Numeric TextField
/*
Core SWING Advanced Programming
By Kim Topley
ISBN: 0 13 083292 8
Publisher: Prentice Hall
*/
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DecimalFormat;
import java.text.ParseException;
import java.text.ParsePosition;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.text.AbstractDocument;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
import javax.swing.text.PlainDocument;
import javax.swing.text.AbstractDocument.Content;
public class NumericTextField extends JTextField implements
NumericPlainDocument.InsertErrorListener {
public NumericTextField() {
this(null, 0, null);
}
public NumericTextField(String text, int columns, DecimalFormat format) {
super(null, text, columns);
NumericPlainDocument numericDoc = (NumericPlainDocument) getDocument();
if (format != null) {
numericDoc.setFormat(format);
}
numericDoc.addInsertErrorListener(this);
}
public NumericTextField(int columns, DecimalFormat format) {
this(null, columns, format);
}
public NumericTextField(String text) {
this(text, 0, null);
}
public NumericTextField(String text, int columns) {
this(text, columns, null);
}
public void setFormat(DecimalFormat format) {
((NumericPlainDocument) getDocument()).setFormat(format);
}
public DecimalFormat getFormat() {
return ((NumericPlainDocument) getDocument()).getFormat();
}
public void formatChanged() {
// Notify change of format attributes.
setFormat(getFormat());
}
// Methods to get the field value
public Long getLongValue() throws ParseException {
return ((NumericPlainDocument) getDocument()).getLongValue();
}
public Double getDoubleValue() throws ParseException {
return ((NumericPlainDocument) getDocument()).getDoubleValue();
}
public Number getNumberValue() throws ParseException {
return ((NumericPlainDocument) getDocument()).getNumberValue();
}
// Methods to install numeric values
public void setValue(Number number) {
setText(getFormat().format(number));
}
public void setValue(long l) {
setText(getFormat().format(l));
;
}
public void setValue(double d) {
setText(getFormat().format(d));
}
public void normalize() throws ParseException {
// format the value according to the format string
setText(getFormat().format(getNumberValue()));
}
// Override to handle insertion error
public void insertFailed(NumericPlainDocument doc, int offset, String str,
AttributeSet a) {
// By default, just beep
Toolkit.getDefaultToolkit().beep();
}
// Method to create default model
protected Document createDefaultModel() {
return new NumericPlainDocument();
}
// Test code
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
DecimalFormat format = new DecimalFormat("#,###.###");
format.setGroupingUsed(true);
format.setGroupingSize(3);
format.setParseIntegerOnly(false);
JFrame f = new JFrame("Numeric Text Field Example");
final NumericTextField tf = new NumericTextField(10, format);
tf.setValue((double) 123456.789);
JLabel lbl = new JLabel("Type a number: ");
f.getContentPane().add(tf, "East");
f.getContentPane().add(lbl, "West");
tf.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
try {
tf.normalize();
Long l = tf.getLongValue();
System.out.println("Value is (Long)" + l);
} catch (ParseException e1) {
try {
Double d = tf.getDoubleValue();
System.out.println("Value is (Double)" + d);
} catch (ParseException e2) {
System.out.println(e2);
}
}
}
});
f.pack();
f.setVisible(true);
}
}
class NumericPlainDocument extends PlainDocument {
public NumericPlainDocument() {
setFormat(null);
}
public NumericPlainDocument(DecimalFormat format) {
setFormat(format);
}
public NumericPlainDocument(AbstractDocument.Content content,
DecimalFormat format) {
super(content);
setFormat(format);
try {
format
.parseObject(content.getString(0, content.length()),
parsePos);
} catch (Exception e) {
throw new IllegalArgumentException(
"Initial content not a valid number");
}
if (parsePos.getIndex() != content.length() - 1) {
throw new IllegalArgumentException(
"Initial content not a valid number");
}
}
public void setFormat(DecimalFormat fmt) {
this.format = fmt != null ? fmt : (DecimalFormat) defaultFormat.clone();
decimalSeparator = format.getDecimalFormatSymbols()
.getDecimalSeparator();
groupingSeparator = format.getDecimalFormatSymbols()
.getGroupingSeparator();
positivePrefix = format.getPositivePrefix();
positivePrefixLen = positivePrefix.length();
negativePrefix = format.getNegativePrefix();
negativePrefixLen = negativePrefix.length();
positiveSuffix = format.getPositiveSuffix();
positiveSuffixLen = positiveSuffix.length();
negativeSuffix = format.getNegativeSuffix();
negativeSuffixLen = negativeSuffix.length();
}
public DecimalFormat getFormat() {
return format;
}
public Number getNumberValue() throws ParseException {
try {
String content = getText(0, getLength());
parsePos.setIndex(0);
Number result = format.parse(content, parsePos);
if (parsePos.getIndex() != getLength()) {
throw new ParseException("Not a valid number: " + content, 0);
}
return result;
} catch (BadLocationException e) {
throw new ParseException("Not a valid number", 0);
}
}
public Long getLongValue() throws ParseException {
Number result = getNumberValue();
if ((result instanceof Long) == false) {
throw new ParseException("Not a valid long", 0);
}
return (Long) result;
}
public Double getDoubleValue() throws ParseException {
Number result = getNumberValue();
if ((result instanceof Long) == false
&& (result instanceof Double) == false) {
throw new ParseException("Not a valid double", 0);
}
if (result instanceof Long) {
result = new Double(result.doubleValue());
}
return (Double) result;
}
public void insertString(int offset, String str, AttributeSet a)
throws BadLocationException {
if (str == null || str.length() == 0) {
return;
}
Content content = getContent();
int length = content.length();
int originalLength = length;
parsePos.setIndex(0);
// Create the result of inserting the new data,
// but ignore the trailing newline
String targetString = content.getString(0, offset) + str
+ content.getString(offset, length - offset - 1);
// Parse the input string and check for errors
do {
boolean gotPositive = targetString.startsWith(positivePrefix);
boolean gotNegative = targetString.startsWith(negativePrefix);
length = targetString.length();
// If we have a valid prefix, the parse fails if the
// suffix is not present and the error is reported
// at index 0. So, we need to add the appropriate
// suffix if it is not present at this point.
