import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.Timer;
import javax.swing.UIManager;

/**
 * 模擬血壓計類,高壓、低壓
 *
 * @author 樊俊彬
 * @Time 2013-12-10
 */
public class Blood extends JFrame {

 private static final long serialVersionUID = 1L;
 private Image iBuffer;
 private MyCanvas bloodCanvas = new MyCanvas();
 private JTextField highPressText, lowPressText;

 // 畫布長寬
 private final int CANVAS_WIDTH = 400;
 private final int CANVAS_HEIGHT = 800;

 // 玻璃外殼長寬與起始坐標
 private final int BLOOD_WIDTH = 30;
 private final int BLOOD_HEIGHT = 650;
 private final int BLOOD_X = CANVAS_WIDTH / 2 - BLOOD_WIDTH / 2;
 private final int BLOOD_Y = 50;

 // 框架大小與起始坐標
 private final int FRAME_WIDTH = 120;
 private final int FRAME_HEIGHT = 720;
 private final int FRAME_X = CANVAS_WIDTH / 2 - FRAME_WIDTH / 2;
 private final int FRAME_Y = BLOOD_Y - 20;

 // 0刻度線的橫縱坐標與長度
 private final int ZORELINE_Y = BLOOD_Y + BLOOD_HEIGHT - 10;
 private final int ZORELINE_X = CANVAS_WIDTH / 2 + BLOOD_WIDTH / 2;
 private final int LINE_LENGTH = 8;

 // 輸入的高壓、低壓
 private int highPressInput, lowPressInput;

 // 高、低壓水銀柱的動態高度
 int highPressHeight = 0;
 int lowPressHeight = 0;
 int startLow = BLOOD_Y;

 // 高、低水銀計時器
 Timer highPressTimer, lowPressTimer;

 public Blood() {

  super("自定義血壓計模型-FreeDoman");
  this.setDefaultCloseOperation(EXIT_ON_CLOSE);
  this.setBounds(300, 50, CANVAS_WIDTH, CANVAS_HEIGHT + 20);

  // 添加控制到框架北部區
  JPanel topPanel = new JPanel();
  this.add(topPanel, BorderLayout.NORTH);
  highPressText = new JTextField(5);
  lowPressText = new JTextField(5);

  JButton pressButton = new JButton("顯示");
  pressButton.addActionListener(new ActionListener() {

   @Override
   public void actionPerformed(ActionEvent arg0) {
    highPressInput = Integer.parseInt(highPressText.getText());
    lowPressInput = Integer.parseInt(lowPressText.getText());

    ActionListener highPressTaskPerformer = new ActionListener() {
     public void actionPerformed(ActionEvent evt) {
      // 高度增加 1像素/0.01s,只到滿足輸入的要求,停止計時
      highPressHeight += 1;
      bloodCanvas.repaint();
      if (highPressHeight == highPressInput * 2) {
       highPressTimer.stop();

       // 低壓水銀柱計時器嵌套于高壓計時器內部,有先后順序(高壓先走,后低壓)
       startLow = ZORELINE_Y - highPressHeight;
       ActionListener lowPressTaskPerformer = new ActionListener() {
        public void actionPerformed(ActionEvent evt) {
         lowPressHeight += 1;
         bloodCanvas.repaint();
         if (lowPressHeight == ZORELINE_Y
           - lowPressInput * 2 - startLow)
          lowPressTimer.stop();
        }
       };
       lowPressTimer = new Timer(10, lowPressTaskPerformer);
       lowPressTimer.start();
      }
     }
    };
    // 定義每0.01秒執行一次的事件監聽器
    highPressTimer = new Timer(10, highPressTaskPerformer);
    highPressTimer.start();
   }
  });

  topPanel.add(new JLabel("高壓值", JLabel.CENTER));
  topPanel.add(highPressText);
  topPanel.add(new JLabel("低壓值", JLabel.CENTER));
  topPanel.add(lowPressText);
  // topPanel.add(new JLabel("心率", JLabel.CENTER));
  topPanel.add(pressButton);
  // 添加畫布到中央區
  this.add(bloodCanvas, BorderLayout.CENTER);
  this.setResizable(false);
  this.setVisible(true);
 }

