org.omus.data
Class CounterField

java.lang.Object
  |
  +--org.omus.data.DataField
        |
        +--org.omus.data.CounterField

All Implemented Interfaces:

java.lang.Cloneable, java.io.Serializable

public class CounterField

extends DataField

A special class for synchronizing int values. This is the only subclass of DataField that is not just a Java class corresponding to an ActionScript datatype. It makes it possible to modify int values relative to their current value and thus avoid any synchronization issues that might occur if different clients modify the int value of a group property concurrently.

An example: Let's assume you created a Flash client that shows a basket and each user in the group can put any amount of apples into the basket and take any amount out of it. If two users put an apple into that basket concurrrently and both clients add 1 to the current number of apples and then send the new total value to the server, only one of the two apples gets added to the group property on the server side. If a property is configured to be a counter, the setValue method of the client side PropertySet object changes the value relative to the current value. This way the server receives two "add 1 apple" commands and thus both apples are added to the basket. In other words: If "foo" is the name of a property configured as a counter, then setValue("foo",-4) called in PropertySet in the client means: "subtract 4 from the current value" and only the relative change is submitted to the server.

See Also:

Serialized Form

Constructor Summary

CounterField(java.lang.String n, int v)
Creates a new CounterField with the specified name and initial value.

Method Summary

void	accept(FieldVisitor fv) Accepts a visitor.
void	add(int dif) Adds the specified value to the int value of this CounterField.
int	get() Returns the current value of this CounterField.
void	reset() Resets the value of this CounterField to the initial value.
void	set(int newValue) Sets the value of this CounterField to the specified value.
java.lang.String	toString()

Methods inherited from class org.omus.data.DataField

addListener, appendMarshalledField, clone, getMarshalledField, getName, removeListener

Methods inherited from class java.lang.Object

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

Constructor Detail

CounterField

public CounterField(java.lang.String n,
                    int v)

Creates a new CounterField with the specified name and initial value.

Method Detail

get

public int get()

Returns the current value of this CounterField.

set

public void set(int newValue)

Sets the value of this CounterField to the specified value.

reset

public void reset()

Resets the value of this CounterField to the initial value.

add

public void add(int dif)

Adds the specified value to the int value of this CounterField. Negative values are permitted.

accept

public void accept(FieldVisitor fv)

Description copied from class: DataField

Accepts a visitor. The visitor pattern is useful if you want to extend the functionality of all DataFields without modifying their API.

Overrides:

accept in class DataField

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object