adding pausable time

Author: Kevin Harrington

src/main/java/com/neuronrobotics/sdk/pid/IPauseTimeListener.java

@@ -0,0 +1,6 @@
+package com.neuronrobotics.sdk.pid;
+
+public interface IPauseTimeListener {
+	
+	public  void pause(boolean val);
+}

src/main/java/com/neuronrobotics/sdk/pid/PausableTime.java

@@ -0,0 +1,62 @@
+package com.neuronrobotics.sdk.pid;
+
+import java.util.ArrayList;
+
+public class PausableTime {
+	private static long timePaused = 0;
+	private static long durationPaused = 0;
+	private static boolean paused =false;
+	private static ArrayList<IPauseTimeListener> listeners = new ArrayList<IPauseTimeListener>();
+	
+	public static long currentTimeMillis() {
+		if(!paused)
+			return System.currentTimeMillis()-durationPaused;
+		return timePaused;
+	}
+	
+	public static void pause(boolean val) {
+		if(val)
+			timePaused=System.currentTimeMillis();
+		else 
+			durationPaused+=(System.currentTimeMillis()-timePaused);
+		
+		paused=val;
+		for(int i=0;i<listeners.size();i++)
+			listeners.get(i).pause(val);
+	}
+	
+	
+	public static void step(long ms) {
+		new Thread(()->{
+			boolean start = paused;
+			pause(false);
+			sleep(ms);
+			pause(start);
+		}).start();
+	}
+	
+	public static void sleep(long durationMS) {
+		try {
+			Thread.sleep(durationMS);
+		} catch (InterruptedException e) {
+			throw new RuntimeException(e);
+		}
+		while(paused) {
+			try {
+				Thread.sleep(1);
+			} catch (InterruptedException e) {
+				throw new RuntimeException(e);
+			}
+		}
+	}
+	
+	public static void addIPauseTimeListener(IPauseTimeListener l) {
+		if(listeners.contains(l))
+			return;
+		listeners.add(l);
+	}
+	public static void removeIPauseTimeListener(IPauseTimeListener l) {
+		if(listeners.contains(l))
+			listeners.remove(l);
+	}
+}