Text Width Checker, useful to avoid line wrap

After seeing 'one too many' code example posted to usenet
that was broken due to line wrap, I threw together this
simple little text width checker.

/I hope the Text Width Checker might be of use to others./

You can launch the Text Width Checker at
<http://www.physci.org/twc.jnlp>

The *latest version* of the code will be/is here
<http://www.physci.org/test/code/TextWidthCheck.java>

The *current version* of the code, right now, is..

<sscce>
package org.physci.tool.text.textwidthcheck;

import java.awt.Container;
import java.awt.Window;
import java.awt.FlowLayout;
import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JToolBar;
import javax.swing.JScrollPane;
import javax.swing.ScrollPaneConstants;
import javax.swing.JLabel;
import javax.swing.JTextArea;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JSpinner;
import javax.swing.SpinnerNumberModel;
import javax.swing.SwingUtilities;
import javax.swing.border.EmptyBorder;
import javax.swing.event.ChangeListener;
import javax.swing.event.ChangeEvent;

/**
A text width checker. Useful for checking text that
might be broken or reformatted by reaching the maximum
line length available for the desired medium (e.g.
usenet, a command line), is within the constraints.

@author Andrew Thompson
@version 0.1
*/
public class TextWidthCheck extends JPanel {

  public TextWidthCheck() {
    super( new BorderLayout() );

    int defaultWidth = 80;

    String inputText =
      getTextStringLineTens(defaultWidth) +
      "\n" +
      getTextStringLineUnits(defaultWidth);

    JPanel textPanel = new JPanel( new BorderLayout() );

    final JTextArea scale =
      getTextArea( inputText,2,defaultWidth );
    scale.setEnabled(false);
    textPanel.add(
      new JScrollPane(
        scale,
        ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
        ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER
        ),
        BorderLayout.NORTH );

    final JTextArea input = getTextArea(
      "Paste text to be checked, here.\n\n" +
      "If the width of any line is greater than "+
      "the maximum number of\ncharacters set above, "+
      "a horizontal scroll-bar will appear.\n\n" +
      "The longest line of the current text, " +
      "is 62 chars wide.\n",
      15,defaultWidth );
    input.setCaretPosition(0);
    input.moveCaretPosition(input.getDocument().getLength());
    textPanel.add(new JScrollPane(
        input,
        ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
        ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED
        ),
        BorderLayout.CENTER );
    add( textPanel, BorderLayout.CENTER );

    JToolBar toolbar = new JToolBar(
      "Options",
      JToolBar.HORIZONTAL);
    toolbar.setFloatable(false);
    toolbar.setLayout( new FlowLayout(5) );

    final JSpinner charWidth = new JSpinner(
      new SpinnerNumberModel(
        new Integer(defaultWidth),
        new Integer(44),
        new Integer(100),
        new Integer(1) ));
    charWidth.addChangeListener( new ChangeListener() {
        public void stateChanged(ChangeEvent ce) {
          int chars =
            ((Integer)charWidth.getValue())
            .intValue();
          scale.setColumns( chars );
          scale.setText( getTextStringLine(chars) );
          input.setColumns( chars );
          validate();
          Container root = getTopLevelAncestor();
          if (root instanceof Window) {
            ((Window)root).pack();
          }
        }
      } );
    toolbar.add( charWidth );

    toolbar.add( new JLabel("Target width (characters)") );

    toolbar.addSeparator();

    final String tabSpace = " ";
    Integer[] tabSizes = new Integer[tabSpace.length()];
    for (int ii=0; ii<tabSizes.length; ii++) {
      tabSizes[ii] = ii+1;
    }
    final JComboBox tabSize = new JComboBox( tabSizes );
    tabSize.setSelectedItem(4);

    JButton replaceTabs = new JButton("Replace Tabs");
    replaceTabs.setMnemonic('r');
    replaceTabs.addActionListener( new ActionListener(){
        public void actionPerformed(ActionEvent ae) {
          int size = tabSize.getSelectedIndex()+1;
          String space = tabSpace.substring( 0,size );
          input.setText(
            input.getText().replaceAll("\t",space) );
        }
      } );
    toolbar.add(replaceTabs);

    toolbar.add(new JLabel("Spaces per tab"));

    toolbar.add(tabSize);

    JPanel toolPanel = new JPanel(new BorderLayout(0,0));
    toolPanel.add( toolbar, BorderLayout.CENTER );
    add( toolPanel, BorderLayout.NORTH );

    setBorder( new EmptyBorder(5,5,5,5) );
  }

  String getTextStringLine(int num) {
    return getTextStringLineTens(num) +
      "\n" +
      getTextStringLineUnits(num);
  }

  String getTextStringLineTens(int num) {
    StringBuffer buffer = new StringBuffer();
    for (int ii=0; ii<num; ii++) {
      if ((ii+1)%10==0) {
        buffer.append(""+((ii/10)+1));
      } else {
        buffer.append(" ");
      }
    }
    return buffer.toString();
  }

  String getTextStringLineUnits(int num) {
    StringBuffer buffer = new StringBuffer();
    for (int ii=0; ii<num; ii++) {
      buffer.append(""+(ii+1)%10);
    }
    return buffer.toString();
  }

  JTextArea getTextArea(
    String content,
    int rows,
    int cols) {

    JTextArea temp = new JTextArea( content, rows, cols );
    Font tempFont = temp.getFont();
    Font font = new Font(
      "Monospaced",
      Font.PLAIN,
      tempFont.getSize()+4);
    temp.setFont(font);
    return temp;
  }

  public static void main(String[] args) {
    Thread t = new Thread() {
      public void run() {
        JFrame f = new JFrame("Text Width Check");
        f.setContentPane( new TextWidthCheck() );
        f.setLocationByPlatform(true);
        f.setResizable(false);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setVisible(true);
      }
    };
    SwingUtilities.invokeLater(t);
  }
}
<sscce>

This message x-posted to comp.lang.java.programmer
& comp.lang.java.help, with follow-ups set to c.l.j.help
only. If you don't like the follow-ups, please feel free
to set them differently.

Andrew T.