/* MODE D'EMPLOI
 * =============
 * - creer une ligne qui apparaitra dans le cadran superieur droit
 * - creer une seconde ligne respectant la meme contrainte
 * - appeler draw2lines()
 * - cliquer sur line1 puis sur line2
 * - la premiere apparait en jaune, la seconde en bleu, SOPC en rouge
 */
package line_v5;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
    
  /*
   * Example of how to use a LineDrawer to draw a line ax+by+c=0
   * [very bad programming : should be totally rewritten !]
   */
    
/**
 * Class LineDrawer - To draw a given line in a 2D basic graphical panel.
 * @author am; modified DB, JC, DB
 * @version 09/2003; modified 10/2004, 09/2006
 */
class LineDrawer extends JPanel
{
  private final  int   leftMargin   = 20 ;
  private final  int   rightMargin  = 20 ;
  private final  int   topMargin    = 20 ;
  private final  int   bottomMargin = 20 ;
  private final  Color bg           = new Color(222,222,222); // Color.lightGray;
  private final  Color fg           = Color.black;
  private  int zeroX;
  private  int zeroY;
  private  int maxX;
  private  int maxY;
  private  int boundBoxX;
  private  int boundBoxY;
  private Line droite1, droite2;
  private static JFrame f=null;
  private static LineDrawer lineDrawer;

  /* Method drawLine
   * Draw a line ax+by+c=0 in a 2D basic graphical panel
   * (try, for example, with : a=0.7, b=3.0, c=-210)
   */
  public static void draw2Lines( final Line lin1, final Line lin2 )
  {
    // Define the drawing frame dimensions
    final int width  = 800 ;
    final int height = 600 ;
    
    // Create a drawing frame
    if (f==null)
      {
      f = new JFrame( "LineDrawer demo" );
      f.addWindowListener(
        new WindowAdapter()
        {
          public void windowClosing( WindowEvent e )
          {
//            System.exit( 0 );
            f=null;
          } // windowClosing()
        } // WindowAdapter
      ); // addWindowListener()
        
      // Create the LineDrawer panel and insert it into the frame
      lineDrawer = new LineDrawer( lin1, lin2 );
      f.getContentPane().add( lineDrawer, BorderLayout.CENTER );
      f.setSize( new Dimension( width, height ) );
      f.setVisible( true );
      } // if no frame
    else
      System.out.println( "Fermer d'abord la fenêtre graphique !" );
      // TODO: permettre de redessiner d'autres droites sans fermer
  } // draw2Lines()
  
  /**
   * Draw the given line
   * Draw the line ax+by+c=0 in a fixed drawing area without scaling.
   * If the line doesn't cross this zone, an error message is prompted.
   * @param li a Line
   */
  private void drawLine( final Graphics g, final Line li, final int numLine )
  {
    double a, b, c ; // Coefficients of the line ax+by+c=0 to draw
    String e; // equation de la droite
    // Initialize the coefficients of the line ax+by+c=0
    a = li.getA() ; 
    b = li.getB() ;
    c = li.getC() ;
    e = li.toString();

    if ( a==0.0 && b==0.0 )
    {
      g.drawString( e + "  is not a line !",
        maxX/3, zeroY/(5-numLine)) ;
      return;
    }
    
    // Draw line ax+by+c=0
    /* Il faut tester l'intersection de la droite avec la bounding box */
    
    double x,y;
    double Px[] = new double[2];
    double Py[] = new double[2];
    int nbPoints = 0;
    
    if ( (b != 0) && (nbPoints < 2)){
        x = 0;
        y = -c/b;
        //system.out.println("Intersection x=0 en : "+ y);
        if( (y >= 0) && (y <= boundBoxY)){
            Px[nbPoints] = x;
            Py[nbPoints] = y;
            nbPoints ++;
        }
        if(nbPoints < 2){
            x = boundBoxX;
            y = (-c -a*x)/b;
            //system.out.println("Intersection x=" + boundBoxX + " en y = " +  y);
            if( (y >= 0) && (y <= boundBoxY)){
                Px[nbPoints] = x;
                Py[nbPoints] = y;
                nbPoints ++;
            }
        }
    }
    
    if ( (a != 0) && (nbPoints < 2)) {
        y = 0;
        x = -c/a;
        //system.out.println("Intersection y=0 en x = "+ x);
        if( (x > 0) && (x < boundBoxX)){
            Px[nbPoints] = x;
            Py[nbPoints] = y;
            nbPoints ++;
        }
        if(nbPoints < 2){
            y = boundBoxY;
            x = (-c - b*y)/a;
            //system.out.println("Intersection y =" + boundBoxY + " en x = " + x);
            if( (x > 0) && (x < boundBoxX)){
                Px[nbPoints] = x;
                Py[nbPoints] = y;
                nbPoints ++;
            }
        }
    }
    
