package awb;

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

/** MultiLineLabel Class
*   Eric Jewart
*   7 January 1997
*   Based on MultiLineLabel Class found in D. Flanagan's
*   _Java_In_A_Nutshell_.
*
*   The MultiLineLabel displays some text like a regular
*   Java Label.  Unlike a regular Label, it allows the
*   text to include \n characters.
*
*   This class includes a large number of utility functions
*   which I will not document here but which are documented
*   in _Nutshell_.
*
*   Variables
*   ---------
*   int LEFT
*   int CENTER
*   int RIGHT
*	Three different ways to align your label.
*
*   Constructors
*   ------------
*   MultiLineLabel(String, int, int, int)
*	The String is the message to be displayed.  The first 
*	int is the width of the side margins, the second is the
*	height of the top and bottom margins, and the third is
*	the alignment (MultiLineLabel.LEFT, .CENTER, or .RIGHT).
*
*   MultiLineLabel(String, int, int)
*	Same as above except the alignment defaults to LEFT.
*
*   MultiLineLabel(String, int)
*	Uses default margins.  The int specifies alignment.
*
*   MultiLineLabel(String)
*	Uses default margins and alignment.
*/

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;

    // break label into array of lines
    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();
    }

    // figure out how large the font is, how wide each line is
    // and how wide the widest line is
    protected void measure() {
	try {
	    FontMetrics fm = this.getFontMetrics(this.getFont());

	    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];
	    }
	}
	catch (NullPointerException ex) { return; }
    }

    // four different constructors
    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 setText(String label) {
	setLabel(label);
    }

    public void setLabel(String label) {
	newLabel(label);
	measure();
	repaint();
    }

    public String getText() {
	String ret = "";
	for (int i = 0; i < lines.length; i++)
	    ret = ret + lines[i] + "\n";
 	return ret;
    }

    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 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);
    }

    // draw label
    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);
	}
    }

}