package Demo628;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;

public class ImageRote
{
 public static void main(String[] args)
 {
  JFrame frame = new TransformFrame();
  frame.setVisible(true);
 }
}

class TransformFrame extends JFrame implements ActionListener
{
 //添加幾個(gè)按鈕方便操作。
 JButton rote = new JButton("旋轉(zhuǎn)") ;
 JButton flipX= new JButton("水平翻轉(zhuǎn)");
 JButton flipY= new JButton("垂直翻轉(zhuǎn)");
 JButton zoomIn = new JButton("放大") ;
 JButton zoomOut = new JButton("縮小") ;
 public TransformFrame()
 {
  setTitle("TransformTest");
  setSize(400, 400);
  addWindowListener(new WindowAdapter()
  {
   public void windowClosing(WindowEvent e)
   {
    System.exit(0);
   }
  });
  Container contentPane = getContentPane();
  canvas = new TransPanel();
  contentPane.add(canvas, "Center");
  JPanel buttonPanel = new JPanel();
  buttonPanel.add(rote);
  rote.addActionListener(this);
  buttonPanel.add(flipX);
  flipX.addActionListener(this);
  buttonPanel.add(flipY);
  flipY.addActionListener(this);
  
  buttonPanel.add(zoomIn) ;
  zoomIn.addActionListener(this) ;
  buttonPanel.add(zoomOut) ;
  zoomOut.addActionListener(this) ;
  contentPane.add(buttonPanel, "North");
 }

 public void actionPerformed(ActionEvent event)
 {
  Object source = event.getSource();
  //對(duì)于source == ???這種方法，在特殊的情況下出現(xiàn)錯(cuò)誤，所以，需要酌情使用event.getSource().equals()方法來替代==
  if (source == rote)
  {
   canvas.setRotate();
  } else
  if (source == flipX)
  {
   canvas.flipX();
  } else
  if (source == flipY)
  {
   canvas.flipY();
  } else
  if (source == zoomIn)
  {
   canvas.zoomIn();
  } else
  if (source == zoomOut)
  {
   canvas.zoomOut();
  }
 }
 private TransPanel canvas;
}

class TransPanel extends JPanel
{
 //水平翻轉(zhuǎn)比例的標(biāo)志。-1表示需要進(jìn)行水平翻轉(zhuǎn)
 int m_nFlipXScale = 1 ;
 //垂直翻轉(zhuǎn)比例的標(biāo)志。-1表示需要進(jìn)行垂直翻轉(zhuǎn)
 int m_nFlipYScale = 1 ; 
 //旋轉(zhuǎn)的角度。因?yàn)楣こ绦枰?，代碼中直接寫成了90，可以根據(jù)具體需要?jiǎng)討B(tài)修改，以符合實(shí)際情況
 int roteAngle = 0 ; 
 //縮放比例。默認(rèn)的比例0表示沒有翻轉(zhuǎn)，具體的翻轉(zhuǎn)大小通過一個(gè)方法:getZoomSize()獲取
 int zoomLevel = 0 ;
 public TransPanel()
 {
  //首先載入一張圖片。
  img = new ImageIcon("D000.GIF").getImage();
 }
 public void paintComponent(Graphics g)
 {
  super.paintComponent(g);
  g.drawImage(img,0,0,this) ;
  
  drawTransImage(g,img.getWidth(this),img.getHeight(this),zoomLevel) ;
  
 }
 
 public void drawTransImage(Graphics g,int drawx,int drawy,int zoom)
 {
  int x = 0 ;
  int y = 0 ;
  int w = img.getWidth(this) ;
  int h = img.getHeight(this) ;
  int zoomw = getZoomSize(w,zoom) ;
  int zoomh = getZoomSize(h,zoom) ;
  int xPos = 0 ;
  int yPos = 0 ;
  if (m_nFlipXScale == -1)
    xPos = -zoomw ;
  if (m_nFlipYScale == -1)
    yPos = -zoomh ; 
  Graphics2D g2 = (Graphics2D)g ;
  //轉(zhuǎn)換坐標(biāo)原點(diǎn)。這步不要也成，但是將當(dāng)前位置轉(zhuǎn)換為坐標(biāo)原點(diǎn)后，可以節(jié)省好多計(jì)算步驟，非常好用。
   //不過記得用完了以后，一定要把原點(diǎn)轉(zhuǎn)換回來，要不然其他地方就亂了
  g2.translate(drawx,drawy);
  if (roteAngle != 0)
    g2.rotate(Math.toRadians(m_nFlipXScale * m_nFlipYScale * roteAngle),zoomw >> 1,zoomh >> 1);
    //上面的m_nFlipXScale * m_nFlipYScale需要特殊說明一下：因?yàn)閷?shí)際使用中，可能遇到各種組合的情況，比如
    //先flipX或者flipY以后然后再旋轉(zhuǎn)，這時(shí)候，圖片的旋轉(zhuǎn)方向就會(huì)出現(xiàn)錯(cuò)誤，加上這段代碼可以保證無論使用哪種組合
    //操作方式，都保證在旋轉(zhuǎn)圖片的時(shí)候是按照順時(shí)針的方向進(jìn)行旋轉(zhuǎn)。
  if (m_nFlipXScale == -1)
    g2.scale(-1,1);//第一個(gè)值表示水平，-1表示等寬水平翻轉(zhuǎn)，Math.abs(m_nFlipXScale)的值越大，出來的圖片就越寬
  if (m_nFlipYScale == -1)
    g2.scale(1,-1);//第二個(gè)值表示垂直，-1表示等高垂直翻轉(zhuǎn)，Math.abs(m_nFlipYScale)的值越大，出來的圖片就越高
  //顯示圖片
  g2.drawImage(img,xPos,yPos,xPos + zoomw,yPos + zoomh,x,y,w,h,null) ;
  g2.translate(-drawx,-drawy);  
 }
 public void setRotate()
 {
  roteAngle += 90 ;
  roteAngle %= 360 ;
  repaint();
 }
 public void flipX()
 {
  m_nFlipXScale = -m_nFlipXScale ;
  repaint();
 }
 
 public void flipY()
 {
  m_nFlipYScale = -m_nFlipYScale ;
  repaint();
 } 
 
 public void zoomIn()
 {
  zoomLevel++ ;
  repaint();
 }
 
 public void zoomOut()
 {
  zoomLevel-- ;
  repaint();
 }
 
 public static final int getZoomSize(int sourceSize,int zoomLevel)
 {
  if (zoomLevel == 0)
    return sourceSize ;
  else
  if (zoomLevel < 0)
   return sourceSize / (Math.abs(zoomLevel) + 1) ;
  else
   return sourceSize * (zoomLevel + 1) ;
  } 
 private Image img;
}