package ch12.project;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JTextArea;
import javax.swing.JFileChooser;
import java.awt.Toolkit;
import java.awt.datatransfer.*;
import java.awt.Font;
import java.awt.Color;
import java.io.*;
/*步骤一:创建类NoteBookDemo*/
public class NoteBookDemo extends JFrame implements ActionListener {
/*步骤二,添加NoteBookDemo类的成员,如菜单相关组件、文本区、打开或保存操作时用到的文件名、剪贴板、文件对话框。*/ 
	//菜单栏、菜单和菜单项
	JMenuBar menuBar = new JMenuBar();
	 JMenu file = new JMenu("文件"),
	 edit = new JMenu("编辑"); 
	 JMenuItem[] menuItem ={
	 new JMenuItem("新建"),
	 new JMenuItem("打开"),
	 new JMenuItem("保存"),
	 new JMenuItem("退出"),
	 new JMenuItem("全选"),
	 new JMenuItem("复制"),
	 new JMenuItem("剪切"),
	 new JMenuItem("粘贴"),
	 };
JTextArea textArea = new JTextArea();//记事本文本区
 String fileName = "NoName";//打开或保存时用到的文件名
 Toolkit toolKit = Toolkit.getDefaultToolkit();
 Clipboard clipboard = toolKit.getSystemClipboard();//剪贴板对象
 
 //打开和保存文件对话框对象
 private JFileChooser openFileDialog = new JFileChooser();
 private JFileChooser saveFileDialog = new JFileChooser();

/*步骤三,添加NoteBookDemo类的无参构造方法,在无参构造方法中进行界面布局和事件处理的注册监听。*/
 public NoteBookDemo() {
	 // 设置窗体的title、字体、背景色、大小等属性
	 setTitle("Java记事本");
	 setFont(new Font("Times New Roman",Font.PLAIN,15));
	 setBackground(Color.white);
	 setSize(500,500);
	 //添加菜单栏和菜单
	 setJMenuBar(menuBar);
	 menuBar.add(file);
	 menuBar.add(edit);
	 //添加菜单项
	 for(int i=0;i<4;i++)
	 {
	 file.add(menuItem[i]);
	 edit.add(menuItem[i+4]);
	 }
	 //添加文本区
	 this.getContentPane().add(textArea);
	 //设置关闭窗体时释放窗体资源并退出系统 
	 this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	 //每个菜单项都是事件源,注册监听,由本类对象监听
	 for(int i=0;i<menuItem.length;i++)
	 {
	 menuItem[i].addActionListener(this);
	 }
	 }

 /*步骤四,创建openFile和writeFile方法,完成文件的打开和保存。*/
//读文件(打开)
 public void openFile(String fileName){
 try{
 File file = new File(fileName);
 FileReader readIn = new FileReader(file);
 int size = (int)file.length();
 int charsRead = 0;
 char[] content = new char[size];
 while(readIn.ready())
 charsRead += readIn.read(content,charsRead,size-charsRead);
 readIn.close();
 textArea.setText(new String(content,0,charsRead));
 }catch(Exception e)
 {
 System.out.println("Error opening file!");
 }
 } 
 
 //写文件(保存)
 public void writeFile(String fileName){
 try{
 File file = new File(fileName);
 FileWriter write = new FileWriter(file);
 write.write(textArea.getText());
 write.close();
 }catch(Exception e){
 System.out.println("Error closing file!");
 }
 }




	public void actionPerformed(ActionEvent e) {
		// TODO Auto-generated method stub
		//步骤五:完成actionPerformed方法,对菜单项产生的事件进行响应,完成新建、打开、保存、退出四项文件操作功能和全选、复制、剪切、粘帖四项编辑功能。
		Object eventSource = e.getSource();
	 if(eventSource == menuItem[0])//菜单项:新建
	 {
	 textArea.setText("");
	 }
	 else if(eventSource == menuItem[1])//菜单项:打开
	 {
	 openFileDialog.showOpenDialog(this);
	 fileName = openFileDialog.getSelectedFile().getPath();
	 if(fileName != null)
	 {
	 openFile(fileName);
	 }
	 }
	 else if(eventSource ==menuItem[2])//菜单项:保存
	 {
	 saveFileDialog.showSaveDialog(this);
	 fileName = saveFileDialog.getSelectedFile().getPath();
	 if(fileName !=null)
	 {
	 writeFile(fileName);
	 }
	 }
	 else if(eventSource==menuItem[3])//菜单项:退出
	 {
	 System.exit(0);
	 }
	 else if(eventSource == menuItem[4])//菜单项:全选
	 {
	 textArea.selectAll();
	 }
	 else if(eventSource == menuItem[5])//菜单项:复制
	 {
	 String text = textArea.getSelectedText();
	 StringSelection selection= new StringSelection(text);
	 clipboard.setContents(selection,null);
	 }
	 else if(eventSource == menuItem[6])//菜单项:剪切
	 {
	 String text = textArea.getSelectedText();
	 StringSelection selection = new StringSelection(text);
	 clipboard.setContents(selection,null);
	 textArea.replaceRange("",textArea.getSelectionStart(),
	 textArea.getSelectionEnd());
	 
	 }
	 else if(eventSource == menuItem[7])//菜单项:粘贴
	 {
	 Transferable contents = clipboard.getContents(this);
	 if(contents==null)
	 return;
	 String text;
	 text="";
	 try{
	 text = (String)contents.getTransferData(DataFlavor.stringFlavor);
	 
	 }
	catch(UnsupportedFlavorException ex){ }
		 catch(IOException ex){ }
	 textArea.replaceRange(text,
	 textArea.getSelectionStart(),textArea.getSelectionEnd()); 
	 }

		}
	public static void main(String[] args) {
		// 步骤六:完成main方法,创建窗体NoteBookDemo的对象,并显示运行。
		NoteBookDemo noteBook = new NoteBookDemo();
		noteBook.setVisible(true);

			}
}