agi.foundation.infrastructure

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

Class ExtensionCollection

java.lang.Object

agi.foundation.compatibility.BaseCollection<T>

agi.foundation.infrastructure.DefinitionalObjectCollection<ObjectExtension>

agi.foundation.infrastructure.ExtensionCollection

All Implemented Interfaces:

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

public class ExtensionCollection
extends DefinitionalObjectCollection<ObjectExtension>

A collection of extensions to an ExtensibleObject.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ExtensionCollection() Initializes a new instance.
	ExtensionCollection(ExtensibleObject owner) Initializes a new instance.
protected	ExtensionCollection(ExtensionCollection existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkForSameDefinition(DefinitionalObjectCollection<ObjectExtension> other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(ExtensionCollection 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 collection.
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.
<T> T	getByType(TypeLiteral<T> typeLiteralT) Gets the first extension of the specified type that is in this collection.
ExtensibleObject	getOwner() Gets the owner of this collection.
protected void	insertItem(int index, ObjectExtension item) Inserts an element in the collection at the specified index.
protected void	removeItem(int index) Removes the element at the specified index of the collection.
protected void	setItem(int index, ObjectExtension item) Replaces the element at the specified index.

Methods inherited from class agi.foundation.infrastructure.DefinitionalObjectCollection

addRange, freeze, freezeAggregatedObjects, getDefinitionHashCode, getIsFrozen, isSameDefinition, throwIfFrozen

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

ExtensionCollection

public ExtensionCollection(@Nonnull
                           ExtensibleObject owner)

Initializes a new instance.

Parameters:

owner - The ExtensibleObject that owns this collection and the extensions within it.

ExtensionCollection

protected ExtensionCollection()

Initializes a new instance. The Owner (get) property must be set explicitly after using this constructor.

ExtensionCollection

protected ExtensionCollection(@Nonnull
                              ExtensionCollection 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

Overrides:

clone in class DefinitionalObjectCollection<ObjectExtension>

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(DefinitionalObjectCollection<ObjectExtension> other)

Description copied from class: DefinitionalObjectCollection

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 DefinitionalObjectCollection<ObjectExtension>

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(ExtensionCollection 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 ExtensionCollection.checkForSameDefinition(agi.foundation.infrastructure.DefinitionalObjectCollection<agi.foundation.infrastructure.ObjectExtension>) method.

Overrides:

computeCurrentDefinitionHashCode in class DefinitionalObjectCollection<ObjectExtension>

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 DefinitionalObjectCollection<ObjectExtension>

Parameters:

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

getByType

@Nullable
public final <T> T getByType(TypeLiteral<T> typeLiteralT)

Gets the first extension of the specified type that is in this collection.

Type Parameters:

T - The type of the extension to get.

Parameters:

typeLiteralT - A TypeLiteral object representing the generic type T.

Returns:

The extension, or null if an extension of the specified type is not contained in this collection.

getOwner

public final ExtensibleObject getOwner()

Gets the owner of this collection.

clearItems

protected void clearItems()

Removes all elements from the collection.

Overrides:

clearItems in class DefinitionalObjectCollection<ObjectExtension>

insertItem

protected void insertItem(int index,
                          ObjectExtension item)

Inserts an element in the collection at the specified index.

Overrides:

insertItem in class DefinitionalObjectCollection<ObjectExtension>

Parameters:

index - The index.

item - The element.

Throws:

IllegalStateException - Thrown when the adding an ObjectExtension instance to more than one ExtensibleObject.

removeItem

protected void removeItem(int index)

Removes the element at the specified index of the collection.

Overrides:

removeItem in class DefinitionalObjectCollection<ObjectExtension>

Parameters:

index - The index.

setItem

protected void setItem(int index,
                       ObjectExtension item)

Replaces the element at the specified index.

Overrides:

setItem in class DefinitionalObjectCollection<ObjectExtension>

Parameters:

index - The index.

item - The new element.

Throws:

IllegalStateException - Thrown when the adding an ObjectExtension instance to more than one ExtensibleObject.