Java에서 사용자가 제공하는 BPM 값에 따라 화면에서 문자를 플래시로 만들 수 있습니까?

Question

스윙에서는 창을 만들고 사용자가 입력 한 BPM (Beats per minute)에 따라 화면에 글자가 깜박 거리기를 원합니다. 정확하게 깜박이는 타이밍에 대해 궁금해하고있었습니다. 스윙 타이머를 사용해 보았지만 그다지 정확하지 않아 일시 중지 또는 지연이 많이 발생합니다. System.nanoTime() 및 System.currentTimeMillis()을 사용하는 것에 대해 들었지만 타이머를 만들기 위해 타이머를 구현하는 방법을 알지 못했습니다. 어떤 도움을 주시면 감사하겠습니다!

Note.java

import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.JLabel; 
import javax.swing.JButton; 
import java.awt.event.*; 
import java.awt.*; 

public class Note extends JFrame implements ActionListener { 

JPanel mainScreen = new JPanel(); 
JPanel south = new JPanel(); 
JPanel north = new JPanel(); 

//emptyNumberMain = how many empty panels you want to use 
public int emptyNumberMain = 2; 
JPanel[] emptyMain = new JPanel[emptyNumberMain]; 

JLabel title = new JLabel("Fretboard Trainer!"); 
JButton start = new JButton("Start!"); 

public static void main(String[] args) { 
    new Note(); 
} 

public Note() { 
    super("Random Note!"); 
    setSize(300,300); 
    setResizable(false); 
    setDefaultCloseOperation(EXIT_ON_CLOSE); 

    //creates emptyNumberMain amount of empty panels 
    for (int i = 0; i < emptyNumberMain; i++) { 
     emptyMain[i] = new JPanel(); 
    } 


    mainScreen.setLayout(new BorderLayout()); 

    south.setLayout(new GridLayout(1,1)); 
    south.add(emptyMain[0]); 
    south.add(start); 
    south.add(emptyMain[1]); 

    north.setLayout(new GridLayout(1,2)); 
    north.add(title); 

    title.setHorizontalAlignment(JLabel.CENTER); 
    title.setFont(title.getFont().deriveFont(32f)); 
    start.addActionListener(this); 

    mainScreen.add(north, BorderLayout.NORTH); 
    mainScreen.add(south, BorderLayout.SOUTH); 
    add(mainScreen); 
    setVisible(true); 
} 

public void actionPerformed(ActionEvent e) { 
    if (e.getSource() == start) { 
     dispose(); 
     new RandomNote(); 
    } 
} 
} 

RandomNote.java

import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.JLabel; 
import java.util.Random; 
import javax.swing.Timer; 
import javax.swing.JSlider; 
import java.awt.event.*; 
import java.awt.*; 

public class RandomNote extends JFrame { 

    JPanel noteScreen = new JPanel(); 
    JPanel center = new JPanel(); 
    JPanel southSlider = new JPanel(); 
    JLabel bpm = new JLabel(); 
    //emptyNumber = how many empty panels you want to use 
    int emptyNumber = 2; 
    JPanel[] empty = new JPanel[emptyNumber]; 

    JLabel rndNote = new JLabel(); 
    JSlider slider = new JSlider(0,200,100); 

    Timer timer2 = new Timer(100, new ActionListener() { 
     @Override 
     public void actionPerformed(ActionEvent e) { 
      bpm.setText(Integer.toString(slider.getValue())); 
      timer.setDelay((int) ((60.0/slider.getValue()) * 1000)); 
     } 
    }); 
    public RandomNote() { 
     super("Random Notes!"); 
     timer.start(); 
     timer2.start(); 
     setSize(500,500); 
     setDefaultCloseOperation(EXIT_ON_CLOSE); 
     setResizable(false); 

     //creates variable emptyNumber amount of empty panels 
     for (int i = 0; i < emptyNumber; i++) { 
      empty[i] = new JPanel(); 
     } 

     noteScreen.setLayout(new BorderLayout()); 

     center.setLayout(new GridLayout(1,1)); 
     center.add(rndNote); 

     southSlider.setLayout(new GridLayout(3,1)); 
     slider.setLabelTable(slider.createStandardLabels(20)); 
     slider.setPaintTicks(true); 
     slider.setPaintLabels(true); 
     slider.setMinorTickSpacing(5); 
     slider.setMajorTickSpacing(20); 
     southSlider.add(slider); 
     southSlider.add(bpm); 

     rndNote.setHorizontalAlignment(JLabel.CENTER); 
     rndNote.setFont(rndNote.getFont().deriveFont(32f)); 


     noteScreen.add(center, BorderLayout.CENTER); 
     noteScreen.add(southSlider, BorderLayout.SOUTH); 
     add(noteScreen); 
     setVisible(true); 
    } 

    Timer timer = new Timer(1000, new ActionListener() { 
     @Override 
     public void actionPerformed(ActionEvent e) { 
      rndNote.setText(noteOutput()); 
     } 
    }); 

    public static String noteOutput() { 
     Random rand = new Random(); 
     String[] note = {"A", "B", "C", "D", "E", "F", "G"}; 
     int randNum = rand.nextInt(7); 
     return note[randNum]; 
    } 
} 

Answer 1

나를 밖으로 점프 즉각적인 것은 이것입니다 ... 당신이 업데이트해야 할 이유

Timer timer2 = new Timer(100, new ActionListener() { 
    @Override 
    public void actionPerformed(ActionEvent e) { 
     bpm.setText(Integer.toString(slider.getValue())); 
     timer.setDelay((int) ((60.0/slider.getValue()) * 1000)); 
    } 
}); 

텍스트 및 100 밀리 초마다 타이머를 재설정?

