Metronome class
A stream of DateTime events at intervals centered on anchor.
This stream accounts for drift but only guarantees that events are delivered on or after the interval. If the system is busy for longer than two intervals, only one will be delivered.
anchor defaults to clock.now
, which means the stream represents a
self-correcting periodic timer. If anchor is the epoch, then the stream is
synchronized to wall-clock time. It can be anchored anywhere in time, but
this does not delay the first delivery.
Examples:
new Metronome.epoch(aMinute).listen((d) => print(d));
Could print the following stream of events, anchored by epoch, till the stream is canceled:
2014-05-04 14:06:00.001
2014-05-04 14:07:00.000
2014-05-04 14:08:00.003
...
Example anchored in the future (now = 2014-05-05 20:06:00.123)
new IsochronousStream.periodic(aMillisecond * 100,
anchorMs: DateTime.parse("2014-05-05 21:07:00"))
.listen(print);
2014-05-04 20:06:00.223
2014-05-04 20:06:00.324
2014-05-04 20:06:00.423
...
Constructors
- Metronome.epoch(Duration interval, { Clock clock: const Clock() })
- Metronome.periodic(Duration interval, { Clock clock: const Clock(), DateTime anchor })
Properties
- anchor → DateTime
-
final
- clock → Clock
-
final
- interval → Duration
-
final
- isBroadcast → bool
-
Whether this stream is a broadcast stream.
read-only, override
-
first
→ Future<
DateTime> -
The first element of this stream. [...]
read-only, inherited
- hashCode → int
-
The hash code for this object. [...]
read-only, inherited
-
isEmpty
→ Future<
bool> -
Whether this stream contains any elements. [...]
read-only, inherited
-
last
→ Future<
DateTime> -
The last element of this stream. [...]
read-only, inherited
-
length
→ Future<
int> -
The number of elements in this stream. [...]
read-only, inherited
- runtimeType → Type
-
A representation of the runtime type of the object.
read-only, inherited
-
single
→ Future<
DateTime> -
The single element of this stream. [...]
read-only, inherited
Methods
-
listen(
void onData(DateTime event), { Function onError, void onDone(), bool cancelOnError }) → StreamSubscription< DateTime> -
Adds a subscription to this stream. [...]
override
-
any(
bool test(T element)) → Future< bool> -
Checks whether
test
accepts any element provided by this stream. [...]inherited -
asBroadcastStream(
{void onListen(StreamSubscription< T> subscription), void onCancel(StreamSubscription< T> subscription) }) → Stream< DateTime> -
Returns a multi-subscription stream that produces the same events as this. [...]
inherited
-
asyncExpand<
E>( Stream< E> convert(T event)) → Stream< E> -
Transforms each element into a sequence of asynchronous events. [...]
inherited
-
asyncMap<
E>( FutureOr< E> convert(T event)) → Stream< E> -
Creates a new stream with each data event of this stream asynchronously
mapped to a new event. [...]
inherited
-
cast<
R>( ) → Stream< R> -
Adapt this stream to be a
Stream<R>
. [...]inherited -
contains(
Object needle) → Future< bool> -
Returns whether
needle
occurs in the elements provided by this stream. [...]inherited -
distinct(
[bool equals(T previous, T next) ]) → Stream< DateTime> -
Skips data events if they are equal to the previous data event. [...]
inherited
-
drain<
E>( [E futureValue ]) → Future< E> -
Discards all data on this stream, but signals when it is done or an error
occurred. [...]
inherited
-
elementAt(
int index) → Future< DateTime> -
Returns the value of the
index
th data event of this stream. [...]inherited -
every(
bool test(T element)) → Future< bool> -
Checks whether
test
accepts all elements provided by this stream. [...]inherited -
expand<
S>( Iterable< S> convert(T element)) → Stream< S> -
Transforms each element of this stream into a sequence of elements. [...]
inherited
-
firstWhere(
bool test(T element), { DateTime orElse() }) → Future< DateTime> -
Finds the first element of this stream matching
test
. [...]inherited -
fold<
S>( S initialValue, S combine(S previous, T element)) → Future< S> -
Combines a sequence of values by repeatedly applying
combine
. [...]inherited -
forEach(
void action(T element)) → Future -
Executes
action
on each element of this stream. [...]inherited -
handleError(
Function onError, { bool test(dynamic error) }) → Stream< DateTime> -
Creates a wrapper Stream that intercepts some errors from this stream. [...]
inherited
-
join(
[String separator = "" ]) → Future< String> -
Combines the string representation of elements into a single string. [...]
inherited
-
lastWhere(
bool test(T element), { DateTime orElse() }) → Future< DateTime> -
Finds the last element in this stream matching
test
. [...]inherited -
map<
S>( S convert(T event)) → Stream< S> -
Transforms each element of this stream into a new stream event. [...]
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed. [...]
inherited
-
pipe(
StreamConsumer< DateTime> streamConsumer) → Future -
Pipes the events of this stream into
streamConsumer
. [...]inherited -
reduce(
DateTime combine(T previous, T element)) → Future< DateTime> -
Combines a sequence of values by repeatedly applying
combine
. [...]inherited -
singleWhere(
bool test(T element), { DateTime orElse() }) → Future< DateTime> -
Finds the single element in this stream matching
test
. [...]inherited -
skip(
int count) → Stream< DateTime> -
Skips the first
count
data events from this stream. [...]inherited -
skipWhile(
bool test(T element)) → Stream< DateTime> -
Skip data events from this stream while they are matched by
test
. [...]inherited -
take(
int count) → Stream< DateTime> -
Provides at most the first
count
data events of this stream. [...]inherited -
takeWhile(
bool test(T element)) → Stream< DateTime> -
Forwards data events while
test
is successful. [...]inherited -
timeout(
Duration timeLimit, { void onTimeout(EventSink< T> sink) }) → Stream< DateTime> -
Creates a new stream with the same events as this stream. [...]
inherited
-
toList(
) → Future< List< DateTime>> -
Collects all elements of this stream in a List. [...]
inherited
-
toSet(
) → Future< Set< DateTime>> -
Collects the data of this stream in a Set. [...]
inherited
-
toString(
) → String -
Returns a string representation of this object.
inherited
-
transform<
S>( StreamTransformer< DateTime, S> streamTransformer) → Stream< S> -
Applies
streamTransformer
to this stream. [...]inherited -
where(
bool test(T event)) → Stream< DateTime> -
Creates a new stream from this stream that discards some elements. [...]
inherited
Operators
-
operator ==(
dynamic other) → bool -
The equality operator. [...]
inherited