// Wavelet.java

import java.applet.Applet;
import java.awt.*;

public class Wavelet
	extends java.applet.Applet
{
	public static final String name    = "Wavelet";
	public static final String version = "1.0";
	public static double values[];
	static double 		a[];
	public static int	n,k;
	public static double xMarginFactor,yMarginFactor;
	public static int	distance,level;
	Plot 				plot;
	ButtonPanel			buttons;
	TextArea			textarea;
	Scribble			scribble;
	GridBagConstraints	constraints;
	
	Button				bUP,bDOWN;
	Checkbox			haarCB,other1CB,other2CB;

	public void init()
	{
		int		i;
		this.values = new double[2048];
		this.a = new double[1000];
		Color bgColor = new Color(255,255,255);
		
		xMarginFactor = 0.1;
		yMarginFactor = 0.1;
		
		plot = new Plot(this);
		plot.setBackground(bgColor);
		
		constraints = new GridBagConstraints();
		buttons = new ButtonPanel(this);
		
		// add UP button
		constraints.weightx = 1.0;
		constraints.gridx = 0;
		constraints.gridy = 0;
		constraints.anchor = GridBagConstraints.CENTER;
		constraints.fill = GridBagConstraints.HORIZONTAL;
		bUP = new Button("UP");
		buttons.gridbag.setConstraints(bUP,constraints);
		buttons.add(bUP);

		// add DOWN button
		constraints.gridx = GridBagConstraints.RELATIVE;
		constraints.anchor = GridBagConstraints.CENTER;
		constraints.fill = GridBagConstraints.HORIZONTAL;
		bDOWN = new Button("DOWN");
		buttons.gridbag.setConstraints(bDOWN,constraints);
		buttons.add(bDOWN);

		
		// add Haar checkbox
		constraints.gridx = 0;
		constraints.gridy = 1;
		constraints.anchor = GridBagConstraints.CENTER;
		constraints.fill = GridBagConstraints.HORIZONTAL;
		Checkbox haarCB = new Checkbox("Haar",buttons.cbg,true);
		buttons.gridbag.setConstraints(haarCB,constraints);
		buttons.add(haarCB);

		// add other1 checkbox
		constraints.gridx = GridBagConstraints.RELATIVE;
		Checkbox other1CB = new Checkbox("Other1",buttons.cbg,false);
		buttons.gridbag.setConstraints(other1CB,constraints);
		buttons.add(other1CB);

		// add other2 checkbox
		Checkbox other2CB = new Checkbox("Other2",buttons.cbg,false);
		buttons.gridbag.setConstraints(other2CB,constraints);
		buttons.add(other2CB);

		// buttons.addCheckbox("other1",false);
		// buttons.addCheckbox("other2",false);
		textarea = new TextArea(10,40);
		textarea.setEditable(false);
		scribble = new Scribble(this);
		scribble.setBackground(bgColor);
		
		setLayout(new GridLayout(4,1,10,10));
		
		add(plot);
		add(buttons);
		add(textarea);
		add(scribble);
		
		// initialize to some dummy function		
		n = 16;
		k = 4;
		distance = 1;	// distance is distance to next value entry
		level = k;
		
		this.values[0] = 0.05;
		this.values[1] = 0.4;
		this.values[2] = 0.1;
		this.values[3] = 0.4;
		this.values[4] = 0.15;
		this.values[5] = 0.6;
		this.values[6] = 0.2;
		this.values[7] = 0.2;
		this.values[8] = 0.25;
		this.values[9] = 0.3;
		this.values[10] = 0.35;
		this.values[11] = 0.2;
		this.values[12] = 0.4;
		this.values[13] = 0.1;
		this.values[14] = 0.45;
		this.values[15] = 0.3;
		this.values[16] = 0.5;
		this.values[17] = 0.5;
		this.values[18] = 0.55;
		this.values[19] = 0.6;
		this.values[20] = 0.6;
		this.values[21] = 0.5;
		this.values[22] = 0.65;
		this.values[23] = 0.6;
		this.values[24] = 0.7;
		this.values[25] = 0.6;
		this.values[26] = 0.75;
		this.values[27] = 0.6;
		this.values[28] = 0.8;
		this.values[29] = 0.5;
		this.values[30] = 0.85;
		this.values[31] = 0.5;
		
		for (i=0; i<n; i++) { 
			this.a[2*i] = this.values[2*i]; 
			this.a[2*i+1] = this.values[2*i+1]; 
		}
		Graphics g = this.plot.getGraphics();
		repaint();

	}
	
	public void paint(Graphics g)
	{
		int		width,height;
		int		xmargin,xscale;
		int		ymargin,yscale;
		int		x1,x2,y1,y2;
		int		i,j,jj;
		int		pwr,skip;
	
