numberformatdemo.java

JavaTM 2 SDK, Standard Edition Documentation

/*
 * @(#)NumberFormatDemo.java	1.1 96/11/23
 *
 * (C) Copyright Taligent, Inc. 1996 - All Rights Reserved
 * (C) Copyright IBM Corp. 1996 - All Rights Reserved
 *
 * Portions copyright (c) 1996 Sun Microsystems, Inc. All Rights Reserved.
 *
 *   The original version of this source code and documentation is copyrighted
 * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
 * materials are provided under terms of a License Agreement between Taligent
 * and Sun. This technology is protected by multiple US and International
 * patents. This notice and attribution to Taligent may not be removed.
 *   Taligent is a registered trademark of Taligent, Inc.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL purposes and without
 * fee is hereby granted provided that this copyright notice
 * appears in all copies. Please refer to the file "copyright.html"
 * for further important copyright and licensing information.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 *
 */

import java.applet.Applet;
import java.awt.event.*;
import java.awt.*;
import java.util.*;
import java.lang.*;
import java.text.*;

/**
 * Concrete class for demonstrating how to convert binary numbers into text
 * strings for meaningful display.
 * The following is the instruction on how to run the number format demo.
 * <p>
 * ===================
 * <P>Number formatters convert binary numbers (integer or float data types)
 * into text strings for meaningful display. The number formatters:
 * <UL>
 * <LI>Provide control over every aspect of the display, including separator
 * characters, optional digits, maximum and minimum decimal and integer places,
 * and optional prefixes and suffixes </LI>
 * <LI>Can produce currency and percentage formats and can be extended to
 * produce other formats </LI>
 * <LI>Allow you to specify new formats with string patterns and can retrieve
 * the normalized pattern </LI>
 * <LI>Can parse anything they can format, for use when converting text input
 * into binary data </LI>
 * </UL>
 * <P><CENTER>
 * <A HREF="#localized">Localized Formats</A> &nbsp;
 * <A HREF="#patterns">Creating Formats with Patterns </A> &nbsp;
 * <A HREF="#parsing">Parsing Text </A>
 * </CENTER></P>
 * <HR>
 * <H3><A NAME="localized">Localized Formats </A></H3>
 * <P>The number formatters let you format numbers in the ways that are
 * appropriate for any user's conventions, including country-specific formats
 * such as currencies.  You can also specify other formatting options such as
 * minimum and maximum number of digits displayed.
 * </P>
 * <P> The applet displays the number in two formats&#151;the Java 1.0
 * representation (&quot;Java 1.0 Number&quot;), and the localized format
 * generated by the number formatters (&quot;New Number&quot;).
 * </P>
 * <TABLE WIDTH=100% CELLPADDING=5>
 * <TR>
 * <TH ALIGN=left VALIGN=bottom>To See This...</TH>
 * <TH ALIGN=left VALIGN=bottom>Do This...</TH>
 * </TR>
 * <TR>
 * <TD WIDTH=50% VALIGN=top> Localized number formats.  In the international
 * string, the separator characters change to reflect the conventions used by
 * different countries.
 * </TD>
 * <TD VALIGN=top>
 * <TABLE CELLSPACING=0 CELLPADDING=0>
 * <TR>
 * <TD WIDTH=10 VALIGN=top> 1.
 * </TD>
 * <TD> Pull down the Locale menu
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH=10 VALIGN=top> 2.
 * </TD>
 * <TD> Try several different locales with the up and down arrow keys
 * (on Windows) or the mouse button (on Macintosh)
 * </TD>
 * </TR>
 * </TABLE>
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH=50% VALIGN=top> Localized currency formats.  The formatter adds
 * a prefix or suffix to indicate the currency unit.  It also uses a minus sign
 * or parentheses to indicate negative numbers, as appropriate.
 * </TD>
 * <TD VALIGN=top>
 * <TABLE CELLSPACING=0 CELLPADDING=0>
 * <TR>
 * <TD WIDTH=10 VALIGN=top> 1.
 * </TD>
 * <TD> Click on the <I> Currency </I> button
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH=10 VALIGN=top> 2.
 * </TD>
 * <TD> Pull down the Locale menu and try several different locales
 * </TD>
 * </TR>
 * </TABLE>
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH=50% VALIGN=top> Setting formatting options, for example,
 * specifying a precise  number of decimal places.
 * </TD>
 * <TD VALIGN=top>
 * <TABLE CELLSPACING=0 CELLPADDING=0>
 * <TR>
 * <TD WIDTH=10 VALIGN=top> 1.
 * </TD>
 * <TD> Type &quot;3&quot; in the <I>Min </I> field for <I> Decimal Count </I>
