/*----------------------------------------------------------------------+
|	Title:	RangeDisplay.java                                       |
|                                                                       |
|	Author:	David E. Joyce                                          |
|		Department of Mathematics and Computer Science          |
|       	Clark University                                        |
|       	Worcester, MA 01610-1477                                |
|       	U.S.A.                                                  |									|                                                                       |
|		http://aleph0.clarku.edu/~djoyce/home.html              |
|		djoyce@clarku.edu                                       |
|                                                                       |
|	Date:	February, 2001.                                         |
+----------------------------------------------------------------------*/


import java.awt.*;
import java.awt.event.*;

public class RangeDisplay extends Canvas {

  Color background;      // background color for the window
  Range R;               // the range being displayed

  //display data
  double x[], y[];       // the (x,y) coordinates for the center of the herd
  double s_rad, t_rad;   // relative radii of circles

  RangeDisplay (Range R_init, Color bg_init) {
    R = R_init;
    R.display = this;
    background = bg_init;
    resetRangeDisplay();
    addMouseListener(new MouseClickListener());
  }

  void resetRangeDisplay() {
    // compute some display constants
    x = new double[R.n_herds];
    y = new double[R.n_herds];
    if (R.n_herds == 1) {                 // special computations when one herd
      x[0] = 0.0;
      y[0] = 0.0;
      s_rad = 0.0;
      t_rad = 1.0;
    } else {                            // more than one herd
      double theta = 2*Math.PI/R.n_herds;
      for (int i=0; i<R.n_herds; ++i) {
        x[i] = Math.cos(i*theta);
        y[i] = Math.sin(i*theta);
      }
      double sin = Math.sin(theta/2.0);
      s_rad = 1.0/(1.0 + sin);          // relative radius of circle centers
      t_rad = s_rad*sin;                // relative radius of circles
    }  
  }

  Image offscreen;
  Dimension offscreensize;
  Graphics offgraphics;
  Color black = new Color(0);

  public void update(Graphics g) {
    g.setColor(background);
    Dimension d = getSize();
    if ((offscreen == null) || (d.width != offscreensize.width) 
		|| (d.height != offscreensize.height)) {
      offscreen = createImage(d.width, d.height);
      offscreensize = d;
      offgraphics = offscreen.getGraphics();
      offgraphics.setFont(g.getFont());
    }
    drawHerds(offgraphics);
    offgraphics.setColor(black);
    offgraphics.drawString(R.day+"", getSize().width/2-10, getSize().height/2+5);
    g.drawImage(offscreen, 0, 0, null);
  }

  public void drawHerds(Graphics g) {
    g.setColor(background);
    Dimension d = getSize();
    g.fillRect(0,0,d.width,d.height);
    
    int center_x = d.width/2;
    int center_y = d.height/2;
    double min = (center_x < center_y) ? center_x : center_y;
    double radius = s_rad*min;
    int herd_radius = (int)Math.round(t_rad*min);
    g.fillRect(0, 0, d.width, d.height);
    for (int i=0; i<R.n_herds; ++i) {   // color each herd
      g.setColor(R.H[i].chooseColor());
      // draw the herd in that color
      int h_x = center_x + (int)Math.round(radius*x[i]) - herd_radius;
      int h_y = center_y + (int)Math.round(radius*y[i]) - herd_radius;
      g.fillOval (h_x, h_y, 2*herd_radius, 2*herd_radius);
    }
  }

  public void paint(Graphics g) {
    update(g);
  }
  
  private class MouseClickListener extends MouseAdapter {
  
    public void mouseClicked(MouseEvent e) {
      int ex = e.getX();
      int ey = e.getY();
      Dimension d = getSize();
      int center_x = d.width/2;
      int center_y = d.height/2;
      double min = (center_x < center_y) ? center_x : center_y;
      double radius = s_rad*min;
      int herd_radius = (int)Math.round(t_rad*min);
      int herd_radius_squared = herd_radius*herd_radius;
      // see if (x,y) is in one of the herds
      int i;
      for (i=0; i<R.n_herds; ++i) {
        int h_x = center_x + (int)Math.round(radius*x[i]);
        int h_y = center_y + (int)Math.round(radius*y[i]);
        int dx2 = (h_x - ex)*(h_x - ex);
        int dy2 = (h_y - ey)*(h_y - ey);
        if (dx2 + dy2 < herd_radius_squared)
          break;
      }
      if (i < R.n_herds && R.selected_herd != i) {
        R.selected_herd = i;
        R.indivStats.clear();
      }
    }
  }
}