package ij.gui;

import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
import java.io.*;
import java.awt.datatransfer.*;
import java.util.ArrayList;
import ij.*;
import ij.process.*;
import ij.measure.*;
import ij.plugin.filter.Analyzer;
import ij.text.TextWindow;

/** This class is an extended ImageWindow that displays histograms. */
public class HistogramWindow extends ImageWindow implements Measurements, ActionListener, 
	ClipboardOwner, ImageListener, RoiListener, Runnable {
	
	static final int WIN_WIDTH = 300;
	static final int WIN_HEIGHT = 240;
	static final int HIST_WIDTH = 256;
	static final int HIST_HEIGHT = 128;
	static final int BAR_HEIGHT = 12;
	static final int XMARGIN = 20;
	static final int YMARGIN = 10;
	static final int INTENSITY=0, RED=1, GREEN=2, BLUE=3;
	
	protected ImageStatistics stats;
	protected long[] histogram;
	protected LookUpTable lut;
	protected Rectangle frame = null;
	protected Button list, save, copy, log, live, rgb;
	protected Label value, count;
	protected static String defaultDirectory = null;
	protected int decimalPlaces;
	protected int digits;
	protected long newMaxCount;
	protected int plotScale = 1;
	protected boolean logScale;
	protected Calibration cal;
	protected int yMax;
	public static int nBins = 256;
		
	private int srcImageID;			// ID of source image
	private ImagePlus srcImp;		// source image for live histograms
	private Thread bgThread;		// thread background drawing
	private boolean doUpdate;	// tells background thread to update
	private int channel;				// RGB channel
	private String blankLabel;
	private boolean stackHistogram;
	    
	/** Displays a histogram using the title "Histogram of ImageName". */
	public HistogramWindow(ImagePlus imp) {
		super(NewImage.createRGBImage("Histogram of "+imp.getShortTitle(), WIN_WIDTH, WIN_HEIGHT, 1, NewImage.FILL_WHITE));
		showHistogram(imp, 256, 0.0, 0.0);
	}

	/** Displays a histogram using the specified title and number of bins. 
		Currently, the number of bins must be 256 expect for 32 bit images. */
	public HistogramWindow(String title, ImagePlus imp, int bins) {
		super(NewImage.createRGBImage(title, WIN_WIDTH, WIN_HEIGHT, 1, NewImage.FILL_WHITE));
		showHistogram(imp, bins, 0.0, 0.0);
	}

	/** Displays a histogram using the specified title, number of bins and histogram range.
		Currently, the number of bins must be 256 and the histogram range range must be the 
		same as the image range expect for 32 bit images. */
	public HistogramWindow(String title, ImagePlus imp, int bins, double histMin, double histMax) {
		super(NewImage.createRGBImage(title, WIN_WIDTH, WIN_HEIGHT, 1, NewImage.FILL_WHITE));
		showHistogram(imp, bins, histMin, histMax);
	}

	/** Displays a histogram using the specified title, number of bins, histogram range and yMax. */
	public HistogramWindow(String title, ImagePlus imp, int bins, double histMin, double histMax, int yMax) {
		super(NewImage.createRGBImage(title, WIN_WIDTH, WIN_HEIGHT, 1, NewImage.FILL_WHITE));
		this.yMax = yMax;
		showHistogram(imp, bins, histMin, histMax);
	}

	/** Displays a histogram using the specified title and ImageStatistics. */
	public HistogramWindow(String title, ImagePlus imp, ImageStatistics stats) {
		super(NewImage.createRGBImage(title, WIN_WIDTH, WIN_HEIGHT, 1, NewImage.FILL_WHITE));
		//IJ.log("HistogramWindow: "+stats.histMin+"  "+stats.histMax+"  "+stats.nBins);
		this.yMax = stats.histYMax;
		showHistogram(imp, stats);
	}

	/** Draws the histogram using the specified title and number of bins.
		Currently, the number of bins must be 256 expect for 32 bit images. */
	public void showHistogram(ImagePlus imp, int bins) {
		showHistogram(imp, bins, 0.0, 0.0);
	}

