в 17:44, 31 мая 2010

2010-05-31T17:44:26Z

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2010-05-31T15:18:20Z

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== Custom Document Filter ==



<source lang="java">
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.text.AbstractDocument;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
import javax.swing.text.DocumentFilter;
class IntegerRangeDocumentFilter extends DocumentFilter {
public IntegerRangeDocumentFilter() {
}
public void insertString(DocumentFilter.FilterBypass fb, int offset, String string,
AttributeSet attr) throws BadLocationException {
System.out.println("insert string"+ string);
System.out.println(offset);
super.insertString(fb, offset, string, attr);
}
public void remove(DocumentFilter.FilterBypass fb, int offset, int length)
throws BadLocationException {
System.out.println("remove");

super.remove(fb, offset, length);
}
public void replace(DocumentFilter.FilterBypass fb, int offset, int length, String text,
AttributeSet attrs) throws BadLocationException {
System.out.println("replace");
super.replace(fb, offset, length, text, attrs);
}
}
public class RangeSample {
public static void main(String args[]) {
JFrame frame = new JFrame("Range Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTextField textFieldOne = new JTextField();
Document textDocOne = textFieldOne.getDocument();
DocumentFilter filterOne = new IntegerRangeDocumentFilter();
((AbstractDocument) textDocOne).setDocumentFilter(filterOne);
frame.add(textFieldOne);
frame.setSize(250, 150);
frame.setVisible(true);
}
}</source>



== Element Walker ==



<source lang="java">
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.text.Document;
import javax.swing.text.Element;
import javax.swing.text.ElementIterator;
public class ElementSample {
public static void main(String args[]) {
JFrame frame = new JFrame("Element Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JTextArea textArea = new JTextArea();
JScrollPane scrollPane = new JScrollPane(textArea);
JButton button = new JButton("Show Elements");
ActionListener actionListener = new ActionListener() {
public void actionPerformed(ActionEvent actionEvent) {
Document document = textArea.getDocument();
ElementIterator iterator = new ElementIterator(document);
Element element = iterator.first();
while (element != null) {
System.out.println(element.getStartOffset());
element = iterator.next();
}
}
};
button.addActionListener(actionListener);
frame.add(scrollPane, BorderLayout.CENTER);
frame.add(button, BorderLayout.SOUTH);
frame.setSize(250, 250);
frame.setVisible(true);
}
}</source>



== extends PlainDocument to create a float value type text field ==



<source lang="java">
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.PlainDocument;
class JTextFieldFilter extends PlainDocument {
public static final String FLOAT = "0123456789.";
protected String acceptedChars = null;
protected boolean negativeAccepted = false;
public JTextFieldFilter() {
this(FLOAT);
}
public JTextFieldFilter(String acceptedchars) {
acceptedChars = acceptedchars;
}
public void setNegativeAccepted(boolean negativeaccepted) {
if (acceptedChars.equals(FLOAT)) {
negativeAccepted = negativeaccepted;
acceptedChars += "-";
}
}
public void insertString(int offset, String str, AttributeSet attr) throws BadLocationException {
if (str == null)
return;
for (int i = 0; i < str.length(); i++) {
if (acceptedChars.indexOf(str.valueOf(str.charAt(i))) == -1)
return;
}
if (acceptedChars.equals(FLOAT) || (acceptedChars.equals(FLOAT + "-") && negativeAccepted)) {
if (str.indexOf(".") != -1) {
if (getText(0, getLength()).indexOf(".") != -1) {
return;
}
}
}
if (negativeAccepted && str.indexOf("-") != -1) {
if (str.indexOf("-") != 0 || offset != 0) {
return;
}
}
super.insertString(offset, str, attr);
}
}
public class Main extends JFrame {
public static void main(String[] argv) throws Exception {
new Main();
}
public Main() {
JTextField tf1b;
JLabel l1b;
setLayout(new FlowLayout());
l1b = new JLabel("only float");
tf1b = new JTextField(10);
getContentPane().add(l1b);
getContentPane().add(tf1b);
tf1b.setDocument(new JTextFieldFilter(JTextFieldFilter.FLOAT));
setSize(300, 300);
setVisible(true);
}
}</source>



