WorldObserver (libgdx-utils-box2d)

java.lang.Object
- net.dermetfan.gdx.physics.box2d.WorldObserver

```
public class WorldObserver
extends java.lang.Object
```
Notifies a WorldObserver.Listener of changes in the world. Does NOT work on HTML5!

Since:

0.6.0

Author:

dermetfan

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`WorldObserver.BodyChange` the changes of a `Body`
`static interface`	`WorldObserver.Change<T>` the changes of an object in a world since the last time `WorldObserver.Change.update(Object)` was called
`static class`	`WorldObserver.DistanceJointChange` the changes of a `DistanceJoint`
`static class`	`WorldObserver.FixtureChange` the changes of a `Fixture`
`static class`	`WorldObserver.FrictionJointChange` the changes of a `FrictionJoint`
`static class`	`WorldObserver.GearJointChange` the changes of a `GearJoint`
`static class`	`WorldObserver.JointChange<T extends com.badlogic.gdx.physics.box2d.Joint>` the changes of a `Joint`
`static interface`	`WorldObserver.Listener` the listener notified by a `WorldObserver`
`static class`	`WorldObserver.MotorJointChange` the changes of a `MotorJoint`
`static class`	`WorldObserver.MouseJointChange` the changes of a `MouseJoint`
`static class`	`WorldObserver.PrismaticJointChange` the changes of a `PrismaticJoint`
`static class`	`WorldObserver.RevoluteJointChange` the changes of a `RevoluteJoint`
`static class`	`WorldObserver.RopeJointChange` the changes of a `RopeJoint`
`static class`	`WorldObserver.UnexpectedListener` A Listener that calls another Listener on unpredictable/unexpected events.
`static class`	`WorldObserver.WeldJointChange` the changes of a `WeldJoint`
`static class`	`WorldObserver.WheelJointChange` the changes of a `WheelJoint`
`static class`	`WorldObserver.WorldChange` the changes of a `World`

Field Summary

Fields
Modifier and Type	Field and Description
`private com.badlogic.gdx.utils.IntMap<WorldObserver.BodyChange>`	`bodyChanges` the BodyChanges used to track Bodies, keys are hashes computed by `Box2DUtils#hashCode(Body)` because a World pools its Bodies
`private com.badlogic.gdx.utils.IntMap<com.badlogic.gdx.physics.box2d.Body>`	`currentBodies` the Bodies by `hash` since this/the last time `update(World, float)` was called
`private com.badlogic.gdx.utils.IntMap<com.badlogic.gdx.physics.box2d.Fixture>`	`currentFixtures` the Fixtures by `hash` since this/the last time `update(World, float)` was called
`private com.badlogic.gdx.utils.Array<com.badlogic.gdx.physics.box2d.Joint>`	`currentJoints` the Joints since this/the last time `update(World, float)` was called
`private com.badlogic.gdx.utils.IntMap<WorldObserver.FixtureChange>`	`fixtureChanges` the FixtureChanges used to track Fixtures, keys are hashes computed by `Box2DUtils#hashCode(Fixture)` because a world pools its Fixtures
`private com.badlogic.gdx.utils.ObjectMap<com.badlogic.gdx.physics.box2d.Joint,WorldObserver.JointChange>`	`jointChanges` the JointChanges used to track Joints
`private WorldObserver.Listener`	`listener` The Listener to notify.
`private com.badlogic.gdx.utils.IntMap<com.badlogic.gdx.physics.box2d.Body>`	`previousBodies` the Bodies by `hash` since this/the last time `update(World, float)` was called
`private com.badlogic.gdx.utils.IntMap<com.badlogic.gdx.physics.box2d.Fixture>`	`previousFixtures` the Fixtures by `hash` since this/the last time `update(World, float)` was called
`private com.badlogic.gdx.utils.Array<com.badlogic.gdx.physics.box2d.Joint>`	`previousJoints` the Joints since this/the last time `update(World, float)` was called
`private com.badlogic.gdx.utils.Array<com.badlogic.gdx.physics.box2d.Body>`	`tmpBodies` temporary array used internally
`private WorldObserver.WorldChange`	`worldChange` the WorldChange used to track the World

Constructor Summary

Constructors
Constructor and Description

WorldObserver()
creates a new WorldObserver with no listener

WorldObserver(WorldObserver.Listener listener)

