io.silverspoon.bulldog.devices.switches.Button Maven / Gradle / Ivy

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package io.silverspoon.bulldog.devices.switches;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import io.silverspoon.bulldog.core.Edge;
import io.silverspoon.bulldog.core.Signal;
import io.silverspoon.bulldog.core.gpio.DigitalInput;
import io.silverspoon.bulldog.core.gpio.event.InterruptEventArgs;
import io.silverspoon.bulldog.core.gpio.event.InterruptListener;

public class Button implements InterruptListener {

   private static final int DEFAULT_DEBOUNCE_TIME_MS = 0;

   private DigitalInput input;
   private Signal activeState = Signal.Low;
   private List listeners = Collections.synchronizedList(new ArrayList());

   public Button(DigitalInput input, int debounceMilliseconds, Signal activeState) {
      this.input = input;
      this.input.setInterruptDebounceMs(debounceMilliseconds);
      this.input.addInterruptListener(this);
      this.input.enableInterrupts();
      this.activeState = activeState;
   }

   public Button(DigitalInput input, Signal activeState) {
      this(input, DEFAULT_DEBOUNCE_TIME_MS, activeState);
   }

   protected void fireButtonReleased() {
      synchronized (listeners) {
         for (ButtonListener listener : listeners) {
            listener.buttonReleased();
         }
      }
   }

   protected void fireButtonPressed() {
      synchronized (listeners) {
         for (ButtonListener listener : listeners) {
            listener.buttonPressed();
         }
      }
   }

   public void addListener(ButtonListener listener) {
      this.listeners.add(listener);
   }

   public void removeListener(ButtonListener listener) {
      this.listeners.remove(listener);
   }

   public void clearListeners() {
      this.listeners.clear();
   }

   @Override
   public void interruptRequest(InterruptEventArgs args) {
      if (args.getEdge() == Edge.Rising && activeState == Signal.High) {
         fireButtonPressed();
      } else if (args.getEdge() == Edge.Falling && activeState == Signal.Low) {
         fireButtonPressed();
      } else {
         fireButtonReleased();
      }
   }

   public boolean isButtonPressed() {
      return input.read() == activeState;
   }

}