flycanvas.java

设计模式Java版

import java.awt.event.*;
import com.sun.java.swing.*;
import com.sun.java.swing.event.*;
import com.sun.java.swing.text.*;
import com.sun.java.swing.border.*;
import com.sun.java.accessibility.*;

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;

public class FlyCanvas extends JxFrame
   implements MouseMotionListener
{
 Folder folder;
 Vector names;
 FolderFactory fact;
 final int Top = 30, Left = 30;
 final int  W = 50, H = 30;
 final int VSpace = 80, HSpace=70, HCount = 3;
 String selectedName="";
//-------------------------------  
 public FlyCanvas()
  {
  super("Flyweight Canvas");

  loadNames();
  JPanel jp = new JPanel();
  getContentPane().add(jp);
  setSize(new Dimension(300,300));
  addMouseMotionListener(this);
  setVisible(true);
  repaint();
  }
//-------------------------------  
private void loadNames()
  {
     names = new Vector();
  
     fact = new FolderFactory();
     names.addElement("Alan");   
     names.addElement("Barry");  
     names.addElement("Charlie");
     names.addElement("Dave");   
     names.addElement("Edward"); 
     names.addElement("Fred");   
     names.addElement("George"); 
     selectedName = "Charlie";  
  }
//-------------------------------
  public void paint(Graphics g)
  {
     Folder f;
     String name;

     int j = 0;      //count number in row
     int row = Top;  //start in upper left
     int x = Left;
     
     //go through all the names and folders
     for (int i = 0; i< names.size(); i++)
     {
     name = (String)names.elementAt(i);
     if(name.equals(selectedName))
        f = fact.getFolder(true);
     else
        f = fact.getFolder(false);
     //have that folder draw itself at this spot
     f.Draw(g, x, row, name);
     
     x = x + HSpace;          //change to next posn
     j++;
     if (j >= HCount)         //reset for next row
        {
        j = 0;         
        row += VSpace;
        x = Left;
        }
     }
  }
//-------------------------------  
  public void mouseMoved(MouseEvent e)
  {
     int j = 0;      //count number in row
  int row = Top;  //start in upper left
  int x = Left;
  
  //go through all the names and folders
  for (int i = 0; i< names.size(); i++)
  {
  //see if this folder contains the mouse
  Rectangle r = new Rectangle(x,row,W,H);
  if (r.contains(e.getX(), e.getY()))
   {
   selectedName=(String)names.elementAt(i);
   repaint();
   }
  x = x + HSpace;          //change to next posn
  j++;
  if (j >= HCount)         //reset for next row
     {
     j = 0;         
     row += VSpace;
     x = Left;
     }
  }

  }
  public void mouseDragged(MouseEvent e){}
  
//-------------------------------  
  static public void main(String[] argv)
  {
     new FlyCanvas();
  }
}
//=======================================
class Folder extends JPanel
{
   private Color color;
   final int W = 50, H = 30;
   public Folder(Color c)
   {
      color = c;
   }
//-------------------------------  
   public void Draw(Graphics g, int tx, int ty, String name)
   {
      g.setColor(Color.black);            //outline
      g.drawRect(tx, ty, W, H);
      g.drawString(name, tx, ty + H+15);  //title
      
      g.setColor(color);                  //fill rectangle 
      g.fillRect(tx+1, ty+1, W-1, H-1);
      
      g.setColor(Color.lightGray);        //bend line   
      g.drawLine(tx+1, ty+H-5, tx+W-1, ty+H-5);
      
      g.setColor(Color.black);            //shadow lines
      g.drawLine(tx, ty+H+1, tx+W-1, ty+H+1);
      g.drawLine(tx+W+1, ty, tx+W+1, ty+H);

      g.setColor(Color.white);            //highlight lines
      g.drawLine(tx+1, ty+1, tx+W-1, ty+1);
      g.drawLine(tx+1, ty+1, tx+1, ty+H-1);  
   }
}
//=======================================
class FolderFactory
{
   Folder unSelected, Selected;
   public FolderFactory()
      {
      Color brown = new Color(0x5f5f1c);
      Selected =  new Folder(brown);
      unSelected = new Folder(Color.yellow);
      }
//-------------------------------  
   public Folder getFolder(boolean isSelected)
   {
      if (isSelected) 
         return Selected;
      else
         return unSelected;
   }

}