package username.analysis;

/**
 * A simple way to graph points.
 *
 * @author Samuel A. Rebelsky
 * @version 1.0 of April 2006
 */
public class Graph
{

// +------------------+-------------------------------------
// | Design Decisions |
// +------------------+

/*

(1) Graphs provide a simple wrapper for the Screen class, adding
axis marks and changing the name of the setCharAt method to plot.

 */


// +--------+-----------------------------------------------
// | Fields |
// +--------+

  /** The underlying screen used for the graph. */
  Screen screen;

  /** The character used to plot points. */
  char point;


// +--------------+-----------------------------------------
// | Constructors |
// +--------------+

  /**
   * Build a graph of specified height and width.
   */
  public Graph(int _width, int _height)
  {
    // Create the screen
    this.screen = new Screen(_width+1, _height+1);
    // Fill in the axes
    screen.setCharAt(0,0,'+');
    for (int x = 1; x <= _width; x++) {
      screen.setCharAt(x, 0, '-');
    }
    for (int y = 1; y <= _height; y++) {
      screen.setCharAt(0, y, '|');
    } 
    // Set the default plot character
    point = '*';
  } // Graph(int, int)


// +------------------+-------------------------------------
// | Standard Methods |
// +------------------+

  /**
   * Convert to a string (e.g., for printing).
   */
  public String toString()
  {
    return this.screen.toString();
  } // toString()


// +----------------+---------------------------------------
// | Public Methods |
// +----------------+

  /**
   * Plot a point at (x,y).  If (x,y) is not within the displayable
   * portion, show nothing.
   */
  public void plot(int x, int y)
  {
    this.screen.setCharAt(x,y,this.point);
  } // plot(int, int)

  /**
   * Set the character used to plot points.
   */
  public void setPlotChar(char ch)
  {
    this.point = ch;
  } // setPlotChar(char)
} // class Graph