agi.foundation.propagators

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

Class ConstantStateStoppablePropagator

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.propagators.StoppablePropagatorDefinition

agi.foundation.propagators.ConstantStateStoppablePropagator

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable

public class ConstantStateStoppablePropagator
extends StoppablePropagatorDefinition

A StoppablePropagator that always returns the initial state passed in at propagation time. This can be useful when you are modeling a trajectory with multiple propagators strung together and one of those segments is in some way fixed for a time, such as landed or docked.

Constructor Summary

Constructors

Modifier	Constructor and Description
	ConstantStateStoppablePropagator() Initialize a new instance.
protected	ConstantStateStoppablePropagator(ConstantStateStoppablePropagator existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.
	ConstantStateStoppablePropagator(Duration step) Initialize a new instance.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkForSameDefinition(ConstantStateStoppablePropagator other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(StoppablePropagatorDefinition 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.
Duration	getStep() Gets the default step that this propagator will take.
StoppablePropagator	getStoppablePropagator(EvaluatorGroup group, List<StateElementAdapterDefinition> previousAdapters) Creates and initialize the actual StoppablePropagator.
void	setStep(Duration value) Sets the default step that this propagator will take.

Methods inherited from class agi.foundation.propagators.StoppablePropagatorDefinition

addAnyConditionSatisfied, checkForSameDefinition, containsAdapter, enumerateDependencies, freezeAggregatedObjects, getAdapter, getAllAdapters, getDirection, getStoppablePropagator, getStoppablePropagator, getStoppingConditions, getTimeTolerance, onAnyConditionSatisfied, removeAdapter, removeAnyConditionSatisfied, setAdapter, setTimeTolerance

Methods inherited from class agi.foundation.infrastructure.DefinitionalObject

areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, freeze, 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

ConstantStateStoppablePropagator

public ConstantStateStoppablePropagator()

Initialize a new instance.

ConstantStateStoppablePropagator

public ConstantStateStoppablePropagator(@Nonnull
                                        Duration step)

Initialize a new instance.

Parameters:

step - The step that this propagator should take.

ConstantStateStoppablePropagator

protected ConstantStateStoppablePropagator(@Nonnull
                                           ConstantStateStoppablePropagator 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(StoppablePropagatorDefinition 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).

Overrides:

checkForSameDefinition in class StoppablePropagatorDefinition

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(ConstantStateStoppablePropagator 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 ConstantStateStoppablePropagator.checkForSameDefinition(agi.foundation.propagators.StoppablePropagatorDefinition) method.

Overrides:

computeCurrentDefinitionHashCode in class StoppablePropagatorDefinition

Returns:

The computed hash code.

getStep

@Nonnull
public final Duration getStep()

Gets the default step that this propagator will take. Individual StoppingConditions may know at what rate they should be sampled, and that step will be used instead of this if it is less than this step. Also when restepping this value will not be used.

setStep

public final void setStep(@Nonnull
                          Duration value)

Sets the default step that this propagator will take. Individual StoppingConditions may know at what rate they should be sampled, and that step will be used instead of this if it is less than this step. Also when restepping this value will not be used.

getStoppablePropagator

public StoppablePropagator getStoppablePropagator(EvaluatorGroup group,
                                                  List<StateElementAdapterDefinition> previousAdapters)

Creates and initialize the actual StoppablePropagator.

Specified by:

getStoppablePropagator in class StoppablePropagatorDefinition

Parameters:

group - The group to use to initialize any evaluators that will be used.

previousAdapters - The previous adapters to use to configure this propagators adapters.

Returns:

The propagator for this StoppablePropagatorDefinition.