import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.applet.Applet;
/*類CropTest是Applet的子類，該類實現(xiàn)了MouseListener接口，目的是實現(xiàn)圖像的剪切*/
public class CropTest extends Applet implements MouseListener{
	/*聲明一個Image對象oldimgObj，用于存放加載的原始圖像*/
	Image oldimgObj;
	/*聲明一個Image對象newimgObj，用于存放處理后的圖像*/
	Image newimgObj;
	/*聲明兩個整型變量x和y，用于獲得鼠標單擊的位置坐標*/
	int x,y;
	/*聲明一個Graphics對象*/
	Graphics g = getGraphics();
	/*定義幾個整型變量，用于圖像的處理，x1、y1分別代表剪切圖像的左上角的橫縱坐標，width和height代表剪切圖像的大小，clickNum代表鼠標單擊圖像的次數(shù)*/
	int x1,y1,width,height,clickNum=1;
	public void init(){
		/*獲得載入的圖像對象，賦給oldimgObj對象*/
		oldimgObj = getImage(getCodeBase(),"a014.jpg");
		/*讓newimgObj剛開始也指向載入的圖像對象*/
		newimgObj = oldimgObj;
		/*為該程序類所在的Applet注冊鼠標時間監(jiān)聽器*/
		addMouseListener(this);
	}
	/*paint方法用于將圖像顯示出來*/
	public void paint(Graphics g){
		/*獲得處理后圖像的寬度*/
		int width = newimgObj.getWidth(this);
		/*獲得處理后圖像的高度*/
		int height = newimgObj.getHeight(this);
		/*獲得當前窗口的大小*/
		Dimension mensionObj = getSize();
		/*下面的兩個語句根據(jù)圖像大小和窗口大小的比較，來決定width和height變量的取值*/
		if(width>mensionObj.width) width = mensionObj.width;
		if(height>mensionObj.height) height = mensionObj.height;
		//g.drawImage(newimgObj,(mensionObj.width-width)/2,(mensionObj.height-height)/2,this);
		g.drawImage(newimgObj,0,0,this);
	}
	/*下面的幾個方法實現(xiàn)MouseListener接口*/
	public void mouseClicked(MouseEvent e){
	}
	public void mouseEntered(MouseEvent e){
	}
	public void mouseExited(MouseEvent e){
	}
	/*重寫mousePressed方法，獲得鼠標按下時的位置*/
	public void mousePressed(MouseEvent e){
		/*將獲得的鼠標單擊位置的橫縱坐標分別賦給x和y*/
		x = e.getX();
		y = e.getY();
	}
	public void mouseReleased(MouseEvent e){
		/*獲得鼠標松開時的位置*/
		x1 = e.getX();
		y1 = e.getY();
		/*下面的四行語句根據(jù)鼠標兩次單擊的位置來確定圖像的width和height*/
		if(x1>x) width = x1-x;
		else width = x-x1;
		if(y1>y) height = y1-y;
		else height = y-y1;
		ImageFilter filterObj = new CropImageFilter(x,y,width,height);
		/*根據(jù)提取的圖像建立新的圖像數(shù)據(jù)*/
		ImageProducer producerObj = new FilteredImageSource(oldimgObj.getSource(),filterObj);
		/*生成新的圖像對象，并將該對象返回*/
		newimgObj = createImage(producerObj);
		repaint();
		oldimgObj = newimgObj;
	}
}