gumbo.util.state
Class States.ImmutableStateSet

java.lang.Object
  |
  +--gumbo.util.GumboCollections.ImmutableCollection
        |
        +--gumbo.util.state.States.ImmutableStateSet

All Implemented Interfaces:

java.util.Collection, java.util.Set, StateSet

Direct Known Subclasses:

Interactors.ImmutableInteractorState

Enclosing class:

States

public static class States.ImmutableStateSet

extends GumboCollections.ImmutableCollection

implements StateSet

Immutable wrapper for a target state set. Identity (hashCode(), equals()) forwards to the target object, which is possible because target identity is based on contents.

Constructor Summary

States.ImmutableStateSet(StateSet target)

Method Summary

boolean	change(java.lang.Object remove, java.lang.Object add) Removes then adds the specified state flags, as allowed by the state policy.
boolean	change(StateSet changes) Performs a "masked change" by imposing a target's state set changes (deltas) on this state set, as allowed by the state policy, with the union of the target's old and new states acting as the mask.
boolean	changeAll(java.util.Collection remove, java.util.Collection add) Removes then adds the specified state flags, as allowed by the state policy.
java.util.Set	getOldState() Gets a singleton immutable view of this set's old state value, which was the state value prior to the last transit, or the same state value as the current one after a reset.
StatePolicy	getStatePolicy() Gets the state policy for this state set, which assures that the state value contains valid combinations and types of state flags following state initialization and transition.
StateSet	getStateSet() Gets a singleton immutable view of this set, which is the current state value, resulting from the last reset or transit.
boolean	reset(java.util.Collection state) Resets (re-initializes) this state set's value to a new state, as allowed by the state policy.
boolean	set(java.util.Collection state) Sets this state set's value to a new state, as allowed by the state policy.
boolean	transit(java.util.Collection input) Causes this state set's value to transit from one state to another (possibly with no change in value) according to an input value.

Methods inherited from class gumbo.util.GumboCollections.ImmutableCollection

add, addAll, clear, contains, containsAll, equals, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Set

add, addAll, clear, contains, containsAll, equals, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray

Constructor Detail

States.ImmutableStateSet

public States.ImmutableStateSet(StateSet target)

Method Detail

getStatePolicy

public StatePolicy getStatePolicy()

Description copied from interface: StateSet

Gets the state policy for this state set, which assures that the state value contains valid combinations and types of state flags following state initialization and transition.

Specified by:

getStatePolicy in interface StateSet

Returns:

The policy. Null if none.

reset

public boolean reset(java.util.Collection state)

Description copied from interface: StateSet

Resets (re-initializes) this state set's value to a new state, as allowed by the state policy. Unlike other mutators, the old state will be left equal to the new state. If there is no policy, this state set will be effectively cleared and the new state added. If reset is not allowed, should throw UnsupportedOperationException.

Specified by:

reset in interface StateSet

Parameters:

state - The new state value (Object). Never null.

Returns:

True if the contents of this set changed (same as for Set.add() and Set.remove()).

set

public boolean set(java.util.Collection state)

Description copied from interface: StateSet

Sets this state set's value to a new state, as allowed by the state policy. Effectively a clear() then addAll(), as a single operation.

Specified by:

set in interface StateSet

Parameters:

state - The new state value (Object). Never null.

Returns:

True if the contents of this set changed (same as for Set.add() and Set.remove()).

change

public boolean change(StateSet changes)

Description copied from interface: StateSet

Performs a "masked change" by imposing a target's state set changes (deltas) on this state set, as allowed by the state policy, with the union of the target's old and new states acting as the mask. Effectively a removeAll() of the target's old state, then an addAll() of its new state, as a single operation.

Specified by:

change in interface StateSet

Parameters:

changes - The state value changes. Never null.

Returns:

True if the contents of this set changed (same as for Set.add() and Set.remove()).

change

public boolean change(java.lang.Object remove,
                      java.lang.Object add)

Description copied from interface: StateSet

Removes then adds the specified state flags, as allowed by the state policy. Effectively a remove() then add(), as a single operation.

Specified by:

change in interface StateSet

Parameters:

remove - Flag to be removed. None if null.

add - Flag to be added. None if null.

Returns:

True if the contents of this set changed (same as for Set.add() and Set.remove()).

changeAll

public boolean changeAll(java.util.Collection remove,
                         java.util.Collection add)

Description copied from interface: StateSet

Removes then adds the specified state flags, as allowed by the state policy. Effectively a removeAll() then addAll(), as a single operation.

Specified by:

changeAll in interface StateSet

Parameters:

remove - Flags to be removed. Never null.

add - Flags to be added. Never null.

Returns:

True if the contents of this set changed (same as for Set.add() and Set.remove()).

transit

public boolean transit(java.util.Collection input)

Description copied from interface: StateSet

Causes this state set's value to transit from one state to another (possibly with no change in value) according to an input value. If there is no policy nothing happens.

Specified by:

transit in interface StateSet

Parameters:

input - The input value (Object). Never null.

Returns:

True if the contents of this set changed (same as for Set.add() and Set.remove()).

getOldState

public java.util.Set getOldState()

Description copied from interface: StateSet

Gets a singleton immutable view of this set's old state value, which was the state value prior to the last transit, or the same state value as the current one after a reset.

Specified by:

getOldState in interface StateSet

Returns:

The view (Object). Never null.

getStateSet

public StateSet getStateSet()

Description copied from interface: StateSet

Gets a singleton immutable view of this set, which is the current state value, resulting from the last reset or transit.

Specified by:

getStateSet in interface StateSet

Returns:

The view (Object). Never null.