Module com.pi4j.crowpi

Package com.pi4j.crowpi.components

Class ButtonComponent

java.lang.Object

com.pi4j.crowpi.components.Component

com.pi4j.crowpi.components.ButtonComponent

All Implemented Interfaces:

DigitalEventProvider<ButtonComponent.ButtonState>, EventProvider<DigitalEventListener<ButtonComponent.ButtonState>,ButtonComponent.ButtonState>, SimpleEventProvider<ButtonComponent.ButtonState>

public class ButtonComponent
extends Component
implements DigitalEventProvider<ButtonComponent.ButtonState>

Implementation of the CrowPi buttons using GPIO with Pi4J

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	ButtonComponent.ButtonState	All available states reported by the button component.

Field Summary

Fields

Modifier and Type	Field	Description
protected static final long	DEFAULT_DEBOUNCE	Default debounce time in microseconds
protected final com.pi4j.io.gpio.digital.DigitalInput	digitalInput	Pi4J digital input instance used by this component

Fields inherited from class com.pi4j.crowpi.components.Component

logger

Constructor Summary

Constructors

Constructor	Description
ButtonComponent(com.pi4j.context.Context pi4j, int address, boolean inverted, long debounce)	Creates a new button component with custom GPIO address and debounce time.
ButtonComponent(com.pi4j.context.Context pi4j, Button button)	Creates a new button component using the default setup for the given CrowPi button.

Method Summary

Modifier and Type	Method	Description
void	dispatchSimpleEvents(ButtonComponent.ButtonState state)	Analyzes the given value passed by an event and triggers 0-n simple events based on it.
com.pi4j.io.gpio.digital.DigitalInput	getDigitalInput()	Returns the Pi4J DigitalInput associated with this component.
ButtonComponent.ButtonState	getState()	Returns the current state of the touch sensor
boolean	isDown()	Checks if button is currently pressed
boolean	isUp()	Checks if button is currently depressed (= NOT pressed)
ButtonComponent.ButtonState	mapDigitalState(com.pi4j.io.gpio.digital.DigitalState digitalState)	Maps a DigitalState to a well-known ButtonComponent.ButtonState
void	onDown(SimpleEventHandler handler)	Sets or disables the handler for the onDown event.
void	onUp(SimpleEventHandler handler)	Sets or disables the handler for the onUp event.

Methods inherited from class com.pi4j.crowpi.components.Component

sleep, triggerSimpleEvent

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.pi4j.crowpi.components.events.DigitalEventProvider

addListener, removeListener

Field Details

DEFAULT_DEBOUNCE

protected static final long DEFAULT_DEBOUNCE

Default debounce time in microseconds

See Also:

• Constant Field Values

digitalInput

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

Pi4J digital input instance used by this component

Constructor Details

ButtonComponent

public ButtonComponent(com.pi4j.context.Context pi4j,
 Button button)

Creates a new button component using the default setup for the given CrowPi button.

Parameters:

pi4j - Pi4J context

button - Desired CrowPi button

ButtonComponent

public ButtonComponent(com.pi4j.context.Context pi4j,
 int address,
 boolean inverted,
 long debounce)

Creates a new button component with custom GPIO address and debounce time.

Parameters:

pi4j - Pi4J context

address - GPIO address of button

inverted - Specify if button state is inverted

debounce - Debounce time in microseconds

Method Details

getState

public ButtonComponent.ButtonState getState()

Returns the current state of the touch sensor

Returns:

Current button state

isDown

public boolean isDown()

Checks if button is currently pressed

Returns:

True if button is pressed

isUp

public boolean isUp()

Checks if button is currently depressed (= NOT pressed)

Returns:

True if button is depressed

mapDigitalState

public ButtonComponent.ButtonState mapDigitalState(com.pi4j.io.gpio.digital.DigitalState digitalState)

Maps a DigitalState to a well-known ButtonComponent.ButtonState

Specified by:

mapDigitalState in interface DigitalEventProvider<ButtonComponent.ButtonState>

Parameters:

digitalState - Pi4J digital state to map

Returns:

Mapped touch state

dispatchSimpleEvents

public void dispatchSimpleEvents(ButtonComponent.ButtonState state)

Analyzes the given value passed by an event and triggers 0-n simple events based on it. This method allows mapping various value/state changes to simple events. Must be attached using DigitalEventProvider.addListener(EventHandler).

Specified by:

dispatchSimpleEvents in interface SimpleEventProvider<ButtonComponent.ButtonState>

Parameters:

state - Event value

onDown

public void onDown(SimpleEventHandler handler)

Sets or disables the handler for the onDown event. This event gets triggered whenever the button is pressed. Only a single event handler can be registered at once.

Parameters:

handler - Event handler to call or null to disable

onUp

public void onUp(SimpleEventHandler handler)

Sets or disables the handler for the onUp event. This event gets triggered whenever the button is no longer pressed. Only a single event handler can be registered at once.

Parameters:

handler - Event handler to call or null to disable

getDigitalInput

public com.pi4j.io.gpio.digital.DigitalInput getDigitalInput()

Returns the Pi4J DigitalInput associated with this component.

Specified by:

getDigitalInput in interface DigitalEventProvider<ButtonComponent.ButtonState>

Returns:

Pi4J DigitalInput instance