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Number formatters convert binary numbers (integer or float data types) * into text strings for meaningful display. The number formatters: *
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. *
*The applet displays the number in two formats—the Java 1.0 * representation ("Java 1.0 Number"), and the localized format * generated by the number formatters ("New Number"). *
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| Localized number formats. In the international * string, the separator characters change to reflect the conventions used by * different countries. * | *
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| 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. * | *
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| Setting formatting options, for example, * specifying a precise number of decimal places. * | *
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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. *
*Patterns can either be invariant (for use only by programmers) or * localized (for use by end users). Click on the Localized Pattern * box to change the state. *
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| You can edit the pattern to create a new format. * | *
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| You can edit the prefix and suffix strings, and * create different patterns for positive and negative numbers. * | *
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The number formatters not only format for any language, but can parse * numbers displayed in any language back into binary format. *
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| Changes to the international number are parsed * and reflected in the Java 1.0 Number field. * | *
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The parsing mechanism is somewhat lenient. For example, a thousands * separator character can be misplaced and the parser still returns the * correct value.
*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.
*You can type in other numbers in either number field or enter a * completely new pattern to see different formatting behaviors. Try it out! *
* @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 ItemListener { /** * Constructs a new NumberFormatFrame that is initially invisible. */ public NumberFormatFrame(DemoApplet applet) { super("Number Formatting Demo"); this.applet = applet; startInitialization(); // set up event handling for text items MyKeyAdapter keyListener = new MyKeyAdapter(); inputText.addKeyListener(keyListener); patternText.addKeyListener(keyListener); outputText.addKeyListener(keyListener); posSuffix.addKeyListener(keyListener); posPrefix.addKeyListener(keyListener); negSuffix.addKeyListener(keyListener); negPrefix.addKeyListener(keyListener); decMax.addKeyListener(keyListener); decMin.addKeyListener(keyListener); intMax.addKeyListener(keyListener); intMin.addKeyListener(keyListener); // set up event handling for "item events" getPercent.addItemListener(this); getCurrency.addItemListener(this); getInstance.addItemListener(this); getLocalized.addItemListener(this); localeMenu.addItemListener(this); // set up event handling for window events addWindowListener(new MyWindowAdapter()); finishInitialization(); } /** * Sets up the window. */ public void startInitialization() { //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() ); } } localeMenu.select( Locale.US.getDisplayName()); // For starters, use the default format for the selected locale in the // menu setFormatFromLocale(); } /** * Set window's initial state. */ public void finishInitialization() { inputText.setText("-1234.56"); clickedRightButton(); } /** * Handles keyboard events for all text items */ class MyKeyAdapter extends KeyAdapter { public void keyReleased(KeyEvent evt) { if (evt.getSource() == inputText) { inputChanged(evt); } else if (evt.getSource() == patternText) { patternChanged(evt); } else if (evt.getSource() == outputText) { outputChanged(evt); } else if (evt.getSource() == posSuffix) { posSuffixChanged(evt); } else if (evt.getSource() == posPrefix) { posPrefixChanged(evt); } else if (evt.getSource() == negSuffix) { negSuffixChanged(evt); } else if (evt.getSource() == negPrefix) { negPrefixChanged(evt); } else if (evt.getSource() == decMax) { decMaxChanged(evt); } else if (evt.getSource() == decMin) { decMinChanged(evt); } else if (evt.getSource() == intMax) { intMaxChanged(evt); } else if (evt.getSource() == intMin) { intMinChanged(evt); } } } /** * Handles state changes of the radio buttons and the locale menu */ public void itemStateChanged(ItemEvent evt) { if (evt.getSource() == getPercent) { clickedGetPercent(); } else if (evt.getSource() == getCurrency) { clickedGetCurrency(); } else if (evt.getSource() == getInstance) { clickedGetDefault(); } else if (evt.getSource() == getLocalized) { isLocalized = getLocalized.getState(); handleNewFormat(); } else if (evt.getSource() == localeMenu) { selectedLocaleMenu(); } } /** * Handles window events. */ class MyWindowAdapter extends WindowAdapter { 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 == true) { 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(); } /** * 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 */ public void workaroundSetText(TextComponent area, String newText) { String foo = workaround(area.getText()); if (foo.equals(newText)) return; area.setText(newText); //if (area.gotFocus()) // area.select(newText.length(),newText.length()); } /** * Update the attributes. */ public void updateAttributes() { workaroundSetText(intMin,toString(format.getMinimumIntegerDigits()) ); workaroundSetText(intMax,toString(format.getMaximumIntegerDigits()) ); workaroundSetText(decMin,toString(format.getMinimumFractionDigits()) ); workaroundSetText(decMax,toString(format.getMaximumFractionDigits()) ); workaroundSetText(negPrefix,format.getNegativePrefix() ); workaroundSetText(negSuffix,format.getNegativeSuffix() ); workaroundSetText(posPrefix,format.getPositivePrefix() ); workaroundSetText(posSuffix,format.getPositiveSuffix() ); } /** * Get the default number formatter. */ public void clickedGetDefault() { setFormatFromLocale(); } /** * Update the number formatter with currency attribute. */ public void clickedGetCurrency() { setFormatFromLocale(); } /** * Update the number formatter with percentage attribute. */ public void clickedGetPercent() { setFormatFromLocale(); } /** * Update the number formatter when a new locale is selected. */ public void selectedLocaleMenu() { setFormatFromLocale(); } /** * If the user changes the input number, format it immediately */ public void inputChanged(KeyEvent ev) { clickedRightButton(); } /** * If the user changes the output number, format it immediately */ public void outputChanged(KeyEvent ev) { clickedLeftButton(); } /** * Update the text in the input area to use the new number format. */ public void clickedRightButton() { String leftString = workaround(inputText.getText()); Number num; try { num = new Double(leftString); } catch (IllegalArgumentException e) { outputText.setText(""); inputText.selectAll(); return; } workaroundSetText(outputText,format.format(num)); } /** * Update the text in the output area to use the new number format. */ public void clickedLeftButton() { String rightString = workaround(outputText.getText()); Number num; ParsePosition status = new ParsePosition(0); try { num = format.parse(rightString, status); } catch (IllegalArgumentException e) { errorText("Exception: " + e.getClass() + e.getMessage()); inputText.setText(""); outputText.selectAll(); return; } if (status.getIndex() != rightString.length()) { errorText("excess text: " + rightString.substring(status.getIndex(), rightString.length())); } workaroundSetText(inputText, num.toString() ); } /** * When the user changes the field containing the pattern, a new format * needs to be constructed from the pattern, then redisplay everything. */ public void patternChanged(KeyEvent ev) { String foo = workaround(patternText.getText()); try { if (isLocalized == true) { format.applyLocalizedPattern(foo); errorText("Pattern: " + foo + " -> " + format.toLocalizedPattern()); } else { format.applyPattern(foo); errorText("Pattern: " + foo + " -> " + format.toPattern()); } } catch (Exception bar) { errorText("Exception: " + bar.getClass() + bar.getMessage()); } updateAttributes(); clickedRightButton(); } //------------------------------------------------------------ // package private //------------------------------------------------------------ void addWithFont(Container container, Component foo, Font font) { if (font != null) foo.setFont(font); container.add(foo); } //{{DECLARE_CONTROLS Panel localePanel; CheckboxGroup group1; Label label1; Label label2; Label label3; Choice localeMenu; Label localeLabel; TextField inputText; TextField outputText; //Button rightButton; //Button leftButton; TextField patternText; Label label4; TextField negPrefix; TextField negSuffix; TextField posPrefix; TextField posSuffix; Label label5; Label label6; Label label7; Label label8; TextField intMin; TextField intMax; TextField decMin; TextField decMax; Label label9; Label label10; Label label11; Label label12; Checkbox getInstance; Checkbox getCurrency; Checkbox getPercent; Checkbox getLocalized; Label label13; Label label14; //}} //------------------------------------------------------------ // private //------------------------------------------------------------ private void buildGUI() { //{{INIT_CONTROLS setBackground(Utility.bgColor); // MD 8/7 // shouldn't be necessary, but it is! setLayout(new FlowLayout(FlowLayout.CENTER,2,2)); // INPUT/OUTPUT/PATTERN Panel creditPanel = new Panel(); label1=new Label("Decimal Number Formatting Demo", Label.CENTER); label1.setFont(Utility.titleFont); creditPanel.add(label1); label13=new Label(creditString, Label.CENTER); label13.setFont(Utility.creditFont); creditPanel.add(label13); Utility.fixGrid(creditPanel,1); add(creditPanel); // IO Panel ioPanel = new Panel(); label3=new Label("1.1 Number", Label.RIGHT); label3.setFont(Utility.labelFont); ioPanel.add(label3); outputText=new TextField(FIELD_COLUMNS); outputText.setFont(Utility.editFont); ioPanel.add(outputText); /*Panel gap1 = new Panel(); gap1.setLayout(null); gap1.setSize(5,5); gap1.add(outputText); Panel gap2 = new Panel(); gap2.setLayout(null); gap2.setSize(5,5); gap2.add(outputText); */ label2=new Label("1.0 Number", Label.RIGHT); label2.setFont(Utility.labelFont); ioPanel.add(label2); inputText=new TextField(FIELD_COLUMNS); inputText.setFont(Utility.editFont); ioPanel.add(inputText); label4=new Label("Pattern", Label.RIGHT); label4.setFont(Utility.labelFont); ioPanel.add(label4); patternText=new TextField(FIELD_COLUMNS); patternText.setFont(Utility.editFont); ioPanel.add(patternText); ioPanel.add(new Label(" ")); getLocalized=new Checkbox("Localized Pattern"); getLocalized.setFont(Utility.labelFont); ioPanel.add(getLocalized); Utility.fixGrid(ioPanel,2); add(ioPanel); // LOCALE localePanel=new Panel(); localeLabel=new Label("Locale:"); localeLabel.setFont(Utility.labelFont); localePanel.add("loc",localeLabel); localeMenu= new Choice(); localeMenu.setBackground(Utility.choiceColor); localeMenu.setFont(Utility.choiceFont); localePanel.add(localeMenu); // FORMAT CHECKS group1= new CheckboxGroup(); getInstance=new Checkbox("Default Format",group1, true); getInstance.setFont(Utility.labelFont); localePanel.add(getInstance); getCurrency=new Checkbox("Currency Format",group1, false); getCurrency.setFont(Utility.labelFont); localePanel.add(getCurrency); getPercent=new Checkbox("Percent Format",group1, false); getPercent.setFont(Utility.labelFont); localePanel.add(getPercent); Utility.fixGrid(localePanel,1); Panel bottomPanel = new Panel(); bottomPanel.add(localePanel); BorderPanel x = new BorderPanel(); x.setBackground(Utility.bgColor); x.setLayout(null); x.setSize(8,130); bottomPanel.add(x); // PARAMETERS Panel parameterPanel = new Panel(); parameterPanel.add(new Label(" ")); label11=new Label("Min", Label.CENTER); label11.setFont(Utility.labelFont); parameterPanel.add(label11); label12=new Label("Max", Label.CENTER); label12.setFont(Utility.labelFont); parameterPanel.add(label12); label9=new Label("Integers", Label.RIGHT); label9.setFont(Utility.labelFont); parameterPanel.add(label9); intMin=new