agi.foundation.geometry

(agi.foundation.core-2024r2.jar)

Class AxesFixedOffset

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.geometry.Axes

agi.foundation.geometry.AxesFixedOffset

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable, IServiceProvider

public class AxesFixedOffset
extends Axes

An axes whose orientation does not change with respect to the axes in which it is defined.

Constructor Summary

Constructors

Modifier	Constructor and Description
	AxesFixedOffset() Initializes a new instance.
protected	AxesFixedOffset(AxesFixedOffset existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.
	AxesFixedOffset(Axes referenceAxes, UnitQuaternion offset) Initializes a new instance with the specified parameters.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkForSameDefinition(Axes other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(AxesFixedOffset other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
Object	clone(CopyContext context) Clones this object using the specified context.
protected int	computeCurrentDefinitionHashCode() Computes a hash code based on the current properties of this object.
void	enumerateDependencies(DependencyEnumerator enumerator) Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon.
AxesEvaluator	getEvaluator(EvaluatorGroup group) Gets an evaluator that can be used to find the transformation from the ReferenceAxes (get / set) to to a new Axes at a given JulianDate.
UnitQuaternion	getOffset() Gets the offset of this axes, specified as a rotation from the ReferenceAxes (get / set).
Axes	getReferenceAxes() Gets the axes from which this axes is offset.
void	setOffset(UnitQuaternion value) Sets the offset of this axes, specified as a rotation from the ReferenceAxes (get / set).
void	setReferenceAxes(Axes value) Sets the axes from which this axes is offset.

Methods inherited from class agi.foundation.geometry.Axes

checkForSameDefinition, getEvaluator, getRoot, getService, getVectorElement, getVectorElement

Methods inherited from class agi.foundation.infrastructure.DefinitionalObject

areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, freeze, freezeAggregatedObjects, getCollectionHashCode, getCollectionHashCode, getCollectionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDictionaryHashCode, getIsFrozen, isSameDefinition, throwIfFrozen

Methods inherited from class java.lang.Object

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

Constructor Detail

AxesFixedOffset

public AxesFixedOffset()

Initializes a new instance. The user must set ReferenceAxes (get / set). Offset (get / set) is initialized to Identity (get).

AxesFixedOffset

public AxesFixedOffset(Axes referenceAxes,
                       @Nonnull
                       UnitQuaternion offset)

Initializes a new instance with the specified parameters.

Parameters:

referenceAxes - The axes from which this axes is offset.

offset - The offset, specified as a rotation from the referenceAxes.

AxesFixedOffset

protected AxesFixedOffset(@Nonnull
                          AxesFixedOffset existingInstance,
                          @Nonnull
                          CopyContext context)

Initializes a new instance as a copy of an existing instance.

See ICloneWithContext.clone(CopyContext) for more information about how to implement this constructor in a derived class.

Parameters:

existingInstance - The existing instance to copy.

context - A CopyContext that controls the depth of the copy.

Throws:

ArgumentNullException - Thrown when existingInstance or context is null.

Method Detail

clone

public Object clone(CopyContext context)

Clones this object using the specified context.

This method should be implemented to call a copy constructor on the class of the object being cloned. The copy constructor should take the CopyContext as a parameter in addition to the existing instance to copy. The copy constructor should first call CopyContext.addObjectMapping(T, T) to identify the newly constructed instance as a copy of the existing instance. It should then copy all fields, using CopyContext.updateReference(T) to copy any reference fields.

A typical implementation of ICloneWithContext:

public static class MyClass implements ICloneWithContext {
    public MyClass(MyClass existingInstance, CopyContext context) {
        context.addObjectMapping(existingInstance, this);
        someReference = context.updateReference(existingInstance.someReference);
    }

    @Override
    public final Object clone(CopyContext context) {
        return new MyClass(this, context);
    }

    private Object someReference;
}

In general, all fields that are reference types should be copied with a call to CopyContext.updateReference(T). There are a couple of exceptions:

1. Fields that are aggregate parts of the object should always be copied. A referenced object is an aggregate if properties or methods on the object being copied can modify the externally-visible value of the referenced object.
2. If the semantics of the referenced object require that it have a single parent, owner, context, etc., and the object being copied is that parent, owner, or context, then the referenced object should always be copied.

