org.leialearns.utilities

Class Setting<T>

java.lang.Object

org.leialearns.utilities.Setting<T>

Type Parameters:

T - The type of the value

public class Setting<T>
extends Object

Encapsulates a reference to a value that can be set only once. Declare a final Setting<T> instead of a final T property, if the value is not known when the object is constructed, but otherwise behaves like a final property. A setting reference is thread-safe.

Constructor Summary

Constructors

Constructor and Description
Setting(String name) Creates a new Setting instance.
Setting(String name, Expression<T> defaultExpression) Creates a new Setting instance.
Setting(String name, T defaultValue) Creates a new Setting instance.

Method Summary

Methods

Modifier and Type	Method and Description
T	get() Returns the value of this setting.
boolean	isFixated() Returns a flag that indicates whether the value of this setting is already fixated.
boolean	offer(T value) Offers the value as a candidate for the reference.
void	set(T value) Sets the value, if possible.
String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Setting

public Setting(String name,
       Expression<T> defaultExpression)

Creates a new Setting instance. The default value is used in case the setting is not set before the getter is called.

Parameters:

name - A label for the setting

defaultExpression - An expression that lazily returns a default value

Setting

public Setting(String name,
       T defaultValue)

Creates a new Setting instance. The default value is used in case the setting is not set before the getter is called.

Parameters:

name - A label for the setting

defaultValue - The default value

Setting

public Setting(String name)

Creates a new Setting instance.

Parameters:

name - A label for the setting

Method Detail

set

public void set(T value)

Sets the value, if possible.

Parameters:

value - The value to set

Throws:

IllegalStateException - If the reference was already set to another value

get

public T get()

Returns the value of this setting. If the values was not set, it is set to the (lazily evaluated) default value first. If the expression that calculates the default value returns null, an IllegalStateException is thrown.

Returns:

The value of this setting

Throws:

IllegalStateException

isFixated

public boolean isFixated()

Returns a flag that indicates whether the value of this setting is already fixated.

Returns:

true if the value is fixated; false otherwise

offer

public boolean offer(T value)

Offers the value as a candidate for the reference.

Parameters:

value - The candidate value for this setting

Returns:

true if the given value is equal to the value of the setting; false otherwise

toString

public String toString()

Overrides:

toString in class Object