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

// a nice little component from O'Reilly
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;

	public MultiLineLabel(String label, int mw, int mh, int a)
	{
		newLabel(label);
		setMarginWidth(mw);
		setMarginHeight(mh);
		setAlignment(a);
	}
	public MultiLineLabel(String label, int alignment)
	{
		this(label,10,10,alignment);
	}
	public MultiLineLabel(String label)
	{
		this(label,10,10,LEFT);
	}
	public MultiLineLabel()
	{
		this("",10,10,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 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);
		}
	}
}