com.diozero.api.AbstractDigitalInputDevice Maven / Gradle / Ivy
package com.diozero.api;
/*
* #%L
* Organisation: mattjlewis
* Project: Device I/O Zero - Core
* Filename: AbstractDigitalInputDevice.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%
*/
public abstract class AbstractDigitalInputDevice extends GpioInputDevice
implements DigitalInputDeviceInterface {
protected boolean activeHigh;
private Action activatedAction;
private Action deactivatedAction;
private boolean listenerEnabled;
public AbstractDigitalInputDevice(int gpio, boolean activeHigh) {
super(gpio);
this.activeHigh = activeHigh;
}
/**
* Get active high configuration.
*
* @return Returns false if configured as pull-up, true for all other pull
* up / down options.
*/
public boolean isActiveHigh() {
return activeHigh;
}
@Override
protected void enableDeviceListener() {
if (! listenerEnabled) {
setListener();
listenerEnabled = true;
}
}
@Override
protected void disableDeviceListener() {
if (activatedAction == null && deactivatedAction == null) {
if (listenerEnabled) {
removeListener();
listenerEnabled = false;
}
}
}
@Override
public void valueChanged(DigitalInputEvent event) {
event.setActiveHigh(activeHigh);
if (activatedAction != null && event.isActive()) {
activatedAction.action();
}
if (deactivatedAction != null && !event.isActive()) {
deactivatedAction.action();
}
super.valueChanged(event);
}
/**
* Action to perform when the device state is active.
*
* @param action
* Action callback object.
*/
public void whenActivated(Action action) {
activatedAction = action;
if (action == null) {
disableDeviceListener();
} else {
enableDeviceListener();
}
}
/**
* Action to perform when the device state is inactive.
*
* @param action
* Action callback object.
*/
public void whenDeactivated(Action action) {
deactivatedAction = action;
if (action == null) {
disableDeviceListener();
} else {
enableDeviceListener();
}
}
protected abstract void setListener();
protected abstract void removeListener();
}