1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.regexp;
19
20 import java.applet.Applet;
21 import java.awt;
22 import java.awt.event.TextEvent;
23 import java.awt.event.TextListener;
24 import java.awt.event.WindowAdapter;
25 import java.awt.event.WindowEvent;
26 import java.io.CharArrayWriter;
27 import java.io.PrintWriter;
28
29 /**
30 * Interactive demonstration and testing harness for regular expressions classes.
31 * @author <a href="mailto:jonl@muppetlabs.com">Jonathan Locke</a>
32 * @version $Id: REDemo.java 518156 2007-03-14 14:31:26Z vgritsenko $
33 */
34 public class REDemo extends Applet implements TextListener
35 {
36 /**
37 * Matcher and compiler objects
38 */
39 RE r = new RE();
40 REDebugCompiler compiler = new REDebugCompiler();
41
42 /**
43 * Components
44 */
45 TextField fieldRE; // Field for entering regexps
46 TextField fieldMatch; // Field for entering match strings
47 TextArea outRE; // Output of RE compiler
48 TextArea outMatch; // Results of matching operation
49
50 /**
51 * Add controls and init applet
52 */
53 public void init()
54 {
55 // Add components using the dreaded GridBagLayout
56 GridBagLayout gb = new GridBagLayout();
57 setLayout(gb);
58 GridBagConstraints c = new GridBagConstraints();
59 c.insets = new Insets(5, 5, 5, 5);
60 c.anchor = GridBagConstraints.EAST;
61 gb.setConstraints(add(new Label("Regular expression:", Label.RIGHT)), c);
62 c.gridy = 0;
63 c.anchor = GridBagConstraints.WEST;
64 gb.setConstraints(add(fieldRE = new TextField("\\[([:javastart:][:javapart:]*)\\]", 40)), c);
65 c.gridx = 0;
66 c.gridy = GridBagConstraints.RELATIVE;
67 c.anchor = GridBagConstraints.EAST;
68 gb.setConstraints(add(new Label("String:", Label.RIGHT)), c);
69 c.gridy = 1;
70 c.gridx = GridBagConstraints.RELATIVE;
71 c.anchor = GridBagConstraints.WEST;
72 gb.setConstraints(add(fieldMatch = new TextField("aaa([foo])aaa", 40)), c);
73 c.gridy = 2;
74 c.gridx = GridBagConstraints.RELATIVE;
75 c.fill = GridBagConstraints.BOTH;
76 c.weighty = 1.0;
77 c.weightx = 1.0;
78 gb.setConstraints(add(outRE = new TextArea()), c);
79 c.gridy = 2;
80 c.gridx = GridBagConstraints.RELATIVE;
81 gb.setConstraints(add(outMatch = new TextArea()), c);
82
83 // Listen to text changes
84 fieldRE.addTextListener(this);
85 fieldMatch.addTextListener(this);
86
87 // Initial UI update
88 textValueChanged(null);
89 }
90
91 /**
92 * Say something into RE text area
93 * @param s What to say
94 */
95 void sayRE(String s)
96 {
97 outRE.setText(s);
98 }
99
100 /**
101 * Say something into match text area
102 * @param s What to say
103 */
104 void sayMatch(String s)
105 {
106 outMatch.setText(s);
107 }
108
109 /**
110 * Convert throwable to string
111 * @param t Throwable to convert to string
112 */
113 String throwableToString(Throwable t)
114 {
115 String s = t.getClass().getName();
116 String m;
117 if ((m = t.getMessage()) != null)
118 {
119 s += "\n" + m;
120 }
121 return s;
122 }
123
124 /**
125 * Change regular expression
126 * @param expr Expression to compile
127 */
128 void updateRE(String expr)
129 {
130 try
131 {
132 // Compile program
133 r.setProgram(compiler.compile(expr));
134
135 // Dump program into RE feedback area
136 CharArrayWriter w = new CharArrayWriter();
137 compiler.dumpProgram(new PrintWriter(w));
138 sayRE(w.toString());
139 System.out.println(w);
140 }
141 catch (Exception e)
142 {
143 r.setProgram(null);
144 sayRE(throwableToString(e));
145 }
146 catch (Throwable t)
147 {
148 r.setProgram(null);
149 sayRE(throwableToString(t));
150 }
151 }
152
153 /**
154 * Update matching info by matching the string against the current
155 * compiled regular expression.
156 * @param match String to match against
157 */
158 void updateMatch(String match)
159 {
160 try
161 {
162 // If the string matches the regexp
163 if (r.match(match))
164 {
165 // Say that it matches
166 String out = "Matches.\n\n";
167
168 // Show contents of parenthesized subexpressions
169 for (int i = 0; i < r.getParenCount(); i++)
170 {
171 out += "$" + i + " = " + r.getParen(i) + "\n";
172 }
173 sayMatch(out);
174 }
175 else
176 {
177 // Didn't match!
178 sayMatch("Does not match");
179 }
180 }
181 catch (Throwable t)
182 {
183 sayMatch(throwableToString(t));
184 }
185 }
186
187 /**
188 * Called when text values change
189 * @param e TextEvent
190 */
191 public void textValueChanged(TextEvent e)
192 {
193 // If it's a generic update or the regexp changed...
194 if (e == null || e.getSource() == fieldRE)
195 {
196 // Update regexp
197 updateRE(fieldRE.getText());
198 }
199
200 // We always need to update the match results
201 updateMatch(fieldMatch.getText());
202 }
203
204 /**
205 * Main application entrypoint.
206 * @param arg Command line arguments
207 */
208 static public void main(String[] arg)
209 {
210 Frame f = new Frame("RE Demo");
211 // f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
212 f.addWindowListener(new WindowAdapter()
213 {
214 public void windowClosing(WindowEvent e)
215 {
216 System.exit(0);
217 }
218 });
219 REDemo demo = new REDemo();
220 f.add(demo);
221 demo.init();
222 f.pack();
223 f.setVisible(true);
224 }
225 }
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