spinnertest.java

Java编程例子(全新)演示基础的Java 功能,例如类,对象的使用,过程的调用,.

/**
   @version 1.01 2004-05-05
   @author Cay Horstmann
*/

import java.awt.*;
import java.awt.event.*;
import java.text.*;
import java.util.*;
import javax.swing.*;

/**
   A program to test spinners.
*/
public class SpinnerTest
{
   public static void main(String[] args)
   {
      SpinnerFrame frame = new SpinnerFrame();
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.setVisible(true);
   }
}

/**
   A frame with a panel that contains several spinners and
   a button that displays the spinner values.
*/
class SpinnerFrame extends JFrame
{
   public SpinnerFrame()
   {
      setTitle("SpinnerTest");
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
      JPanel buttonPanel = new JPanel();
      okButton = new JButton("Ok");
      buttonPanel.add(okButton);
      add(buttonPanel, BorderLayout.SOUTH);

      mainPanel = new JPanel();
      mainPanel.setLayout(new GridLayout(0, 3));
      add(mainPanel, BorderLayout.CENTER);

      JSpinner defaultSpinner = new JSpinner();
      addRow("Default", defaultSpinner);

      JSpinner boundedSpinner = new JSpinner(new SpinnerNumberModel(5, 0, 10, 0.5));
      addRow("Bounded", boundedSpinner);

      String[] fonts = GraphicsEnvironment
         .getLocalGraphicsEnvironment()
         .getAvailableFontFamilyNames();

      JSpinner listSpinner = new JSpinner(new SpinnerListModel(fonts));
      addRow("List", listSpinner);

      JSpinner reverseListSpinner = new JSpinner(
         new 
            SpinnerListModel(fonts)
            {
               public Object getNextValue() 
               { 
                  return super.getPreviousValue(); 
               }
               public Object getPreviousValue() 
               { 
                  return super.getNextValue(); 
               }
            });
      addRow("Reverse List", reverseListSpinner);

      JSpinner dateSpinner = new JSpinner(new SpinnerDateModel());
      addRow("Date", dateSpinner);

      JSpinner betterDateSpinner = new JSpinner(new SpinnerDateModel());
      String pattern = ((SimpleDateFormat) DateFormat.getDateInstance()).toPattern();
      betterDateSpinner.setEditor(new JSpinner.DateEditor(betterDateSpinner, pattern));
      addRow("Better Date", betterDateSpinner);

      JSpinner timeSpinner = new JSpinner(
         new SpinnerDateModel(
            new GregorianCalendar(2000, Calendar.JANUARY, 1, 12, 0, 0).getTime(), 
               null, null, Calendar.HOUR));
      addRow("Time", timeSpinner);
      
      JSpinner permSpinner = new JSpinner(new PermutationSpinnerModel("meat"));
      addRow("Word permutations", permSpinner);
   }

   /**
      Adds a row to the main panel.
      @param labelText the label of the spinner
      @param spinner the sample spinner
   */
   public void addRow(String labelText, final JSpinner spinner)
   {
      mainPanel.add(new JLabel(labelText));
      mainPanel.add(spinner);
      final JLabel valueLabel = new JLabel();
      mainPanel.add(valueLabel);
      okButton.addActionListener(new
         ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               Object value = spinner.getValue();
               valueLabel.setText(value.toString());
            }
         });
   }

   public static final int DEFAULT_WIDTH = 400;
   public static final int DEFAULT_HEIGHT = 250;  

   private JPanel mainPanel;
   private JButton okButton;
}

/**
   A model that dynamically generates word permutations
*/
class PermutationSpinnerModel extends AbstractSpinnerModel
{ 
   /**
      Constructs the model.
      @param w the word to permute
   */
   public PermutationSpinnerModel(String w) 
   {
      word = w;
   }

   public Object getValue() 
   { 
      return word; 
   }
   
   public void setValue(Object value)
   {
      if (!(value instanceof String)) 
         throw new IllegalArgumentException();
      word = (String) value;
      fireStateChanged();
   }
   
   public Object getNextValue() 
   { 
      int[] codePoints = toCodePointArray(word);
      for (int i = codePoints.length - 1; i > 0; i--)
      {
         if (codePoints[i - 1] < codePoints[i])
         {
            int j = codePoints.length - 1;
            while (codePoints[i - 1] > codePoints[j]) j--;
            swap(codePoints, i - 1, j);
            reverse(codePoints, i, codePoints.length - 1);
            return new String(codePoints, 0, codePoints.length);
         }
      }
      reverse(codePoints, 0, codePoints.length - 1);
      return new String(codePoints, 0, codePoints.length);
   }

   public Object getPreviousValue()
   {
      int[] codePoints = toCodePointArray(word);
      for (int i = codePoints.length - 1; i > 0; i--)
      {
         if (codePoints[i - 1] > codePoints[i])
         {
            int j = codePoints.length - 1;
            while (codePoints[i - 1] < codePoints[j]) j--;
            swap(codePoints, i - 1, j);
            reverse(codePoints, i, codePoints.length - 1);
            return new String(codePoints, 0, codePoints.length);
         }
      }
      reverse(codePoints, 0, codePoints.length - 1);
      return new String(codePoints, 0, codePoints.length);
   }

   private static int[] toCodePointArray(String str)
   {
      int[] codePoints = new int[str.codePointCount(0, str.length())];
      for (int i = 0, j = 0; i < str.length(); i++, j++)
      {
         int cp = str.codePointAt(i);
         if (Character.isSupplementaryCodePoint(cp)) i++;
         codePoints[j] = cp;
      }
      return codePoints;
   }  

   private static void swap(int[] a, int i, int j)
   {
      int temp = a[i];
      a[i] = a[j];
      a[j] = temp;
   }

   private static void reverse(int[] a, int i, int j)
   {
      while (i < j) { swap(a, i, j); i++; j--; }
   }

   private String word;
}