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package com.cn.wangk.tools;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Calendar;
import java.util.GregorianCalendar;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
/** *//**
 * Bean to display a month calendar in a JPanel. Only works for the Western
 * calendar.
 * 
 * @author Ian F. Darwin, http://www.darwinsys.com/
 * @version $Id: Cal.java,v 1.5 2004/02/09 03:33:45 ian Exp $
 */
public class Cal extends JPanel{
 /** *//** The currently-interesting year (not modulo 1900!) */
 protected int yy;
 /** *//** Currently-interesting month and day */
 protected int mm, dd;
 /** *//** The buttons to be displayed */
 protected JButton labs[][];
 /** *//** The number of day squares to leave blank at the start of this month */
 protected int leadGap = 0;
 /** *//** A Calendar object used throughout */
 Calendar calendar = new GregorianCalendar();
 /** *//** Today's year */
 protected final int thisYear = calendar.get(Calendar.YEAR);
 /** *//** Today's month */
 protected final int thisMonth = calendar.get(Calendar.MONTH);
 /** *//** One of the buttons. We just keep its reference for getBackground(). */
 private JButton b0;
 /** *//** The month choice */
 private JComboBox monthChoice;
 /** *//** The year choice */
 private JComboBox yearChoice;
 /** *//**
  * Construct a Cal, starting with today.
  */
 Cal(){
  super();
  setYYMMDD(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH),
    calendar.get(Calendar.DAY_OF_MONTH));
  buildGUI();
  recompute();
 }
 /** *//**
  * Construct a Cal, given the leading days and the total days
  * 
  * @exception IllegalArgumentException
  *        If year out of range
  */
 Cal(int year, int month, int today){
  super();
  setYYMMDD(year, month, today);
  buildGUI();
  recompute();
 }
 private void setYYMMDD(int year, int month, int today){
  yy = year;
  mm = month;
  dd = today;
 }
 String[] months ={ "January", "February", "March", "April", "May", "June",
   "July", "August", "September", "October", "November", "December" };
 /** *//** Build the GUI. Assumes that setYYMMDD has been called. */
 private void buildGUI(){
  getAccessibleContext().setAccessibleDescription(
    "Calendar not accessible yet. Sorry!");
  setBorder(BorderFactory.createEtchedBorder());
  setLayout(new BorderLayout());
  JPanel tp = new JPanel();
  tp.add(monthChoice = new JComboBox());
  for (int i = 0; i < months.length; i++)
   monthChoice.addItem(months[i]);
  monthChoice.setSelectedItem(months[mm]);
  monthChoice.addActionListener(new ActionListener(){
   public void actionPerformed(ActionEvent ae){
    int i = monthChoice.getSelectedIndex();
    if (i >= 0){
     mm = i;
     // System.out.println("Month=" + mm);
     recompute();
    }
   }
  });
  monthChoice.getAccessibleContext().setAccessibleName("Months");
  monthChoice.getAccessibleContext().setAccessibleDescription(
    "Choose a month of the year");
  tp.add(yearChoice = new JComboBox());
  yearChoice.setEditable(true);
  for (int i = yy - 5; i < yy + 5; i++)
   yearChoice.addItem(Integer.toString(i));
  yearChoice.setSelectedItem(Integer.toString(yy));
  yearChoice.addActionListener(new ActionListener(){
   public void actionPerformed(ActionEvent ae){
    int i = yearChoice.getSelectedIndex();
    if (i >= 0){
     yy = Integer.parseInt(yearChoice.getSelectedItem()
       .toString());
     // System.out.println("Year=" + yy);
     recompute();
    }
   }
  });
  add(BorderLayout.CENTER, tp);
  JPanel bp = new JPanel();
  bp.setLayout(new GridLayout(7, 7));
  labs = new JButton[6][7]; // first row is days
  bp.add(b0 = new JButton("S"));
  bp.add(new JButton("M"));
  bp.add(new JButton("T"));
  bp.add(new JButton("W"));
  bp.add(new JButton("R"));
  bp.add(new JButton("F"));
  bp.add(new JButton("S"));
  ActionListener dateSetter = new ActionListener(){
   public void actionPerformed(ActionEvent e){
    String num = e.getActionCommand();
    if (!num.equals("")){
     // set the current day highlighted
     setDayActive(Integer.parseInt(num));
     // When this becomes a Bean, you can
     // fire some kind of DateChanged event here.
