File	Doc	Category	Size	Date	Package
Cal.java	API Doc	Example	7386	Sat Nov 25 12:54:46 GMT 2000	None

Cal

• java.lang.Object
  • java.awt.Component
    • java.awt.Container
      • javax.swing.JComponent
        • javax.swing.JPanel

Fields Summary
protected int	yy The currently-interesting year (not modulo 1900!)
protected int	mm Currently-interesting month and day
protected int	dd
protected JButton[]	labs The buttons to be displayed
protected int	leadGap The number of day squares to leave blank at the start of this month
Calendar	calendar A Calendar object used throughout
protected final int	thisYear Today's year
protected final int	thisMonth Today's month
private JButton	b0 One of the buttons. We just keep its reference for getBackground().
private JComboBox	monthChoice The month choice
private JComboBox	yearChoice The year choice
String[]	months
public static final int[]	dom
private int	activeDay

Constructors Summary
Cal() Construct a Cal, starting with today. super(); setYYMMDD(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH), calendar.get(Calendar.DAY_OF_MONTH)); buildGUI(); recompute();
Cal(int year, int month, int today) Construct a Cal, given the leading days and the total days exception IllegalArgumentException If year out of range super(); setYYMMDD(year, month, today); buildGUI(); recompute();

Methods Summary
private void	buildGUI() Build the GUI. Assumes that setYYMMDD has been called. 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);
private void	clearDayActive() Unset any previously highlighted day 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; }
public boolean	isLeap(int year) 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. if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) return true; return false;
public static void	main(java.lang.String[] av) For testing, a main program 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);
protected void	recompute() Compute which days to put where, in the Cal panel // 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();
public void	setDate(int yy, int mm, int dd) Set the year, month, and day // System.out.println("Cal::setDate"); this.yy = yy; this.mm = mm; // starts at 0, like Date this.dd = dd; recompute();
public void	setDayActive(int newDay) Set just the day, on the current month 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;
private void	setYYMMDD(int year, int month, int today) yy = year; mm = month; dd = today;