/*
 * @(#)CBarChartUI.java		0.0.0 99/07/24
 *
 * Copyright (c) 1999 by Willie Wheeler.  All rights reserved.
 */
package stats.plaf.concrete;

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

/**
 * @version	0.0.0 07/24/99
 * @author	Willie Wheeler
 */
public class CBarChartUI extends BarChartUI {
    protected static final int            XPAD = 5, YPAD = 5;
    protected static final int            LABEL_WIDTH = 27;
    protected static final float          FONT_SIZE = 10.0f;

    protected static ComponentUI          ui = new CBarChartUI();

    protected static NumberFormat         nf;
    static {
	nf = NumberFormat.getNumberInstance();
	nf.setMinimumFractionDigits(2);
	nf.setMaximumFractionDigits(2);
    }

    protected double                      max, sum;

    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) {
	Graphics2D g2 = (Graphics2D)g;
	BarChart chart = (BarChart)c;
	int chartWidth = chart.getSize().width;
	int chartHeight = chart.getSize().height;
	int xMin = XPAD + LABEL_WIDTH;
	int xMax = chartWidth - XPAD;
	int xRange = xMax - xMin;
	int yMin = YPAD;
	int yMax = chartHeight - YPAD;
	int yRange = yMax - yMin;
	int numCats = chart.getNumStates();
	int numRangeGroups = chart.getNumRangeGroups();
	double groupWidth = 1.0 / numRangeGroups;

	// Compute column stats.  We assume nonnegative numeric values!
	max = 0.0;
	sum = 0.0;
	for (int i = 0; i < numCats; i++) {
	    double value = chart.getStateValue(i);
	    max = Math.max(value, max);
	    sum += value;
	}

	double tempMax = (max == 0.0 ? 1.0 : max);
	double tempSum = (sum == 0.0 ? 1.0 : sum);
	double div = (chart.getAutoScale() ? tempMax : tempSum);
	double scale = yRange / div;

	// Paint range group lines.
	if (numRangeGroups > 0) {
	    g2.setPaint(Color.lightGray);
	    g2.setStroke(new BasicStroke(1.0f,
					 BasicStroke.CAP_BUTT,
					 BasicStroke.JOIN_BEVEL,
					 0.0f,
					 new float[] { 2.0f, 2.0f },
					 0.0f));
	    for (int i = 0; i < numRangeGroups + 1; i++) {
		int y = yMax - (int)(scale * i * groupWidth * tempSum);
		if (yMin <= y) { g2.drawLine(xMin, y, xMax, y); }
	    }
	    g2.setStroke(new BasicStroke());
	}

	// Paint bars.
	int barWidth = xRange / numCats;
	for (int i = 0; i < numCats; i++) {

	    // Compute the bar bounds.
	    int barHeight = (int)(scale * chart.getStateValue(i));
	    int barX = xMin + (i * barWidth);
	    int barY = yMax - barHeight;

	    // Draw the bar.
	    g2.setPaint(chart.getStateColor(i));
	    g2.fillRect(barX, barY, barWidth, barHeight);
	    g2.setPaint(Color.black);
	    g2.drawRect(barX, barY, barWidth, barHeight);
	}

	// Paint axes.
	g2.setPaint(Color.black);
	g2.drawLine(xMin-1, yMax, xMax, yMax);      // Horizontal axis.
	g2.drawLine(xMin, yMin, xMin, yMax);        // Vertical axis.

	// Paint range groups.
	if (numRangeGroups > 0) {
	    g2.setFont(c.getFont().deriveFont(FONT_SIZE));
	    g2.setStroke(new BasicStroke(1.0f, BasicStroke.CAP_BUTT,
					 BasicStroke.JOIN_BEVEL, 0.0f, new float[] { 2.0f, 2.0f }, 0.0f));
	    for (int i = 1; i <= numRangeGroups; i++) {
		double bd = i * groupWidth;
		int y = yMax - (int)(scale * bd * tempSum);
		if (yMin <= y) {
		    g2.drawLine(xMin-1, y, xMin+1, y);
		    g2.drawString(nf.format(bd), XPAD, y + (int)(FONT_SIZE/2.0f));
		}
	    }
	}
    }
}