Package edu.wpi.first.networktables

Class DoubleTopic

java.lang.Object

edu.wpi.first.networktables.Topic

edu.wpi.first.networktables.DoubleTopic

public final class DoubleTopic
extends Topic

NetworkTables Double topic.

Field Summary

Fields

Modifier and Type	Field	Description
static String	kTypeString	The default type string for this topic type.

Fields inherited from class edu.wpi.first.networktables.Topic

m_handle, m_inst

Constructor Summary

Constructors

Constructor	Description
DoubleTopic(NetworkTableInstance inst, int handle)	Constructor; use NetworkTableInstance.getDoubleTopic() instead.
DoubleTopic(Topic topic)	Construct from a generic topic.

Method Summary

Modifier and Type	Method	Description
DoubleEntry	getEntry(double defaultValue, PubSubOption... options)	Create a new entry for the topic.
DoubleEntry	getEntryEx(String typeString, double defaultValue, PubSubOption... options)	Create a new entry for the topic, with specified type string.
DoublePublisher	publish(PubSubOption... options)	Create a new publisher to the topic.
DoublePublisher	publishEx(String typeString, String properties, PubSubOption... options)	Create a new publisher to the topic, with type string and initial properties.
DoubleSubscriber	subscribe(double defaultValue, PubSubOption... options)	Create a new subscriber to the topic.
DoubleSubscriber	subscribeEx(String typeString, double defaultValue, PubSubOption... options)	Create a new subscriber to the topic, with specified type string.

Methods inherited from class edu.wpi.first.networktables.Topic

deleteProperty, equals, exists, genericPublish, genericPublishEx, genericSubscribe, genericSubscribe, getGenericEntry, getGenericEntry, getHandle, getInfo, getInstance, getName, getProperties, getProperty, getType, getTypeString, hashCode, isCached, isPersistent, isRetained, isValid, setCached, setPersistent, setProperties, setProperty, setRetained

Methods inherited from class java.lang.Object

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

Field Details

kTypeString

public static final String kTypeString

The default type string for this topic type.

See Also:

Constant Field Values

Constructor Details

DoubleTopic

public DoubleTopic(Topic topic)

Construct from a generic topic.

Parameters:

topic - Topic

DoubleTopic

public DoubleTopic(NetworkTableInstance inst, int handle)

Constructor; use NetworkTableInstance.getDoubleTopic() instead.

Parameters:

inst - Instance

handle - Native handle

Method Details

subscribe

public DoubleSubscriber subscribe(double defaultValue, PubSubOption... options)

Create a new subscriber to the topic.

The subscriber is only active as long as the returned object is not closed.

Subscribers that do not match the published data type do not return any values. To determine if the data type matches, use the appropriate Topic functions.

Parameters:

defaultValue - default value used when a default is not provided to a getter function

options - subscribe options

Returns:

subscriber

subscribeEx

public DoubleSubscriber subscribeEx(String typeString, double defaultValue, PubSubOption... options)

Create a new subscriber to the topic, with specified type string.

The subscriber is only active as long as the returned object is not closed.

Subscribers that do not match the published data type do not return any values. To determine if the data type matches, use the appropriate Topic functions.

Parameters:

typeString - type string

defaultValue - default value used when a default is not provided to a getter function

options - subscribe options

Returns:

subscriber

publish

public DoublePublisher publish(PubSubOption... options)

Create a new publisher to the topic.

The publisher is only active as long as the returned object is not closed.

It is not possible to publish two different data types to the same topic. Conflicts between publishers are typically resolved by the server on a first-come, first-served basis. Any published values that do not match the topic's data type are dropped (ignored). To determine if the data type matches, use the appropriate Topic functions.

Parameters:

options - publish options

Returns:

publisher

publishEx

public DoublePublisher publishEx(String typeString, String properties, PubSubOption... options)

Create a new publisher to the topic, with type string and initial properties.

The publisher is only active as long as the returned object is not closed.

It is not possible to publish two different data types to the same topic. Conflicts between publishers are typically resolved by the server on a first-come, first-served basis. Any published values that do not match the topic's data type are dropped (ignored). To determine if the data type matches, use the appropriate Topic functions.

Parameters:

typeString - type string

properties - JSON properties

options - publish options

Returns:

publisher

Throws:

IllegalArgumentException - if properties is not a JSON object

getEntry

public DoubleEntry getEntry(double defaultValue, PubSubOption... options)

Create a new entry for the topic.

Entries act as a combination of a subscriber and a weak publisher. The subscriber is active as long as the entry is not closed. The publisher is created when the entry is first written to, and remains active until either unpublish() is called or the entry is closed.

It is not possible to use two different data types with the same topic. Conflicts between publishers are typically resolved by the server on a first-come, first-served basis. Any published values that do not match the topic's data type are dropped (ignored), and the entry will show no new values if the data type does not match. To determine if the data type matches, use the appropriate Topic functions.

Parameters:

defaultValue - default value used when a default is not provided to a getter function

options - publish and/or subscribe options

Returns:

entry

getEntryEx

public DoubleEntry getEntryEx(String typeString, double defaultValue, PubSubOption... options)

Create a new entry for the topic, with specified type string.

Entries act as a combination of a subscriber and a weak publisher. The subscriber is active as long as the entry is not closed. The publisher is created when the entry is first written to, and remains active until either unpublish() is called or the entry is closed.

It is not possible to use two different data types with the same topic. Conflicts between publishers are typically resolved by the server on a first-come, first-served basis. Any published values that do not match the topic's data type are dropped (ignored), and the entry will show no new values if the data type does not match. To determine if the data type matches, use the appropriate Topic functions.

Parameters:

typeString - type string

defaultValue - default value used when a default is not provided to a getter function

options - publish and/or subscribe options

Returns:

entry