AsciiTable.java Source code

Introduction

Here is the source code for AsciiTable.java

Source

//Send questions, comments, bug reports, etc. to the authors:

//Rob Warner (rwarner@interspatial.com)
//Robert Harris (rbrt_harris@yahoo.com)

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;

/**
 * Displays ASCII Codes
 */
public class AsciiTable {
    // The number of characters to show.
    private static final int MAX_CHARS = 128;

    // Names for each of the columns
    private static final String[] COLUMN_NAMES = { "Char", "Dec", "Hex", "Oct", "Bin", "Name" };

    // The names of the first 32 characters
    private static final String[] CHAR_NAMES = { "NUL", "SOH", "STX", "ETX", "EOT", "ENQ", "ACK", "BEL", "BS",
            "TAB", "LF", "VT", "FF", "CR", "SO", "SI", "DLE", "DC1", "DC2", "DC3", "DC4", "NAK", "SYN", "ETB",
            "CAN", "EM", "SUB", "ESC", "FS", "GS", "RS", "US", "Space" };

    // The font to use for displaying characters
    private Font font;

    // The background colors to use for the rows
    private Color[] colors = new Color[MAX_CHARS];

    /**
     * Runs the application
     */
    public void run() {
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("ASCII Codes");
        createContents(shell);
        shell.pack();
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch()) {
                display.sleep();
            }
        }
        // Call dispose to dispose any resources created
        // we have created
        dispose();
        display.dispose();
    }

    /**
     * Disposes the resources created
     */
    private void dispose() {
        // We created this font; we must dispose it
        if (font != null) {
            font.dispose();
        }

        // We created the colors; we must dispose them
        for (int i = 0, n = colors.length; i < n; i++) {
            if (colors[i] != null) {
                colors[i].dispose();
            }
        }
    }

    /**
     * Creates the font
     */
    private void createFont() {
        // Create a font that will display the range
        // of characters. "Terminal" works well in
        // Windows
        font = new Font(Display.getCurrent(), "Terminal", 10, SWT.NORMAL);
    }

    /**
     * Creates the columns for the table
     * 
     * @param table the table
     * @return TableColumn[]
     */
    private TableColumn[] createColumns(Table table) {
        TableColumn[] columns = new TableColumn[COLUMN_NAMES.length];
        for (int i = 0, n = columns.length; i < n; i++) {
            // Create the TableColumn with right alignment
            columns[i] = new TableColumn(table, SWT.RIGHT);

            // This text will appear in the column header
            columns[i].setText(COLUMN_NAMES[i]);
        }
        return columns;
    }

    /**
     * Creates the window's contents (the table)
     * 
     * @param composite the parent composite
     */
    private void createContents(Composite composite) {
        composite.setLayout(new FillLayout());

        // The system font will not display the lower 32
        // characters, so create one that will
        createFont();

        // Create a table with visible headers
        // and lines, and set the font that we
        // created
        Table table = new Table(composite, SWT.SINGLE | SWT.FULL_SELECTION);
        table.setHeaderVisible(true);
        table.setLinesVisible(true);
        table.setRedraw(false);
        table.setFont(font);

        // Create the columns
        TableColumn[] columns = createColumns(table);

        for (int i = 0; i < MAX_CHARS; i++) {
            // Create a background color for this row
            colors[i] = new Color(table.getDisplay(), 255 - i, 127 + i, i);

            // Create the row in the table by creating
            // a TableItem and setting text for each
            // column
            int c = 0;
            TableItem item = new TableItem(table, SWT.NONE);
            item.setText(c++, String.valueOf((char) i));
            item.setText(c++, String.valueOf(i));
            item.setText(c++, Integer.toHexString(i).toUpperCase());
            item.setText(c++, Integer.toOctalString(i));
            item.setText(c++, Integer.toBinaryString(i));
            item.setText(c++, i < CHAR_NAMES.length ? CHAR_NAMES[i] : "");
            item.setBackground(colors[i]);
        }

        // Now that we've set the text into the columns,
        // we call pack() on each one to size it to the
        // contents.
        for (int i = 0, n = columns.length; i < n; i++) {
            columns[i].pack();
        }

        // Set redraw back to true so that the table
        // will paint appropriately
        table.setRedraw(true);
    }

    /**
     * The application entry point
     * 
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        new AsciiTable().run();
    }
}