import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.DefaultMutableTreeNode;

public class TextEditor extends JFrame{
  JMenuBar mbMenu = new JMenuBar();
  JMenu mDatei = new JMenu("Datei");
  JMenuItem miNew = new JMenuItem("Neu");
  JMenuItem miOpen = new JMenuItem("Oeffen");
  JMenuItem miSave = new JMenuItem("Speichern");
  JMenuItem miClose = new JMenuItem("Beenden");

  JTextArea jta = new JTextArea();
  JTree tFontName;
  JLabel lblFontGroess = new JLabel("Groess:");
  JComboBox cmbFontSize= new JComboBox();
  JLabel lblFontSchrift = new JLabel("Schriftschnitt:");
  JCheckBox chbFontFett = new JCheckBox("fett");
  JLabel lblNoName = new JLabel();
  JCheckBox chbFontKursiv = new JCheckBox("kursiv");
  JButton btnStand = new JButton("Standartfont");
  JScrollPane spText = new JScrollPane(jta);
  JScrollPane spFont;
  JPanel pnlFontDetail = new JPanel(new GridLayout(3,2));
  JPanel pnlFont = new JPanel(new BorderLayout()); 
  
  Font currentFont = new Font("Dialog",Font.PLAIN,12);
  File currentDir = null;
  File currentFile = null;
  String currentFontName = "Dialog";
  int rowOfStand = 0;
  
  public TextEditor(){

    super("Editor");

    mbMenu.add(mDatei);
    mDatei.add(miNew);
    mDatei.add(miOpen);
    mDatei.add(miSave);
    mDatei.addSeparator();
    mDatei.add(miClose);

    DefaultMutableTreeNode node = new DefaultMutableTreeNode("Scriftart");
    DefaultMutableTreeNode child;
    String [] fontNames = GraphicsEnvironment.getLocalGraphicsEnvironment().
      getAvailableFontFamilyNames();
    for (String font : fontNames){
      child = new DefaultMutableTreeNode(font);
      node.add(child);
    }
    rowOfStand = java.util.Arrays.binarySearch(fontNames,currentFontName)+1;
    tFontName = new JTree(node);
    tFontName.setVisibleRowCount(5);
    spFont = new JScrollPane(tFontName);
    
    for(int i= 6;i<21;i++)
      cmbFontSize.addItem( i );
    //cmbFontSize.setPopupVisible(true);//这样可以么？
    pnlFontDetail.add(lblFontGroess);
    pnlFontDetail.add(cmbFontSize);
    pnlFontDetail.add(lblFontSchrift);
    pnlFontDetail.add(chbFontFett);
    pnlFontDetail.add(lblNoName);
    pnlFontDetail.add(chbFontKursiv);
    
    Panel pnlSide = new Panel(new BorderLayout());
    Panel pnlButton = new Panel();
    pnlButton.add(btnStand);
    pnlFont.add(spFont,BorderLayout.NORTH);
    pnlFont.add(pnlFontDetail,BorderLayout.CENTER);  
    pnlSide.add(pnlFont,BorderLayout.NORTH);
    pnlSide.add(pnlButton,BorderLayout.CENTER);
    
    add(spText,BorderLayout.CENTER);
    add(pnlSide,BorderLayout.EAST);
    
    
    // add Listener
    
    miNew.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e){
        jta.setText("");
        currentFile=null;
      }
    });
    miOpen.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e){
        loadFile();
      }
    });
    miSave.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e){
        saveFile();
      }
    });
    miClose.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e){
        dispose();
      }
    });
    tFontName.addTreeSelectionListener(new TreeSelectionListener(){
      public void valueChanged(TreeSelectionEvent e){
        currentFontName = e.getPath().getLastPathComponent().toString();
        setFont();
      }
    });    
    cmbFontSize.addItemListener(new ItemListener() {
      public void itemStateChanged(ItemEvent e){
        setFont();
      }
    });
    
    chbFontFett.addItemListener(new ItemListener() {
      public void itemStateChanged(ItemEvent e){
        setFont();
      }
    });
    chbFontKursiv.addItemListener(new ItemListener() {
      public void itemStateChanged(ItemEvent e){
        setFont();
      }
    });
    btnStand.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e){
        fontReset();
      }
    });
    
    fontReset();
    jta.setLineWrap(true);
    setJMenuBar(mbMenu);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setSize(700,500);
    setVisible(true);
  }  
  
  
  public void fontReset(){
    tFontName.setSelectionRow(rowOfStand);
    cmbFontSize.setSelectedItem(12);
    chbFontFett.setSelected(false);
    chbFontKursiv.setSelected(false);
    setFont();
  }
  public void setFont(){
    int fontStyle = 0;
    if(chbFontFett.isSelected())
      fontStyle = fontStyle + Font.BOLD;
    if(chbFontKursiv.isSelected())
      fontStyle = fontStyle + Font.ITALIC;
    if(fontStyle==0)
      fontStyle = Font.PLAIN;
      
    int fontSize = (Integer) (cmbFontSize.getSelectedItem());  
    currentFont = new Font(currentFontName,fontStyle,fontSize);
    jta.setFont(currentFont);  
  }
  public void loadFile(){
    JFileChooser jfc = new JFileChooser(currentDir);
    jfc.showOpenDialog(this);
    if (jfc.getSelectedFile()==null)
      return;
    currentDir=jfc.getCurrentDirectory();
    currentFile=jfc.getSelectedFile();
    StringBuffer content = new StringBuffer((int) currentFile.length());
    try{
      BufferedReader reader = new BufferedReader(new FileReader(currentFile));
      char[] buffer = new char[4096];
      int read = 0;
      while((read = reader.read(buffer))!=-1)
        content.append(buffer,0,read);
      reader.close();
    }
    catch(IOException ex){
      JOptionPane.showMessageDialog(this," Laden der datei fehlgeschlagen!",
        "Feler",JOptionPane.ERROR_MESSAGE);
    }
    jta.setText(content.toString());
  }
  
  public void saveFile(){
    if (currentFile==null){
      JFileChooser jfc = new JFileChooser(currentDir);
      jfc.showSaveDialog(this);
      if (jfc.getSelectedFile()==null)
        return;
      currentDir=jfc.getCurrentDirectory();
      currentFile=jfc.getSelectedFile();    
    }
    try{
      BufferedWriter writer = new BufferedWriter(new FileWriter(currentFile));
      writer.write(jta.getText());
      writer.close();
    }
    catch(IOException ex){
      JOptionPane.showMessageDialog(this,"Spreichern der Datei fehlgeschlagen!",
        "Feler",JOptionPane.ERROR_MESSAGE);
    }
  }
  
  
  public static void main(String[] args){
    new TextEditor();  
  }  
}