agi.foundation.infrastructure

(agi.foundation.core-2024r3.jar)

Class DefinitionalObjectCollection<T>

java.lang.Object

agi.foundation.compatibility.BaseCollection<T>

agi.foundation.infrastructure.DefinitionalObjectCollection<T>

Type Parameters:

T - The DefinitionalObject type.

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable, Iterable<T>, Collection<T>, List<T>

Direct Known Subclasses:

AccessConstraintCollection, AccessQueryCollection, CcsdsOrbitEphemerisMessageFile, CommunicationAccessQueryCollection, EntityFilterCollection, ExtensibleObjectCollection, ExtensionCollection, GnssLinkBudgetScalarsCollection, GpsSignalGeneratorCollection, LinkPath, NavigationReceiverChannelCollection, NavigationSignalCollection, NPlateModel, PlatformCollection, PointScattererFrequencyBandCollection, PointScattererInformationCollection, ServiceProviderCollection, SignalDataCollection

public class DefinitionalObjectCollection<T>
extends BaseCollection<T>
implements ICloneWithContext, IFreezable, IEquatableDefinition, IEnumerateDependencies

A collection of DefinitionalObject objects.

Constructor Summary

Constructors

Modifier	Constructor and Description
	DefinitionalObjectCollection() Initializes a new instance.
protected	DefinitionalObjectCollection(DefinitionalObjectCollection<T> existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.
protected	DefinitionalObjectCollection(DefinitionalObjectCollection<T> existingInstance, CopyContext context, boolean copyContainedObjects) Initializes a new instance as a copy of an existing instance.
	DefinitionalObjectCollection(List<T> list) Initializes a new instance wrapping an existing list.

Method Summary

Modifier and Type	Method and Description
void	addRange(Iterable<? extends T> values) Adds the elements of the specified collection to the end of the DefinitionalObjectCollection.
protected boolean	checkForSameDefinition(DefinitionalObjectCollection<T> other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected void	clearItems() Removes all elements from the DefinitionalObjectCollection
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.
void	freeze() Freezes this object.
protected void	freezeAggregatedObjects() Called by DefinitionalObjectCollection.freeze() to also freeze any objects that are considered to be a part of this object.
int	getDefinitionHashCode() Gets a hash code representing the definition of this object.
boolean	getIsFrozen() Gets a value indicating whether this object is frozen.
protected void	insertItem(int index, T item) Inserts an element into the DefinitionalObjectCollection at the specified index.
boolean	isSameDefinition(Object other) Determines if this object has the same definition as another object.
protected void	removeItem(int index) Removes the element at the specified index of the DefinitionalObjectCollection.
protected void	setItem(int index, T item) Replaces the element at the specified index.
protected void	throwIfFrozen() Throws ObjectFrozenException if this object IsFrozen (get).

Methods inherited from class agi.foundation.compatibility.BaseCollection

add, add, addAll, addAll, clear, contains, containsAll, get, getItems, indexOf, isEmpty, iterator, lastIndexOf, listIterator, listIterator, remove, remove, removeAll, retainAll, set, size, subList, toArray, toArray

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.List

equals, hashCode, replaceAll, sort, spliterator

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

DefinitionalObjectCollection

public DefinitionalObjectCollection()

Initializes a new instance.

DefinitionalObjectCollection

public DefinitionalObjectCollection(@Nonnull
                                    List<T> list)

Initializes a new instance wrapping an existing list.

Parameters:

list - The list to wrap.

DefinitionalObjectCollection

protected DefinitionalObjectCollection(@Nonnull
                                       DefinitionalObjectCollection<T> 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.

DefinitionalObjectCollection

protected DefinitionalObjectCollection(@Nonnull
                                       DefinitionalObjectCollection<T> existingInstance,
                                       @Nonnull
                                       CopyContext context,
                                       boolean copyContainedObjects)

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.

copyContainedObjects - Indicates whether objects in the collection should be copied to a new instance.