    //system.out.println("nbIntersection : " + nbPoints);
    /* Si la doite intersect la bounding box */
    if( (nbPoints == 2) &&
    ( (Px[0] != Px[1]) || (Py[0] != Py[1]) ) ){
        /* On met les points à la meme echelle que l'affichage */
        Px[0] = Px[0] * 100 + zeroX;
        Px[1] = Px[1] * 100 + zeroX;
        
        Py[0] = -Py[0] * 100 + zeroY;
        Py[1] = -Py[1] * 100 + zeroY;
        
        //system.out.println("P1 = (" + Px[0] + "," + Py[0] + ") P2 = (" + Px[1] + "," + Py[1] + ")");
        g.drawLine((int)Px[0], (int)Py[0], (int)Px[1], (int)Py[1]);
    }
    else
    { 
      // if no, prompt a message of error in the drawing area
      g.drawString("Line  " + e + "  is out of drawing bounds",
        maxX/3, zeroY/(5-numLine)) ;
    } 
} // drawLine()
    
  /**
   * Create a 2D graphical panel to draw lines
   */
  private LineDrawer( final Line d1, final Line d2 )
  {
    droite1 = d1;
    droite2 = d2;
    // Initialize drawing colors, border, opacity.
    setBackground(bg);
    setForeground(fg);
    setBorder(BorderFactory.createCompoundBorder(
    BorderFactory.createRaisedBevelBorder(),
    BorderFactory.createLoweredBevelBorder()));
  } // LineDrawer()


  /** prepare drawing zone
   */
  public void paintComponent(final Graphics g)
  {
    super.paintComponent(g);      //clears the background

    // getInsets() = get the external padding of the component (i.e. the
    //   minimum amount of space between the component and the edges of
    //   its display area
    // getWidth() = get the current width of the component, measured in 
    //   pixels
    Insets insets = getInsets();
     zeroX = insets.left + leftMargin;
     zeroY = getHeight() - insets.bottom - bottomMargin ;
     maxX  = getWidth()  - insets.right  - rightMargin ;
     maxY  = insets.top  + topMargin;
     boundBoxX = (maxX - zeroX) / 100;
     boundBoxY = (zeroY - maxY) / 100;
    
    //system.out.println("(zeroX,zeroY) = ("+ zeroX + "," + zeroY + ") (maxX, maxY) = ("+ maxX + "," + maxY + 
    //    ") (boundBoxX,boundBoxY) = ("+ boundBoxX + "," + boundBoxY + ")");
    
    //g.drawLine(x1, y1, x2, y2);
    //   +----> x
    //   |
    //   y
        
    // Draw axis x (horizontal axis)
  
    g.drawLine(zeroX, zeroY, maxX , zeroY);
    g.drawString("x", maxX+5, zeroY+3);


    // Draw axis y (vertical axis)
    g.drawLine(zeroX, zeroY, zeroX, maxY);
    g.drawString("y", zeroX-3, maxY-3);


    // Mark point (0,0)
    g.drawString("(0,0)",zeroX-10, zeroY+15);


    // Draw scale x
    for (int i = 100 ; i < maxX ; i+=100 )
    {
      g.drawLine(i+zeroX, zeroY-5, i+zeroX, zeroY+5);
      g.drawString(String.valueOf(i), i+zeroX-7, zeroY-7);
    } // for


    // Draw scale y
    for (int j = 100 ; j < zeroY ; j+=100 )
    {
      g.drawLine(zeroX-5, zeroY-j, zeroX+5, zeroY-j);
      g.drawString(String.valueOf(j), zeroX-20, zeroY-j-5);
    } // for
    
    g.setColor(Color.yellow);
    drawLine( g, droite1, 1 );
    g.setColor(Color.blue);
    drawLine( g, droite2, 2 );
    g.setColor(Color.red);
    g.drawString( droite1.estSOPC(droite2), maxX/3, zeroY/2 );
    g.setColor(fg);
  } // paintComponent()
  
} // LineDrawer