/****************************************/
/*					*/
/*	  万年暦 ver.1.00   		*/
/*					*/
/*	1997/ 2/15  宍戸　輝光		*/
/*					*/
/****************************************/
import java.awt.*;
import java.util.Date;

public class cl100 extends java.applet.Applet {

	String day[]={"Sun","Mon","Tue","Wed","Thu","fri","Sat"};
	int n[]={31,28,31,30,31,30,31,31,30,31,30,31}; /*月の日数*/
	int year,month,i,j,week;

	Date d;

	Label yearLabel,monthLabel;
	TextField input_year,input_month;
	Button go;
	Panel p1,p2;

	Font f;

	Image screen;
	Graphics g_screen;

	public void init() {

		resize(400,340);
		setBackground(Color.green);

		screen=createImage(360,256);
		g_screen=screen.getGraphics();

		yearLabel=new Label();
		monthLabel=new Label();

		input_year=new TextField(6);
		input_month=new TextField(4);

		go=new Button();

		f=new Font("TimesRoman",Font.PLAIN,12);

		input_year.setFont(f);
		input_month.setFont(f);

		input_year.setBackground(Color.white);
		input_month.setBackground(Color.white);

		yearLabel.setFont(f);
		monthLabel.setFont(f);

		go.setFont(f);

		f=new Font("TimesRoman",Font.BOLD,16);
		g_screen.setFont(f);

		yearLabel.setText("year");
		monthLabel.setText("month");

		go.setLabel("G o");

		p1=new Panel();
		p2=new Panel();

		setLayout((LayoutManager)null);

		add(p1);
		add(p2);

		p1.reshape(0,0,400,32);
		p2.reshape(0,292,400,48);

		p1.setLayout(new FlowLayout(FlowLayout.CENTER,16,4));
		p2.setLayout(new FlowLayout(FlowLayout.CENTER,16,4));

		p1.add(yearLabel);
		p1.add(input_year);
		p1.add(monthLabel);
		p1.add(input_month);

		p2.add(go);

		d=new Date();

		input_year.setText(String.valueOf(d.getYear()+1900));/*現在の年*/
		input_month.setText(String.valueOf(d.getMonth()+1));/*現在の月*/

		drawScreen();
		repaint();

	}

	public void drawScreen() {

		String s;
		int x,y,pn;
		FontMetrics fm;

		g_screen.setColor(Color.white);
		g_screen.fillRect(1,1,358,255);
		g_screen.setColor(Color.black);
		g_screen.drawRect(0,0,359,255);

		try {

			month=Integer.parseInt(input_month.getText());
			year=Integer.parseInt(input_year.getText());

		}

		catch (NumberFormatException e) { /*入力エラー*/

			input_year.setText(String.valueOf(d.getYear()+1900));
			input_month.setText(String.valueOf(d.getMonth()+1));

			year=d.getYear()+1900;
			month=d.getMonth()+1;

		}

		if (year<1 ||year>9999 ||month<1 ||month>12) {/*無効な入力*/

			input_year.setText(String.valueOf(d.getYear()+1900));
			input_month.setText(String.valueOf(d.getMonth()+1));

			year=d.getYear()+1900;
			month=d.getMonth()+1;
 
		}

		s=year+" / "+month; /*表示用年月文字列*/

		for (i=1;i<8;i++) /*線を引く*/
			g_screen.drawLine(0,i*32+16,360,i*32+16);

		g_screen.setFont(new Font("TimesRoman",Font.PLAIN,12));

		for (i=0;i<7;i++) /*曜日名表示*/
			g_screen.drawString(day[i],i*48+4,47);

		f=new Font("TimesRoman",Font.PLAIN,16);
		g_screen.setFont(f);

		fm=g_screen.getFontMetrics(f); /*年月表示のセンタリング処理*/

		x=(int)((360-fm.stringWidth(s))/2);
		y=(int)((32-fm.getAscent())/2);

		g_screen.setColor(Color.black);
		g_screen.drawString(s,x,32-y); /*年月表示*/

		if ((year % 4)==0 && (year % 100)!=0) /*閏年なら２月は２９日まで*/
			n[1]=29;
		else
			if ((year % 400)==0)
				n[1]=29;
			else
				n[1]=28;

		pn=0;

		for (i=0;i<month-1;i++) /*年始から月初めまでの曜日のずれ*/
			pn+=n[i] % 7;

		i=(first(year)+pn) % 7; /*月初めの曜日*/

		j=1;
		week=0;

		do { /*日付表示*/

			if (j<10)
				s=" "+j;
			else
				s=String.valueOf(j);

			g_screen.drawString(s,i*48+4,32*week+80-y);
			j++;
			i++;

			if (i>6) {

				i=0;
				week++;

			}	

		} while(j<=n[month-1]);

	}

	public int first(int year) { /*指定した年の元旦の曜日を返す*/

		int f;

		f=year+(year-1)/4-(year-1)/100+(year-1)/400; /*元旦の曜日のずれ*/

		return (f % 7); /*ずれから曜日を求める*/

	}

	public boolean action(Event evt,Object what) {

		if (evt.target==go) { /*Go ボタンの処理*/

			drawScreen(); /*カレンダー作成*/
			repaint();    /*画面表示*/

			return true;

		}

		return false;

	}

	public void paint(Graphics g){

		g.drawImage(screen,20,32,this); /*カレンダーのイメージを表示*/

	}

	public void update(Graphics g){     /*updateをオーバーライド*/

		paint(g);

	}

}