     // Also, build a similar daySetter for day-of-week btns.
    }
   }
  };
  // Construct all the buttons, and add them.
  for (int i = 0; i < 6; i++)
   for (int j = 0; j < 7; j++){
    bp.add(labs[i][j] = new JButton(""));
    labs[i][j].addActionListener(dateSetter);
   }
  add(BorderLayout.SOUTH, bp);
 }
 public final static int dom[] ={ 31, 28, 31, 30, /**//* jan feb mar apr */
 31, 30, 31, 31, /**//* may jun jul aug */
 30, 31, 30, 31 /**//* sep oct nov dec */
 };
 /** *//** Compute which days to put where, in the Cal panel */
 protected void recompute(){
  // System.out.println("Cal::recompute: " + yy + ":" + mm + ":" + dd);
  if (mm < 0 || mm > 11)
   throw new IllegalArgumentException("Month " + mm
     + " bad, must be 0-11");
  clearDayActive();
  calendar = new GregorianCalendar(yy, mm, dd);
  // Compute how much to leave before the first.
  // getDay() returns 0 for Sunday, which is just right.
  leadGap = new GregorianCalendar(yy, mm, 1).get(Calendar.DAY_OF_WEEK) - 1;
  // System.out.println("leadGap = " + leadGap);
  int daysInMonth = dom[mm];
  if (isLeap(calendar.get(Calendar.YEAR)) && mm > 1)
   ++daysInMonth;
  // Blank out the labels before 1st day of month
  for (int i = 0; i < leadGap; i++){
   labs[0][i].setText("");
  }
  // Fill in numbers for the day of month.
  for (int i = 1; i <= daysInMonth; i++){
   JButton b = labs[(leadGap + i - 1) / 7][(leadGap + i - 1) % 7];
   b.setText(Integer.toString(i));
  }
  // 7 days/week * up to 6 rows
  for (int i = leadGap + 1 + daysInMonth; i < 6 * 7; i++){
   labs[(i) / 7][(i) % 7].setText("");
  }
  // Shade current day, only if current month
  if (thisYear == yy && mm == thisMonth)
   setDayActive(dd); // shade the box for today
  // Say we need to be drawn on the screen
  repaint();
 }
 /** *//**
  * isLeap() returns true if the given year is a Leap Year.
  * 
  * "a year is a leap year if it is divisible by 4 but not by 100, except
  * that years divisible by 400 *are* leap years." -- Kernighan & Ritchie,
  * _The C Programming Language_, p 37.
  */
 public boolean isLeap(int year){
  if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
   return true;
  return false;
 }
 /** *//** Set the year, month, and day */
 public void setDate(int yy, int mm, int dd){
  // System.out.println("Cal::setDate");
  this.yy = yy;
  this.mm = mm; // starts at 0, like Date
  this.dd = dd;
  recompute();
 }
 /** *//** Unset any previously highlighted day */
 private void clearDayActive(){
  JButton b;
  // First un-shade the previously-selected square, if any
  if (activeDay > 0){
   b = labs[(leadGap + activeDay - 1) / 7][(leadGap + activeDay - 1) % 7];
   b.setBackground(b0.getBackground());
   b.repaint();
   activeDay = -1;
  }
 }
 private int activeDay = -1;
 /** *//** Set just the day, on the current month */
 public void setDayActive(int newDay){
  clearDayActive();
  // Set the new one
  if (newDay <= 0)
   dd = new GregorianCalendar().get(Calendar.DAY_OF_MONTH);
  else
   dd = newDay;
  // Now shade the correct square
  Component square = labs[(leadGap + newDay - 1) / 7][(leadGap + newDay - 1) % 7];
  square.setBackground(Color.red);
  square.repaint();
  activeDay = newDay;
 }
 /** *//** For testing, a main program */
 public static void main(String[] av){
  JFrame f = new JFrame("Cal");
  Container c = f.getContentPane();
  c.setLayout(new FlowLayout());
  // for this test driver, hardcode 1995/02/10.
  c.add(new Cal(1995, 2 - 1, 10));
  // and beside it, the current month.
  c.add(new Cal());
  f.pack();
  f.setVisible(true);
 }
}