package Main;

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

public class ExampleGUI3 extends JFrame{
  private JTabbedPane tabbedPane;
  private JTextPane messageArea;
  JPanel mainPanel;

  private class NewTabListener implements ActionListener{
    public void actionPerformed(ActionEvent arg0){
      StyledDocument doc = (StyledDocument)messageArea.getDocument();
      try{
        doc.insertString(doc.getLength(), "new line\n", null);
      }
      catch (BadLocationException e){
        e.printStackTrace();
      }
      tabbedPane.add("tab", new JPanel());
      mainPanel.revalidate();
    }
  }

  private GridBagConstraints setGridBagConstraints(int gridx,
      int gridy,
      int gridwidth,
      int gridheight,
      double weightx,
      double weighty,
      int fill,
      int anchor,
      int insets1,
      int insets2,
      int insets3,
      int insets4){
    GridBagConstraints gridConstr = new GridBagConstraints();

    gridConstr.gridx = gridx;
    gridConstr.gridy = gridy;
    gridConstr.gridwidth = gridwidth;
    gridConstr.gridheight = gridheight;
    gridConstr.weightx = weightx;
    gridConstr.weighty = weighty;
    gridConstr.fill = fill;
    gridConstr.anchor = anchor;
    /* Insets(int top, int left, int bottom, int right) */
    gridConstr.insets = new Insets(insets1, insets2, insets3, insets4);

    return gridConstr;
  }

  public ExampleGUI3(){
    setTitle("Example GUI");
    setDefaultCloseOperation(EXIT_ON_CLOSE);

    tabbedPane = new JTabbedPane();
    tabbedPane.setPreferredSize(new Dimension(800, 540));

    messageArea = new JTextPane(){
      public Dimension getPreferredScrollableViewportSize(){
        return new Dimension(800, 60);
      }
    };

    JScrollPane jsp = new JScrollPane(messageArea);

    mainPanel = new JPanel();
    mainPanel.setPreferredSize(new Dimension(800, 600));

    mainPanel.setLayout(new GridBagLayout());
    GridBagConstraints gridConstr;

    gridConstr = setGridBagConstraints
      (0, 0, 1, 1, 1.0, 0.9, GridBagConstraints.BOTH,
     //gx,gy,gw,gh,wx,  wy
       GridBagConstraints.CENTER, 0, 0, 0, 0);
    mainPanel.add(tabbedPane, gridConstr);

    gridConstr = setGridBagConstraints
      (0, 1, 1, 1, 1.0, 0.1, GridBagConstraints.BOTH,
       GridBagConstraints.CENTER, 0, 0, 0, 0);
    mainPanel.add(jsp, gridConstr);

    JMenuBar menuBar = new JMenuBar();
    JMenu menu = new JMenu("menu");
    JMenuItem newTab = new JMenuItem("new tab");
    menu.add(newTab);
    menuBar.add(menu);
    newTab.addActionListener(new NewTabListener());

    setJMenuBar(menuBar);
    getContentPane().add(mainPanel, BorderLayout.CENTER);
    pack();
  }

  public static void main(String[] args){
    ExampleGUI exampleGUI = new ExampleGUI();
    exampleGUI.setVisible(true);
  }
}