따라서 간단한 대답은 JSlider에서 ChangeListener을 사용하여 슬라이더의 값이 변경되는시기를 결정하는 것입니다. 내가

import java.awt.AlphaComposite; 
import java.awt.Color; 
import java.awt.Dimension; 
import java.awt.EventQueue; 
import java.awt.Graphics; 
import java.awt.Graphics2D; 
import java.awt.GridBagConstraints; 
import java.awt.GridBagLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import javax.swing.Icon; 
import javax.swing.JFrame; 
import javax.swing.JLabel; 
import javax.swing.JPanel; 
import javax.swing.JSlider; 
import javax.swing.Timer; 
import javax.swing.UIManager; 
import javax.swing.UnsupportedLookAndFeelException; 
import javax.swing.event.ChangeEvent; 
import javax.swing.event.ChangeListener; 

public class Main { 
    public static void main(String[] args) { 
     new Main(); 
    } 

    public Main() { 
     EventQueue.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       try { 
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
       } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { 
        ex.printStackTrace(); 
       } 

       JFrame frame = new JFrame("Testing"); 
       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
       frame.add(new TestPane()); 
       frame.pack(); 
       frame.setLocationRelativeTo(null); 
       frame.setVisible(true); 
      } 
     }); 
    } 

    public class TestPane extends JPanel { 

     private AnimatableLabel label; 

     public TestPane() { 
      setLayout(new GridBagLayout()); 
      GridBagConstraints gbc = new GridBagConstraints(); 
      gbc.fill = GridBagConstraints.HORIZONTAL; 
      gbc.gridwidth = GridBagConstraints.REMAINDER; 
      label = new AnimatableLabel("BMP"); 
      label.setHorizontalAlignment(JLabel.CENTER); 
      add(label, gbc); 
      label.start(); 

      JSlider slider = new JSlider(10, 200); 
      slider.addChangeListener(new ChangeListener() { 
       @Override 
       public void stateChanged(ChangeEvent e) { 
        label.setBPM(slider.getValue()); 
       } 
      }); 
      slider.setValue(60); 

      add(slider, gbc); 
     } 

     @Override 
     public Dimension getPreferredSize() { 
      return new Dimension(200, 200); 
     } 

    } 

    public class AnimatableLabel extends JLabel { 

     private Timer pulseTimer; 
     private Timer fadeTimer; 

     private double bpm = 60; 
     private double alpha = 0; 
     private Long pulsedAt; 

     public AnimatableLabel(String text, Icon icon, int horizontalAlignment) { 
      super(text, icon, horizontalAlignment); 
      setBackground(Color.RED); 
      initTimer(); 
     } 

     public AnimatableLabel(String text, int horizontalAlignment) { 
      super(text, horizontalAlignment); 
      setBackground(Color.RED); 
      initTimer(); 
     } 

     public AnimatableLabel(String text) { 
      super(text); 
      setBackground(Color.RED); 
      initTimer(); 
     } 

     public AnimatableLabel(Icon image, int horizontalAlignment) { 
      super(image, horizontalAlignment); 
      setBackground(Color.RED); 
      initTimer(); 
     } 

     public AnimatableLabel(Icon image) { 
      super(image); 
      setBackground(Color.RED); 
      initTimer(); 
     } 

     public AnimatableLabel() { 
      setBackground(Color.RED); 
      initTimer(); 
     } 

     public void start() { 
      updateTimer(); 
     } 

     public void stop() { 
      pulseTimer.stop(); 
      fadeTimer.stop(); 
     } 

     protected void initTimer() { 
      pulseTimer = new Timer((int)(getDuration()), new ActionListener() { 
       @Override 
       public void actionPerformed(ActionEvent e) { 
        pulsedAt = System.currentTimeMillis(); 
        alpha = 1.0; 
        repaint(); 
       } 
      }); 
      pulseTimer.setInitialDelay(0); 
      pulseTimer.setCoalesce(true); 

      fadeTimer = new Timer(5, new ActionListener() { 
       @Override 
       public void actionPerformed(ActionEvent e) { 
        if (pulsedAt == null) { 
         return; 
        } 

        long fadingDuration = System.currentTimeMillis() - pulsedAt;     
        alpha = 1.0 - (fadingDuration/getDuration()); 
        if (alpha > 1.0) { 
         alpha = 1.0; 
        } else if (alpha < 0.0) { 
         alpha = 0.0; 
        } 
        repaint(); 
       } 
      }); 
      fadeTimer.setCoalesce(true); 
     } 

     protected double getDuration() { 
      return (60.0/bpm) * 1000.0; 
     } 

     protected void updateTimer() { 
      fadeTimer.stop(); 
      pulseTimer.stop(); 
      pulseTimer.setDelay((int)getDuration()); 

      pulseTimer.start(); 
      fadeTimer.start(); 
     } 

     public void setBPM(double bpm) { 
      this.bpm = bpm; 
      setText(Double.toString(bpm)); 
      updateTimer(); 
     } 

     public double getBPM() { 
      return bpm; 
     } 

     @Override 
     protected void paintComponent(Graphics g) { 
      Graphics2D g2d = (Graphics2D) g.create(); 
      g2d.setComposite(AlphaComposite.SrcOver.derive((float)alpha)); 
      g2d.setColor(Color.RED); 
      g2d.fillRect(0, 0, getWidth(), getHeight()); 
      g2d.dispose(); 
      super.paintComponent(g); 
     } 

    } 
}