		
		Graphics gg = this.plot.getGraphics();
		
		width = this.plot.size().width;
		height = this.plot.size().height;
		xmargin = (int) (width*this.xMarginFactor);
		ymargin = (int) (height*this.yMarginFactor);
		xscale = width - 2*xmargin;
		yscale = height - 2*ymargin;
		
		x1 = xmargin + (int)(this.a[0]*xscale);
		y1 = ymargin + (int)(this.a[1]*yscale);
		
		this.textarea.appendText("clear plot\n");

		gg.setColor(this.plot.getBackground());
		gg.fillRect(0,0,width,height);
		gg.setColor(this.plot.getForeground());

		for (j=this.distance; j<this.n; j+=this.distance) {
			jj = 2*j;
			x2 = xmargin + (int)(this.a[jj]*xscale);
			y2 = ymargin + (int)(this.a[jj+1]*yscale);
			gg.drawLine(x1,y1,x2,y2);
			x1 = x2;
			y1 = y2;
		}
		
	}

	public void start()
	{
	}

	public void stop()
	{
	}

	public void destroy()
	{
	}

	public String getAppletInfo()
	{
		return name + " version " + version;
	}
	
	void update(String bname) {
		int			j,jj,jk;
		Checkbox	activeCB;
		String		s;
		
		// this.textarea.appendText("button " + bname + " pushed\n");
		activeCB = buttons.cbg.getCurrent();
		s = activeCB.getLabel();
		this.textarea.appendText("checkbox " + s + " active\n");
		
		if (s.compareTo("Haar") == 0) {
			if (bname.equals("UP"))  {
				if (this.distance > 1) {
					this.level++;
					this.textarea.appendText("go up one level to " + level + "\n");
					this.distance /= 2;
					for (j=0; j<this.n; j+=2*this.distance) {
						jj = 2*j;
						jk = 2*(j+this.distance);
						this.a[jk] += this.a[jj];
						this.a[jk+1] += this.a[jj+1];
						this.a[jj] = 2*this.a[jj] - this.a[jk];
						this.a[jj+1] = 2*this.a[jj+1] - this.a[jk+1];
					}
				}
			}
		
			else if (bname.equals("DOWN")) {
				if (this.distance < this.n) {
					this.level--;
					this.textarea.appendText("go down one level to " + level + "\n");
					for (j=0; j<this.n; j+= 2*this.distance) {
						jj = 2*j;
						jk = 2*(j+this.distance);
						this.a[jj] = (this.a[jj] + this.a[jk])/2.0;
						this.a[jj+1] = (this.a[jj+1] + this.a[jk+1])/2.0;
						this.a[jk] -= this.a[jj];
						this.a[jk+1] -= this.a[jj+1];
					}
					
					this.distance *= 2;
				}
			}
			else if (bname.equals("EXIT")) {
				// System.exit();
			}
		}
		Graphics g = this.getGraphics();
		g.setColor(this.plot.getBackground());
		g.fillRect(0,0,this.plot.size().width,this.plot.size().height);
		g.setColor(this.plot.getForeground());

		repaint();
	}
}
	
class ButtonPanel extends Panel {
	Wavelet				outerparent;
	CheckboxGroup		cbg;
	GridBagLayout		gridbag;
	
	ButtonPanel(Wavelet target) {
		outerparent = target;
		gridbag = new GridBagLayout();
		this.setLayout(gridbag);
		cbg = new CheckboxGroup();
	}
	
	public boolean action(Event evt, Object arg) {
		if (evt.target instanceof Button) {
			// this.outerparent.textarea.appendText("button " + arg + " pushed\n");
			this.outerparent.update((String)arg);
			return(true);
		}
		else return false;
	}
}

class Scribble extends Canvas {
	Wavelet	outerparent;
	int		lastX,lastY;
	int		width,height;
	
	Scribble(Wavelet target) {
		this.outerparent = target;
	}
	
	public boolean mouseDown(Event evnt,int x,int y) {
		// this.outerparent.textarea.appendText("mouse down\n");
		this.clear();
		this.lastX = x;
		this.lastY = y;
		outerparent.values[0] = x;
		outerparent.values[1] = y;
		outerparent.n = 1;
		this.width = this.size().width;
		this.height = this.size().height;
		this.outerparent.textarea.appendText("width = " + this.width +
							"; height = " + this.height + "\n");
		return true;
	}
	
	public boolean mouseDrag(Event evnt,int x,int y) {
		if (outerparent.n < 1024) {
			Graphics g = this.getGraphics();
			g.drawLine(lastX,lastY,x,y);
			this.lastX = x;
			this.lastY = y;
			outerparent.values[2*outerparent.n] = x;
			outerparent.values[2*outerparent.n+1] = y;
			outerparent.n++;
		}
		return true;
	}
	
	public boolean mouseUp(Event evnt,int x,int y) {
		int		i;
		int		n;
		
