edu.umd.cs.jazz
Class ZConstraintGroup

java.lang.Object
  |
  +--edu.umd.cs.jazz.ZSceneGraphObject
        |
        +--edu.umd.cs.jazz.ZNode
              |
              +--edu.umd.cs.jazz.ZGroup
                    |
                    +--edu.umd.cs.jazz.ZTransformGroup
                          |
                          +--edu.umd.cs.jazz.ZConstraintGroup

All Implemented Interfaces:

java.lang.Cloneable, java.io.Serializable, ZSerializable, ZTransformable

Direct Known Subclasses:

ZStickyGroup

public class ZConstraintGroup

extends ZTransformGroup

implements java.io.Serializable

ZConstraintGroup is a transform group that changes its transform based on a computation defined in a specified method. Every time the camera view is changed, the method is called, recomputing the transform. Thus, depending on the algorithm chosen, various dynamic behaviors can be created.

Sub-classes must override the ZTransformGroup.getTransform() method of ZTransformGroup.getTransform() to define a new transform. This class stores a reference to a camera so, for example, a sub-class could define a constraint dependent on the camera so that the children move whenever the camera view changes.

Warning: Serialized and ZSerialized objects of this class will not be compatible with future Jazz releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Jazz. A future release of Jazz will provide support for long term persistence.

Author:

Benjamin B. Bederson

See Also:

ZStickyGroup, Serialized Form

camera

protected ZCamera camera

The camera the constraint is related to

ZConstraintGroup

public ZConstraintGroup()

Constructs a new constraint group. This constructor does not specify a camera to be used in calculating the constraint. Set the camera separately to make the node behave properly.

See Also:

setCamera(edu.umd.cs.jazz.ZCamera)

ZConstraintGroup

public ZConstraintGroup(ZCamera camera)

Constructs a new constraint group with a specified camera.

Parameters:

camera - The camera the node is related to.

ZConstraintGroup

public ZConstraintGroup(ZNode child)

Constructs a new constraint group that decorates the specified child.

Parameters:

child - The child that should go directly below this node.

ZConstraintGroup

public ZConstraintGroup(ZCamera camera,
                        ZNode child)

Constructs a new constraint group with a specified camera that decorates the specified child.

Parameters:

camera - The camera the node is related to.

child - The child that should go directly below this node.

finalize

public void finalize()

Disposes of this constraint group when it is no longer used.

Overrides:

finalize in class java.lang.Object

init

protected void init(ZCamera camera)

Internal method to help node construction.

updateObjectReferences

protected void updateObjectReferences(ZObjectReferenceTable objRefTable)

Called to update internal object references after a clone operation by ZSceneGraphObject.clone().

Overrides:

updateObjectReferences in class ZSceneGraphObject

Parameters:

objRefTable - Table mapping from uncloned objects to their cloned versions.

See Also:

ZSceneGraphObject.updateObjectReferences(edu.umd.cs.jazz.util.ZObjectReferenceTable)

computeTransform

public java.awt.geom.AffineTransform computeTransform()

Computes the constraint that defines the child to not move even as the camera view changes. This is called whenever the camera view changes. This should be overrided by sub-classes defining constraints.

Returns:

The new transform

updateTransform

protected void updateTransform()

Internal method to recompute the constraint transform. This should be called whenever some internal state that can affect the constraint changes.

getCamera

public ZCamera getCamera()

Get the camera that this node is related to.

Returns:

the camera

setCamera

public void setCamera(ZCamera camera)

Set the camera that this node is related to

Parameters:

camera - The new camera

writeObject

public void writeObject(ZObjectOutputStream out)
                 throws java.io.IOException

Write out all of this object's state.

Specified by:

writeObject in interface ZSerializable

Overrides:

writeObject in class ZTransformGroup

Parameters:

out - The stream that this object writes into

java.io.IOException

writeObjectRecurse

public void writeObjectRecurse(ZObjectOutputStream out)
                        throws java.io.IOException

Specify which objects this object references in order to write out the scenegraph properly

Specified by:

writeObjectRecurse in interface ZSerializable

Overrides:

writeObjectRecurse in class ZTransformGroup

Parameters:

out - The stream that this object writes into

java.io.IOException

setState

public void setState(java.lang.String fieldType,
                     java.lang.String fieldName,
                     java.lang.Object fieldValue)

Set some state of this object as it gets read back in. After the object is created with its default no-arg constructor, this method will be called on the object once for each bit of state that was written out through calls to ZObjectOutputStream.writeState() within the writeObject method.

Specified by:

setState in interface ZSerializable

Overrides:

setState in class ZTransformGroup

Parameters:

fieldType - The fully qualified type of the field

fieldName - The name of the field

fieldValue - The value of the field