Example: Using Find and Replace

RSyntaxTextArea has built-in support for search and replace operations, with all of the options you'd expect, including:

• Search forward or backward
• Match case
• Regular expressions
• Whole word
• Mark all

These actions are done with the SearchEngine class. This class contains self-explanatory methods for all your searching needs:

• find(RTextArea, SearchContext) - Find the next/previous match with any of the above options.
• replace(RTextArea, SearchContext) - Finds the next/previous match and replaces it with new text.
• replaceAll(RTextArea, SearchContext) - Finds all matches and replaces them with the new text.

Each of these methods takes two parameters: The RSyntaxTextArea instance to search in, and a SearchContext specifying what to search for, how to search for it, and whether to mark all occurrences when a match is found.

Note: For Find and Replace dialogs or tool bars, consider using the RSTAUI project. It contains those components for integration with RSyntaxTextArea's searching API, as well as other components typically used in text editor applications.

Using the SearchEngine class makes implementing Find & Replace in an RSyntaxTextArea extremely easy. Below is a simple example of how it can be used:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

import org.fife.ui.rtextarea.*;
import org.fife.ui.rsyntaxtextarea.*;

/**
 * A simple example showing how to do search and replace in a RSyntaxTextArea.
 * The toolbar isn't very user-friendly, but this is just to show you how to use
 * the API.<p>
 * 
 * This example uses RSyntaxTextArea 2.5.6.
 */
public class FindAndReplaceDemo extends JFrame implements ActionListener {

   private static final long serialVersionUID = 1L;

   private RSyntaxTextArea textArea;
   private JTextField searchField;
   private JCheckBox regexCB;
   private JCheckBox matchCaseCB;

   public FindAndReplaceDemo() {

      JPanel cp = new JPanel(new BorderLayout());

      textArea = new RSyntaxTextArea(20, 60);
      textArea.setSyntaxEditingStyle(SyntaxConstants.SYNTAX_STYLE_JAVA);
      textArea.setCodeFoldingEnabled(true);
      RTextScrollPane sp = new RTextScrollPane(textArea);
      cp.add(sp);

      // Create a toolbar with searching options.
      JToolBar toolBar = new JToolBar();
      searchField = new JTextField(30);
      toolBar.add(searchField);
      final JButton nextButton = new JButton("Find Next");
      nextButton.setActionCommand("FindNext");
      nextButton.addActionListener(this);
      toolBar.add(nextButton);
      searchField.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent e) {
            nextButton.doClick(0);
         }
      });
      JButton prevButton = new JButton("Find Previous");
      prevButton.setActionCommand("FindPrev");
      prevButton.addActionListener(this);
      toolBar.add(prevButton);
      regexCB = new JCheckBox("Regex");
      toolBar.add(regexCB);
      matchCaseCB = new JCheckBox("Match Case");
      toolBar.add(matchCaseCB);
      cp.add(toolBar, BorderLayout.NORTH);

      setContentPane(cp);
      setTitle("Find and Replace Demo");
      setDefaultCloseOperation(EXIT_ON_CLOSE);
      pack();
      setLocationRelativeTo(null);

   }

   public void actionPerformed(ActionEvent e) {

      // "FindNext" => search forward, "FindPrev" => search backward
      String command = e.getActionCommand();
      boolean forward = "FindNext".equals(command);

      // Create an object defining our search parameters.
      SearchContext context = new SearchContext();
      String text = searchField.getText();
      if (text.length() == 0) {
         return;
      }
      context.setSearchFor(text);
      context.setMatchCase(matchCaseCB.isSelected());
      context.setRegularExpression(regexCB.isSelected());
      context.setSearchForward(forward);
      context.setWholeWord(false);

      boolean found = SearchEngine.find(textArea, context).wasFound();
      if (!found) {
         JOptionPane.showMessageDialog(this, "Text not found");
      }

   }

   public static void main(String[] args) {
      // Start all Swing applications on the EDT.
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            try {
               String laf = UIManager.getSystemLookAndFeelClassName();
               UIManager.setLookAndFeel(laf);
            } catch (Exception e) { /* never happens */ }
            FindAndReplaceDemo demo = new FindAndReplaceDemo();
            demo.setVisible(true);
            demo.textArea.requestFocusInWindow();
         }
      });
   }

}