package com.vci.client.framework.util;
/* 
在许多Windows应用程序里面，最常见的是IE的地�?栏，当我们在ComboBox的文本框内容时， 
它的下拉列表中自动列出最匹配的项目，并且将最匹配的项目显示在输入框中�?   
在Java中有个JComboBox类，它可以实现下拉�?�择或�?�输入�?�择�? 
但是它本身没有提供自动查找和完成功能。我们现在就�?   “改装�?�这个类，使它具有自动查找和完成功能�?   
  
改装思路如下�?   
1.先继承一个JComboBox类，将其setEditable为true.   这样的话，用户才可以在combobox上输入文字�??   
2.我们知道combobox的输入框是一个JTextField,   可以通过comboBox.getEditor().getEditorComponent()取得这个文本框�??   
3.为这个文本框加上�?个KeyListener.   
4.当用户在文本框中按键时，会解发keyReleased事件，我们在这个事件里写主要的实现自动查找和完成的代码�??   
思想就是这么�?单，而自动查找的算法，任何一个对编程不陌生的人都可以写出。以下我列出完整的程序代码：   
*/ 

import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.List;
import java.util.Vector;

import javax.swing.ComboBoxModel;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JTextField;

public   class   JAutoCompleteComboBox   extends   JComboBox   {   
        /**
	 * 
	 */
	private static final long serialVersionUID = 5745551810254985651L;
		private   AutoCompleter   completer; 

        public   JAutoCompleteComboBox() 
        { 
                super(); 
                addCompleter(); 
        } 

        public   JAutoCompleteComboBox(ComboBoxModel   cm)   { 
                super(cm); 
                addCompleter(); 
        } 
        
        public   JAutoCompleteComboBox(Object[]   items)   { 
                super(items); 
                addCompleter(); 
        } 
        
        public   JAutoCompleteComboBox(List   v)   { 
                super((Vector)   v); 
                addCompleter(); 
        } 

        private   void   addCompleter()   { 
                setEditable(true); 
                completer   =   new   AutoCompleter(this); 
        } 

        public   void   autoComplete(String   str)   { 
                this.completer.autoComplete(str,str.length()); 
        } 

        public   String   getText()   { 
                return   ((JTextField)   getEditor().getEditorComponent()).getText(); 
        } 

        public   void   setText(String   text)   { 
                ((JTextField)   getEditor().getEditorComponent()).setText(text); 
        } 

        public   boolean   containsItem(String   itemString) 
        { 
                for   (int   i   =   0;   i   <   this.getModel().getSize();   i++)   { 
                        String   _item   =   " "   +   this.getModel().getElementAt(i); 
                        if   (_item.equals(itemString)) 
                                return   true; 
                } 
                return   false; 
        } 
        
        public   static   void   main(String[]   args) 
        { 
                JFrame   frame   =   new   JFrame(); 
                Object[]   items   =   new   Object[] 
                {   "abc ",   "aab ",   "aba ",   "hpp ",   "pp ",   "hlp "   }; 
                DefaultComboBoxModel   model   =   new   DefaultComboBoxModel(); 
                JComboBox   cmb   =   new   JAutoCompleteComboBox(model); 
                
                model.addElement( "abc "); 
                model.addElement( "hh "); 
                model.addElement( "aba "); 
                model.addElement( "hpp "); 
                model.addElement( "pp "); 
                model.addElement( "hlp "); 
                model.addElement( "alp "); 
                model.addElement( "plp "); 
                frame.getContentPane().add(cmb); 
                frame.setSize(400,   80); 
                frame.setVisible(true); 
        } 
}   
  
/**   
  *   自动完成器�?�自动找到最匹配的项目，并排在列表的�?前面�? 
  *   
  *   @author   Turbo   Chen 
  */ 

class   AutoCompleter   implements   KeyListener,   ItemListener   {   

        private   JComboBox   owner   =   null; 
        private   JTextField   editor   =   null; 

        private   ComboBoxModel   model   =   null;   

        public   AutoCompleter(JComboBox   comboBox) 
        { 
                owner   =   comboBox; 
                editor   =   (JTextField)   comboBox.getEditor().getEditorComponent(); 
                editor.addKeyListener(this); 
                model   =   comboBox.getModel();   
                owner.addItemListener(this); 
        } 
        
        public   void   keyTyped(KeyEvent   e)   {   } 

        public   void   keyPressed(KeyEvent   e)   {   } 

        public   void   keyReleased(KeyEvent   e) 
        { 
                char   ch   =   e.getKeyChar(); 
                if   (ch   ==   KeyEvent.CHAR_UNDEFINED) 
                        return; 

                int   caretPosition   =   editor.getCaretPosition(); 
                String   str   =   editor.getText(); 
                if   (str.length()   ==   0) 
                return; 
                autoComplete(str,   caretPosition); 
        } 
        
        /** 
          *   自动完成。根据输入的内容，在列表中找到相似的项目. 
          */ 
        protected   void   autoComplete(String   strf,   int   caretPosition) 
        { 
                Object[]   opts; 
                opts   =   getMatchingOptions(strf.substring(0,   caretPosition)); 
                if   (owner   !=   null)   { 
                		model   =   new   DefaultComboBoxModel(opts); 
                        owner.setModel(model); 
                        owner.setSelectedIndex(-1);
                } 
//                if   (opts.length   >   0)   { 
//                        String   str   =   opts[0].toString(); 
//                        if(caretPosition > str.length()){
//                        	caretPosition = str.length();
//                        }
                		editor.setText(strf);
                        editor.setCaretPosition(strf.length()); 
                        if   (owner   !=   null)   { 
                                try   { 
                                        owner.showPopup(); 
                                }   catch   (Exception   ex)   { 
                                        ex.printStackTrace(); 
                                } 
                        } 
//                } 
        } 
        
        /** 
          *   
          *   找到相似的项�?,   并且将之排列到数组的�?前面�? 
          *   @param   str   
          *   @return   返回�?有项目的列表�? 
          */ 
        protected   Object[]   getMatchingOptions(String   str) 
        { 
                List   v   =   new   Vector(); 
                List   v1   =   new   Vector(); 
                
                for   (int   k   =   0;   k   <   model.getSize();   k++)   { 
                        Object   itemObj   =   model.getElementAt(k); 
                        if   (   itemObj!=null   )   { 
                                String   item   =   itemObj.toString().toLowerCase(); 
                                if   (item.startsWith(str.toLowerCase())) {
                                	v.add(model.getElementAt(k)); 
                                }else  if(item.contains(str.toLowerCase())){
                                	v.add(model.getElementAt(k)); 
                                }else{
                                	v1.add(model.getElementAt(k)); 
                                }
                        }else 
                                v1.add(model.getElementAt(k)); 
                } 
                for   (int   i   =   0;   i   <   v1.size();   i++)   { 
                        v.add(v1.get(i)); 
                } 
                if   (v.isEmpty()) 
                        v.add(str); 
                return   v.toArray(); 
        } 
        public   void   itemStateChanged(ItemEvent   event) 
        { 
                if   (event.getStateChange()   ==   ItemEvent.SELECTED) 
                { 
                        int   caretPosition   =   editor.getCaretPosition(); 
                        if   (caretPosition   !=   -1)   { 
                                try   { 
                                        editor.moveCaretPosition(caretPosition); 
                                }   catch   (IllegalArgumentException   ex)   { 
                                        ex.printStackTrace(); 
                                } 
                        } 
                } 
        } 
}