/hdf-java/ncsa/hdf/view/Chart.java

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 * Copyright by The HDF Group.                                               *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of the HDF Java Products distribution.                  *
 * The full copyright notice, including terms governing use, modification,   *
 * and redistribution, is contained in the files COPYING and Copyright.html. *
 * COPYING can be found at the root of the source code distribution tree.    *
 * Or, see http://hdfgroup.org/products/hdf-java/doc/Copyright.html.         *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 ****************************************************************************/

package ncsa.hdf.view;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.reflect.Array;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JDialog;
import javax.swing.JPanel;
import javax.swing.WindowConstants;

/**
 * ChartView displays histogram/line chart of selected row/column of table data
 * or image. There are two types of chart, histogram and line plot.
 * 
 * @author Peter X. Cao
 * @version 2.4 9/6/2007
 */
public class Chart extends JDialog implements ActionListener {

    /**
     * 
     */
    private static final long serialVersionUID = 6306479533747330357L;

    /** histogram style chart */
    public static final int HISTOGRAM = 0;

    /** line style chart */
    public static final int LINEPLOT = 1;

    /** The default colors of lines for selected columns */
    public static final Color[] LINE_COLORS = { Color.black, Color.red,
            Color.green.darker(), Color.blue, Color.magenta, Color.pink,
            Color.yellow, Color.orange, Color.gray, Color.cyan };

    /** the data values of line points or histogram */
    protected double data[][];

    /** Panel that draws plot of data values. */
    protected ChartPanel chartP;

    /** number of data points */
    protected int numberOfPoints;

    /** the style of chart: histogram or line */
    private int chartStyle;

    /** the maximum value of the Y axis */
    private double ymax;

    /** the minimum value of the Y axis */
    private double ymin;

    /** the maximum value of the X axis */
    private double xmax;

    /** the minimum value of the X axis */
    private double xmin;

    /** line labels */
    private String lineLabels[];

    /** line colors */
    private Color lineColors[];

    /** number of lines */
    private int numberOfLines;

    /* the data to plot against */
    private double[] xData = null;

    /**
     * True if the original data is integer (byte, short, integer, long).
     */
    private boolean isInteger;

    private java.text.DecimalFormat format;

    /**
     * Constructs a new ChartView given data and data ranges.
     * <p>
     * 
     * @param owner
     *            the owner frame of this dialog.
     * @param title
     *            the title of this dialog.
     * @param style
     *            the style of the chart. Valid values are: HISTOGRAM and LINE
     * @param data
     *            the two dimensional data array: data[linenumber][datapoints]
     * @param xData
     *            the range of the X values, xRange[0]=xmin, xRange[1]=xmax.
     * @param yRange
     *            the range of the Y values, yRange[0]=ymin, yRange[1]=ymax.
     */
    public Chart(Frame owner, String title, int style, double[][] data,
            double[] xData, double[] yRange) {
        super(owner, title, false);
        setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
        format = new java.text.DecimalFormat("0.00E0");

        if (data == null) {
            return;
        }

        this.chartStyle = style;
        this.data = data;

        if (style == HISTOGRAM) {
            isInteger = true;
        }
        else {
            isInteger = false;
        }

        if (xData != null) {
            int len = xData.length;
            if (len == 2) {
                this.xmin = xData[0];
                this.xmax = xData[1];
            }
            else {
                this.xData = xData;
                xmin = xmax = xData[0];
                for (int i = 0; i < len; i++) {
                    if (xData[i] < xmin) {
                        xmin = xData[i];
                    }

                    if (xData[i] > xmax) {
                        xmax = xData[i];
                    }
                }
            }
        }
        else {
            this.xmin = 1;
            this.xmax = data[0].length;
        }

        this.numberOfLines = Array.getLength(data);
        this.numberOfPoints = Array.getLength(data[0]);
        this.lineColors = LINE_COLORS;

        if (yRange != null) {
            // data range is given
            this.ymin = yRange[0];
            this.ymax = yRange[1];
        }
        else {
            // search data range from the data
            findDataRange();
        }

        if ((ymax < 0.0001) || (ymax > 100000)) {
            format = new java.text.DecimalFormat("###.####E0#");
        }
        chartP = new ChartPanel();
        chartP.setBackground(Color.white);

        createUI();
    }

    /**
     * Creates and layouts GUI components.
     */
    protected void createUI() {
        Window owner = getOwner();

        JPanel contentPane = (JPanel) getContentPane();
        contentPane.setLayout(new BorderLayout(5, 5));
        contentPane.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
        int w = 640 + (ViewProperties.getFontSize() - 12) * 15;
        int h = 400 + (ViewProperties.getFontSize() - 12) * 10;

        contentPane.setPreferredSize(new Dimension(w, h));

        contentPane.add(chartP, BorderLayout.CENTER);

        JButton button = new JButton("Close");
        button.addActionListener(this);
        button.setActionCommand("Close");
        JPanel tmp = new JPanel();
        tmp.add(button);
        contentPane.add(tmp, BorderLayout.SOUTH);

        Point l = owner.getLocation();
        l.x += 220;
        l.y += 100;
        setLocation(l);
        pack();
    }

    public void actionPerformed(ActionEvent e) {
        String cmd = e.getActionCommand();

        if (cmd.equals("Close")) {
            dispose();
        }
    }

    /** Sets the color of each line of a line plot */
    public void setLineColors(Color c[]) {
        lineColors = c;
    }

    /** Sets the labels of each line. */
    public void setLineLabels(String l[]) {
        lineLabels = l;
    }

    /** Set the data type of the plot data to be integer. */
    public void setTypeToInteger() {
        isInteger = true;
    }

