verysimpleeditor.java

JAVA APPLET easy and flexible

/*
 *  VerySimpleEditor
 *
 * Created: Wed Apr 11 18:55:30 2001
 * $Revision$
 * Modified: $Date$
 *
 * Author: Jun Inamori
 * E-mail: [e-mail]
 *
 * Copyright (c) 1998-2000 Jun Inamori
 * 2-24-7 Shinsenri-Kitamachi, Toyonaka ,
 * Osaka 560-0081 , Japan.
 * All rights reserved.
 *
 */
package com.oopreserch.example;

import java.awt.event.*;
import java.io.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.filechooser.*;

import com.oopreserch.xml.util.*;

/**
 * @author Jun Inamori
 */

// This class represents the main window of the editor.
// So, it should be the subclass of JFrame.
// And, because we have already written the GUI in XML,
// this class extends XMLFrame_1_0.
// According to the user's action, the buttons and the menue
// items should be enbabled or disabled.
// For example, when the user modified the text, the button
// for saving the document should be enabled.
// To implement this feature, this class need to accept
// DocumentEvent.
// So, this class implements DocumentListener.
public class VerySimpleEditor 
    extends XMLPanel_1_0 implements DocumentListener{

    static final private String TITLE="VerySimpleEditor";

    // The following 4 variables will be retrieved
    // from "gui", which is accessible within the subclass
    // of XMLFrame_1_0.
    static private Action new_a=null;
    static private Action open_a=null;
    static private Action save_a=null;
    static private JTextArea text=null;

    static private File file=null;
    static private boolean wasModified=false;

    // This variable will be retrieved from "res",
    // which is availalble through the subclass
    // of XMLFrame_1_0.
    static private String warn=null;

    static final private VerySimpleAbout about_diag=new VerySimpleAbout();
    static final private VerySimpleError err_diag=new VerySimpleError();

    final private JFileChooser file_diag=new JFileChooser(System.getProperty("user.home"));

    static private JApplet applet=null;

    public VerySimpleEditor(JApplet ap){
	// At the time the Window beeing closed,
	// exitApp() will be invoked.
	super();
	applet=ap;

	// Based on the Locale, read the property resource file.
	// It may be VerySimpleEditor.properties,
	// VerySimpleEditor_ja.properties,
	// VerySimpleEditor_fr.properties or others.
	// Each property resource file points the XML file
	// for this GUI.
	// Parse the XML file pointed by the "xml_url" property
	// and place the Components on the JFrame.
	readXML();

	// After the XML file is parsed, all the Components
	// are accessible from "gui" dictionary.
	// To add the required ActionListener to each
	// Component, we should define "iniParts()" method.
	// And all the actions on JToolBar are also available
	// in "gui" dictionary.
	// Same actions can be embed onto JMenu.
	// The "iniParts()" method is the good place
	// to prepare the JMenu.
	iniParts();
    }

    public void iniParts(){
	new_a=(Action)gui.getAction("new_doc");
	open_a=(Action)gui.getAction("open_doc");
	save_a=(Action)gui.getAction("save_doc");

	JMenu f_menu=new JMenu(res.getString("MenuTitle"));
	(f_menu.add(new_a)).setText(res.getString("NewMenu"));
	(f_menu.add(open_a)).setText(res.getString("OpenMenu"));
	(f_menu.add(save_a)).setText(res.getString("SaveMenu"));
	f_menu.addSeparator();

	JMenuItem exit_m=new JMenuItem(res.getString("ExitMenu"));
	exit_m.addActionListener(new ActionListener(){
	    public void actionPerformed(ActionEvent ev){
		exitApp();
	    }
	});
	f_menu.add(exit_m);

	JMenuBar m_bar=new JMenuBar();
	m_bar.add(f_menu);
	applet.setJMenuBar(m_bar);

	new_a.setEnabled(false);
	save_a.setEnabled(false);

	JButton about_b=(JButton)gui.getGUI("about");
	about_b.addActionListener(new ActionListener(){
	    public void actionPerformed(ActionEvent ev){
		aboutApp();
	    }
	});

	text=(JTextArea)gui.getGUI("text");
	(text.getDocument()).addDocumentListener(this);

	file_diag.setFileSelectionMode(JFileChooser.FILES_ONLY);
	warn=res.getString("Warning");
    }

    public void invokeAction(ToolBarEvent tbe){
    	int act_num=tbe.getNumber();
	switch(act_num){
	case 1:
	    newFile();
	    break;
	case 2:
	    openFile();
	    break;
	case 3:
	    saveFile();
	    break;
	default:
	    break;
	}
    }

    // Member of DocumentListener interface.
    public void changedUpdate(DocumentEvent ev){
	modified();
    }

    // Member of DocumentListener interface.
    public void insertUpdate(DocumentEvent ev){
	modified();
    }

    // Member of DocumentListener interface.
    public void removeUpdate(DocumentEvent ev){
	modified();
    }

    private void modified(){
	if(!wasModified){
	    wasModified=true;
	    new_a.setEnabled(false);
	    open_a.setEnabled(false);
	    save_a.setEnabled(true);
	}
    }

    private void newFile(){
	text.setText("");
	file=null;
	wasModified=false;
	new_a.setEnabled(false);
	open_a.setEnabled(true);
	save_a.setEnabled(false);
    }

    private void openFile(){
	file_diag.rescanCurrentDirectory();
	file_diag.setSelectedFile(null);
	if(file_diag.showOpenDialog(null)!=JFileChooser.APPROVE_OPTION) {
	    return;
	}
	file=file_diag.getSelectedFile();
	// Read the file and display the content on JTextArea...
	try{
	    int size=(int)(file.length());
	    byte[] content=new byte[size];
	    FileInputStream fis=new FileInputStream(file);
	    fis.read(content);
	    fis.close();
	    text.setText(new String(content,"UTF-8"));
	}
	catch(Exception ex){
	    err_diag.showMessage("Error",ex.toString());
	}
	wasModified=false;
	new_a.setEnabled(true);
	open_a.setEnabled(true);
	save_a.setEnabled(false);
    }

    private void saveFile(){
	if(file==null){
	    file_diag.rescanCurrentDirectory();
	    file_diag.setSelectedFile(null);
	    if(file_diag.showSaveDialog(null)!=JFileChooser.APPROVE_OPTION) {
		return;
	    }
	    file=file_diag.getSelectedFile();
	}
	// Write the text on JTextArea into File...
	try{
	    BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file),"UTF-8"));
	    text.write(bw);
	    bw.flush();
	    bw.close();
	}
	catch(Exception ex){
	    err_diag.showMessage("Error",ex.toString());
	}
	wasModified=false;
	new_a.setEnabled(true);
	open_a.setEnabled(true);
	save_a.setEnabled(false);
    }

    private void aboutApp(){
	about_diag.openDiag();
    }

    public void exitApp(){
	err_diag.showMessage("Warning","This is Applet!");
    }

} //End of : VerySimpleEditor