Java Swing How to - Replace text with Image as you type

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Question

We would like to know how to replace text with Image as you type.

Answer

//from   w ww .  j av  a  2s  .c o  m
import java.awt.Dimension;
import java.net.URL;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextPane;
import javax.swing.SwingUtilities;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.AbstractDocument;
import javax.swing.text.BadLocationException;
import javax.swing.text.SimpleAttributeSet;
import javax.swing.text.StyleConstants;
import javax.swing.text.StyledDocument;
import javax.swing.text.Utilities;

public class Main {

  static ImageIcon anImage;
  static final String imageToken = ":)";
  String[] imageTokens = { imageToken };

  private void initComponents() {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JTextPane textPane = new JTextPane();
    ((AbstractDocument) textPane.getDocument())
        .addDocumentListener(new DocumentListener() {
          @Override
          public void insertUpdate(final DocumentEvent de) {
            SwingUtilities.invokeLater(new Runnable() {
              public void run() {
                try {
                  StyledDocument doc = (StyledDocument) de.getDocument();
                  int start = Utilities.getRowStart(textPane,
                      Math.max(0, de.getOffset() - 1));
                  int end = Utilities.getWordStart(textPane, de.getOffset()
                      + de.getLength());

                  String text = doc.getText(start, end - start);

                  for (String emoticon : imageTokens) {
                    int i = text.indexOf(emoticon);
                    while (i >= 0) {
                      final SimpleAttributeSet attrs = new SimpleAttributeSet(
                          doc.getCharacterElement(start + i).getAttributes());
                      if (StyleConstants.getIcon(attrs) == null) {
                        switch (emoticon) {
                        case imageToken:
                          StyleConstants.setIcon(attrs, anImage);
                          break;
                        }
                        doc.remove(start + i, emoticon.length());
                        doc.insertString(start + i, emoticon, attrs);
                      }
                      i = text.indexOf(emoticon, i + emoticon.length());
                    }
                  }
                } catch (BadLocationException ex) {
                  ex.printStackTrace();
                }
              }
            });
          }
          @Override
          public void removeUpdate(DocumentEvent e) {
          }
          @Override
          public void changedUpdate(DocumentEvent e) {
          }
        });

    JScrollPane scrollPane = new JScrollPane(textPane);
    scrollPane.setPreferredSize(new Dimension(300, 300));
    frame.add(scrollPane);
    frame.pack();
    frame.setVisible(true);
  }

  public static void main(String[] args) throws Exception {
    anImage = new ImageIcon(ImageIO.read(
        new URL("http://www.java2s.com/style/download.png")));
    new Main().initComponents();
  }
}

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