GpioLEDComponent.java

package com.pi4j.component.light.impl;

/*
 * #%L
 * **********************************************************************
 * ORGANIZATION  :  Pi4J
 * PROJECT       :  Pi4J :: Device Abstractions
 * FILENAME      :  GpioLEDComponent.java  
 * 
 * This file is part of the Pi4J project. More information about 
 * this project can be found here:  http://www.pi4j.com/
 * **********************************************************************
 * %%
 * Copyright (C) 2012 - 2013 Pi4J
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */


import java.util.concurrent.Future;

import com.pi4j.component.light.LEDBase;
import com.pi4j.component.light.LightStateChangeEvent;
import com.pi4j.io.gpio.GpioPinDigitalOutput;
import com.pi4j.io.gpio.PinState;

public class GpioLEDComponent extends LEDBase {
    
    // internal class members
    GpioPinDigitalOutput pin = null;
    PinState onState = PinState.HIGH;
    PinState offState = PinState.LOW;
    
    /**
     * using this constructor requires that the consumer 
     *  define the LIGHT ON and LIGHT OFF pin states 
     *  
     * @param pin GPIO digital output pin
     * @param onState pin state to set when power is ON
     * @param offState pin state to set when power is OFF
     */
    public GpioLEDComponent(GpioPinDigitalOutput pin, PinState onState, PinState offState) {
        this.pin = pin;
        this.onState = onState;
        this.offState = offState;
    }

    /**
     * default constructor; using this constructor assumes that:
     *  (1) a pin state of HIGH is LIGHT ON
     *  (2) a pin state of LOW  is LIGHT OFF
     *  
     * @param pin GPIO digital output pin
     */
    public GpioLEDComponent(GpioPinDigitalOutput pin) {
        this.pin = pin;        
    }
    
    /**
     * Set the current GPIO digital output pin state
     * based for LIGHT ON 
     */
    @Override
    public void on() {
        // turn the light ON by settings the GPIO pin to the on state
        pin.setState(onState);

        // notify any power state change listeners
        notifyListeners(new LightStateChangeEvent(this, true));
    }

    /**
     * Set the current GPIO digital output pin state
     * based for LIGHT OFF 
     */
    @Override
    public void off() {
        // turn the light OFF by settings the GPIO pin to the off state
        pin.setState(offState);

        // notify any power state change listeners
        notifyListeners(new LightStateChangeEvent(this, false));
    }


    /**
     * Return the current power state based on the  
     * GPIO digital output pin state.
     *  
     * @return boolean is light on 
     */
    @Override
    public boolean isOn() {
        return pin.isState(onState);
    }
    
    @Override
    public Future<?> blink(long delay){
        return pin.blink(delay, onState);
    }
    
    @Override
    public Future<?> blink(long delay, long duration){
        return pin.blink(delay, duration, onState);
    }
    
    @Override
    public Future<?> pulse(long duration){
        return pin.pulse(duration, onState);
    }
    
    @Override
    public Future<?> pulse(long duration, boolean blocking){
        return pin.pulse(duration, onState, blocking);
    }
}