    /** find and set the minimum and maximum values of the data */
    private void findDataRange() {
        if (data == null) {
            return;
        }

        ymin = ymax = data[0][0];
        for (int i = 0; i < numberOfLines; i++) {
            for (int j = 0; j < numberOfPoints; j++) {
                if (data[i][j] < ymin) {
                    ymin = data[i][j];
                }

                if (data[i][j] > ymax) {
                    ymax = data[i][j];
                }
            }
        }
    }

    /** The canvas that paints the data lines. */
    private class ChartPanel extends JComponent {
        private static final long serialVersionUID = -3701826094727309097L;

        /**
         * Paints the plot components.
         */
        @Override
        public void paint(Graphics g) {
            if (numberOfLines <= 0) {
                return; // no data
            }

            Dimension d = getSize();
            int gap = 20;
            int xgap = 2 * gap;
            int ygap = 2 * gap;
            int legendSpace = 0;
            if ((chartStyle == LINEPLOT) && (lineLabels != null)) {
                legendSpace = 60;
            }

            int h = d.height - gap;
            int w = d.width - (3 * gap + legendSpace);
            int xnpoints = Math.min(10, numberOfPoints - 1);
            int ynpoints = 10;

            // draw the X axis
            g.drawLine(xgap, h, w + xgap, h);

            // draw the Y axis
            g.drawLine(ygap, h, ygap, 0);

            // draw x labels
            double xp = 0, x = xmin;
            double dw = (double) w / (double) xnpoints;
            double dx = (xmax - xmin) / xnpoints;
            boolean gtOne = (dx >= 1);
            for (int i = 0; i <= xnpoints; i++) {
                x = xmin + i * dx;
                xp = xgap + i * dw;
                g.drawLine((int) xp, h, (int) xp, h - 5);
                if (gtOne) {
                    g
                            .drawString(String.valueOf((int) x), (int) xp - 5,
                                    h + gap);
                }
                else {
                    g.drawString(String.valueOf(x), (int) xp - 5, h + gap);
                }
            }

            // draw y labels
            double yp = 0, y = ymin;
            double dh = (double) h / (double) ynpoints;
            double dy = (ymax - ymin) / (ynpoints);
            if (dy > 1) {
                dy = Math.round(dy * 10.0) / 10.0;
            }
            for (int i = 0; i <= ynpoints; i++) {
                yp = i * dh;
                y = i * dy + ymin;
                g.drawLine(ygap, h - (int) yp, ygap + 5, h - (int) yp);
                if (isInteger) {
                    g.drawString(String.valueOf((int) y), 0, h - (int) yp + 8);
                }
                else {
                    g.drawString(format.format(y), 0, h - (int) yp + 8);
                }
            }

            Color c = g.getColor();
            double x0, y0, x1, y1;
            if (chartStyle == LINEPLOT) {
                dw = (double) w / (double) (numberOfPoints - 1);

                // use y = a + b* x to calculate pixel positions
                double b = h / (ymin - ymax);
                double a = -b * ymax;
                boolean hasXdata = ((xData != null) && (xData.length >= numberOfPoints));
                double xRatio = (1 / (xmax - xmin)) * w;
                double xD = (xmin / (xmax - xmin)) * w;

                // draw lines for selected spreadsheet columns
                for (int i = 0; i < numberOfLines; i++) {
                    if ((lineColors != null)
                            && (lineColors.length >= numberOfLines)) {
                        g.setColor(lineColors[i]);
                    }

                    // set up the line data for drawing one line a time
                    if (hasXdata) {
                        x0 = xgap + xData[0] * xRatio - xD;
                    }
                    else {
                        x0 = xgap;
                    }
                    y0 = a + b * data[i][0];

                    for (int j = 1; j < numberOfPoints; j++) {
                        if (hasXdata) {
                            x1 = xgap + xData[j] * xRatio - xD;
                        }
                        else {
                            x1 = xgap + j * dw;
                        }

                        y1 = a + b * data[i][j];
                        g.drawLine((int) x0, (int) y0, (int) x1, (int) y1);

                        x0 = x1;
                        y0 = y1;
                    }

                    // draw line legend
                    if ((lineLabels != null)
                            && (lineLabels.length >= numberOfLines)) {
                        x0 = w + legendSpace;
                        y0 = gap + gap * i;
                        g.drawLine((int) x0, (int) y0, (int) x0 + 7, (int) y0);
                        g
                                .drawString(lineLabels[i], (int) x0 + 10,
                                        (int) y0 + 3);
                    }
                }

                g.setColor(c); // set the color back to its default

                // draw a box on the legend
                if ((lineLabels != null)
                        && (lineLabels.length >= numberOfLines)) {
                    g.drawRect(w + legendSpace - 10, 10, legendSpace, 10 * gap);
                }

            } // if (chartStyle == LINEPLOT)
            else if (chartStyle == HISTOGRAM) {
                // draw histogram for selected image area
                xp = xgap;
                yp = 0;
                g.setColor(Color.blue);
                int barWidth = w / numberOfPoints;
                if (barWidth <= 0) {
                    barWidth = 1;
                }
                dw = (double) w / (double) numberOfPoints;
                for (int j = 0; j < numberOfPoints; j++) {
                    xp = xgap + j * dw;
                    yp = (int) (h * (data[0][j] - ymin) / (ymax - ymin));
                    g.fillRect((int) xp, (int) (h - yp), barWidth, (int) yp);
                }

                g.setColor(c); // set the color back to its default
            } // else if (chartStyle == HISTOGRAM)
        } // public void paint(Graphics g)
    } // private class ChartPanel extends Canvas

}