org.dynalang.mop.collections
Class ListMetaobjectProtocol

java.lang.Object
  org.dynalang.mop.collections.ListMetaobjectProtocol

All Implemented Interfaces:

BaseMetaobjectProtocol, CallProtocol, ClassBasedMetaobjectProtocol, MetaobjectProtocol

public class ListMetaobjectProtocol
extends java.lang.Object
implements ClassBasedMetaobjectProtocol

A metaobject protocol that knows how to manipulate Java lists.

Version:

$Id: $

Author:

Attila Szegedi

Nested Class Summary

Nested classes/interfaces inherited from interface org.dynalang.mop.BaseMetaobjectProtocol

BaseMetaobjectProtocol.Results

Constructor Summary

ListMetaobjectProtocol()

Method Summary

java.lang.Object	call(java.lang.Object callable, CallProtocol callProtocol, java.util.Map args) Calls a callable object with named arguments.
java.lang.Object	call(java.lang.Object callable, CallProtocol callProtocol, java.lang.Object... args) Calls a callable object with positional arguments.
java.lang.Object	call(java.lang.Object target, java.lang.Object callableId, CallProtocol callProtocol, java.util.Map args) Calls a method on the target object with supplied named arguments.
java.lang.Object	call(java.lang.Object target, java.lang.Object callableId, CallProtocol callProtocol, java.lang.Object... args) Calls a method on the target object with supplied positional arguments.
BaseMetaobjectProtocol.Results	delete(java.lang.Object target, long propertyId) Handles the delete attempt from the list.
BaseMetaobjectProtocol.Results	delete(java.lang.Object target, java.lang.Object propertyId) Handles the delete attempt from the list.
java.lang.Object	get(java.lang.Object target, long propertyId) Retrieves a value from the list.
java.lang.Object	get(java.lang.Object target, java.lang.Object propertyId) Retrieves a value from the list.
java.lang.Boolean	has(java.lang.Object target, long propertyId) Tells whether the index is valid for the list.
java.lang.Boolean	has(java.lang.Object target, java.lang.Object propertyId) Tells whether the index is valid for the list.
boolean	isAuthoritativeForClass(java.lang.Class clazz) Returns whether this metaobject protocol has authority over objects of the specified class.
java.util.Iterator<java.util.Map.Entry>	properties(java.lang.Object target) Returns mappings from indexes to elements for a list.
java.util.Iterator<? extends java.lang.Object>	propertyIds(java.lang.Object target) Returns an iterator over all indexes in a list
BaseMetaobjectProtocol.Results	put(java.lang.Object target, long propertyId, java.lang.Object value, CallProtocol callProtocol) Puts an element into the list.
BaseMetaobjectProtocol.Results	put(java.lang.Object target, java.lang.Object propertyId, java.lang.Object value, CallProtocol callProtocol) Puts an element into the list.
java.lang.Object	representAs(java.lang.Object object, java.lang.Class targetClass) Returns a representation of the specified target object as an object of the specified target class.

Methods inherited from class java.lang.Object

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

Constructor Detail

ListMetaobjectProtocol

public ListMetaobjectProtocol()

Method Detail

isAuthoritativeForClass

public boolean isAuthoritativeForClass(java.lang.Class clazz)

Description copied from interface: ClassBasedMetaobjectProtocol

Returns whether this metaobject protocol has authority over objects of the specified class. Note that if a MOP claims that it has authority over objects of a certain class, it can still return BaseMetaobjectProtocol.Results.noAuthority for certain objects. In that case - when used in CompositeClassBasedMetaobjectProtocol - the other participating MOPs will also be given the chance to handle the object after this MOP was given the chance first.

Specified by:

isAuthoritativeForClass in interface ClassBasedMetaobjectProtocol

Parameters:

clazz - the class of the handled object

Returns:

true if this metaobject protocol has authority over objects of the specified class, false otherwise.

call

public java.lang.Object call(java.lang.Object callable,
                             CallProtocol callProtocol,
                             java.util.Map args)

Description copied from interface: CallProtocol

Calls a callable object with named arguments.

