Module com.pi4j.crowpi

Package com.pi4j.crowpi.components.events

Class DigitalEventListener<V>

java.lang.Object

com.pi4j.crowpi.components.events.DigitalEventListener<V>

Type Parameters:

V - Target type of event value which gets passed to event handler.

All Implemented Interfaces:

EventListener, com.pi4j.event.Listener, com.pi4j.io.gpio.digital.DigitalListener<com.pi4j.io.gpio.digital.DigitalStateChangeEvent>, com.pi4j.io.gpio.digital.DigitalStateChangeListener

public class DigitalEventListener<V>
extends Object
implements EventListener, com.pi4j.io.gpio.digital.DigitalStateChangeListener

Generic implementation of EventListener for Pi4J DigitalInput instances. Can be registered as a DigitalStateChangeListener within Pi4J.

Whenever a Pi4J DigitalStateChangeEvent occurs, the provided DigitalState gets converted into the target type DigitalEventListener by calling the provided mapper function. This mapped value then gets passed to the provided EventHandler to actually handle the event with the function provided by the user.

Field Summary

Fields

Modifier and Type	Field	Description
protected final com.pi4j.io.gpio.digital.DigitalInput	digitalInput	Pi4J digital input to which this digital event listener has been attached
protected final EventHandler<V>	handler	Handler function which gets called
protected final Function<com.pi4j.io.gpio.digital.DigitalState,V>	mapper	Mapper function which transforms DigitalState into DigitalEventListener

Constructor Summary

Constructors

Constructor	Description
DigitalEventListener(com.pi4j.io.gpio.digital.DigitalInput digitalInput, Function<com.pi4j.io.gpio.digital.DigitalState,V> mapper, EventHandler<V> handler)	Creates a new digital event listener for the given digital input which uses the provided mapper and event handler.

Method Summary

Modifier and Type	Method	Description
void	onDigitalStateChange(com.pi4j.io.gpio.digital.DigitalStateChangeEvent event)	Handles incoming Pi4J events by calling our own handler with the mapped value from mapper.
void	remove()	Removes this digital event listener, therefore preventing any future execution.

Methods inherited from class java.lang.Object

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

Field Details

digitalInput

protected final com.pi4j.io.gpio.digital.DigitalInput digitalInput

Pi4J digital input to which this digital event listener has been attached

mapper

protected final Function<com.pi4j.io.gpio.digital.DigitalState,V> mapper

Mapper function which transforms DigitalState into DigitalEventListener

handler

protected final EventHandler<V> handler

Handler function which gets called

Constructor Details

DigitalEventListener

public DigitalEventListener(com.pi4j.io.gpio.digital.DigitalInput digitalInput,
 Function<com.pi4j.io.gpio.digital.DigitalState,V> mapper,
 EventHandler<V> handler)

Creates a new digital event listener for the given digital input which uses the provided mapper and event handler. This class instance gets automatically registered as a DigitalStateChangeListener for the passed DigitalInput.

Parameters:

digitalInput - Digital input where event listener gets attached

mapper - Mapping function from DigitalState to target type DigitalEventListener

handler - Handler function which gets called

Method Details

onDigitalStateChange

public void onDigitalStateChange(com.pi4j.io.gpio.digital.DigitalStateChangeEvent event)

Handles incoming Pi4J events by calling our own handler with the mapped value from mapper.

Specified by:

onDigitalStateChange in interface com.pi4j.io.gpio.digital.DigitalStateChangeListener

Parameters:

event - Pi4J event

remove

public void remove()

Removes this digital event listener, therefore preventing any future execution.

Specified by:

remove in interface EventListener