FutureValue<TInput, TOutput> abstract class
abstract class FutureValue<TInput, TOutput> { FutureValue() : _outputChangedHandle = new EventHandle<EventArgs>(), _inputChangedHandle = new EventHandle<EventArgs>(), _errorHandle = new EventHandle<Object>(); TInput get input => _input; void set input(TInput value) { _input = value; if(_future == null) { _startFuture(); } else { _pending = true; } _inputChangedHandle.fireEvent(EventArgs.empty); } TOutput get output => _output; EventRoot<EventArgs> get outputChanged => _outputChangedHandle; EventRoot<EventArgs> get inputChanged => _inputChangedHandle; EventRoot get error => _errorHandle; abstract Future<TOutput> getFuture(TInput value); void _startFuture() { assert(_future == null); assert(!_pending); _future = getFuture(_input); _future.handleException(_futureException); _future.then(_futureCompleted); } bool _futureException(Object exception) { assert(_future != null); _future = null; _errorHandle.fireEvent(exception); _cleanup(); return true; } void _futureCompleted(TOutput value) { assert(_future != null); _future = null; _output = value; _outputChangedHandle.fireEvent(EventArgs.empty); _cleanup(); } void _cleanup() { if(_pending) { _pending = false; _startFuture(); } } TInput _input; Future<TOutput> _future; TOutput _output; bool _pending = false; final EventHandle<EventArgs> _outputChangedHandle; final EventHandle<EventArgs> _inputChangedHandle; final EventHandle<Object> _errorHandle; }
Subclasses
SendPortValue<TInput, TOutput>
Constructors
new FutureValue() #
FutureValue() : _outputChangedHandle = new EventHandle<EventArgs>(), _inputChangedHandle = new EventHandle<EventArgs>(), _errorHandle = new EventHandle<Object>();
Properties
TInput input #
TInput get input => _input;
void set input(TInput value) { _input = value; if(_future == null) { _startFuture(); } else { _pending = true; } _inputChangedHandle.fireEvent(EventArgs.empty); }
final EventRoot<EventArgs> inputChanged #
EventRoot<EventArgs> get inputChanged => _inputChangedHandle;
final EventRoot<EventArgs> outputChanged #
EventRoot<EventArgs> get outputChanged => _outputChangedHandle;
final Type runtimeType #
A representation of the runtime type of the object.
external Type get runtimeType;
Operators
bool operator ==(other) #
The equality operator.
The default behavior for all Object
s is to return true if and
only if this
and
other are the same object.
If a subclass overrides the equality operator it should override
the hashCode
method as well to maintain consistency.
bool operator ==(other) => identical(this, other);
Methods
new FutureValue() #
FutureValue() : _outputChangedHandle = new EventHandle<EventArgs>(), _inputChangedHandle = new EventHandle<EventArgs>(), _errorHandle = new EventHandle<Object>();
int hashCode() #
Get a hash code for this object.
All objects have hash codes. Hash codes are guaranteed to be the
same for objects that are equal when compared using the equality
operator ==
. Other than that there are no guarantees about
the hash codes. They will not be consistent between runs and
there are no distribution guarantees.
If a subclass overrides hashCode
it should override the
equality operator as well to maintain consistency.
external int hashCode();
noSuchMethod(String name, List args) #
noSuchMethod
is invoked when users invoke a non-existant method
on an object. The name of the method and the arguments of the
invocation are passed to noSuchMethod
. If noSuchMethod
returns a value, that value becomes the result of the original
invocation.
The default behavior of noSuchMethod
is to throw a
noSuchMethodError
.
external Dynamic noSuchMethod(String name, List args);
const Object() #
Creates a new Object
instance.
Object
instances have no meaningful state, and are only useful
through their identity. An Object
instance is equal to itself
only.
const Object();
String toString() #
Returns a string representation of this object.
external String toString();