Specified by:

call in interface CallProtocol

Parameters:

callable - the callable object

callProtocol - a marshaller that should be used by this metaobject protocol to convert the arguments to conform to expected argument types for the call.

args - the named arguments for the callable object. null must be treated as empty map. Usually, the map keys are strings, but it is possible that some protocols support non-string keys.

Returns:

BaseMetaobjectProtocol.Results#noAuthority as this MOP has no concept of callables

call

public java.lang.Object call(java.lang.Object callable,
                             CallProtocol callProtocol,
                             java.lang.Object... args)

Description copied from interface: CallProtocol

Calls a callable object with positional arguments.

Specified by:

call in interface CallProtocol

Parameters:

callable - the callable object

callProtocol - a marshaller that should be used by this metaobject protocol to convert the arguments to conform to expected argument types for the call.

args - the positional arguments for the callable object. null must be treated as empty array.

Returns:

BaseMetaobjectProtocol.Results#noAuthority as this MOP has no concept of callables

call

public java.lang.Object call(java.lang.Object target,
                             java.lang.Object callableId,
                             CallProtocol callProtocol,
                             java.lang.Object... args)

Description copied from interface: MetaobjectProtocol

Calls a method on the target object with supplied positional arguments. Must behave identically to:

 Object callable = get(target, callableId);
 if(callable instanceof Results) {
     return callable;
 }
 return call(callable, args);
 

Specified by:

call in interface MetaobjectProtocol

Parameters:

target - the target object

callableId - the ID of the method to call

callProtocol - a marshaller that should be used by this metaobject protocol to convert the arguments to conform to expected argument types for the call.

args - the arguments of the call

Returns:

BaseMetaobjectProtocol.Results#noAuthority as this MOP has no concept of callables

call

public java.lang.Object call(java.lang.Object target,
                             java.lang.Object callableId,
                             CallProtocol callProtocol,
                             java.util.Map args)

Description copied from interface: MetaobjectProtocol

Calls a method on the target object with supplied named arguments. Must behave identically to:

 Object callable = get(target, callableId);
 if(callable instanceof Results) {
     return callable;
 }
 return call(callable, args);
 

Specified by:

call in interface MetaobjectProtocol

Parameters:

target - the target object

callableId - the ID of the method to call

callProtocol - a marshaller that should be used by this metaobject protocol to convert the arguments to conform to expected argument types for the call.

args - the arguments of the call

Returns:

BaseMetaobjectProtocol.Results#noAuthority as this MOP has no concept of callables

delete

public BaseMetaobjectProtocol.Results delete(java.lang.Object target,
                                             long propertyId)

Handles the delete attempt from the list. Note that the list semantics actually don't allow an element to be deleted from it.

Specified by:

delete in interface MetaobjectProtocol

Parameters:

target - the list to remove element from

propertyId - the numeric index of the element

Returns:

If the index is within the bounds of the target list, BaseMetaobjectProtocol.Results#notDeleteable is returned. If the index is out of bounds, or the target is not a list, BaseMetaobjectProtocol.Results#noAuthority is returned.

delete

public BaseMetaobjectProtocol.Results delete(java.lang.Object target,
                                             java.lang.Object propertyId)

Handles the delete attempt from the list. Note that the list semantics actually don't allow an element to be deleted from it.

Specified by:

delete in interface BaseMetaobjectProtocol

Parameters:

target - the list to remove element from

propertyId - the numeric index of the element

Returns:

If the index is a number, and it is within the bounds of the list, BaseMetaobjectProtocol.Results#notDeleteable is returned. If the index is out of bounds, or the target is not a list, BaseMetaobjectProtocol.Results#noAuthority is returned.

get

public java.lang.Object get(java.lang.Object target,
                            long propertyId)

Retrieves a value from the list.

Specified by:

get in interface MetaobjectProtocol

Parameters:

target - the list to retrieve from

propertyId - the numeric index of the element

Returns:

If the list contains the element, returns it. If the index is out of bounds, or the target is not a list, BaseMetaobjectProtocol.Results#noAuthority is returned.

get

public java.lang.Object get(java.lang.Object target,
                            java.lang.Object propertyId)

Retrieves a value from the list.

