Groovy example source code file (RegexCoachController.groovy)

This example Groovy source code file (RegexCoachController.groovy) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

actionlistener, actionlistener, awt, event, keyadapter, keyadapter, match, no, patternsyntaxexception, regex, regexhighliter, regexhighliter, swingbuilder, swingbuilder

The Groovy RegexCoachController.groovy source code

// Groovy Regex Coach - Copyright 2007 Jeremy Rayner

import groovy.swing.SwingBuilder
import java.awt.Color
import java.awt.event.ActionEvent
import java.awt.event.ActionListener
import java.awt.event.KeyAdapter
import java.awt.event.KeyEvent
import java.util.regex.PatternSyntaxException
import javax.swing.text.DefaultHighlighter.DefaultHighlightPainter

// inspired by http://weitz.de/regex-coach/

// define the view
def swing = new SwingBuilder()

def gui = swing.build(RegexCoachView)

def highlighter = new RegexHighliter(swing: swing)
swing.regexPane.addKeyListener(highlighter)
swing.targetPane.addKeyListener(highlighter)
swing.scanLeft.addActionListener(highlighter)
swing.scanRight.addActionListener(highlighter)
gui.show()

class RegexHighliter extends KeyAdapter implements ActionListener {
    def swing // reference to the view
    int scanIndex // how many times to execute matcher.find()
    def orange = new DefaultHighlightPainter(Color.ORANGE)
    def yellow = new DefaultHighlightPainter(Color.YELLOW)
    def red = new DefaultHighlightPainter(Color.RED)

    // react to user actions
    public void actionPerformed(ActionEvent event) {
        if (event.actionCommand == '<<-') {scanIndex = Math.max(scanIndex - 1, 0)}
        if (event.actionCommand == '->>') {scanIndex++}
        doHighlights()
    }
    public void keyReleased(KeyEvent event) {
        scanIndex = 0
        doHighlights()
    }

    private resetView() {
        swing.regexPane.highlighter.removeAllHighlights()
        swing.targetPane.highlighter.removeAllHighlights()
        swing.regexStatus.text = ' '
        swing.targetStatus.text = ' '
    }

    // the main regex logic
    private doHighlights() {
        try {
            resetView()
            // note: get the text from the underlying document,
            // otherwise carriage return/line feeds different when using the JTextPane text
            def regex = swing.regexPane.document.getText(0, swing.regexPane.document.length)
            def target = swing.targetPane.document.getText(0, swing.targetPane.document.length)

            def matcher = (target =~ regex)

            // scan past the matches before the match we want
            int scan = 0
            while (scan < scanIndex) {
                matcher.find()
                scan++
            }
            if (matcher.find()) {
                // highlight any captured groups
                int i = 0
                while (i++ < matcher.groupCount()) {
                    swing.targetPane.highlighter.addHighlight(matcher.start(i), matcher.end(i), orange)
                }
                // highlight whole match
                swing.targetPane.highlighter.addHighlight(matcher.start(), matcher.end(), yellow)
                if (regex.length() != 0) {
                    swing.targetStatus.text = "Match #${scanIndex + 1} from ${matcher.start()} to ${matcher.end()}."
                }
            } else {// not found
                scanIndex = Math.max(scan - 1, 0)
                if (scanIndex > 0) {doHighlights()}
                swing.targetStatus.text = "No match."
            }
        } catch (PatternSyntaxException e) {
            swing.regexPane.highlighter.addHighlight(e.index, e.index + 2, red)
            swing.regexStatus.text = e.description
        }
    }
}