== extends PlainDocument to create alpha and numeric value based field field ==



<source lang="java">
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.PlainDocument;
class JTextFieldFilter extends PlainDocument {
public static final String ALPHA = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
public static final String NUMERIC = "0123456789";
public static final String ALPHA_NUMERIC = ALPHA + NUMERIC;
protected String acceptedChars = null;
protected boolean negativeAccepted = false;
public JTextFieldFilter() {
this(ALPHA_NUMERIC);
}
public JTextFieldFilter(String acceptedchars) {
acceptedChars = acceptedchars;
}
public void setNegativeAccepted(boolean negativeaccepted) {
if (acceptedChars.equals(ALPHA_NUMERIC)) {
negativeAccepted = negativeaccepted;
acceptedChars += "-";
}
}
public void insertString(int offset, String str, AttributeSet attr) throws BadLocationException {
if (str == null)
return;
for (int i = 0; i < str.length(); i++) {
if (acceptedChars.indexOf(str.valueOf(str.charAt(i))) == -1)
return;
}
if (negativeAccepted) {
if (str.indexOf(".") != -1) {
if (getText(0, getLength()).indexOf(".") != -1) {
return;
}
}
}
if (negativeAccepted && str.indexOf("-") != -1) {
if (str.indexOf("-") != 0 || offset != 0) {
return;
}
}
super.insertString(offset, str, attr);
}
}
public class Main extends JFrame{
public static void main(String[] argv) throws Exception {
new Main();
}
public Main() {
JTextField tf1c;
JLabel l1c;
setLayout(new FlowLayout());
l1c = new JLabel("only float(can be negative)");
tf1c = new JTextField(10);
getContentPane().add(l1c);
getContentPane().add(tf1c);
JTextFieldFilter jtff = new JTextFieldFilter(JTextFieldFilter.ALPHA_NUMERIC);
jtff.setNegativeAccepted(true);
tf1c.setDocument(jtff);

setSize(300,300);
setVisible(true);
}
}</source>



== Implement a document cleaner that maps lowercase letters to uppercase ==



<source lang="java">
import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.text.AbstractDocument;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.DocumentFilter;

public class Main{
public static void main(String[] args) {
DocumentFilter dfilter = new UpperCaseFilter();
JTextArea jta = new JTextArea();
((AbstractDocument) jta.getDocument()).setDocumentFilter(dfilter);
JFrame frame = new JFrame("UpcaseFilter");
frame.getContentPane().add(jta, java.awt.BorderLayout.CENTER);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(200, 120);
frame.setVisible(true);
}
}
class UpperCaseFilter extends DocumentFilter {
public void insertString(DocumentFilter.FilterBypass fb, int offset, String text,
AttributeSet attr) throws BadLocationException {
fb.insertString(offset, text.toUpperCase(), attr);
}
public void replace(DocumentFilter.FilterBypass fb, int offset, int length, String text,
AttributeSet attr) throws BadLocationException {
fb.replace(offset, length, text.toUpperCase(), attr);
}
}</source>



== Limit JTextField input to a maximum length ==



<source lang="java">
import javax.swing.JTextField;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.PlainDocument;
class JTextFieldLimit extends PlainDocument {
private int limit;
JTextFieldLimit(int limit) {
super();
this.limit = limit;
}
public void insertString(int offset, String str, AttributeSet attr)
throws BadLocationException {
if (str == null)
return;
if ((getLength() + str.length()) <= limit) {
super.insertString(offset, str, attr);
}
}
}
public class Main {
public static void main(String[] argv) {
JTextField textfield1 = new JTextField(15);
textfield1.setDocument(new JTextFieldLimit(10));
}
}</source>

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