corejava/corejava第10版/v2ch11/stroke/StrokeTest.java

package stroke;

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

/**
 * This program demonstrates different stroke types.
 * @version 1.04 2016-05-10
 * @author Cay Horstmann
 */
public class StrokeTest
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(() ->
         {
            JFrame frame = new StrokeTestFrame();
            frame.setTitle("StrokeTest");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setVisible(true);
         });
   }
}

/**
 * This frame lets the user choose the cap, join, and line style, and shows the resulting stroke.
 */
class StrokeTestFrame extends JFrame
{
   private StrokeComponent canvas;
   private JPanel buttonPanel;

   public StrokeTestFrame()
   {
      canvas = new StrokeComponent();
      add(canvas, BorderLayout.CENTER);

      buttonPanel = new JPanel();
      buttonPanel.setLayout(new GridLayout(3, 3));
      add(buttonPanel, BorderLayout.NORTH);

      ButtonGroup group1 = new ButtonGroup();
      makeCapButton("Butt Cap", BasicStroke.CAP_BUTT, group1);
      makeCapButton("Round Cap", BasicStroke.CAP_ROUND, group1);
      makeCapButton("Square Cap", BasicStroke.CAP_SQUARE, group1);

      ButtonGroup group2 = new ButtonGroup();
      makeJoinButton("Miter Join", BasicStroke.JOIN_MITER, group2);
      makeJoinButton("Bevel Join", BasicStroke.JOIN_BEVEL, group2);
      makeJoinButton("Round Join", BasicStroke.JOIN_ROUND, group2);

      ButtonGroup group3 = new ButtonGroup();
      makeDashButton("Solid Line", false, group3);
      makeDashButton("Dashed Line", true, group3);
   }

   /**
    * Makes a radio button to change the cap style.
    * @param label the button label
    * @param style the cap style
    * @param group the radio button group
    */
   private void makeCapButton(String label, final int style, ButtonGroup group)
   {
      // select first button in group
      boolean selected = group.getButtonCount() == 0;
      JRadioButton button = new JRadioButton(label, selected);
      buttonPanel.add(button);
      group.add(button);
      button.addActionListener(event -> canvas.setCap(style));
      pack();
   }

   /**
    * Makes a radio button to change the join style.
    * @param label the button label
    * @param style the join style
    * @param group the radio button group
    */
   private void makeJoinButton(String label, final int style, ButtonGroup group)
   {
      // select first button in group
      boolean selected = group.getButtonCount() == 0;
      JRadioButton button = new JRadioButton(label, selected);
      buttonPanel.add(button);
      group.add(button);
      button.addActionListener(event -> canvas.setJoin(style));
   }

   /**
    * Makes a radio button to set solid or dashed lines
    * @param label the button label
    * @param style false for solid, true for dashed lines
    * @param group the radio button group
    */
   private void makeDashButton(String label, final boolean style, ButtonGroup group)
   {
      // select first button in group
      boolean selected = group.getButtonCount() == 0;
      JRadioButton button = new JRadioButton(label, selected);
      buttonPanel.add(button);
      group.add(button);
      button.addActionListener(event -> canvas.setDash(style));
   }
}

/**
 * This component draws two joined lines, using different stroke objects, and allows the user to 
 * drag the three points defining the lines.
 */
class StrokeComponent extends JComponent
{
   private static final Dimension PREFERRED_SIZE = new Dimension(400, 400); 
   private static int SIZE = 10;

   private Point2D[] points;
   private int current;
   private float width;
   private int cap;
   private int join;
   private boolean dash;

   public StrokeComponent()
   {
      addMouseListener(new MouseAdapter()
         {
            public void mousePressed(MouseEvent event)
            {
               Point p = event.getPoint();
               for (int i = 0; i < points.length; i++)
               {
                  double x = points[i].getX() - SIZE / 2;
                  double y = points[i].getY() - SIZE / 2;
                  Rectangle2D r = new Rectangle2D.Double(x, y, SIZE, SIZE);
                  if (r.contains(p))
                  {
                     current = i;
                     return;
                  }
               }
            }

            public void mouseReleased(MouseEvent event)
            {
               current = -1;
            }
         });

      addMouseMotionListener(new MouseMotionAdapter()
         {
            public void mouseDragged(MouseEvent event)
            {
               if (current == -1) return;
               points[current] = event.getPoint();
               repaint();
            }
         });

      points = new Point2D[3];
      points[0] = new Point2D.Double(200, 100);
      points[1] = new Point2D.Double(100, 200);
      points[2] = new Point2D.Double(200, 200);
      current = -1;
      width = 8.0F;
   }

   public void paintComponent(Graphics g)
   {
      Graphics2D g2 = (Graphics2D) g;
      GeneralPath path = new GeneralPath();
      path.moveTo((float) points[0].getX(), (float) points[0].getY());
      for (int i = 1; i < points.length; i++)
         path.lineTo((float) points[i].getX(), (float) points[i].getY());
      BasicStroke stroke;
      if (dash)
      {
         float miterLimit = 10.0F;
         float[] dashPattern = { 10F, 10F, 10F, 10F, 10F, 10F, 30F, 10F, 30F, 10F, 30F, 10F, 10F,
               10F, 10F, 10F, 10F, 30F };
         float dashPhase = 0;
         stroke = new BasicStroke(width, cap, join, miterLimit, dashPattern, dashPhase);
      }
      else stroke = new BasicStroke(width, cap, join);
      g2.setStroke(stroke);
      g2.draw(path);
   }

   /**
    * Sets the join style.
    * @param j the join style
    */
   public void setJoin(int j)
   {
      join = j;
      repaint();
   }

   /**
    * Sets the cap style.
    * @param c the cap style
    */
   public void setCap(int c)
   {
      cap = c;
      repaint();
   }

   /**
    * Sets solid or dashed lines.
    * @param d false for solid, true for dashed lines
    */
   public void setDash(boolean d)
   {
      dash = d;
      repaint();
   }
   
   public Dimension getPreferredSize() { return PREFERRED_SIZE; }
}