com.diozero.devices.Button Maven / Gradle / Ivy
package com.diozero.devices;
/*
* #%L
* Organisation: diozero
* Project: Device I/O Zero - Core
* Filename: Button.java
*
* This file is part of the diozero project. More information about this project
* can be found at http://www.diozero.com/
* %%
* Copyright (C) 2016 - 2020 diozero
* %%
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
* #L%
*/
import com.diozero.api.*;
import com.diozero.internal.provider.GpioDeviceFactoryInterface;
import com.diozero.util.RuntimeIOException;
/**
* Provides push button related utility methods.
* From the ButtonTest example:
* 
*
* {@code
*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:
* 
*
* {@code
*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);
*}
* }
*
*/
public class Button extends DigitalInputDevice {
/**
* Pull up / down configuration defaults to NONE.
* @param gpio GPIO to which the button is connected.
* @throws RuntimeIOException If an I/O error occurred.
*/
public Button(int gpio) throws RuntimeIOException {
super(gpio, GpioPullUpDown.NONE, GpioEventTrigger.BOTH);
}
/**
* @param gpio GPIO to which the button is connected.
* @param pud Pull up / down configuration (NONE, PULL_UP, PULL_DOWN).
* @throws RuntimeIOException If an I/O error occurred.
*/
public Button(int gpio, GpioPullUpDown pud) throws RuntimeIOException {
super(gpio, pud, GpioEventTrigger.BOTH);
}
/**
* @param deviceFactory Device factory to use to contruct the device.
* @param gpio GPIO for the button.
* @param pud Pull up / down configuration (NONE, PULL_UP, PULL_DOWN).
* @throws RuntimeIOException If an I/O error occurred.
*/
public Button(GpioDeviceFactoryInterface deviceFactory, int gpio, GpioPullUpDown pud) throws RuntimeIOException {
super(deviceFactory, gpio, pud, GpioEventTrigger.BOTH);
}
/**
* Get the current state.
* @return Return true if the button is currently pressed.
*/
public boolean isPressed() {
return isActive();
}
/**
* Get the current state.
* @return Return true if the button is currently released.
*/
public boolean isReleased() {
return !isActive();
}
/**
* Action to perform when the button is pressed.
* @param action Action function to invoke.
*/
public void whenPressed(Action action) {
whenActivated(action);
}
/**
* Action to perform when the button is released.
* @param action Action function to invoke.
*/
public void whenReleased(Action action) {
whenDeactivated(action);
}
}