/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements.  See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 518156 2007-03-14 14:31:26Z 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);    }}