textfielddemo.java

java tutorial.sun公司官方出品。java入门书籍。最新版

/*
 * Copyright (c) 1995 - 2008 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Sun Microsystems nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */ 

package components;

/*
 * TextFieldDemo.java requires one additional file:
 * content.txt
 */

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import javax.swing.*;
import javax.swing.text.*;
import javax.swing.event.*;
import javax.swing.GroupLayout.*;

public class TextFieldDemo extends JFrame
                           implements DocumentListener {
    
    private JTextField entry;
    private JLabel jLabel1;
    private JScrollPane jScrollPane1;
    private JLabel status;
    private JTextArea textArea;
    
    final static Color  HILIT_COLOR = Color.LIGHT_GRAY;
    final static Color  ERROR_COLOR = Color.PINK;
    final static String CANCEL_ACTION = "cancel-search";
    
    final Color entryBg;
    final Highlighter hilit;
    final Highlighter.HighlightPainter painter;
    
    
    public TextFieldDemo() {
        initComponents();
        
        InputStream in = getClass().getResourceAsStream("content.txt");
        try {
            textArea.read(new InputStreamReader(in), null);
        } catch (IOException e) {
            e.printStackTrace();
        }
        
        hilit = new DefaultHighlighter();
        painter = new DefaultHighlighter.DefaultHighlightPainter(HILIT_COLOR);
        textArea.setHighlighter(hilit);
        
        entryBg = entry.getBackground();
        entry.getDocument().addDocumentListener(this);
        
        InputMap im = entry.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
        ActionMap am = entry.getActionMap();
        im.put(KeyStroke.getKeyStroke("ESCAPE"), CANCEL_ACTION);
        am.put(CANCEL_ACTION, new CancelAction());
    }
    
    /** This method is called from within the constructor to
     * initialize the form.
     */

    private void initComponents() {
        entry = new JTextField();
        textArea = new JTextArea();
        status = new JLabel();
        jLabel1 = new JLabel();

        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setTitle("TextFieldDemo");

        textArea.setColumns(20);
        textArea.setLineWrap(true);
        textArea.setRows(5);
        textArea.setWrapStyleWord(true);
        textArea.setEditable(false);
        jScrollPane1 = new JScrollPane(textArea);

        jLabel1.setText("Enter text to search:");

        GroupLayout layout = new GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        
	//Create a parallel group for the horizontal axis
	ParallelGroup hGroup = layout.createParallelGroup(GroupLayout.Alignment.LEADING);
	
	//Create a sequential and a parallel groups
	SequentialGroup h1 = layout.createSequentialGroup();
	ParallelGroup h2 = layout.createParallelGroup(GroupLayout.Alignment.TRAILING);
	
	//Add a container gap to the sequential group h1
	h1.addContainerGap();
	
	//Add a scroll pane and a label to the parallel group h2
	h2.addComponent(jScrollPane1, GroupLayout.Alignment.LEADING, GroupLayout.DEFAULT_SIZE, 450, Short.MAX_VALUE);
	h2.addComponent(status, GroupLayout.Alignment.LEADING, GroupLayout.DEFAULT_SIZE, 450, Short.MAX_VALUE);
	
	//Create a sequential group h3
	SequentialGroup h3 = layout.createSequentialGroup();
	h3.addComponent(jLabel1);
	h3.addPreferredGap(LayoutStyle.ComponentPlacement.RELATED);
	h3.addComponent(entry, GroupLayout.DEFAULT_SIZE, 321, Short.MAX_VALUE);
	 
	//Add the group h3 to the group h2
	h2.addGroup(h3);
	//Add the group h2 to the group h1
	h1.addGroup(h2);

	h1.addContainerGap();
	
	//Add the group h1 to the hGroup
	hGroup.addGroup(GroupLayout.Alignment.TRAILING, h1);
	//Create the horizontal group
	layout.setHorizontalGroup(hGroup);
	
        
	//Create a parallel group for the vertical axis
	ParallelGroup vGroup = layout.createParallelGroup(GroupLayout.Alignment.LEADING);
	//Create a sequential group v1
	SequentialGroup v1 = layout.createSequentialGroup();
	//Add a container gap to the sequential group v1
	v1.addContainerGap();
	//Create a parallel group v2
	ParallelGroup v2 = layout.createParallelGroup(GroupLayout.Alignment.BASELINE);
	v2.addComponent(jLabel1);
	v2.addComponent(entry, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE);
	//Add the group v2 tp the group v1
	v1.addGroup(v2);
	v1.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED);
	v1.addComponent(jScrollPane1, GroupLayout.DEFAULT_SIZE, 233, Short.MAX_VALUE);
	v1.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED);
	v1.addComponent(status);
	v1.addContainerGap();
	
	//Add the group v1 to the group vGroup
	vGroup.addGroup(v1);
	//Create the vertical group
	layout.setVerticalGroup(vGroup);
	pack();
    }

    public void search() {
        hilit.removeAllHighlights();
        
        String s = entry.getText();
        if (s.length() <= 0) {
            message("Nothing to search");
            return;
        }
        
        String content = textArea.getText();
        int index = content.indexOf(s, 0);
        if (index >= 0) {   // match found
            try {
                int end = index + s.length();
                hilit.addHighlight(index, end, painter);
                textArea.setCaretPosition(end);
                entry.setBackground(entryBg);
                message("'" + s + "' found. Press ESC to end search");
            } catch (BadLocationException e) {
                e.printStackTrace();
            }
        } else {
            entry.setBackground(ERROR_COLOR);
            message("'" + s + "' not found. Press ESC to start a new search");
        }
    }

    void message(String msg) {
        status.setText(msg);
    }

    // DocumentListener methods
    
    public void insertUpdate(DocumentEvent ev) {
        search();
    }
    
    public void removeUpdate(DocumentEvent ev) {
        search();
    }
    
    public void changedUpdate(DocumentEvent ev) {
    }
    
    class CancelAction extends AbstractAction {
        public void actionPerformed(ActionEvent ev) {
            hilit.removeAllHighlights();
            entry.setText("");
            entry.setBackground(entryBg);
        }
    }
    
    
    public static void main(String args[]) {
        //Schedule a job for the event dispatch thread:
        //creating and showing this application's GUI.
	SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                //Turn off metal's use of bold fonts
                UIManager.put("swing.boldMetal", Boolean.FALSE);
		new TextFieldDemo().setVisible(true);
            }
        });
    }
    
   
}