		// this.outerparent.textarea.appendText("mouse up\n");
		n = outerparent.n;
		
		outerparent.k = 1;
		i = 2;
		while (i<=n) { outerparent.k++; i*=2;}
		outerparent.k--;					// k is the largest power of 2 in n
		outerparent.n = i/2;
		this.outerparent.textarea.appendText("n = " + outerparent.n +
										"; level = " + outerparent.k + "\n");
		
		outerparent.distance = 1;			// distance is distance to next value entry
		outerparent.level = outerparent.k;	// level is the current level being displayed
		
		
		for (i=0; i<n; i++) {
			this.outerparent.a[2*i] = 
				this.outerparent.values[2*i]/this.width;
			this.outerparent.a[2*i+1] = 
				this.outerparent.values[2*i+1]/this.height;
		}
		
		return true;
	}	
	
	public void clear() {
		this.outerparent.textarea.appendText("clear canvas\n");
		Graphics g = this.getGraphics();
		g.setColor(this.getBackground());
		g.fillRect(0,0,this.width,this.height);
		g.setColor(this.getForeground());
	}
}

class Plot extends Canvas {
	Wavelet	outerparent;
	int		mini;			/* index of point to move */
	int		width,height;
	int		xmargin,ymargin;
	int		xscale,yscale;
	
	Plot(Wavelet target) {
		this.outerparent = target;
		this.width = this.size().width;
		this.height = this.size().height;
		this.xmargin = (int) (this.width*target.xMarginFactor);
		this.ymargin = (int) (this.height*target.yMarginFactor);
		this.xscale = this.width - 2*this.xmargin;
		this.yscale = this.height - 2*this.ymargin;
	}
	
	public boolean mouseDown(Event evnt,int x,int y) {
		double		minDist,dist,dx,dy,fx,fy;
		int			i,j;
		
		this.outerparent.textarea.appendText("mouse down at " +
			x + ", " + y +"\n");
		this.width = this.size().width;
		this.height = this.size().height;
		this.xmargin = (int) (this.width*this.outerparent.xMarginFactor);
		this.ymargin = (int) (this.height*this.outerparent.yMarginFactor);
		this.xscale = this.width - 2*this.xmargin;
		this.yscale = this.height - 2*this.ymargin;
		fx = x - this.xmargin;
		fx = fx/this.xscale;
		fy = y - this.ymargin;
		fy = fy/this.yscale;
		this.outerparent.textarea.appendText("mouse down at " +
			fx + ", " + fy +"\n");
		
		dx = (double)fx - this.outerparent.a[0];
		dy = (double)fy - this.outerparent.a[1];
		minDist = Math.sqrt(dx*dx+dy*dy);
		this.mini = 0;
		for (i=2*this.outerparent.distance; 
			  i<2*this.outerparent.n; 
			  i+=2*this.outerparent.distance) {
			dx = (double)fx - this.outerparent.a[i];
			dy = (double)fy - this.outerparent.a[i+1];
			dist = Math.sqrt(dx*dx+dy*dy);
			if (dist < minDist) {
				minDist = dist;
				this.mini = i;
			}
		}
		this.outerparent.textarea.appendText("closest point is " +
								this.mini + "\n");
		return true;
	}
	
	public boolean mouseDrag(Event evnt,int x,int y) {
		double		fx,fy;
		
		this.outerparent.textarea.appendText("mouse drag\n");
		this.width = this.size().width;
		this.height = this.size().height;
		this.xmargin = (int) (this.width*this.outerparent.xMarginFactor);
		this.ymargin = (int) (this.height*this.outerparent.yMarginFactor);
		this.xscale = this.width - 2*this.xmargin;
		this.yscale = this.height - 2*this.ymargin;
		fx = x - this.xmargin;
		fx = fx/this.xscale;
		fy = y - this.ymargin;
		fy = fy/this.yscale;
		this.outerparent.a[this.mini] = fx;
		this.outerparent.a[this.mini+1] = fy;
		this.outerparent.textarea.appendText("move point " +
				this.mini + " to (" + fx + ", " + fy + ")\n");
		this.outerparent.repaint();
		return true;
	}
	
	public boolean mouseUp(Event evnt,int x,int y) {
		this.outerparent.textarea.appendText("mouse up\n");
		return true;
	}	
	
}