if (gotPositive == true || gotNegative == true) {
String suffix;
int suffixLength;
int prefixLength;
if (gotPositive == true && gotNegative == true) {
// This happens if one is the leading part of
// the other - e.g. if one is "(" and the other "(("
if (positivePrefixLen > negativePrefixLen) {
gotNegative = false;
} else {
gotPositive = false;
}
}
if (gotPositive == true) {
suffix = positiveSuffix;
suffixLength = positiveSuffixLen;
prefixLength = positivePrefixLen;
} else {
// Must have the negative prefix
suffix = negativeSuffix;
suffixLength = negativeSuffixLen;
prefixLength = negativePrefixLen;
}
// If the string consists of the prefix alone,
// do nothing, or the result won't parse.
if (length == prefixLength) {
break;
}
// We can't just add the suffix, because part of it
// may already be there. For example, suppose the
// negative prefix is "(" and the negative suffix is
// "$)". If the user has typed "(345$", then it is not
// correct to add "$)". Instead, only the missing part
// should be added, in this case ")".
if (targetString.endsWith(suffix) == false) {
int i;
for (i = suffixLength - 1; i > 0; i--) {
if (targetString
.regionMatches(length - i, suffix, 0, i)) {
targetString += suffix.substring(i);
break;
}
}
if (i == 0) {
// None of the suffix was present
targetString += suffix;
}
length = targetString.length();
}
}
format.parse(targetString, parsePos);
int endIndex = parsePos.getIndex();
if (endIndex == length) {
break; // Number is acceptable
}
// Parse ended early
// Since incomplete numbers don't always parse, try
// to work out what went wrong.
// First check for an incomplete positive prefix
if (positivePrefixLen > 0 && endIndex < positivePrefixLen
&& length <= positivePrefixLen
&& targetString.regionMatches(0, positivePrefix, 0, length)) {
break; // Accept for now
}
// Next check for an incomplete negative prefix
if (negativePrefixLen > 0 && endIndex < negativePrefixLen
&& length <= negativePrefixLen
&& targetString.regionMatches(0, negativePrefix, 0, length)) {
break; // Accept for now
}
// Allow a number that ends with the group
// or decimal separator, if these are in use
char lastChar = targetString.charAt(originalLength - 1);
int decimalIndex = targetString.indexOf(decimalSeparator);
if (format.isGroupingUsed() && lastChar == groupingSeparator
&& decimalIndex == -1) {
// Allow a "," but only in integer part
break;
}
if (format.isParseIntegerOnly() == false
&& lastChar == decimalSeparator
&& decimalIndex == originalLength - 1) {
// Allow a ".", but only one
break;
}
// No more corrections to make: must be an error
if (errorListener != null) {
errorListener.insertFailed(this, offset, str, a);
}
return;
} while (true == false);
// Finally, add to the model
super.insertString(offset, str, a);
}
public void addInsertErrorListener(InsertErrorListener l) {
if (errorListener == null) {
errorListener = l;
return;
}
throw new IllegalArgumentException(
"InsertErrorListener already registered");
}
public void removeInsertErrorListener(InsertErrorListener l) {
if (errorListener == l) {
errorListener = null;
}
}
public interface InsertErrorListener {
public abstract void insertFailed(NumericPlainDocument doc, int offset,
String str, AttributeSet a);
}
protected InsertErrorListener errorListener;
protected DecimalFormat format;
protected char decimalSeparator;
protected char groupingSeparator;
protected String positivePrefix;
protected String negativePrefix;
protected int positivePrefixLen;
protected int negativePrefixLen;
protected String positiveSuffix;
protected String negativeSuffix;
protected int positiveSuffixLen;
protected int negativeSuffixLen;
protected ParsePosition parsePos = new ParsePosition(0);
protected static DecimalFormat defaultFormat = new DecimalFormat();
}
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