	/** Draws the histogram using the specified title, number of bins and histogram range.
		Currently, the number of bins must be 256 and the histogram range range must be 
		the same as the image range expect for 32 bit images. */
	public void showHistogram(ImagePlus imp, int bins, double histMin, double histMax) {
		boolean limitToThreshold = (Analyzer.getMeasurements()&LIMIT)!=0;
		if (channel!=INTENSITY && imp.getType()==ImagePlus.COLOR_RGB) {
			ColorProcessor cp = (ColorProcessor)imp.getProcessor();
			ImageProcessor ip = cp.getChannel(channel, null);
			ImagePlus imp2 = new ImagePlus("", ip);
			imp2.setRoi(imp.getRoi());
			stats = imp2.getStatistics(AREA+MEAN+MODE+MIN_MAX, bins, histMin, histMax);
		} else
			stats = imp.getStatistics(AREA+MEAN+MODE+MIN_MAX+(limitToThreshold?LIMIT:0), bins, histMin, histMax);
		showHistogram(imp, stats);
	}

	/** Draws the histogram using the specified title and ImageStatistics. */
	public void showHistogram(ImagePlus imp, ImageStatistics stats) {
		stackHistogram = stats.stackStatistics;
		if (list==null)
			setup(imp);
		this.stats = stats;
		cal = imp.getCalibration();
		boolean limitToThreshold = (Analyzer.getMeasurements()&LIMIT)!=0;
		imp.getMask();
		histogram = stats.getHistogram();
		if (limitToThreshold && histogram.length==256) {
			ImageProcessor ip = imp.getProcessor();
			if (ip.getMinThreshold()!=ImageProcessor.NO_THRESHOLD) {
				int lower = scaleDown(ip, ip.getMinThreshold());
				int upper = scaleDown(ip, ip.getMaxThreshold());
				for (int i=0; i<lower; i++)
					histogram[i] = 0L;
				for (int i=upper+1; i<256; i++)
					histogram[i] = 0L;
			}
		}
		lut = imp.createLut();
		int type = imp.getType();
		boolean fixedRange = type==ImagePlus.GRAY8 || type==ImagePlus.COLOR_256 || type==ImagePlus.COLOR_RGB;
		ImageProcessor ip = this.imp.getProcessor();
		ip.setColor(Color.white);
		ip.resetRoi();
		ip.fill();
		ImageProcessor srcIP = imp.getProcessor();
		drawHistogram(imp, ip, fixedRange, stats.histMin, stats.histMax);
		this.imp.updateAndDraw();
	}

	private void setup(ImagePlus imp) {
		boolean isRGB = imp.getType()==ImagePlus.COLOR_RGB;
 		Panel buttons = new Panel();
 		int hgap = IJ.isMacOSX()||isRGB?1:5;
		buttons.setLayout(new FlowLayout(FlowLayout.RIGHT,hgap,0));
		int trim = IJ.isMacOSX()?6:0;
		list = new TrimmedButton("List", trim);
		list.addActionListener(this);
		buttons.add(list);
		copy = new TrimmedButton("Copy", trim);
		copy.addActionListener(this);
		buttons.add(copy);
		log = new TrimmedButton("Log", trim);
		log.addActionListener(this);
		buttons.add(log);
		if (!stackHistogram) {
			live = new TrimmedButton("Live", trim);
			live.addActionListener(this);
			buttons.add(live);
		}
		if (imp!=null && isRGB && !stackHistogram) {
			rgb = new TrimmedButton("RGB", trim);
			rgb.addActionListener(this);
			buttons.add(rgb);
		}
		if (!(IJ.isMacOSX()&&isRGB)) {
			Panel valueAndCount = new Panel();
			valueAndCount.setLayout(new GridLayout(2,1,0,0));
			blankLabel = IJ.isMacOSX()?"           ":"                ";
			value = new Label(blankLabel);
			Font font = new Font("Monospaced", Font.PLAIN, 12);
			value.setFont(font);
			valueAndCount.add(value);
			count = new Label(blankLabel);
			count.setFont(font);
			valueAndCount.add(count);
			buttons.add(valueAndCount);
		}
		add(buttons);
		pack();
    }
    
	public void setup() {setup(null);}

	public void mouseMoved(int x, int y) {
		if (value==null || count==null)
			return;
		if ((frame!=null)  && x>=frame.x && x<=(frame.x+frame.width)) {
			x = x - frame.x;
			if (x>255) x = 255;
			int index = (int)(x*((double)histogram.length)/HIST_WIDTH);
			String vlabel=null, clabel=null;
			if (blankLabel.length()==11) // OS X
				{vlabel=" "; clabel=" ";}
			else
				{vlabel=" value="; clabel=" count=";}
			String v = vlabel+d2s(cal.getCValue(stats.histMin+index*stats.binSize))+blankLabel;
			String c = clabel+histogram[index]+blankLabel;
			int len = vlabel.length() + blankLabel.length();
			value.setText(v.substring(0,len));
			count.setText(c.substring(0,len));
		} else {
			value.setText(blankLabel);
			count.setText(blankLabel);
		}
	}
	
