/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.regexp;
import java.applet.Applet;
import java.awt.*;
import java.awt.event.TextEvent;
import java.awt.event.TextListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.CharArrayWriter;
import java.io.PrintWriter;
/**
* Interactive demonstration and testing harness for regular expressions classes.
* @author <a href="mailto:jonl@muppetlabs.com">Jonathan Locke</a>
* @version $Id: REDemo.java 126149 2004-02-19 02:35:28Z vgritsenko $
*/
public class REDemo extends Applet implements TextListener
{
/**
* Matcher and compiler objects
*/
RE r = new RE();
REDebugCompiler compiler = new REDebugCompiler();
/**
* Components
*/
TextField fieldRE; // Field for entering regexps
TextField fieldMatch; // Field for entering match strings
TextArea outRE; // Output of RE compiler
TextArea outMatch; // Results of matching operation
/**
* Add controls and init applet
*/
public void init()
{
// Add components using the dreaded GridBagLayout
GridBagLayout gb = new GridBagLayout();
setLayout(gb);
GridBagConstraints c = new GridBagConstraints();
c.insets = new Insets(5, 5, 5, 5);
c.anchor = GridBagConstraints.EAST;
gb.setConstraints(add(new Label("Regular expression:", Label.RIGHT)), c);
c.gridy = 0;
c.anchor = GridBagConstraints.WEST;
gb.setConstraints(add(fieldRE = new TextField("\\[([:javastart:][:javapart:]*)\\]", 40)), c);
c.gridx = 0;
c.gridy = GridBagConstraints.RELATIVE;
c.anchor = GridBagConstraints.EAST;
gb.setConstraints(add(new Label("String:", Label.RIGHT)), c);
c.gridy = 1;
c.gridx = GridBagConstraints.RELATIVE;
c.anchor = GridBagConstraints.WEST;
gb.setConstraints(add(fieldMatch = new TextField("aaa([foo])aaa", 40)), c);
c.gridy = 2;
c.gridx = GridBagConstraints.RELATIVE;
c.fill = GridBagConstraints.BOTH;
c.weighty = 1.0;
c.weightx = 1.0;
gb.setConstraints(add(outRE = new TextArea()), c);
c.gridy = 2;
c.gridx = GridBagConstraints.RELATIVE;
gb.setConstraints(add(outMatch = new TextArea()), c);
// Listen to text changes
fieldRE.addTextListener(this);
fieldMatch.addTextListener(this);
// Initial UI update
textValueChanged(null);
}
/**
* Say something into RE text area
* @param s What to say
*/
void sayRE(String s)
{
outRE.setText(s);
}
/**
* Say something into match text area
* @param s What to say
*/
void sayMatch(String s)
{
outMatch.setText(s);
}
/**
* Convert throwable to string
* @param t Throwable to convert to string
*/
String throwableToString(Throwable t)
{
String s = t.getClass().getName();
String m;
if ((m = t.getMessage()) != null)
{
s += "\n" + m;
}
return s;
}
/**
* Change regular expression
* @param expr Expression to compile
*/
void updateRE(String expr)
{
try
{
// Compile program
r.setProgram(compiler.compile(expr));
// Dump program into RE feedback area
CharArrayWriter w = new CharArrayWriter();
compiler.dumpProgram(new PrintWriter(w));
sayRE(w.toString());
System.out.println(w);
}
catch (Exception e)
{
r.setProgram(null);
sayRE(throwableToString(e));
}
catch (Throwable t)
{
r.setProgram(null);
sayRE(throwableToString(t));
}
}
/**
* Update matching info by matching the string against the current
* compiled regular expression.
* @param match String to match against
*/
void updateMatch(String match)
{
try
{
// If the string matches the regexp
if (r.match(match))
{
// Say that it matches
String out = "Matches.\n\n";
// Show contents of parenthesized subexpressions
for (int i = 0; i < r.getParenCount(); i++)
{
out += "$" + i + " = " + r.getParen(i) + "\n";
}
sayMatch(out);
}
else
{
// Didn't match!
sayMatch("Does not match");
}
}
catch (Throwable t)
{
sayMatch(throwableToString(t));
}
}
/**
* Called when text values change
* @param e TextEvent
*/
public void textValueChanged(TextEvent e)
{
// If it's a generic update or the regexp changed...
if (e == null || e.getSource() == fieldRE)
{
// Update regexp
updateRE(fieldRE.getText());
}
// We always need to update the match results
updateMatch(fieldMatch.getText());
}
/**
* Main application entrypoint.
* @param arg Command line arguments
*/
static public void main(String[] arg)
{
Frame f = new Frame("RE Demo");
// f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
REDemo demo = new REDemo();
f.add(demo);
demo.init();
f.pack();
f.setVisible(true);
}
}