Method Details

• extractValue

  protected NodeSignal.NodeSignalState extractValue(Node.Data data)

  Description copied from class: Signal

  Extracts the value for this signal from the given signal data node.

  Specified by:

  extractValue in class Signal<NodeSignal.NodeSignalState>

  Parameters:

  data - the data node to extract the value from, or null if the node doesn't exist in the tree

  Returns:

  the signal value

• usageChangeValue

  protected Object usageChangeValue(Node.Data data)

  Description copied from class: Signal

  Gets a reference value that will be used to determine whether a dependency based on previous usage should be invalidated. This is done by getting one reference value when the dependency occurs and then comparing that to the current value to determine if the value has changed.

  The implementation should return an object that changes if and only if the Signal.value() of this signal changes.

  Specified by:

  usageChangeValue in class Signal<NodeSignal.NodeSignalState>

  Parameters:

  data - the data node to read from, not null

  Returns:

  a reference value to use for validity checks, may be null

• asValue

  public <T> ValueSignal<T> asValue(Class<T> valueType)

  Creates a value signal backed by the node value of this node. The value of the value signal is the same as NodeSignal.NodeSignalState.value(Class) of this signal. The new signal uses the same validator as this signal.

  Type Parameters:

  T - the value type

  Parameters:

  valueType - the value type, not null

  Returns:

  this signal as a value signal, not null

• asNumber

  public NumberSignal asNumber()

  Creates a number signal backed by the node value of this node. The value of the number signal is the same as NodeSignal.NodeSignalState.value(Class) of this signal. The new signal uses the same validator as this signal. Accessing the value of the signal will throw an exception if the underlying value is not a JSON number.

  Returns:

  this signal as a number signal, not null

• asList

  public <T> ListSignal<T> asList(Class<T> elementType)

  Creates a list signal backed by the list children of this node. The value of the list signal is the same as NodeSignal.NodeSignalState.listChildren() of this signal. The new signal uses the same validator as this signal. Accessing the value of child signal will throw an exception if the underlying value cannot be JSON deserialized as the provided element type.

  Type Parameters:

  T - the element type

  Parameters:

  elementType - the element type, not null

  Returns:

  this signal as a list signal, not null

• asMap

  public <T> MapSignal<T> asMap(Class<T> elementType)

  Creates a map signal backed by the map children of this node. The value of the map signal is the same as NodeSignal.NodeSignalState.mapChildren() of this signal. The new signal uses the same validator as this signal.Accessing the value of child signal will throw an exception if the underlying value cannot be JSON deserialized as the provided element type.

  Type Parameters:

  T - the element type

  Parameters:

  elementType - the element type, not null

  Returns:

  this signal as a map signal, not null

• insertChildWithValue

  public InsertOperation<NodeSignal> insertChildWithValue(Object value, ListSignal.ListPosition at)

  Inserts a new node with the given value as a list node at the given list position. The operation fails if the position is not valid at the time when the operation is processed.

  Parameters:

  value - the value to insert

  at - the insert position, not null

  Returns:

  an operation containing a signal for the inserted entry and the eventual result

• insertChild

  public InsertOperation<NodeSignal> insertChild(ListSignal.ListPosition at)

  Inserts a new node with no value as a list node at the given list position. The operation fails if the position is not valid at the time when the operation is processed.

  Parameters:

  at - the insert position, not null

  Returns:

  an operation containing a signal for the inserted entry and the eventual result

• putChildWithValue

  public SignalOperation<Void> putChildWithValue(String key, Object value)

  Associates the given value with the given key. If a map child already exists for the given key, then the value of that node is updated. If no map child exists, then a new node is created with the given value.

  Note that this operation does not give direct access to the child signal that was created or updated. Use putChildWithValue(String, Object) for that purpose.

  Parameters:

  key - the key to use, not null

  value - the value to set

  Returns:

  an operation containing the eventual result

• putChildIfAbsent

  public InsertOperation<NodeSignal> putChildIfAbsent(String key)

  Creates a new node with no value if a map node with the given key doesn't already exist. The returned operation has a reference to a signal that corresponds to the given key regardless of whether a node existed for the key. The operation will be resolved as successful regardless of whether the key was already used.

  Parameters:

  key - the key to use, not null

  Returns:

  an operation containing a signal for the entry and the eventual result

• adoptAt

  public SignalOperation<Void> adoptAt(Signal<?> node, ListSignal.ListPosition at)

  Adopts the given node as a list child at the given location. The node must be a member of the same node tree. It will be detached from its current location in the tree. The operation fails if the position is not valid at the time when the operation is processed.

  Parameters:

  node - the signal to adopt, not null

  at - the target list location, not null

  Returns:

  an operation containing the eventual result

• adoptAs

  public SignalOperation<Void> adoptAs(Signal<?> signal, String key)

  Adopts the given node as a map child with the given key. The node must be a member of the same node tree. It will be detached from its current location in the tree. The operation fails if there is already a map child with the same key at the time when the operation is processed.

  Parameters:

  signal - the signal to adopt, not null

  key - the key to use, not null

  Returns:

  an operation containing the eventual result

• removeChild

  public SignalOperation<Void> removeChild(NodeSignal child)

  Removes the given child from this node. The operation fails if the child is not a child of this node at the time when the operation is processed.

  Parameters:

  child - the child to remove, not null

  Returns:

  an operation containing the eventual result

• removeChild

  public SignalOperation<Void> removeChild(String key)

  Removes the map child with the given key. The operation will be resolved as successful if a mapping existed and as a failure if there was no mapping when the operation was processed.

  Parameters:

  key - the key to use, not null

  Returns:

  an operation containing the eventual result

• clear

  public SignalOperation<Void> clear()

  Removes all list children and map children from this node.

  Overrides:

  clear in class Signal<NodeSignal.NodeSignalState>

  Returns:

  an operation containing the eventual result

• withValidator

  public NodeSignal withValidator(Predicate<SignalCommand> validator)

  Wraps this signal with a validator. The validator is used to check all value changing commands issued through the new signal instance and all child signals. If this signal has a validator, then the new signal will use both validators.

  This signal will keep its current configuration and changes applied through this instance will be visible through the wrapped instance.

  Parameters:

  validator - the validator to use, not null

  Returns:

  a new node signal that uses the validator, not null

• asReadonly

  public NodeSignal asReadonly()

  Wraps this signal to not accept changes. Child node signals retrieved through the wrapped signal will also not accept changes.

  This signal will keep its current configuration and changes applied through this instance will be visible through the wrapped instance.

  Returns:

  the new readonly node signal, not null

• equals

  public boolean equals(Object obj)

  Overrides:

  equals in class Object

• hashCode

  public int hashCode()

  Overrides:

  hashCode in class Object

• toString

  public String toString()

  Overrides:

  toString in class Object