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org.eclipse.swt.graphics
Class TextStyle  view TextStyle download TextStyle.java

java.lang.Object
  extended byorg.eclipse.swt.graphics.TextStyle

public class TextStyle
extends java.lang.Object

TextStyle defines a set of styles that can be applied to a range of text.

The hashCode() method in this class uses the values of the public fields to compute the hash value. When storing instances of the class in hashed collections, do not modify these fields after the object has been inserted.

Application code does not need to explicitly release the resources managed by each instance when those instances are no longer required, and thus no dispose() method is provided.

Since:
3.0

Field Summary
 Color background
          the background of the style
 Font font
          the font of the style
 Color foreground
          the foreground of the style
 
Constructor Summary
TextStyle(Font font, Color foreground, Color background)
          Create a new text style with the specified font, foreground and background.
 
Method Summary
 boolean equals(java.lang.Object object)
          Determine whether this Object is semantically equal to another Object.
 int hashCode()
          Get a value that represents this Object, as uniquely as possible within the confines of an int.
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

font

public Font font
the font of the style


foreground

public Color foreground
the foreground of the style


background

public Color background
the background of the style

Constructor Detail

TextStyle

public TextStyle(Font font,
                 Color foreground,
                 Color background)
Create a new text style with the specified font, foreground and background.

Method Detail

equals

public boolean equals(java.lang.Object object)
Description copied from class: java.lang.Object
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 java.lang.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 java.lang.NullPointerException.

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

The default implementation returns this == o.


hashCode

public int hashCode()
Description copied from class: java.lang.Object
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 java.util.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)