, to ensure that this method never completes abruptly with a RuntimeException.

This method will be called when performing string concatenation with this object. If the result is null, string concatenation will instead use "null".

The default implementation returns getClass().getName() + "@" + Integer.toHexString(hashCode()).

Overrides:
toString in interface Object
Returns:
the String representing this Object, which may be null

SimpleAttributeSet.java -- Copyright (C) 2004, 2005 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.