 * &#151;the formatter appends zeroes to display the specified number of
 * decimal places
 * </TD>
 * </TR>
 * </TABLE>
 * </TD>
 * </TR>
 * </TABLE>
 * <HR WIDTH=50% ALIGN=left>
 * <H3><A NAME="patterns">Creating Formats with Patterns </A></H3>
 * <P> A string pattern can control the output format for a number formatter,
 * making it easy for you to edit a format or provide an editing mechanism
 * for end users.  The pattern also changes to reflect any changes you make
 * programmatically.
 * </P>
 * <P> Patterns can either be invariant (for use only by programmers) or
 * localized (for use by end users).  Click on the <I> Localized Pattern </I>
 * box to change the state.
 * <TABLE WIDTH=100% CELLPADDING=5>
 * <TR>
 * <TH ALIGN=left VALIGN=bottom>To See This...</TH>
 * <TH ALIGN=left VALIGN=bottom>Do This...</TH>
 * </TR>
 * <TR>
 * <TD WIDTH=50% VALIGN=top> You can edit the pattern to create a new format.
 * </TD>
 * <TD VALIGN=top>
 * <TABLE CELLSPACING=0 CELLPADDING=0>
 * <TR>
 * <TD WIDTH=10 VALIGN=top> 1.
 * </TD>
 * <TD> Select the <I> Default Format </I> button and the <I>English
 * (United States) </I> locale
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH=10 VALIGN=top> 2.
 * </TD>
 * <TD> Increase the maximum number for <I>Decimal Count</I>
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH=10 VALIGN=top> 3.
 * </TD>
 * <TD> Delete the &quot;&#35;&quot; characters at the end of the <I>Pattern
 * </I> field and type in zeroes&#151;the decimal places in the <I>New Number
 * </I> field change to zeroes
 * </TD>
 * </TR>
 * </TABLE>
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH=50% VALIGN=top> You can edit the prefix and suffix strings, and
 * create different patterns for positive and negative numbers.
 * </TD>
 * <TD VALIGN=top>
 * <TABLE CELLSPACING=0 CELLPADDING=0>
 * <TR>
 * <TD WIDTH=10 VALIGN=top> 1.
 * </TD>
 * <TD> Type a plus sign (&quot;+&quot;) in the <I> Prefix </I> field for
 * positive numbers to modify the positive number pattern
 * </TD>
 * </TR>
 * <TR>
 * <TD WIDTH=10 VALIGN=top> 2.
 * </TD>
 * <TD> Delete the minus sign from the Java 1.0 number
 * </TD>
 * </TR>
 * </TABLE>
 * </TD>
 * </TR>
 * </TABLE>
 * <HR WIDTH=50% ALIGN=left>
 * <H3><A NAME="parsing">Parsing Text </A></H3>
 * <P>The number formatters not only format for any language, but can parse
 * numbers displayed in any language back into binary format.
 * </P>
 * <TABLE WIDTH=100% CELLPADDING=5>
 * <TR>
 * <TH ALIGN=left VALIGN=bottom>To See This...</TH>
 * <TH ALIGN=left VALIGN=bottom>Do This...</TH>
 * </TR>
 * <TR>
 * <TD WIDTH=50% VALIGN=top> Changes to the international number are parsed
 * and reflected in the <I> Java 1.0 Number </I> field.
 * </TD>
 * <TD VALIGN=top>
 * <TABLE CELLSPACING=0 CELLPADDING=0>
 * <TR>
 * <TD WIDTH=10 VALIGN=top> 1.
 * </TD>
 * <TD> Select the thousands separator character in the <I>New Number </I>
 * field (the comma if you are still in the U.S. locale) and replace it with
 * a number
 * </TD>
 * </TR>
 * </TABLE>
 * </TD>
 * </TR>
 * </TABLE>
 * <P>The parsing mechanism is somewhat lenient. For example, a thousands
 * separator character can be misplaced and the parser still returns the
 * correct value. </P>
 * <P>Though not yet demonstrated here, the number formatters also handle
 * IEEE number symbols such as the infinity sign and NaN (for example, 0/0),
 * creating the correct results for both formatting and parsing. The formatters
 * also return the alignment point so you can line up the end of integer
 * portions correctly even without monospace fonts or with strange number
 * conventions. </P>
 * <P>You can type in other numbers in either number field or enter a
 * completely new pattern to  see different formatting behaviors.  Try it out!
 * </P>
 * @see        java.util.Format
 * @see        java.util.NumberFormat
 * @version    1.1 11/23/96
 * @author     Laura Werner, Mark Davis
*/
// Change history:  Helena Shih 091996: Added comments prior spec review.
public class NumberFormatDemo extends DemoApplet
{
    /**
     * The main function which defines the behavior of the NumberFormatDemo
     * applet when an applet is started.
     */
    public static void main(String argv[]) {
        DemoApplet.showDemo(new NumberFormatFrame(null));
    }

    /**
     * This creates a NumberFormatFrame for the demo applet.
     */
    public Frame createDemoFrame(DemoApplet applet) {
        return new NumberFormatFrame(applet);
    }
}

