package com.example.myapp.console;
import java.awt.event.ActionEvent;
import java.util.Collections;
import java.util.List;
import javax.swing.AbstractAction;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.BadLocationException;
public class Autocomplete implements DocumentListener {
private static enum Mode {
INSERT,
COMPLETION
};
private JTextField textField;
private final List<String> keywords;
private Mode mode = Mode.INSERT;
public Autocomplete(JTextField textField, List<String> keywords) {
this.textField = textField;
this.keywords = keywords;
Collections.sort(keywords);
}
@Override
public void changedUpdate(DocumentEvent ev) { }
@Override
public void removeUpdate(DocumentEvent ev) { }
@Override
public void insertUpdate(DocumentEvent ev) {
if (ev.getLength() != 1)
return;
int pos = ev.getOffset();
String content = null;
try {
content = textField.getText(0, pos + 1);
} catch (BadLocationException e) {
e.printStackTrace();
}
// Find where the word starts
int w;
for (w = pos; w >= 0; w--) {
if (!Character.isLetter(content.charAt(w))) {
break;
}
}
// Too few chars
if (pos - w < 2)
return;
String prefix = content.substring(w + 1).toLowerCase();
int n = Collections.binarySearch(keywords, prefix);
if (n < 0 && -n <= keywords.size()) {
String match = keywords.get(-n - 1);
if (match.startsWith(prefix)) {
// A completion is found
String completion = match.substring(pos - w);
// We cannot modify Document from within notification,
// so we submit a task that does the change later
SwingUtilities.invokeLater(new CompletionTask(completion, pos + 1));
}
} else {
// Nothing found
mode = Mode.INSERT;
}
}
public class CommitAction extends AbstractAction {
/**
*
*/
private static final long serialVersionUID = 5794543109646743416L;
@Override
public void actionPerformed(ActionEvent ev) {
if (mode == Mode.COMPLETION) {
int pos = textField.getSelectionEnd();
StringBuffer sb = new StringBuffer(textField.getText());
sb.insert(pos, " ");
textField.setText(sb.toString());
textField.setCaretPosition(pos + 1);
mode = Mode.INSERT;
} else {
textField.replaceSelection("\t");
}
}
}
private class CompletionTask implements Runnable {
private String completion;
private int position;
CompletionTask(String completion, int position) {
this.completion = completion;
this.position = position;
}
public void run() {
StringBuffer sb = new StringBuffer(textField.getText());
sb.insert(position, completion);
textField.setText(sb.toString());
textField.setCaretPosition(position + completion.length());
textField.moveCaretPosition(position);
mode = Mode.COMPLETION;
}
}
}