// MultiLineLabel.java
// 
// Mark F. Hulber
// May 1996
//
//
//
//

import java.awt.*;
import java.util.*;


public class MultiLineLabel extends Canvas {

   public static final int LEFT = 0;
   public static final int CENTER = 1;
   public static final int RIGHT = 2;
   protected String[] lines;
   protected int num_lines;
   protected int margin_width;
   protected int margin_height;
   protected int line_height;
   protected int line_ascent;
   protected int[] line_widths;
   protected int max_width;
   protected int alignment = LEFT;

  protected void newLabel(String label)
  {
     StringTokenizer t = new StringTokenizer(label, "\n");
     num_lines = t.countTokens();
     lines = new String[num_lines];
     line_widths = new int[num_lines];
     for (int i = 0; i < num_lines; i++) 
        lines[i] = t.nextToken();
  }

  protected void measure()
  {
     FontMetrics fm = this.getFontMetrics(this.getFont());
     if (fm == null) return;
     
     line_height = fm.getHeight();
     line_ascent = fm.getAscent();
     max_width = 0;
     for (int i = 0; i < num_lines; i++) {
        line_widths[i] = fm.stringWidth(lines[i]);
        if (line_widths[i] > max_width) max_width = line_widths[i];
     }
  }

  public MultiLineLabel(String label, int margin_width, int margin_height, 
                        int alignment)
  {   
     
     newLabel(label);
     this.margin_width = margin_width;
     this.margin_height = margin_height;
     this.alignment = alignment;
  }

  public MultiLineLabel(String label, int margin_width, int margin_height)
  {
     this(label, margin_width, margin_height, LEFT);
  }

  public MultiLineLabel(String label, int alignment)
  {

     this(label, 10, 10, alignment);
  }

  public MultiLineLabel(String label)
  {

     this(label, 10, 10, LEFT);
  }

  public void setLabel(String label)
  {

     newLabel(label);
     measure();
     repaint();
  }

  public void setFont(Font f)
  {

     super.setFont(f);
     measure();
     repaint();
  }

  public void setForeground(Color c)
  {
     super.setForeground(c);
     repaint();
  }

  public void setAlignment(int a) 
  {
     alignment = a; repaint(); 
  }

  public void setMarginWidth(int mw) 
  {
     margin_width= mw; repaint();
  }

  public void setMarginHeight(int mh)
  {
     margin_height= mh; repaint();
  }

  public int getAlignment()
  {
     return alignment;
  }

  public int getMarginWidth()
  {
     return margin_width;
  }

  public int getMarginHeight()
  {
     return margin_height; 
  }

  public void addNotify()
  {
     super.addNotify(); measure();
  }

  public Dimension preferredSize()
  {
     return new Dimension(max_width + 2*margin_width,
                          num_lines*line_height + 2*margin_height);
  }

  public Dimension minimumSize()
  {
     return new Dimension(max_width, num_lines*line_height);
  }

  public void paint(Graphics g)
  {

     int x, y;
     Dimension d = this.size();
     y = line_ascent + (d.height-num_lines*line_height)/2;
     for (int i= 0; i < num_lines; i++, y+= line_height) {
       switch(alignment) {
       case LEFT:
          x = margin_width; 
          break;
       case CENTER:
       default:
          x = (d.width -line_widths[i])/2;
          break;
       case RIGHT:
          x = d.width-margin_width-line_widths[i];
          break;
       }
       g.drawString(lines[i],x,y);
     }
  }
}