/**
 * A Frame is a top-level window with a title. The default layout for a frame
 * is BorderLayout.  The NumberFormatFrame class defines the window layout of
 * NumberFormatDemo.
 */
class NumberFormatFrame extends Frame implements KeyListener, ItemListener, WindowListener 
{
    /**
     * Constructs a new NumberFormatFrame that is initially invisible.
     */
    public NumberFormatFrame(DemoApplet applet)
    {
        super("Number Formatting Demo");
        this.applet = applet;
	addWindowListener(this);
        init();
        start();
    }

    /**
     * Initializes the applet. You never need to call this directly, it
     * is called automatically by the system once the applet is created.
     */
    public void init()
    {
        //Get all locales for debugging, but only get G7 locales for demos.
        if (DEBUG == true)
             locales = NumberFormat.getAvailableLocales();
        else locales = Utility.getG7Locales();

        buildGUI();

        // Stick the names of the locales into the locale popup menu
        Locale displayLocale = Locale.getDefault();
        for (int i = 0; i < locales.length; i++) {
            if (locales[i].getCountry().length() > 0) {
                localeMenu.addItem( locales[i].getDisplayName() );
                if (locales[i].equals(Locale.getDefault())) {
                    localeMenu.select(i);
                }
            }
        }

        // For starters, use the default format for the selected locale in the
        // menu
        setFormatFromLocale();
    }

    /**
     * Called to start the applet. You never need to call this method
     * directly, it is called when the applet's document is visited.
     */
    public void start()
    {
        inputText.setText("-1234.56");
        clickedRightButton();
    }


  /* ItemListener method */
  public void itemStateChanged(ItemEvent e) {

    if (e.getSource() == getPercent) {
      clickedGetPercent();
    }
    else
    if (e.getSource() == getCurrency) {
      clickedGetCurrency();
    }
    else
    if (e.getSource() == getInstance) {
      clickedGetDefault();
    }
    else
    if (e.getSource() == getLocalized) {
      isLocalized = getLocalized.getState();
      handleNewFormat();
    }
    else
    if (e.getSource() == localeMenu) {
      selectedLocaleMenu();
    }
  }

  /* Key Listener methods */
  public void keyPressed(KeyEvent e) {
  }

  public void keyReleased(KeyEvent e) {
    if (e.getSource() == inputText) {
      inputChanged();
    }
    else
    if (e.getSource() == patternText) {
      patternChanged();
    }
    else
    if (e.getSource() == outputText) {
      outputChanged();
    }
    else
    if (e.getSource() == posSuffix) {
      posSuffixChanged();
    }
    else
    if (e.getSource() == posPrefix) {
      posPrefixChanged();
    }
    else
    if (e.getSource() == negSuffix) {
      negSuffixChanged();
    }
    else
    if (e.getSource() == negPrefix) {
      negPrefixChanged();
    }
    else
    if (e.getSource() == decMax) {
      decMaxChanged();
    }
    else
    if (e.getSource() == decMin) {
      decMinChanged();
    }
    else
    if (e.getSource() == intMax) {
      intMaxChanged();
    }
    else
    if (e.getSource() == intMin) {
      intMinChanged();
    }
  }

  public void keyTyped(KeyEvent e) {
  }

  /* Window Listener methods */
  public void windowClosed(WindowEvent e) {
  }

  public void windowDeiconified(WindowEvent e) {
  }

  public void windowIconified(WindowEvent e) {
  }

  public void windowActivated(WindowEvent e) {
  }

  public void windowDeactivated(WindowEvent e) {
  }

  public void windowOpened(WindowEvent e) {
  }

  public void windowClosing(WindowEvent e) {
    setVisible(false);
    dispose();

    if (applet != null) {
      applet.demoClosed();
    } else System.exit(0);

  }
 
    /**
     * This function is called when it is necessary to create a new number
     * format.  For example, when a new locale is chosen, a new number
     * format for that locale needs to be created.  Or, when a number
     * format attributes have been changed.
     */
    public void handleNewFormat()
    {
        if (isLocalized) {
               workaroundSetText(patternText,format.toLocalizedPattern() );
        } else workaroundSetText(patternText,format.toPattern() );

        // force the text in the output area to use the new format
        clickedRightButton();
    }

    /**
     * A new number format needs to be created if the attributes are changed.
     */
    public void handleAttributeChange()
    {
        handleNewFormat();
    }
    /**
     * Called when a formatting event has occured.
     */
    public boolean handleFormatting(Event evt, Object obj)
    {
        return true;
    }


    /**
     * Create a new number format if a new locale has been selected.
     */
    public void setFormatFromLocale() {
        // Find the locale corresponding to the currently selected menu item
        int index = localeMenu.getSelectedIndex();
        Locale aLocale = locales[index];

        if (getPercent.getState()) {
            format = (DecimalFormat) NumberFormat.getPercentInstance(aLocale);
        } else if (getCurrency.getState()) {
            format = (DecimalFormat) NumberFormat.getCurrencyInstance(aLocale);
        } else {
            format = (DecimalFormat) NumberFormat.getInstance(aLocale);
        }

        handleNewFormat();

        updateAttributes();
    }

    /**
     * This is used to avoid goofy updates and misplaced cursors