com.diozero.api.GpioInputDevice Maven / Gradle / Ivy
package com.diozero.api;
/*
* #%L
* Organisation: mattjlewis
* Project: Device I/O Zero - Core
* Filename: GpioInputDevice.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 - 2017 mattjlewis
* %%
* 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 java.util.ArrayList;
import java.util.Collection;
/**
* Common base class for digital and analog input devices.
*
* @param
* Event class that extends DeviceEvent. See
* {@link com.diozero.api.DigitalInputEvent DigitalInputEvent} and
* {@link com.diozero.api.AnalogInputEvent AnalogInputEvent}.
*/
public abstract class GpioInputDevice extends GpioDevice
implements InputEventListener {
private Collection> listeners;
/**
* @param gpio
* GPIO to which the device is connected.
*/
public GpioInputDevice(int gpio) {
super(gpio);
listeners = new ArrayList<>();
}
/**
* Add a new listener.
*
* @param listener
* Callback instance.
*/
public void addListener(InputEventListener listener) {
if (listeners.isEmpty()) {
enableDeviceListener();
}
if (!listeners.contains(listener)) {
listeners.add(listener);
}
}
/**
* Remove a specific listener.
*
* @param listener
* Callback instance to remove.
*/
public void removeListener(InputEventListener listener) {
listeners.remove(listener);
if (listeners.isEmpty()) {
disableDeviceListener();
}
}
/**
* Remove all listeners.
*/
public void removeAllListeners() {
listeners.clear();
disableDeviceListener();
}
@Override
public void valueChanged(T event) {
listeners.forEach(listener -> listener.valueChanged(event));
}
protected abstract void enableDeviceListener();
protected abstract void disableDeviceListener();
}