 /**
  * 畫布重繪血壓計
  */
 class MyCanvas extends Canvas {
  public void paint(Graphics g) {

   // 畫邊框
   g.setColor(Color.BLACK);
   g.draw3DRect(FRAME_X, FRAME_Y, FRAME_WIDTH, FRAME_HEIGHT, true);

   // 畫玻璃外殼
   g.setColor(Color.ORANGE);
   g.fill3DRect(BLOOD_X, BLOOD_Y, BLOOD_WIDTH, BLOOD_HEIGHT, true);

   // 高壓水銀柱
   g.setColor(Color.RED);
   g.fill3DRect(BLOOD_X, ZORELINE_Y - highPressHeight, BLOOD_WIDTH,
     highPressHeight, true);

   // 低壓高壓水銀柱
   g.setColor(Color.ORANGE);
   g.fill3DRect(BLOOD_X, startLow, BLOOD_WIDTH, lowPressHeight, true);

   // 畫底部水銀圓球
   g.setColor(Color.RED);
   g.fillOval(CANVAS_WIDTH / 2 - 30, ZORELINE_Y - 5, 60, 60);

   // 右側0刻度線起始刻度與坐標(刻度線縱坐標以line_y漸變)
   int rightStartDegree = 0;

   int line_y = ZORELINE_Y;
   for (; line_y > BLOOD_Y; line_y -= 2) {

    // 2個像素點為一個最小分度 1度
    g.setColor(Color.BLACK);
    g.drawLine(ZORELINE_X, line_y, ZORELINE_X + LINE_LENGTH, line_y);

    // 每隔10最小分度個畫10度刻度線
    if (line_y % 20 == 10) {
     g.setColor(Color.BLUE);
     g.drawLine(ZORELINE_X, line_y,
       ZORELINE_X + LINE_LENGTH * 2, line_y);
     g.drawString(rightStartDegree + "", ZORELINE_X
       + LINE_LENGTH * 3, line_y + 4);
     rightStartDegree += 10;
    }
   }

   // 左側0刻度線起始刻度與坐標(刻度線縱坐標以line_y漸變)
   int leftStartDegree = 0;
   int leftLine_y = ZORELINE_Y;
   for (; leftLine_y > BLOOD_Y; leftLine_y -= 6) {

    // 6個像素點為一個最小分度 1度
    g.setColor(Color.BLACK);
    g.drawLine(BLOOD_X, leftLine_y, BLOOD_X - LINE_LENGTH,
      leftLine_y);

    // 每隔10最小分度個畫10度刻度線
    if (leftLine_y % 20 == 10) {
     g.setColor(Color.BLUE);
     g.drawLine(BLOOD_X, leftLine_y, BLOOD_X - LINE_LENGTH * 2,
       leftLine_y);
     g.drawString(leftStartDegree + "", BLOOD_X - LINE_LENGTH
       * 4, leftLine_y + 4);
     leftStartDegree += 10;
    }
   }
  }

  /**
   * 雙緩沖技術：復雜的計算速度慢于屏幕顯示，用緩沖解決屏幕閃爍問題
   */

  @Override
  public void update(Graphics g) {
   if (iBuffer == null) {
    iBuffer = createImage(this.getSize().width,
      this.getSize().height);

   }
   Graphics gBuffer = iBuffer.getGraphics();
   gBuffer.setColor(getBackground());
   gBuffer.fillRect(0, 0, this.getSize().width, this.getSize().height);
   paint(gBuffer);
   gBuffer.dispose();
   g.drawImage(iBuffer, 0, 0, this);
  }
 }

 public static void main(String[] args) {

  // 設置界面的外觀，為系統外觀
  try {
   UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
  } catch (Exception e) {
   e.printStackTrace();
  }

  new Blood();
 }
}