edu.rice.cs.drjava.config
Class Option<T>

java.lang.Object
  edu.rice.cs.drjava.config.OptionParser<T>
      edu.rice.cs.drjava.config.Option<T>

All Implemented Interfaces:

FormatStrategy<T>, ParseStrategy<T>

Direct Known Subclasses:

BooleanOption, ColorOption, FileOption, FontOption, ForcedChoiceOption, IntegerOption, KeyStrokeOption, LongOption, StringOption, VectorOption

public abstract class Option<T>
extends OptionParser<T>
implements FormatStrategy<T>

An instance of this class represents a configurable option in DrJava that has static type T. Classes can extend this class and the rest of the Configuration typing framework will work for it. Named subclasses aren't even necessary -- but may be convenient in order to re-use code. For example, to make an anonymous class that handles options of static type Integer, with the name "indent.level", you could use the following code:

 Option<Integer> INDENT_LEVEL = new Option<Integer>("indent.level") {
         public Integer parse(String s) {
             return new Integer(s);
         }
     };
 

The precedinjg example is simple because Integers (like most data-type classes defined in the Java libraries) have handy toString() / parsing methods/constructors.

Version:

$Id: Option.java 5232 2010-04-24 00:14:05Z mgricken $

Field Summary

(package private) HashMap<Configuration,Vector<OptionListener<T>>>

listeners A hashtable that maps Configuration objects to a list of listeners for this particular option.

Fields inherited from class edu.rice.cs.drjava.config.OptionParser

defaultValue, map, name

Constructor Summary

Option(String name, T def)
Constructor that takes in a name and default value

Method Summary

(package private) void	addListener(Configuration c, OptionListener<T> l) Magic listener-bag adder
String	format(T value) Formats a statically typed T value as a String.
String	getDefaultString()
(package private) String	getString(DefaultOptionMap om) Uses format() and getOption() so that any changes in format will automatically be applied to getString().
(package private) void	notifyListeners(Configuration config, T val) Sends an OptionEvent to all OptionListeners who have registered on this Option.
(package private) void	removeListener(Configuration c, OptionListener<T> l) Magic listener-bag remover

Methods inherited from class edu.rice.cs.drjava.config.OptionParser

getDefault, getName, getOption, parse, remove, setOption, setString, toString

Methods inherited from class java.lang.Object

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

Field Detail

listeners

final HashMap<Configuration,Vector<OptionListener<T>>> listeners

A hashtable that maps Configuration objects to a list of listeners for this particular option. Part of the magic inner workings of this package.

Constructor Detail

Option

public Option(String name,
              T def)

Constructor that takes in a name and default value

Parameters:

name - the name of this option (eg. "indent.level");

def - the default value for this option (eg. "2")

Method Detail

format

public String format(T value)

Formats a statically typed T value as a String. The default implementation uses the toString() method.

Specified by:

format in interface FormatStrategy<T>

Parameters:

value - the statically-typed value to format into a String

Throws:

NullPointerException - if value is null

getDefaultString

public String getDefaultString()

Specified by:

getDefaultString in class OptionParser<T>

Returns:

the default value as a string

getString

String getString(DefaultOptionMap om)

Uses format() and getOption() so that any changes in format will automatically be applied to getString().

Specified by:

getString in class OptionParser<T>

notifyListeners

void notifyListeners(Configuration config,
                     T val)

Sends an OptionEvent to all OptionListeners who have registered on this Option.

addListener

void addListener(Configuration c,
                 OptionListener<T> l)

Magic listener-bag adder

removeListener

void removeListener(Configuration c,
                    OptionListener<T> l)

Magic listener-bag remover