/*
 * @(#)CLegendUI.java		0.0.1 99/07/29
 *
 * Copyright (c) 1999 by Willie Wheeler.  All rights reserved.
 */
package stats.plaf.concrete;

import java.awt.*;
import javax.swing.*;
import javax.swing.plaf.*;
import stats.*;
import stats.plaf.*;

/**
 * @version	0.0.1 07/29/99
 * @author	Willie Wheeler
 */
public class CLegendUI extends LegendUI {

    protected static final int    XPAD = 5, YPAD = 5;

    protected static ComponentUI  ui = new CLegendUI();

    public static ComponentUI createUI(JComponent c) { return ui; }

    public void installUI(JComponent c) { c.setOpaque(false); }

    public void uninstallUI(JComponent c) { }

    public void paint(Graphics g, JComponent c) {
	Legend legend = (Legend)c;
	int legendWidth = legend.getSize().width;
	int legendHeight = legend.getSize().height;
	int numCats = legend.getNumStates();
	FontMetrics fm = legend.getFontMetrics(legend.getFont());
	int lineHeight = (int)(1.2 * fm.getHeight());
	int boxSide = fm.getHeight() - fm.getLeading();

	// Center legend vertically.
	int allLinesHeight = (numCats+1) * lineHeight;
	int yOff = Math.max(YPAD, (legendHeight - allLinesHeight) / 2);
	g.translate(0, yOff);

	// Paint variable name, centered horizontally.
	String varName = legend.getIndependentsAsString();
	int xOff = Math.max(XPAD, (legendWidth - fm.stringWidth(varName)) / 2);
	g.setColor(legend.getTextColor());
	g.drawString(varName, xOff, boxSide - 3);

	// Center boxes and categories horizontally, and drop down one line.
	int maxCatWidth = 0;
	for (int i = 0; i < numCats; i++) {
	    int catWidth = fm.stringWidth(legend.getStateName(i));
	    maxCatWidth = Math.max(catWidth, maxCatWidth);
	}
	int boxPlusCatsWidth = boxSide + XPAD + maxCatWidth;
	xOff = Math.max(XPAD, (legendWidth - boxPlusCatsWidth) / 2);
	g.translate(xOff, lineHeight);

	// Paint boxes and categories.
	for (int i = 0; i < numCats; i++) {
	    int y = i * lineHeight;
	    g.setColor(legend.getStateColor(i));
	    g.fillRect(0, y, boxSide, boxSide);
	    g.setColor(legend.getTextColor());
	    g.drawRect(0, y, boxSide, boxSide);
	    g.drawString(legend.getStateName(i),
			 boxSide + XPAD,
			 y + boxSide - 3);
	}
    }

    public Dimension getPreferredSize(JComponent c) {
	Legend legend = (Legend)c;
	int numCats = legend.getNumStates();
	FontMetrics fm = legend.getFontMetrics(legend.getFont());

	// Compute preferred width = max(var name width, category widths).
	int varNameWidth = fm.stringWidth(legend.getIndependentsAsString());
	int maxCatWidth = 0;
	for (int i = 0; i < numCats; i++) {
	    int catWidth = fm.stringWidth(legend.getStateName(i));
	    maxCatWidth = Math.max(catWidth, maxCatWidth);
	}
	int boxSide = fm.getHeight() - fm.getLeading();
	int prefWidth = Math.max(varNameWidth, boxSide + XPAD + maxCatWidth) +
	    2*XPAD;

	// Compute preferred height.
	int lineHeight = (int)(1.2 * fm.getHeight());
	int prefHeight = (numCats+1)*lineHeight + 2*YPAD;

	// Return preferred size.
	return new Dimension(prefWidth, prefHeight);
    }

    public Dimension getMinimumSize(JComponent c) {
	return getPreferredSize(c);
    }

    public Dimension getMaximumSize(JComponent c) {
	return getPreferredSize(c);
    }
}