	protected void drawHistogram(ImageProcessor ip, boolean fixedRange) {
		drawHistogram(null, ip, fixedRange, 0.0, 0.0);
	}

	void drawHistogram(ImagePlus imp, ImageProcessor ip, boolean fixedRange, double xMin, double xMax) {
		int x, y;
		long maxCount2 = 0;
		int mode2 = 0;
		long saveModalCount;
		    	
		ip.setColor(Color.black);
		ip.setLineWidth(1);
		decimalPlaces = Analyzer.getPrecision();
		digits = cal.calibrated()||stats.binSize!=1.0?decimalPlaces:0;
		saveModalCount = histogram[stats.mode];
		for (int i = 0; i<histogram.length; i++) {
 			if ((histogram[i] > maxCount2) && (i != stats.mode)) {
				maxCount2 = histogram[i];
				mode2 = i;
  			}
  		}
		newMaxCount = histogram[stats.mode];
		if ((newMaxCount>(maxCount2 * 2)) && (maxCount2 != 0)) {
			newMaxCount = (int)(maxCount2 * 1.5);
  			//histogram[stats.mode] = newMaxCount;
		}
		if (logScale || IJ.shiftKeyDown() && !liveMode())
			drawLogPlot(yMax>0?yMax:newMaxCount, ip);
		drawPlot(yMax>0?yMax:newMaxCount, ip);
		histogram[stats.mode] = saveModalCount;
 		x = XMARGIN + 1;
		y = YMARGIN + HIST_HEIGHT + 2;
		if (imp==null)
			lut.drawUnscaledColorBar(ip, x-1, y, 256, BAR_HEIGHT);
		else
			drawAlignedColorBar(imp, xMin, xMax, ip, x-1, y, 256, BAR_HEIGHT);
		y += BAR_HEIGHT+15;
  		drawText(ip, x, y, fixedRange);
  		srcImageID = imp.getID();
	}
       
	void drawAlignedColorBar(ImagePlus imp, double xMin, double xMax, ImageProcessor ip, int x, int y, int width, int height) {
		ImageProcessor ipSource = imp.getProcessor();
		float[] pixels = null;
		ImageProcessor ipRamp = null;
		if (ipSource instanceof ColorProcessor) {
			ipRamp = new FloatProcessor(width, height);
			if (channel==RED)
				ipRamp.setColorModel(LUT.createLutFromColor(Color.red));
			else if (channel==GREEN)
				ipRamp.setColorModel(LUT.createLutFromColor(Color.green));
			else if (channel==BLUE)
				ipRamp.setColorModel(LUT.createLutFromColor(Color.blue));
			pixels = (float[])ipRamp.getPixels();
		} else
			pixels = new float[width*height];
		for (int j=0; j<height; j++) {
			for(int i=0; i<width; i++)
				pixels[i+width*j] = (float)(xMin+i*(xMax-xMin)/(width - 1));
		}
		double min = ipSource.getMin();
		double max = ipSource.getMax();
		if (!(ipSource instanceof ColorProcessor)) {
			ColorModel cm = null;
			if (imp.isComposite()) {
				if (stats!=null && stats.pixelCount>ipSource.getPixelCount()) { // stack histogram
					cm = LUT.createLutFromColor(Color.white);
					min = stats.min;
					max = stats.max;
				} else
					cm = ((CompositeImage)imp).getChannelLut();
			} else if (ipSource.getMinThreshold()==ImageProcessor.NO_THRESHOLD)
				cm = ipSource.getColorModel();
			else
				cm = ipSource.getCurrentColorModel();
			ipRamp = new FloatProcessor(width, height, pixels, cm);
		}
		ipRamp.setMinAndMax(min,max);
		ImageProcessor bar = null;
		if (ip instanceof ColorProcessor)
			bar = ipRamp.convertToRGB();
		else
			bar = ipRamp.convertToByte(true);
		ip.insert(bar, x,y);
		ip.setColor(Color.black);
		ip.drawRect(x-1, y, width+2, height);
	}

