Package com.diozero.devices

Class Button

java.lang.Object

com.diozero.api.GpioDevice

com.diozero.api.GpioInputDevice<DigitalInputEvent>

com.diozero.api.AbstractDigitalInputDevice

com.diozero.api.DigitalInputDevice

com.diozero.devices.Button

All Implemented Interfaces:

DigitalInputDeviceInterface, InputEventListener<DigitalInputEvent>, Closeable, AutoCloseable

public class Button
extends DigitalInputDevice

Provides push button related utility methods.

From the ButtonTest example:

 
try (Button button = new Button(inputPin, GpioPullUpDown.PULL_UP)) {
	button.addListener(event -> Logger.debug("valueChanged({})", event));
	Logger.debug("Waiting for 10s - *** Press the button connected to input pin " + inputPin + " ***");
	SleepUtil.sleepSeconds(10);
}
 
 

Controlling an LED with a button ButtonControlledLed:

 
try (Button button = new Button(buttonPin, GpioPullUpDown.PULL_UP); LED led = new LED(ledPin)) {
	button.whenPressed(led::on);
	button.whenReleased(led::off);
	Logger.info("Waiting for 10s - *** Press the button connected to pin {} ***", Integer.valueOf(buttonPin));
	SleepUtil.sleepSeconds(10);
}
 
 

Field Summary

Fields inherited from class com.diozero.api.DigitalInputDevice

device

Fields inherited from class com.diozero.api.AbstractDigitalInputDevice

activeHigh

Fields inherited from class com.diozero.api.GpioDevice

gpio

Constructor Summary

Constructors

Constructor	Description
Button(int gpio)	Pull up / down configuration defaults to NONE.
Button(int gpio, GpioPullUpDown pud)
Button(GpioDeviceFactoryInterface deviceFactory, int gpio, GpioPullUpDown pud)

Method Summary

Modifier and Type	Method	Description
boolean	isPressed()	Get the current state.
boolean	isReleased()	Get the current state.
void	whenPressed(Action action)	Action to perform when the button is pressed.
void	whenReleased(Action action)	Action to perform when the button is released.

Methods inherited from class com.diozero.api.DigitalInputDevice

close, getPullUpDown, getTrigger, getValue, isActive, removeListener, setListener

Methods inherited from class com.diozero.api.AbstractDigitalInputDevice

disableDeviceListener, enableDeviceListener, isActiveHigh, valueChanged, whenActivated, whenDeactivated

Methods inherited from class com.diozero.api.GpioInputDevice

addListener, removeAllListeners, removeListener

Methods inherited from class com.diozero.api.GpioDevice

getGpio

Methods inherited from class java.lang.Object

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

Constructor Details

Button

public Button(int gpio)
       throws RuntimeIOException

Pull up / down configuration defaults to NONE.

Parameters:

gpio - GPIO to which the button is connected.

Throws:

RuntimeIOException - If an I/O error occurred.

Button

public Button(int gpio,
GpioPullUpDown pud)
       throws RuntimeIOException

Parameters:

gpio - GPIO to which the button is connected.

pud - Pull up / down configuration (NONE, PULL_UP, PULL_DOWN).

Throws:

RuntimeIOException - If an I/O error occurred.

Button

public Button(GpioDeviceFactoryInterface deviceFactory,
int gpio,
GpioPullUpDown pud)
       throws RuntimeIOException

Parameters:

deviceFactory - Device factory to use to contruct the device.

gpio - GPIO for the button.

pud - Pull up / down configuration (NONE, PULL_UP, PULL_DOWN).

Throws:

RuntimeIOException - If an I/O error occurred.

Method Details

isPressed

public boolean isPressed()

Get the current state.

Returns:

Return true if the button is currently pressed.

isReleased

public boolean isReleased()

Get the current state.

Returns:

Return true if the button is currently released.

whenPressed

public void whenPressed(Action action)

Action to perform when the button is pressed.

Parameters:

action - Action function to invoke.

whenReleased

public void whenReleased(Action action)

Action to perform when the button is released.

Parameters:

action - Action function to invoke.