ProgressCounter.java

package edu.cmu.minorthird.util;

/**
 * Indicates intermediate progress for a trainer, etc.
 *
 */
import java.text.DecimalFormat;

import javax.swing.JProgressBar;

final public class ProgressCounter{

	static private DecimalFormat format=new DecimalFormat("0.00");

	static JProgressBar[] graphicContext=new JProgressBar[0];

	public static void setGraphicContext(JProgressBar[] context){
		graphicContext=context;
	}

	public static void clearGraphicContext(){
		graphicContext=new JProgressBar[0];
	}

	// keep track of the global depth of progress counters
	static int currentDepth=0;

	private static final int TIME_BTWN_OUTPUTS_IN_MS=1000;

	private String task,step;

	private int numSteps;

	private int depth;

	private long startTime;

	private long lastOutputTime;

	private int stepsCompleted;

	private JProgressBar graphicCounter;

	public ProgressCounter(String task,String step,int numSteps){
		this.task=task;
		this.step=step;
		this.stepsCompleted=0;
		this.numSteps=numSteps;
		this.depth=currentDepth++;
		this.startTime=this.lastOutputTime=System.currentTimeMillis();
		if(depth<graphicContext.length){
			synchronized(graphicContext){
				graphicCounter=graphicContext[depth];
				graphicCounter.setValue(0);
				if(numSteps>=0)
					graphicCounter.setMaximum(numSteps);
				graphicCounter.setIndeterminate(numSteps<0);
				graphicCounter.setString(numSteps>=0?(" "+task+" for "+numSteps+" "+
						step+"s "):task);
				graphicCounter.setStringPainted(true);
			}
		}else{
			graphicCounter=null;
		}
	}

	public ProgressCounter(String task,int numSteps){
		this(task,"step",numSteps);
	}

	public ProgressCounter(String task,String step){
		this(task,step,-1);
	}

	public ProgressCounter(String task){
		this(task,"step",-1);
	}

	/** Record one step of progress on the task */
	final public synchronized void progress(){
		stepsCompleted++;
		long time=System.currentTimeMillis();
		if(time-lastOutputTime>TIME_BTWN_OUTPUTS_IN_MS){
			if(graphicCounter!=null){
				synchronized(graphicContext){
					graphicCounter.setValue(stepsCompleted);
				}
			}
			try{
				System.out.flush();
			}catch(Exception e){
			}
			// if (errorArea == null) {
			for(int i=0;i<depth;i++)
				System.out.print("| ");
			if(numSteps>=0){
				try{
					System.out.flush();
				}catch(Exception e){
				}
				System.out.println("Task "+task+": "+
						format.format(100.0*stepsCompleted/numSteps)+"% ("+stepsCompleted+
						"/"+numSteps+" "+step+"s) in "+
						format.format((time-startTime)/1000.0)+" sec");
			}else{
				try{
					System.out.flush();
				}catch(Exception e){
				}
				System.out.println("Task "+task+": "+stepsCompleted+" "+step+"(s) in "+
						format.format((time-startTime)/1000.0)+" sec");
			}
			lastOutputTime=time;
		}
	}

	/** Record this task as completed. */
	public void finished(){
		if(graphicCounter!=null&&graphicCounter.isIndeterminate()){
			synchronized(graphicContext){
				graphicCounter.setIndeterminate(false);
				graphicCounter.setMaximum(stepsCompleted);
				graphicCounter.setValue(stepsCompleted);
				graphicCounter.setStringPainted(false);
			}
		}
		currentDepth=depth;
	}
}