import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.awt.geom.AffineTransform;
import javax.swing.*;
import javax.swing.event.*;

//圖像旋轉(zhuǎn)演示

public class RotateImageDemo extends JFrame{
	JSlider jSlider = new JSlider(JSlider.HORIZONTAL,0,180,0);  //設(shè)定旋轉(zhuǎn)角度
	ImagePane imagePane=new ImagePane(); //繪制圖像的面板
	
	public RotateImageDemo(){
		super("圖像旋轉(zhuǎn)演示"); //調(diào)用父類構(gòu)造函數(shù)
		jSlider.setPaintTicks(true);  //繪制標(biāo)志位	
		jSlider.setMajorTickSpacing(45); //設(shè)置標(biāo)志尺寸
		jSlider.setMinorTickSpacing(5);
		jSlider.setPaintLabels(true); //繪制出數(shù)字
		jSlider.setBorder(new javax.swing.border.TitledBorder(BorderFactory.createEmptyBorder(), "圖像的旋轉(zhuǎn)度")); //設(shè)置邊框
		jSlider.addChangeListener(new ChangeListener() { //滑動(dòng)條jSlider事件處理
			public void stateChanged(ChangeEvent ce) {
				int value=((JSlider) ce.getSource()).getValue(); //獲取設(shè)置值
				double angle =(float)value/180*Math.PI ; //得到旋轉(zhuǎn)角度（弧度制）
				imagePane.ratoteImage((float)angle); //旋轉(zhuǎn)圖像
			}
		});		
		
		Container container=getContentPane(); //得到窗口容器
		imagePane.loadImage("image0.jpg");	//裝載圖片
		container.add(imagePane,BorderLayout.CENTER); //增加組件到容器上
		container.add(jSlider,BorderLayout.SOUTH);
		
		setSize(250,250); //設(shè)置窗口尺寸
		setVisible(true); //設(shè)置窗口可視
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);	 //關(guān)閉窗口時(shí)退出程序		
	}
	
	public static void main(String[] args){
		new RotateImageDemo();
	}
	
	class ImagePane extends JPanel {
		Image image;
		BufferedImage bufImage; //用于顯示的緩沖區(qū)圖像
		BufferedImage originalBufImage; //原始緩沖區(qū)圖像
		Graphics2D bufImageG; //緩沖區(qū)圖像的圖形環(huán)境	
	
		public void loadImage(String fileName) {
			image = this.getToolkit().getImage(fileName); //取得圖像
			MediaTracker mt = new MediaTracker(this); //實(shí)例化媒體加載器
			mt.addImage(image, 0); //增加圖像到加載器中
			try {
				mt.waitForAll(); //等待圖片加載
			} catch (Exception ex) {
				ex.printStackTrace();  //輸出出錯(cuò)信息
			}
			originalBufImage =	new BufferedImage(image.getWidth(this),image.getHeight(this),BufferedImage.TYPE_INT_ARGB); 	//創(chuàng)建原始緩沖區(qū)圖像
			bufImage = originalBufImage;
			bufImageG = bufImage.createGraphics(); //創(chuàng)建bufImage的圖形環(huán)境
			bufImageG.drawImage(image, 0, 0, this); //傳輸源圖像數(shù)據(jù)到緩沖區(qū)圖像中
			repaint(); //重繪組件
		}
	    //過濾圖像
	    public void ratoteImage(double angle) {
			if (bufImage == null)
				return; //如果bufImage為空則直接返回
			BufferedImage filteredBufImage =new BufferedImage(image.getWidth(this) ,image.getHeight(this),BufferedImage.TYPE_INT_ARGB); //過濾后的圖像
			AffineTransform transform = new AffineTransform(); //仿射變換對(duì)象
			transform.rotate(angle,125,75); //旋轉(zhuǎn)圖像
			AffineTransformOp imageOp = new AffineTransformOp(transform, null);//創(chuàng)建仿射變換操作對(duì)象			
			imageOp.filter(originalBufImage, filteredBufImage);//過濾圖像，目標(biāo)圖像在filteredBufImage
			bufImage = filteredBufImage; //讓用于顯示的緩沖區(qū)圖像指向過濾后的圖像
			repaint(); //重繪組件
		}
		
	    //重載容器的paintComponent()方法
		public void paint(Graphics g) {
			super.paintComponent(g);
			if (bufImage != null) {
				Graphics2D g2 = (Graphics2D) g;
				g2.drawImage(bufImage,0,0,this);	//繪制圖片
			}
		}
	}
}