	/** Scales a threshold level to the range 0-255. */
	int scaleDown(ImageProcessor ip, double threshold) {
		double min = ip.getMin();
		double max = ip.getMax();
		if (max>min)
			return (int)(((threshold-min)/(max-min))*255.0);
		else
			return 0;
	}

	void drawPlot(long maxCount, ImageProcessor ip) {
		if (maxCount==0) maxCount = 1;
		frame = new Rectangle(XMARGIN, YMARGIN, HIST_WIDTH, HIST_HEIGHT);
		ip.drawRect(frame.x-1, frame.y, frame.width+2, frame.height+1);
		if (histogram.length<=HIST_WIDTH) {
			int index, y;
			for (int i=0; i<HIST_WIDTH; i++) {
				index = (int)(i*(double)histogram.length/HIST_WIDTH); 
				y = (int)(((double)HIST_HEIGHT*(double)histogram[index])/maxCount);
				if (y>HIST_HEIGHT) y = HIST_HEIGHT;
				ip.drawLine(i+XMARGIN, YMARGIN+HIST_HEIGHT, i+XMARGIN, YMARGIN+HIST_HEIGHT-y);
			}
		} else {
			double xscale = (double)HIST_WIDTH/histogram.length; 
			for (int i=0; i<histogram.length; i++) {
				long value = histogram[i];
				if (value>0L) {
					int y = (int)(((double)HIST_HEIGHT*(double)value)/maxCount);
					if (y>HIST_HEIGHT) y = HIST_HEIGHT;
					int x = (int)(i*xscale)+XMARGIN;
					ip.drawLine(x, YMARGIN+HIST_HEIGHT, x, YMARGIN+HIST_HEIGHT-y);
				}
			}
		}
	}
		
	void drawLogPlot (long maxCount, ImageProcessor ip) {
		frame = new Rectangle(XMARGIN, YMARGIN, HIST_WIDTH, HIST_HEIGHT);
		ip.drawRect(frame.x-1, frame.y, frame.width+2, frame.height+1);
		double max = Math.log(maxCount);
		ip.setColor(Color.gray);
		if (histogram.length<=HIST_WIDTH) {
			int index, y;
			for (int i = 0; i<HIST_WIDTH; i++) {
				index = (int)(i*(double)histogram.length/HIST_WIDTH); 
				y = histogram[index]==0?0:(int)(HIST_HEIGHT*Math.log(histogram[index])/max);
				if (y>HIST_HEIGHT)
					y = HIST_HEIGHT;
				ip.drawLine(i+XMARGIN, YMARGIN+HIST_HEIGHT, i+XMARGIN, YMARGIN+HIST_HEIGHT-y);
			}
		} else {
			double xscale = (double)HIST_WIDTH/histogram.length; 
			for (int i=0; i<histogram.length; i++) {
				long value = histogram[i];
				if (value>0L) {
					int y = (int)(HIST_HEIGHT*Math.log(value)/max);
					if (y>HIST_HEIGHT) y = HIST_HEIGHT;
					int x = (int)(i*xscale)+XMARGIN;
					ip.drawLine(x, YMARGIN+HIST_HEIGHT, x, YMARGIN+HIST_HEIGHT-y);
				}
			}
		}
		ip.setColor(Color.black);
	}
		
	void drawText(ImageProcessor ip, int x, int y, boolean fixedRange) {
		ip.setFont(new Font("SansSerif",Font.PLAIN,12));
		ip.setAntialiasedText(true);
		double hmin = cal.getCValue(stats.histMin);
		double hmax = cal.getCValue(stats.histMax);
		double range = hmax-hmin;
		if (fixedRange&&!cal.calibrated()&&hmin==0&&hmax==255)
			range = 256;
		ip.drawString(d2s(hmin), x - 4, y);
		ip.drawString(d2s(hmax), x + HIST_WIDTH - getWidth(hmax, ip) + 10, y);
        
		double binWidth = range/stats.nBins;
		binWidth = Math.abs(binWidth);
		boolean showBins = binWidth!=1.0 || !fixedRange;
		int col1 = XMARGIN + 5;
		int col2 = XMARGIN + HIST_WIDTH/2;
		int row1 = y+25;
		if (showBins) row1 -= 8;
		int row2 = row1 + 15;
		int row3 = row2 + 15;
		int row4 = row3 + 15;
		long count = stats.longPixelCount>0?stats.longPixelCount:stats.pixelCount;
		String modeCount = " (" + stats.maxCount + ")";
		if (modeCount.length()>12) modeCount = "";
		ip.drawString("Count: " + count, col1, row1);
		ip.drawString("Mean: " + d2s(stats.mean), col1, row2);
		ip.drawString("StdDev: " + d2s(stats.stdDev), col1, row3);
		ip.drawString("Mode: " + d2s(stats.dmode) + modeCount, col2, row3);
		ip.drawString("Min: " + d2s(stats.min), col2, row1);
		ip.drawString("Max: " + d2s(stats.max), col2, row2);
		
		if (showBins) {
			ip.drawString("Bins: " + d2s(stats.nBins), col1, row4);
			ip.drawString("Bin Width: " + d2s(binWidth), col2, row4);
		}
	}