Constructors
Constructor and Description
`WorldObserver()` creates a new WorldObserver with no `listener`
`WorldObserver(WorldObserver.Listener listener)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`WorldObserver.BodyChange`	`getBodyChange(int hash)`
`WorldObserver.FixtureChange`	`getFixtureChange(int hash)`
`WorldObserver.JointChange`	`getJointChange(com.badlogic.gdx.physics.box2d.Joint joint)`
`WorldObserver.Listener`	`getListener()`
`WorldObserver.WorldChange`	`getWorldChange()`
`void`	`setListener(WorldObserver.Listener listener)`
`void`	`update(com.badlogic.gdx.physics.box2d.World world, float step)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - listener
```
private WorldObserver.Listener listener
```
    The Listener to notify. May be null.
  - worldChange
```
private final WorldObserver.WorldChange worldChange
```
    the WorldChange used to track the World
  - bodyChanges
```
private final com.badlogic.gdx.utils.IntMap<WorldObserver.BodyChange> bodyChanges
```
    the BodyChanges used to track Bodies, keys are hashes computed by Box2DUtils#hashCode(Body) because a World pools its Bodies
  - fixtureChanges
```
private final com.badlogic.gdx.utils.IntMap<WorldObserver.FixtureChange> fixtureChanges
```
    the FixtureChanges used to track Fixtures, keys are hashes computed by Box2DUtils#hashCode(Fixture) because a world pools its Fixtures
  - jointChanges
```
private final com.badlogic.gdx.utils.ObjectMap<com.badlogic.gdx.physics.box2d.Joint,WorldObserver.JointChange> jointChanges
```
    the JointChanges used to track Joints
  - tmpBodies
```
private final com.badlogic.gdx.utils.Array<com.badlogic.gdx.physics.box2d.Body> tmpBodies
```
    temporary array used internally
  - currentBodies
```
private final com.badlogic.gdx.utils.IntMap<com.badlogic.gdx.physics.box2d.Body> currentBodies
```
    the Bodies by hash since this/the last time update(World, float) was called
  - previousBodies
```
private final com.badlogic.gdx.utils.IntMap<com.badlogic.gdx.physics.box2d.Body> previousBodies
```
    the Bodies by hash since this/the last time update(World, float) was called
  - currentFixtures
```
private final com.badlogic.gdx.utils.IntMap<com.badlogic.gdx.physics.box2d.Fixture> currentFixtures
```
    the Fixtures by hash since this/the last time update(World, float) was called
  - previousFixtures
```
private final com.badlogic.gdx.utils.IntMap<com.badlogic.gdx.physics.box2d.Fixture> previousFixtures
```
    the Fixtures by hash since this/the last time update(World, float) was called
  - currentJoints
```
private final com.badlogic.gdx.utils.Array<com.badlogic.gdx.physics.box2d.Joint> currentJoints
```
    the Joints since this/the last time update(World, float) was called
  - previousJoints
```
private final com.badlogic.gdx.utils.Array<com.badlogic.gdx.physics.box2d.Joint> previousJoints
```
    the Joints since this/the last time update(World, float) was called
- Constructor Detail
  - WorldObserver
```
public WorldObserver()
```
    creates a new WorldObserver with no listener
  - WorldObserver
```
public WorldObserver(WorldObserver.Listener listener)
```
    Parameters:
    
    listener - the listener
- Method Detail
  - update
```
public void update(com.badlogic.gdx.physics.box2d.World world,
                   float step)
```
    Parameters:
    
    world - Ideally always the same World because its identity is not checked. Passing in another world instance will cause all differences between the two worlds to be processed.
    
    step - the time the world was last stepped with
  - getBodyChange
```
public WorldObserver.BodyChange getBodyChange(int hash)
```
    Parameters:
    
    hash - the hash of the Body (computed via Box2DUtils#hashCode(Body)) which associated BodyChange to return
    
    Returns:
    
    the BodyChange from bodyChanges currently used for the Body with the given hash, or null if not found
  - getFixtureChange
```
public WorldObserver.FixtureChange getFixtureChange(int hash)
```
    Parameters:
    
    hash - the hash of the Fixture (computed via Box2DUtils#hashCode(Fixture)) which associated FixtureChange to return
    
    Returns:
    
    the FixtureChange from fixtureChanges currently used for the Fixture with the given hash, or null if not found
  - getJointChange
```
public WorldObserver.JointChange getJointChange(com.badlogic.gdx.physics.box2d.Joint joint)
```
    Parameters:
    
    joint - the joint which associated JointChange to return
    
    Returns:
    
    the JointChange from jointChanges currently used for the given Joint
  - getWorldChange
```
public WorldObserver.WorldChange getWorldChange()
```
    Returns:
    
    the worldChange
  - getListener
```
public WorldObserver.Listener getListener()
```
    Returns:
    
    the listener
  - setListener
```
public void setListener(WorldObserver.Listener listener)
```
    Parameters:
    
    listener - the listener to set

Class WorldObserver

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

listener

worldChange

bodyChanges

fixtureChanges

jointChanges

tmpBodies

currentBodies

previousBodies

currentFixtures

previousFixtures

currentJoints

previousJoints

Constructor Detail

WorldObserver

WorldObserver

Method Detail

update

getBodyChange

getFixtureChange

getJointChange

getWorldChange

getListener

setListener