//
//	exMDrag2    2001/12/02    by ONOZATO Takehisa
//
//	サンプル：マウスドラッグ（図形の平行移動）
//
//	<applet code="exMDrag2.class" width=400 height=300 ></applet>
//

import java.awt.*;
import java.applet.*;
import java.awt.event.*;

public class exMDrag2 extends Applet implements MouseListener,MouseMotionListener{

	Image ofs; Graphics grf;			//オフスクリーン
	int ofsWidth=400; int ofsHeight=300;
	Color ofsBG=new Color(255,255,255);		//背景色(白)

	int centerX=ofsWidth/2; int centerY=ofsHeight/2; int radius=50;
	int startAngle=30; int arcAngle=300;

	boolean flgMove;
	int startX, startY, endX, endY;
	
    public void init() {

	ofs=createImage(ofsWidth,ofsHeight); grf=ofs.getGraphics();

	addMouseListener(this);
	addMouseMotionListener(this);

	flgMove=false;
	startX=0; startY=0; endX=0; endY=0;		//初期値
    }

    public void update(Graphics g) {
	paint(g);
    }

    public void paint(Graphics g){

	grf.setColor(ofsBG);
	grf.fillRect(0,0,ofsWidth,ofsHeight);			//背景
	grf.setColor(Color.black);
	grf.drawRect(0,0,ofsWidth-1,ofsHeight-1);		//枠線

	if(flgMove){
	    centerX=centerX+endX-startX;
	    centerY=centerY+endY-startY;
	}
	grf.setColor(Color.blue);				//図形の描画
	grf.fillArc(centerX-radius,centerY-radius,
		    2*radius,2*radius,startAngle,arcAngle);
	g.drawImage(ofs,0,0,this);	//オフスクリーンからアプレットへ描画
    }

/*** マウスのイベントプロシージャ ***/
    public void mousePressed(MouseEvent e){
	startX=e.getX(); startY=e.getY();			//マウスの座標取得
	endX=e.getX(); endY=e.getY();
	if(Math.abs(startX-centerX)<radius && Math.abs(startY-centerY)<radius){
	    flgMove=true;
	}
	repaint();
    }
    public void mouseDragged(MouseEvent e) {
	startX=endX; startY=endY;
	endX=e.getX(); endY=e.getY();
	repaint();
    }
    public void mouseReleased(MouseEvent e){
	flgMove=false;
    }
    public void mouseClicked(MouseEvent e){}			//記述しておく必要あり
    public void mouseEntered(MouseEvent e){}
    public void mouseExited(MouseEvent e){}  
    public void mouseMoved(MouseEvent e) {}
}