	/*
	String d2s(double d) {
		if (d==Double.MAX_VALUE||d==-Double.MAX_VALUE)
			return "0";
		else if (Double.isNaN(d))
			return("NaN");
		else if (Double.isInfinite(d))
			return("Infinity");
		else if ((int)d==d)
			return ResultsTable.d2s(d,0);
		else
			return ResultsTable.d2s(d,decimalPlaces);
	}
	*/
	
	private String d2s(double d) {
		if ((int)d==d)
			return IJ.d2s(d, 0);
		else
    		return IJ.d2s(d, 3, 8);
    }
	
	int getWidth(double d, ImageProcessor ip) {
		return ip.getStringWidth(d2s(d));
	}
	
	/** Returns the histogram values as a ResultsTable. */
	public ResultsTable getResultsTable() {
		ResultsTable rt = new ResultsTable();
		rt.showRowNumbers(false);
		rt.setPrecision(digits);
		String vheading = stats.binSize==1.0?"value":"bin start";
		if (cal.calibrated() && !cal.isSigned16Bit()) {
			for (int i=0; i<stats.nBins; i++) {
				rt.setValue("level", i, i);
				rt.setValue(vheading, i, cal.getCValue(stats.histMin+i*stats.binSize));
				rt.setValue("count", i, histogram[i]);
			}
		} else {
			for (int i=0; i<stats.nBins; i++) {
				rt.setValue(vheading, i, cal.getCValue(stats.histMin+i*stats.binSize));
				rt.setValue("count", i, histogram[i]);
			}
		}
		return rt;
	}

	protected void showList() {
		ResultsTable rt = getResultsTable();
		rt.show(getTitle());
	}
	
	protected void copyToClipboard() {
		Clipboard systemClipboard = null;
		try {systemClipboard = getToolkit().getSystemClipboard();}
		catch (Exception e) {systemClipboard = null; }
		if (systemClipboard==null)
			{IJ.error("Unable to copy to Clipboard."); return;}
		IJ.showStatus("Copying histogram values...");
		CharArrayWriter aw = new CharArrayWriter(stats.nBins*4);
		PrintWriter pw = new PrintWriter(aw);
		for (int i=0; i<stats.nBins; i++)
			pw.print(ResultsTable.d2s(cal.getCValue(stats.histMin+i*stats.binSize), digits)+"\t"+histogram[i]+"\n");
		String text = aw.toString();
		pw.close();
		StringSelection contents = new StringSelection(text);
		systemClipboard.setContents(contents, this);
		IJ.showStatus(text.length() + " characters copied to Clipboard");
	}
	
	void replot() {
		ImageProcessor ip = this.imp.getProcessor();
		frame = new Rectangle(XMARGIN, YMARGIN, HIST_WIDTH, HIST_HEIGHT);
		ip.setColor(Color.white);
		ip.setRoi(frame.x-1, frame.y, frame.width+2, frame.height);
		ip.fill();
		ip.resetRoi();
		ip.setColor(Color.black);
		if (logScale) {
			drawLogPlot(yMax>0?yMax:newMaxCount, ip);
			drawPlot(yMax>0?yMax:newMaxCount, ip);
		} else
			drawPlot(yMax>0?yMax:newMaxCount, ip);
		this.imp.updateAndDraw();
	}
	
	/*
	void rescale() {
		Graphics g = img.getGraphics();
		plotScale *= 2;
		if ((newMaxCount/plotScale)<50) {
			plotScale = 1;
			frame = new Rectangle(XMARGIN, YMARGIN, HIST_WIDTH, HIST_HEIGHT);
			g.setColor(Color.white);
			g.fillRect(frame.x, frame.y, frame.width, frame.height);
			g.setColor(Color.black);
		}
		drawPlot(newMaxCount/plotScale, g);
		//ImageProcessor ip = new ColorProcessor(img);
		//this.imp.setProcessor(null, ip);
		this.imp.setImage(img);
	}
	*/
	