If one of these exceptions applies, the CopyContext should be given an opportunity to update the reference before the reference is copied explicitly. Use CopyContext.updateReference(T) to update the reference. If CopyContext.updateReference(T) returns the original object, indicating that the context does not have a replacement registered, then copy the object manually by invoking a Clone method, a copy constructor, or by manually constructing a new instance and copying the values.

alwaysCopy = context.updateReference(existingInstance.alwaysCopy);
if (existingInstance.alwaysCopy != null && alwaysCopy == existingInstance.alwaysCopy) {
    alwaysCopy = (AlwaysCopy) existingInstance.alwaysCopy.clone(context);
}

If you are implementing an evaluator (a class that implements IEvaluator), the IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) method shares some responsibilities with the copy context constructor. Code duplication can be avoided by doing the following:

1. For references to other evaluators ONLY, simply assign the reference in the constructor instead of calling CopyContext.updateReference(T). You should still call CopyContext.updateReference(T) on any references to non-evaluators.
2. Call IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as the last line in the constructor and pass it the same CopyContext passed to the constructor.
3. Implement IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as normal. See the reference documentation for IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) for more information on implementing that method.

public MyClass(MyClass existingInstance, CopyContext context) {
    super(existingInstance, context);
    someReference = context.updateReference(existingInstance.someReference);
    evaluatorReference = existingInstance.evaluatorReference;
    updateEvaluatorReferences(context);
}

@Override
public void updateEvaluatorReferences(CopyContext context) {
    evaluatorReference = context.updateReference(evaluatorReference);
}

@Override
public Object clone(CopyContext context) {
    return new MyClass(this, context);
}

private Object someReference;
private IEvaluator evaluatorReference;

Specified by:

clone in interface ICloneWithContext

Specified by:

clone in class DefinitionalObject

Parameters:

context - The context to use to perform the copy.

Returns:

A new instance which is a copy of this object.

checkForSameDefinition

protected final boolean checkForSameDefinition(Axes other)

Checks to determine if another instance has the same definition as this instance and returns true if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return false for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object).

Specified by:

checkForSameDefinition in class Axes

Parameters:

other - The other instance to compare to this one.

Returns:

true if the two objects are defined equivalently; otherwise false.

checkForSameDefinition

protected boolean checkForSameDefinition(AxesFixedOffset other)

Checks to determine if another instance has the same definition as this instance and returns true if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return false for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object).

Parameters:

other - The other instance to compare to this one.

Returns:

true if the two objects are defined equivalently; otherwise false.

computeCurrentDefinitionHashCode

protected int computeCurrentDefinitionHashCode()

Computes a hash code based on the current properties of this object. Derived classes MUST override this method and compute a hash code that combines: a unique hash code seed, the base implementation result, and the hash codes of all new fields introduced by the derived class which are used in the AxesFixedOffset.checkForSameDefinition(agi.foundation.geometry.Axes) method.

Overrides:

computeCurrentDefinitionHashCode in class Axes

Returns:

The computed hash code.

enumerateDependencies

public void enumerateDependencies(DependencyEnumerator enumerator)

Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon. Derived classes which contain additional dependencies MUST override this method, call the base implementation, and enumerate dependencies introduced by the derived class.

Specified by:

enumerateDependencies in interface IEnumerateDependencies

Overrides:

enumerateDependencies in class DefinitionalObject

Parameters:

enumerator - The enumerator that is informed of the dependencies of this object.

getReferenceAxes

public final Axes getReferenceAxes()

Gets the axes from which this axes is offset.

setReferenceAxes

public final void setReferenceAxes(Axes value)

Sets the axes from which this axes is offset.

getOffset

@Nonnull
public final UnitQuaternion getOffset()

Gets the offset of this axes, specified as a rotation from the ReferenceAxes (get / set).

setOffset

public final void setOffset(@Nonnull
                            UnitQuaternion value)

Sets the offset of this axes, specified as a rotation from the ReferenceAxes (get / set).

getEvaluator

public AxesEvaluator getEvaluator(EvaluatorGroup group)

Gets an evaluator that can be used to find the transformation from the ReferenceAxes (get / set) to to a new Axes at a given JulianDate. The new axes will be represented by a Motion<UnitQuaternion, Cartesian> specifying the orientation of these Axes and any derivative information requested will be Zero (get). Consider using the methods of GeometryTransformer instead of calling this method directly.

Specified by:

getEvaluator in class Axes

Parameters:

group - The group with which to associate the new evaluator. By grouping evaluators that are often evaluated at the same Julian dates, common computations can be performed only once for the entire group instead of multiple times for each evaluator.

Returns:

An evaluator for this Axes.

Throws:

ArgumentNullException - Thrown when group is null.

PropertyInvalidException - Thrown when the ReferenceAxes (get / set) is not initialized.