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

Parameters:

context - The context to use to perform the copy.

Returns:

A new instance which is a copy of this object.

isSameDefinition

public final boolean isSameDefinition(Object other)

Determines if this object has the same definition as another object.

This method is very similar to Object.equals(Object) except that it explicitly considers the "definitions" of the two objects for objects that do not typically act like values. The definition of an object typically includes all of the fields of the object.

Specified by:

isSameDefinition in interface IEquatableDefinition

Parameters:

other - The other instance to compare to this one.

Returns:

true if this object has the same definition as the specified one. false if the other object is null, a different type than this one, or if this object and the specified one have different definitions.

checkForSameDefinition

protected boolean checkForSameDefinition(DefinitionalObjectCollection<T> 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.

getDefinitionHashCode

public final int getDefinitionHashCode()

Gets a hash code representing the definition of this object.

This method is very similar to Object.hashCode() except that it explicitly includes the "definition" of the object even if the object does not typically act like a value. The definition of an object typically includes all of the fields of the object. The value returned by this method should NOT change. This means that two objects for which DefinitionalObjectCollection.isSameDefinition(java.lang.Object) returns true will not necessarily have the same hash code if one or the other was changed after the hash code was first obtained.

Specified by:

getDefinitionHashCode in interface IEquatableDefinition

Returns:

The hash code.

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 DefinitionalObjectCollection.checkForSameDefinition(agi.foundation.infrastructure.DefinitionalObjectCollection<T>) method.

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

Parameters:

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

freezeAggregatedObjects

protected void freezeAggregatedObjects()

Called by DefinitionalObjectCollection.freeze() to also freeze any objects that are considered to be a part of this object. Derived classes which contain additional aggregated objects MUST override this method, call the base implementation, and freeze aggregated objects introduced by the derived class. The objects that need to be frozen in this method are frequently created in this object's constructor and are not settable via properties.

freeze

public final void freeze()

Freezes this object. Further attempts to modify it will result in an ObjectFrozenException.

Specified by:

freeze in interface IFreezable

getIsFrozen

public final boolean getIsFrozen()

Gets a value indicating whether this object is frozen. A frozen object cannot be modified and an ObjectFrozenException will be thrown if an attempt is made to do so.

Specified by:

getIsFrozen in interface IFreezable

throwIfFrozen

protected final void throwIfFrozen()

Throws ObjectFrozenException if this object IsFrozen (get). This method should be called from any method or property that modifies this object.

addRange

public final void addRange(@Nonnull
                           Iterable<? extends T> values)

Adds the elements of the specified collection to the end of the DefinitionalObjectCollection.

Parameters:

values - The collection whose elements should be added to the end of the DefinitionalObjectCollection.

Throws:

ArgumentNullException - Thrown if values is null.

clearItems

protected void clearItems()

Removes all elements from the DefinitionalObjectCollection

Overrides:

clearItems in class BaseCollection<T>

insertItem

protected void insertItem(int index,
                          T item)

Inserts an element into the DefinitionalObjectCollection at the specified index.

Overrides:

insertItem in class BaseCollection<T>

Parameters:

index - The zero-based index at which item should be inserted.

item - The object to insert. The value can be null for reference types.

Throws:

ArgumentOutOfRangeException - Thrown when index is less than zero, or greater than Count (get).

removeItem

protected void removeItem(int index)

Removes the element at the specified index of the DefinitionalObjectCollection.

Overrides:

removeItem in class BaseCollection<T>

Parameters:

index - The zero-based index of the element to remove.

Throws:

ArgumentOutOfRangeException - Thrown when index is less than zero, or greater than Count (get).

setItem

protected void setItem(int index,
                       T item)

Replaces the element at the specified index.

Overrides:

setItem in class BaseCollection<T>

Parameters:

index - The zero-based index of the element to replace.

item - The new value for the element at the specified index. The value can be null for reference types.

Throws:

ArgumentOutOfRangeException - Thrown when index is less than zero, or greater than Count (get).