package com.vci.client.framework.util;
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/*
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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，
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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�?
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在Java中有个JComboBox类，它可以实现下拉�?�择或�?�输入�?�择�?
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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�?
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改装思路如下�?
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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�??
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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�??
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3.为这个文本框加上�?个KeyListener.
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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�??
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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：
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*/
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import java.awt.event.ItemEvent;
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import java.awt.event.ItemListener;
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import java.awt.event.KeyEvent;
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import java.awt.event.KeyListener;
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import java.util.List;
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import java.util.Vector;
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import javax.swing.ComboBoxModel;
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import javax.swing.DefaultComboBoxModel;
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import javax.swing.JComboBox;
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import javax.swing.JFrame;
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import javax.swing.JTextField;
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public class JAutoCompleteComboBox extends JComboBox {
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/**
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*
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*/
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private static final long serialVersionUID = 5745551810254985651L;
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private AutoCompleter completer;
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public JAutoCompleteComboBox()
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{
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super();
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addCompleter();
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}
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public JAutoCompleteComboBox(ComboBoxModel cm) {
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super(cm);
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addCompleter();
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}
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public JAutoCompleteComboBox(Object[] items) {
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super(items);
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addCompleter();
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}
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public JAutoCompleteComboBox(List v) {
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super((Vector) v);
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addCompleter();
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}
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private void addCompleter() {
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setEditable(true);
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completer = new AutoCompleter(this);
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}
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public void autoComplete(String str) {
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this.completer.autoComplete(str,str.length());
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}
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public String getText() {
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return ((JTextField) getEditor().getEditorComponent()).getText();
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}
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public void setText(String text) {
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((JTextField) getEditor().getEditorComponent()).setText(text);
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}
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public boolean containsItem(String itemString)
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{
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for (int i = 0; i < this.getModel().getSize(); i++) {
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String _item = " " + this.getModel().getElementAt(i);
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if (_item.equals(itemString))
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return true;
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}
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return false;
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}
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public static void main(String[] args)
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{
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JFrame frame = new JFrame();
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Object[] items = new Object[]
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{ "abc ", "aab ", "aba ", "hpp ", "pp ", "hlp " };
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DefaultComboBoxModel model = new DefaultComboBoxModel();
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JComboBox cmb = new JAutoCompleteComboBox(model);
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model.addElement( "abc ");
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model.addElement( "hh ");
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model.addElement( "aba ");
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model.addElement( "hpp ");
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model.addElement( "pp ");
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model.addElement( "hlp ");
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model.addElement( "alp ");
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model.addElement( "plp ");
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frame.getContentPane().add(cmb);
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frame.setSize(400, 80);
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frame.setVisible(true);
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}
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}
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/**
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* 自动完成器�?�自动找到最匹配的项目，并排在列表的�?前面�?
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*
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* @author Turbo Chen
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*/
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class AutoCompleter implements KeyListener, ItemListener {
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private JComboBox owner = null;
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private JTextField editor = null;
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private ComboBoxModel model = null;
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public AutoCompleter(JComboBox comboBox)
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{
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owner = comboBox;
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editor = (JTextField) comboBox.getEditor().getEditorComponent();
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editor.addKeyListener(this);
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model = comboBox.getModel();
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owner.addItemListener(this);
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}
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public void keyTyped(KeyEvent e) { }
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public void keyPressed(KeyEvent e) { }
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public void keyReleased(KeyEvent e)
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{
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char ch = e.getKeyChar();
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if (ch == KeyEvent.CHAR_UNDEFINED)
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return;
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int caretPosition = editor.getCaretPosition();
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String str = editor.getText();
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if (str.length() == 0)
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return;
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autoComplete(str, caretPosition);
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}
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/**
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* 自动完成。根据输入的内容，在列表中找到相似的项目.
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*/
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protected void autoComplete(String strf, int caretPosition)
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{
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Object[] opts;
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opts = getMatchingOptions(strf.substring(0, caretPosition));
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if (owner != null) {
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model = new DefaultComboBoxModel(opts);
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owner.setModel(model);
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owner.setSelectedIndex(-1);
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}
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// if (opts.length > 0) {
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// String str = opts[0].toString();
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// if(caretPosition > str.length()){
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// caretPosition = str.length();
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// }
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editor.setText(strf);
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editor.setCaretPosition(strf.length());
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if (owner != null) {
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try {
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owner.showPopup();
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} catch (Exception ex) {
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ex.printStackTrace();
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}
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}
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// }
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}
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/**
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*
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* 找到相似的项�?, 并且将之排列到数组的�?前面�?
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* @param str
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* @return 返回�?有项目的列表�?
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*/
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protected Object[] getMatchingOptions(String str)
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{
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List v = new Vector();
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List v1 = new Vector();
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for (int k = 0; k < model.getSize(); k++) {
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Object itemObj = model.getElementAt(k);
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if ( itemObj!=null ) {
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String item = itemObj.toString().toLowerCase();
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if (item.startsWith(str.toLowerCase())) {
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v.add(model.getElementAt(k));
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}else if(item.contains(str.toLowerCase())){
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v.add(model.getElementAt(k));
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}else{
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v1.add(model.getElementAt(k));
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}
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}else
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v1.add(model.getElementAt(k));
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}
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for (int i = 0; i < v1.size(); i++) {
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v.add(v1.get(i));
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}
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if (v.isEmpty())
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v.add(str);
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return v.toArray();
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}
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public void itemStateChanged(ItemEvent event)
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{
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if (event.getStateChange() == ItemEvent.SELECTED)
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{
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int caretPosition = editor.getCaretPosition();
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if (caretPosition != -1) {
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try {
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editor.moveCaretPosition(caretPosition);
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} catch (IllegalArgumentException ex) {
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ex.printStackTrace();
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}
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}
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}
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}
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}
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