JapaneseCalendar.java Source code

Introduction

Here is the source code for JapaneseCalendar.java

Source

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.text.DateFormat;
import java.text.DateFormatSymbols;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;

import javax.swing.BorderFactory;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class JapaneseCalendar extends JPanel {
    public JapaneseCalendar() {
        setLayout(new BorderLayout());
        final CalendarPane cp = new CalendarPane(Locale.JAPANESE);
        add(cp, BorderLayout.NORTH);
    }

    public static void main(String[] a) {
        JFrame f = new JFrame();

        f.add(new JapaneseCalendar());
        f.pack();
        f.setVisible(true);
    }
}

class CalendarPane extends JPanel {
    final static Locale JAPAN_IMP_ERA = new Locale("ja", "JP", "JP");

    private Locale locale;

    CalendarPane(Locale initLocale) {
        setPreferredSize(new Dimension(400, 400));
        locale = initLocale;
    }

    public void paintComponent(Graphics g) {
        int width = 400;
        int height = 400;

        Calendar cal = Calendar.getInstance(locale);
        cal.setTime(new Date());

        String header = cal.getDisplayName(Calendar.MONTH, Calendar.LONG, locale);
        header += " " + cal.get(Calendar.YEAR);

        FontMetrics fm = g.getFontMetrics();
        Insets insets = getInsets();
        g.setColor(Color.black);
        g.drawString(header, (width - fm.stringWidth(header)) / 2, insets.top + fm.getHeight());

        DateFormatSymbols dfs = new DateFormatSymbols(locale);
        String[] weekdayNames = dfs.getShortWeekdays();
        int fieldWidth = (width - insets.left - insets.right) / 7;
        g.drawString(weekdayNames[Calendar.SUNDAY],
                insets.left + (fieldWidth - fm.stringWidth(weekdayNames[Calendar.SUNDAY])) / 2,
                insets.top + 3 * fm.getHeight());
        g.drawString(weekdayNames[Calendar.MONDAY],
                insets.left + fieldWidth + (fieldWidth - fm.stringWidth(weekdayNames[Calendar.MONDAY])) / 2,
                insets.top + 3 * fm.getHeight());
        g.drawString(weekdayNames[Calendar.TUESDAY],
                insets.left + 2 * fieldWidth + (fieldWidth - fm.stringWidth(weekdayNames[Calendar.TUESDAY])) / 2,
                insets.top + 3 * fm.getHeight());
        g.drawString(weekdayNames[Calendar.WEDNESDAY],
                insets.left + 3 * fieldWidth + (fieldWidth - fm.stringWidth(weekdayNames[Calendar.WEDNESDAY])) / 2,
                insets.top + 3 * fm.getHeight());
        g.drawString(weekdayNames[Calendar.THURSDAY],
                insets.left + 4 * fieldWidth + (fieldWidth - fm.stringWidth(weekdayNames[Calendar.THURSDAY])) / 2,
                insets.top + 3 * fm.getHeight());
        g.drawString(weekdayNames[Calendar.FRIDAY],
                insets.left + 5 * fieldWidth + (fieldWidth - fm.stringWidth(weekdayNames[Calendar.FRIDAY])) / 2,
                insets.top + 3 * fm.getHeight());
        g.drawString(weekdayNames[Calendar.SATURDAY],
                insets.left + 6 * fieldWidth + (fieldWidth - fm.stringWidth(weekdayNames[Calendar.SATURDAY])) / 2,
                insets.top + 3 * fm.getHeight());

        int dom = cal.get(Calendar.DAY_OF_MONTH);
        cal.set(Calendar.DAY_OF_MONTH, 1);
        int col = 0;
        switch (cal.get(Calendar.DAY_OF_WEEK)) {
        case Calendar.MONDAY:
            col = 1;
            break;

        case Calendar.TUESDAY:
            col = 2;
            break;

        case Calendar.WEDNESDAY:
            col = 3;
            break;

        case Calendar.THURSDAY:
            col = 4;
            break;

        case Calendar.FRIDAY:
            col = 5;
            break;

        case Calendar.SATURDAY:
            col = 6;
        }
        cal.set(Calendar.DAY_OF_MONTH, dom);

        int row = 5 * fm.getHeight();
        for (int i = 1; i <= cal.getActualMaximum(Calendar.DAY_OF_MONTH); i++) {
            g.drawString("" + i, insets.left + fieldWidth * col + (fieldWidth - fm.stringWidth("" + i)) / 2, row);
            if (++col > 6) {
                col = 0;
                row += fm.getHeight();
            }
        }
    }

}