TextField(4); intMin.setFont(Utility.editFont); parameterPanel.add(intMin); intMax=new TextField(4); intMax.setFont(Utility.editFont); parameterPanel.add(intMax); label10=new Label("Decimals", Label.RIGHT); label10.setFont(Utility.labelFont); parameterPanel.add(label10); decMin=new TextField(4); decMin.setFont(Utility.editFont); parameterPanel.add(decMin); decMax=new TextField(4); decMax.setFont(Utility.editFont); parameterPanel.add(decMax); parameterPanel.add(new Label(" ")); label7=new Label("Prefix", Label.CENTER); label7.setFont(Utility.labelFont); parameterPanel.add(label7); label8=new Label("Suffix", Label.CENTER); label8.setFont(Utility.labelFont); parameterPanel.add(label8); label6=new Label("Positive", Label.RIGHT); label6.setFont(Utility.labelFont); parameterPanel.add(label6); posPrefix=new TextField(4); posPrefix.setFont(Utility.editFont); parameterPanel.add(posPrefix); posSuffix=new TextField(4); posSuffix.setFont(Utility.editFont); parameterPanel.add(posSuffix); label5=new Label("Negative", Label.RIGHT); label5.setFont(Utility.labelFont); parameterPanel.add(label5); negPrefix=new TextField(4); negPrefix.setFont(Utility.editFont); parameterPanel.add(negPrefix); negSuffix=new TextField(4); negSuffix.setFont(Utility.editFont); parameterPanel.add(negSuffix); Utility.fixGrid(parameterPanel,3); bottomPanel.add(parameterPanel); Utility.fixGrid(bottomPanel,3); Utility.setInsets(bottomPanel,x,new Insets(20,20,2,2)); add(bottomPanel); Panel copyrightPanel = new Panel(); addWithFont (copyrightPanel,new Label(Utility.copyright1, Label.LEFT), Utility.creditFont); addWithFont (copyrightPanel,new Label(Utility.copyright2, Label.LEFT), Utility.creditFont); Utility.fixGrid(copyrightPanel,1); add(copyrightPanel); } private String toString( int anInt ) { Integer intObj = new Integer(anInt); return intObj.toString(); } private int parseIntField(TextComponent text) { int result = 0; try { Integer value = new Integer(workaround(text.getText())); result = value.intValue(); } catch (NumberFormatException e) { } return result; } private void intMinChanged(KeyEvent ev) { format.setMinimumIntegerDigits(parseIntField(intMin)); updateAttributes(); handleAttributeChange(); } private void intMaxChanged(KeyEvent ev) { format.setMaximumIntegerDigits(parseIntField(intMax)); updateAttributes(); handleAttributeChange(); } private void decMinChanged(KeyEvent ev) { format.setMinimumFractionDigits(parseIntField(decMin)); updateAttributes(); handleAttributeChange(); } private void decMaxChanged(KeyEvent ev) { format.setMaximumFractionDigits(parseIntField(decMax)); updateAttributes(); handleAttributeChange(); } private void negPrefixChanged(KeyEvent ev) { format.setNegativePrefix(workaround(negPrefix.getText())); updateAttributes(); handleAttributeChange(); } private void negSuffixChanged(KeyEvent ev) { format.setNegativeSuffix(workaround(negSuffix.getText())); updateAttributes(); handleAttributeChange(); } private void posPrefixChanged(KeyEvent ev) { format.setPositivePrefix(workaround(posPrefix.getText())); updateAttributes(); handleAttributeChange(); } private void posSuffixChanged(KeyEvent ev) { format.setPositiveSuffix(workaround(posSuffix.getText())); updateAttributes(); handleAttributeChange(); } /** * Strips high bits, because of bug in Java */ private static String workaround(String source) { StringBuffer result = new StringBuffer(); for (int i = 0; i < source.length(); ++i) result.append((char)(source.charAt(i) & 0xFF)); return result.toString(); } private void errorText(String s) { if (DEBUG) { System.out.println(s); } } private static final String creditString = "v1.1a6, Demo:"; private static final int FIELD_COLUMNS = 35; private static final boolean DEBUG = false; private static boolean isLocalized = false; // private Choice formatter, locale; private DecimalFormat format; private Locale[] locales; //------------------------------------------------------------ // protected //------------------------------------------------------------ /* this must be protected so that the window adapter can access it */ protected DemoApplet applet; }