GoToDialog.java

package com;

import java.awt.event.KeyEvent;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.KeyStroke;
import javax.swing.text.BadLocationException;

public class GoToDialog {

    private JDialog gotoDialog;
    private JTextArea textArea;

    public GoToDialog(JFrame main, JTextArea textArea) {
        gotoDialog = new JDialog(main, "Переход на строку", true);
        gotoDialog.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        gotoDialog.setSize(300, 110);
        gotoDialog.setResizable(false);
        gotoDialog.setLocationRelativeTo(null);
        gotoDialog.setLayout(null);

        gotoDialog.getRootPane().registerKeyboardAction(e -> gotoDialog.dispose(),
                KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), JComponent.WHEN_IN_FOCUSED_WINDOW);

        this.textArea = textArea;

        initUI();

        gotoDialog.setVisible(true);
    }

    private void initUI() {
        JLabel lineNumber = new JLabel("Номер строки:");
        lineNumber.setBounds(10, 10, 100, 20);
        gotoDialog.add(lineNumber);

        JTextField inputField = new JTextField();
        try {
            int n = textArea.getLineOfOffset(textArea.getCaretPosition()) + 1;
            inputField.setText(String.valueOf(n));
            inputField.selectAll();
        } catch (BadLocationException e) {
            inputField.setText("");
        }
        inputField.setBounds(102, 10, 174, 20);
        gotoDialog.add(inputField);

        int lines = textArea.getLineCount();
        if (lines < 100000) {
            JLabel maxNumber = new JLabel("Макс: " + String.valueOf(lines));
            maxNumber.setBounds(10, 44, 80, 20);
            gotoDialog.add(maxNumber);
        }

        JButton buttonOK = new JButton("ОК");
        buttonOK.setBounds(94, 44, 80, 20);
        buttonOK.addActionListener(e -> {
            try {
                int n = Integer.parseInt(inputField.getText());
                textArea.setCaretPosition(textArea.getLineStartOffset(n - 1));
            } catch (Exception ex) {
            }
            gotoDialog.dispose();
        });
        gotoDialog.add(buttonOK);

        JButton buttonCancel = new JButton("Отмена");
        buttonCancel.setBounds(196, 44, 80, 20);
        buttonCancel.addActionListener(e -> gotoDialog.dispose());
        gotoDialog.add(buttonCancel);
    }
}