	public void actionPerformed(ActionEvent e) {
		Object b = e.getSource();
		if (b==live)
			toggleLiveMode();
		else if (b==rgb)
			changeChannel();
		else if (b==list)
			showList();
		else if (b==copy)
			copyToClipboard();
		else if (b==log) {
			logScale = !logScale;
			replot();
		}
	}
	
	public void lostOwnership(Clipboard clipboard, Transferable contents) {}
	
	public int[] getHistogram() {
		int[] hist = new int[histogram.length];
		for (int i=0; i<histogram.length; i++)
			hist[i] = (int)histogram[i];
		return hist;
	}

	public double[] getXValues() {
		double[] values = new double[stats.nBins];
		for (int i=0; i<stats.nBins; i++)
			values[i] = cal.getCValue(stats.histMin+i*stats.binSize);
		return values;
	}

	private void toggleLiveMode() {
		if (liveMode())
			removeListeners();
		else
			enableLiveMode();
	}
	
	private void changeChannel() {
		ImagePlus imp = WindowManager.getImage(srcImageID);
		if (imp==null || imp.getType()!=ImagePlus.COLOR_RGB) {
			channel = INTENSITY;
			return;
		} else {
			channel++;
			if (channel>BLUE) channel=INTENSITY;
			showHistogram(imp, 256);
			String name = this.imp.getTitle();
			if (name.startsWith("Red ")) name=name.substring(4);
			else if (name.startsWith("Green ")) name=name.substring(6);
			else if (name.startsWith("Blue ")) name=name.substring(5);
			switch (channel) {
				case INTENSITY: this.imp.setTitle(name); break;
				case RED: this.imp.setTitle("Red "+name); break;
				case GREEN: this.imp.setTitle("Green "+name); break;
				case BLUE: this.imp.setTitle("Blue "+name); break;
			}
		}
	}

	private boolean liveMode() {
		return live!=null && live.getForeground()==Color.red;
	}

	private void enableLiveMode() {
		if (bgThread==null) {
			srcImp = WindowManager.getImage(srcImageID);
			if (srcImp==null) return;
			bgThread = new Thread(this, "Live Histogram");
			bgThread.setPriority(Math.max(bgThread.getPriority()-3, Thread.MIN_PRIORITY));
			bgThread.start();
			imageUpdated(srcImp);
		}
		createListeners();
		if (srcImp!=null)
			imageUpdated(srcImp);
	}
	
	// Unused
	public void imageOpened(ImagePlus imp) {
	}

	// This listener is called if the source image content is changed
	public synchronized void imageUpdated(ImagePlus imp) {
		if (imp==srcImp) { 
			doUpdate = true;
			notify();
		}
	}
	
	public synchronized void roiModified(ImagePlus img, int id) {
		if (img==srcImp) {
			doUpdate=true;
			notify();
		}
	}

	// If either the source image or this image are closed, exit
	public void imageClosed(ImagePlus imp) {
		if (imp==srcImp || imp==this.imp) {
			if (bgThread!=null)
				bgThread.interrupt();
			bgThread = null;
			removeListeners();
			srcImp = null;
		}
	}
	
	// the background thread for live plotting.
	public void run() {
		while (true) {
			if (doUpdate && srcImp!=null) {
				if (srcImp.getRoi()!=null)
					IJ.wait(50);	//delay to make sure the roi has been updated
				if (srcImp!=null) {
					if (srcImp.getBitDepth()==16 && ImagePlus.getDefault16bitRange()!=0)
						showHistogram(srcImp, 256, 0, Math.pow(2,ImagePlus.getDefault16bitRange())-1);
					else
						showHistogram(srcImp, 256);
				}
			}
			synchronized(this) {
				if (doUpdate) {
					doUpdate = false;		//and loop again
				} else {
					try {wait();}	//notify wakes up the thread
					catch(InterruptedException e) { //interrupted tells the thread to exit
						return;
					}
				}
			}
		}
	}
	
	private void createListeners() {
		if (srcImp==null)
			return;
		ImagePlus.addImageListener(this);
		Roi.addRoiListener(this);
		if (live!=null) {
			Font font = live.getFont();
			live.setFont(new Font(font.getName(), Font.BOLD, font.getSize()));
			live.setForeground(Color.red);
		}
	}
	
	private void removeListeners() {
		if (srcImp==null)
			return;
		ImagePlus.removeImageListener(this);
		Roi.removeRoiListener(this);
		if (live!=null) {
			Font font = live.getFont();
			live.setFont(new Font(font.getName(), Font.PLAIN, font.getSize()));
			live.setForeground(Color.black);
		}
	}

}

