texteditorframe.java

Java实例入门

  }
  /**File | Exit action performed*/
  public void jMenuFileExit_actionPerformed(ActionEvent e) {
    if (!okToAbandon()) {  return ;}
     System.exit(0);
  }
  /**Help | About action performed*/
  public void jMenuHelpAbout_actionPerformed(ActionEvent e) {
    TextEditorFrame_AboutBox dlg = new TextEditorFrame_AboutBox(this);
    Dimension dlgSize = dlg.getPreferredSize();
    Dimension frmSize = getSize();
    Point loc = getLocation();
    dlg.setLocation((frmSize.width - dlgSize.width) / 2 + loc.x, (frmSize.height - dlgSize.height) / 2 + loc.y);
    dlg.setModal(true);
    dlg.show();
  }
  /**Overridden so we can exit when window is closed*/
  protected void processWindowEvent(WindowEvent e) {
     if (e.getID() == WindowEvent.WINDOW_CLOSING) {
      if (!okToAbandon()) {  return ;}
     System.exit(0);
    }
    super.processWindowEvent(e);

  }

  void jMenuFileNew_actionPerformed(ActionEvent e) {
    if(okToAbandon()){
       jTextArea1.setText("");
       currentFileName = null;
       saveNeeded = false;
       updateTitle();
    }

  }

  void jMenuFileOpen_actionPerformed(ActionEvent e) {
    openFile();
  }

  void jButton1_actionPerformed(ActionEvent e) {
    openFile();
  }

  void jMenuFileSave_actionPerformed(ActionEvent e) {
    saveFile();
  }

  void jButton2_actionPerformed(ActionEvent e) {
    saveFile();
  }

  void jMenuFileSaveas_actionPerformed(ActionEvent e) {
    saveAsFile();
  }

  void jButton3_actionPerformed(ActionEvent e) {
    edit.undo();
    edit.redo();
  }

  void this_windowClosing(WindowEvent e) {
     if (!okToAbandon()) {  show();return;}
     System.exit(0);
  }

  void jMenuEditFont_actionPerformed(ActionEvent e) {
     fontChooser1.setSelectedFont(jTextArea1.getFont());
    if (fontChooser1.showDialog()) {
       jTextArea1.setFont(fontChooser1.getSelectedFont());
     }
     this.repaint();
     jTextArea1.repaint();
  }

  void jMenuEditColor_actionPerformed(ActionEvent e) {
     Color color = JColorChooser.showDialog(this,"Foreground Color",jTextArea1.getForeground());
     if (color != null) {
        jTextArea1.setForeground(color);
      }
      this.repaint();
  }

  void jMenuEditBColor_actionPerformed(ActionEvent e) {
      Color color = JColorChooser.showDialog(this,"Background Color",jTextArea1.getBackground());
     if (color != null) {
        jTextArea1.setBackground(color);
      }
      this.repaint();
  }
  void openFile(){
if (!okToAbandon()) {
    return;
}
if(JFileChooser.APPROVE_OPTION== jFileChooser1.showOpenDialog(this)) {
openSelectedFile(jFileChooser1.getSelectedFile().getPath());
}
this.repaint();
}
void openSelectedFile(String fileName){
  try{
    File file = new File(fileName);
    int fileSize = (int)file.length();
int charsReaded = 0;
    FileReader in = new FileReader(file);
    char[] data = new char[fileSize];
    while(in.ready()) {
      charsReaded += in.read(data, charsReaded, fileSize - charsReaded);
    }
    in.close();
    jTextArea1.setText(new String(data, 0, charsReaded));
    this.currentFileName = fileName;
    this.saveNeeded = false;
    statusBar.setText("打开 "+fileName);
    updateTitle();
  }
  catch (IOException e){
      statusBar.setText("Error opening "+fileName);
  }
}
boolean okToAbandon() {
  if (!saveNeeded) {
    return true;
  }
  int value=JOptionPane.showConfirmDialog(this, "保存文件吗？", "文本编辑", JOptionPane.YES_NO_CANCEL_OPTION) ;
switch (value) {
    case JOptionPane.YES_OPTION: return saveFile();
    case JOptionPane.NO_OPTION: return true;
    case JOptionPane.CANCEL_OPTION:
    default: return false;
  }
}
void updateTitle(){
  String title;
  if (currentFileName == null) {
    title = "未命名文件";
  }else {
    title = currentFileName;
  }
  if(saveNeeded == true){
      title = "* "+title;
  }
  title = "文本编辑器- " + title;
  this.setTitle(title);
}
boolean saveFile() {
  if (currentFileName == null) {
    return saveAsFile();
  }
  try{
    File file = new File (currentFileName);
FileWriter out = new FileWriter(file);
    String text = jTextArea1.getText();
    out.write(text);
    out.close();
    this.saveNeeded = false;
    updateTitle();
    return true;
  }
  catch (IOException e) {
    statusBar.setText("存储"+currentFileName+ "出错");
  }
  return false;
}
boolean saveAsFile() {
this.repaint();
  if (JFileChooser.APPROVE_OPTION == jFileChooser1.showSaveDialog(this)){
    currentFileName = jFileChooser1.getSelectedFile().getPath();
    this.repaint();
    return saveFile();
  }
  else {
    this.repaint();
    return false;
  }
}

  void document1_changedUpdate(DocumentEvent e) {
     saveNeeded = true;
updateTitle();

  }

  void this_ancestorResized(HierarchyEvent e) {

  }

  void document1_insertUpdate(DocumentEvent e) {
    saveNeeded = true;
updateTitle();

  }

  void document1_removeUpdate(DocumentEvent e) {
     saveNeeded = true;
updateTitle();

  }

  void document1_undoableEditHappened(UndoableEditEvent e) {
       edit.addEdit(e.getEdit()) ;
  }

  void jMenuEditCopy_actionPerformed(ActionEvent e) {
     String selText=jTextArea1.getSelectedText();
     if(selText!=null ){
         StringSelection selection=new StringSelection(selText);
         sysClipboard.setContents(selection,null);
     }
  }

  void jMenuEditCut_actionPerformed(ActionEvent e) {
      String selText=jTextArea1.getSelectedText();
      if(selText!=null ){
         StringSelection selection=new StringSelection(selText);
         sysClipboard.setContents(selection,null);
         jTextArea1.replaceSelection("");
     }

  }

  void jMenuEditPaste_actionPerformed(ActionEvent e) {
     Transferable content=sysClipboard.getContents(this);
     if(content==null) return;
     try{
          String text=(String)(content.getTransferData(DataFlavor.stringFlavor)) ;
          jTextArea1.replaceSelection(text);
     }
     catch(Exception ex){
     }
  }



  void jMenuEdit_focusGained(FocusEvent e) {
     boolean selFlag=false;
     if(jTextArea1.getSelectedText() !=null){
         selFlag=true;
     }
     jMenuEditCopy.setEnabled(selFlag) ;
     jMenuEditCut.setEnabled(selFlag) ;
     boolean copyedFlag=false;
     if(sysClipboard.getContents(this)!=null){
         copyedFlag=true;
     }
     jMenuEditPaste.setEnabled(copyedFlag);
     jMenuEditUndo.setEnabled(edit.canUndo());
     jMenuEditRedo.setEnabled(edit.canRedo() );
  }

  void jMenuEditSelAll_actionPerformed(ActionEvent e) {
     jTextArea1.selectAll();
  }

  void jMenuEditUndo_actionPerformed(ActionEvent e) {
     edit.undo();
  }

  void jMenuEditRedo_actionPerformed(ActionEvent e) {
     edit.redo();
  }
}