SWT实现弹出日历控件

实现像网页上的那种用户单击一个Text框然后框下面出现一个日历控件，点击Text框以外的地方日历消失，怎么实现？

 import  org.eclipse.swt.SWT;
 import  org.eclipse.swt.events.MouseAdapter;
 import  org.eclipse.swt.events.MouseEvent;
 import  org.eclipse.swt.graphics.Color;
 import  org.eclipse.swt.graphics.Point;
 import  org.eclipse.swt.widgets.Display;
 import  org.eclipse.swt.widgets.Shell;
 import  org.eclipse.swt.widgets.Text;

 public   class  DateTimeDemo  extends  Shell
 {
     private   static  Display display;

     private  Text text;

     public   static   void  main(String args[])
     {
         try
         {
             display = Display.getDefault();
             DateTimeDemo shell = new  DateTimeDemo(display, SWT.SHELL_TRIM);
             shell.open();
             shell.layout();

             while (!shell.isDisposed())
             {
                 if (!display.readAndDispatch())
                 {
                     display.sleep();
                 }
             }

             display.dispose();
         }
         catch (Exception e)
         {
             e.printStackTrace();
         }
     }

     public  DateTimeDemo(Display display,  int  style)
     {
         super (display, style);
         createContents();
     }

     protected   void  createContents()
     {
         setText("DateTime" );
         setSize(471 ,  140 );
         text = new  Text( this , SWT.BORDER);
         text.setEditable(false );
         text.setBackground(new  Color(display,  255 ,  255 ,  255 ));
         text.setBounds(122 ,  41 ,  228 ,  25 );

         text.addMouseListener(new  MouseAdapter()
         {
             public   void  mouseUp(MouseEvent e)
             {
                 DTDialog dialog = DTDialog.getInstance(DateTimeDemo.this );
                 dialog.open();
             }
         });
     }

     public  Point getDtLocation()
     {
         return   new  Point(text.getLocation().x + DateTimeDemo. this .getLocation().x,
                         text.getLocation().y + DateTimeDemo.this .getLocation().y +  60 );
     }

     public   void  setDate(String str)
     {
         text.setText(str);
     }

     @Override
     protected   void  checkSubclass()
     {
     // Disable the check that prevents subclassing of SWT components
     }
 }

 

 import  org.eclipse.swt.SWT;
 import  org.eclipse.swt.events.FocusAdapter;
 import  org.eclipse.swt.events.FocusEvent;
 import  org.eclipse.swt.events.SelectionAdapter;
 import  org.eclipse.swt.events.SelectionEvent;
 import  org.eclipse.swt.layout.FillLayout;
 import  org.eclipse.swt.widgets.DateTime;
 import  org.eclipse.swt.widgets.Dialog;
 import  org.eclipse.swt.widgets.Display;
 import  org.eclipse.swt.widgets.Shell;

 public   class  DTDialog  extends  Dialog
 {
     private  Object result;

     private  Shell shell;

     private  DateTime dateTime;

     private  DateTimeDemo parent;

     private   static  DTDialog instance;

     public   static  DTDialog getInstance(DateTimeDemo parent)
     {
         if (instance ==  null )
         {
             instance = new  DTDialog(parent);
         }

         return  instance;
     }

     private  DTDialog(DateTimeDemo parent)
     {
         super (parent, SWT.NO_TRIM);
         this .parent = parent;
     }

     public  Object open()
     {
         if (shell ==  null  || shell.isDisposed())
         {
             createContents();
             shell.open();
             shell.layout();
             Display display = getParent().getDisplay();

             while (!shell.isDisposed())
             {
                 if (!display.readAndDispatch())
                 {
                     display.sleep();
                 }
             }

             display.dispose();
         }
         else
         {
             shell.setLocation(parent.getDtLocation());
             shell.setVisible(true );
             shell.setFocus();
         }

         return  result;
     }

     protected   void  createContents()
     {
         shell = new  Shell(getParent(), SWT.NO_TRIM);
         shell.setLayout(new  FillLayout());
         shell.setSize(272 ,  140 );
         shell.setLocation(parent.getDtLocation());
         shell.setText("SWT Dialog" );
         dateTime = new  DateTime(shell, SWT.CALENDAR);

         dateTime.addSelectionListener(new  SelectionAdapter()
         {
             public   void  widgetSelected(SelectionEvent e)
             {
                 parent.setDate(formatDt());
             }
         });

         dateTime.addFocusListener(new  FocusAdapter()
         {
             public   void  focusLost(FocusEvent e)
             {
                 parent.setDate(formatDt());
                 shell.setVisible(false );
             }
         });
     }

     private  String formatDt()
     {
         return  dateTime.getYear() +  "-"  + dateTime.getMonth() +  "-"  + dateTime.getDay();
     }

     public  Shell getShell()
     {
         return  shell;
     }
 }