Specified by:

get in interface CallProtocol

Parameters:

target - the list to retrieve from

propertyId - the numeric index of the element

Returns:

If the list contains the element at the index Number.longValue(), returns it. If the index is out of bounds, or it is not an instance of Number, or the target is not a list, BaseMetaobjectProtocol.Results#noAuthority is returned.

has

public java.lang.Boolean has(java.lang.Object target,
                             long propertyId)

Tells whether the index is valid for the list.

Specified by:

has in interface MetaobjectProtocol

Parameters:

target - the list

propertyId - the index

Returns:

if propertyId is a valid index for this list, returns Boolean.TRUE. If it is not valid, or the target is not a list, returns null (meaning, no authority).

has

public java.lang.Boolean has(java.lang.Object target,
                             java.lang.Object propertyId)

Tells whether the index is valid for the list.

Specified by:

has in interface BaseMetaobjectProtocol

Parameters:

target - the list

propertyId - the index

Returns:

if Number.longValue() of propertyId is a valid index for this list, returns Boolean.TRUE. If it is not valid, or the target is not a list, or propertyId is not a Number, returns null (meaning, no authority).

properties

public java.util.Iterator<java.util.Map.Entry> properties(java.lang.Object target)

Returns mappings from indexes to elements for a list.

Specified by:

properties in interface BaseMetaobjectProtocol

Parameters:

target - the list

Returns:

an iterator of map entries, keys being Integer objects. The iterator does not support removal.

propertyIds

public java.util.Iterator<? extends java.lang.Object> propertyIds(java.lang.Object target)

Returns an iterator over all indexes in a list

Specified by:

propertyIds in interface MetaobjectProtocol

Parameters:

target - the list

Returns:

an iterator of valid indexes (Integer objects). The iterator does not support removal.

put

public BaseMetaobjectProtocol.Results put(java.lang.Object target,
                                          long propertyId,
                                          java.lang.Object value,
                                          CallProtocol callProtocol)

Puts an element into the list.

Specified by:

put in interface MetaobjectProtocol

Parameters:

target - the list to put the element into

propertyId - the numeric index of the element

callProtocol - not used

value - the new value for the property

Returns:

BaseMetaobjectProtocol.Results#ok if the put was successful. If the list is read-only (throws a UnsupportedOperationException on put attempt), BaseMetaobjectProtocol.Results#notWritable is returned. If the index is out of bounds, or the target is not a list, BaseMetaobjectProtocol.Results#noAuthority is returned. If the list throws ClassCastException (because it is limited in types of values it can accept), BaseMetaobjectProtocol.Results#noRepresentation is returned.

put

public BaseMetaobjectProtocol.Results put(java.lang.Object target,
                                          java.lang.Object propertyId,
                                          java.lang.Object value,
                                          CallProtocol callProtocol)

Puts an element into the list.

Specified by:

put in interface BaseMetaobjectProtocol

Parameters:

target - the list to put the element into

propertyId - the numeric index of the element. If this argument is a Number, it's Number.longValue() method is used.

callProtocol - not used

value - the new value for the property

Returns:

BaseMetaobjectProtocol.Results#ok if the put was successful. If the list is read-only (throws a UnsupportedOperationException on put attempt), BaseMetaobjectProtocol.Results#notWritable is returned. If the index is out of bounds, or is not a Number, or the target is not a list, BaseMetaobjectProtocol.Results#noAuthority is returned. If the list throws ClassCastException (because it is limited in types of values it can accept), BaseMetaobjectProtocol.Results#noRepresentation is returned.

representAs

public java.lang.Object representAs(java.lang.Object object,
                                    java.lang.Class targetClass)

Description copied from interface: CallProtocol

Returns a representation of the specified target object as an object of the specified target class. Typical supported target classes would be wrappers for Java primitive types that map to native types of the higher level languages. I.e. if an object is used as a boolean expression, then the language would ask the protocol to interpret it as boolean by calling representAs(Boolean.TYPE).

Specified by:

representAs in interface CallProtocol

Parameters:

object - the object to represent

targetClass - the target class for representation.

Returns:

BaseMetaobjectProtocol.Results#noAuthority as this MOP has no concept of type conversion