/*
**網頁瀏覽器主程序
**WebBrowser.java
*/
import java.awt.*; 
import javax.swing.*;
import javax.swing.text.*;
import java.awt.event.*; 
import javax.swing.event.*;
import javax.swing.border.*;
import javax.swing.filechooser.FileFilter; 
import javax.swing.filechooser.FileView; 
import java.io.*; 
import java.net.*; 
import java.util.*; 

public class WebBrowser extends JFrame implements HyperlinkListener,ActionListener{ 

    //建立工具欄用來顯示地址欄
    JToolBar bar=new JToolBar (); 
    
    //建立網頁顯示界面
    JTextField jurl = new JTextField (60); 
    JEditorPane jEditorPane1 = new JEditorPane ();
    JScrollPane scrollPane = new JScrollPane (jEditorPane1); 
    
    JFileChooser chooser=new JFileChooser (); 
    JFileChooser chooser1=new JFileChooser (); 
    String htmlSource; 
    JWindow window = new JWindow (WebBrowser.this); 
    
    JButton button2=new JButton ("窗口還原");
    Toolkit toolkit = Toolkit.getDefaultToolkit();
    
    //建立菜單欄
    JMenuBar jMenuBar1 = new JMenuBar(); 
    //建立菜單組
    JMenu fileMenu = new JMenu ("文件(F)"); 
    //建立菜單項
    JMenuItem saveAsItem = new JMenuItem ("另存為(A)...");
    JMenuItem exitItem=new JMenuItem ("退出(I)");
    
    JMenu editMenu=new JMenu ("編輯(E)");
    JMenuItem backItem=new JMenuItem ("后退");
    JMenuItem forwardItem=new JMenuItem ("前進");
    
    JMenu viewMenu=new JMenu ("視圖(V)");
    JMenuItem fullscreenItem=new JMenuItem ("全屏(U)"); 
    JMenuItem sourceItem=new JMenuItem ("查看源碼(C)");
    JMenuItem reloadItem=new JMenuItem ("刷新(R)");

    //建立工具欄
    JToolBar toolBar = new JToolBar();
    //建立工具欄中的按鈕組件
    JButton picSave = new JButton("另存為");
    JButton picBack = new JButton("后退");
    JButton picForward = new JButton("前進");
    JButton picView = new JButton("查看源代碼");
    JButton picExit = new JButton("退出");

    JLabel label=new JLabel ("地址"); 
    JButton button=new JButton ("轉向");
    
    Box adress=Box.createHorizontalBox ();    

    //ArrayList對象，用來存放歷史地址
    private ArrayList history=new ArrayList();
    //整型變量，表示歷史地址的訪問順序
    private int historyIndex; 

    /**
    **構造函數
    **初始化圖形用戶界面
    */
    public WebBrowser(){
        
        setTitle ("網頁瀏覽器"); 
        setResizable(false);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                    
        //為jEditorPane1添加事件偵聽
        jEditorPane1.addHyperlinkListener (this);
        
        //為組件fileMenu設置熱鍵‘F’
        fileMenu.setMnemonic('F'); 
        
        saveAsItem.setMnemonic ('S'); 
        //為“另存為”組件設置快捷鍵為ctrl+s
        saveAsItem.setAccelerator (KeyStroke.getKeyStroke (KeyEvent.VK_S,InputEvent.CTRL_MASK)); 
        
        exitItem.setMnemonic('Q'); 
        exitItem.setAccelerator (KeyStroke.getKeyStroke (KeyEvent.VK_E,InputEvent.CTRL_MASK)); 
        
        //將菜單項saveAsItem加入到菜單組fileMenu中
        fileMenu.add (saveAsItem); 
        //在菜單項中添加隔離
        fileMenu.addSeparator (); 
        fileMenu.add (exitItem);
        
        backItem.setMnemonic ('B'); 
        backItem.setAccelerator (KeyStroke.getKeyStroke (KeyEvent.VK_Z,InputEvent.CTRL_MASK)); 
        forwardItem.setMnemonic('D'); 
        forwardItem.setAccelerator (KeyStroke.getKeyStroke (KeyEvent.VK_P,InputEvent.CTRL_MASK)); 
        
        editMenu.setMnemonic('E'); 
        editMenu.add (backItem); 
        editMenu.add (forwardItem);  
        
        viewMenu.setMnemonic('V');
        
        fullscreenItem.setMnemonic('U');
        fullscreenItem.setAccelerator (KeyStroke.getKeyStroke (KeyEvent.VK_U,InputEvent.CTRL_MASK)); 
        sourceItem.setMnemonic('C');
        sourceItem.setAccelerator (KeyStroke.getKeyStroke (KeyEvent.VK_C,InputEvent.CTRL_MASK)); 
        reloadItem.setMnemonic('R');
        reloadItem.setAccelerator (KeyStroke.getKeyStroke (KeyEvent.VK_R,InputEvent.CTRL_MASK)); 
        
        Container contentPane=getContentPane (); 
            
        //設置大小
        scrollPane.setPreferredSize(new Dimension(100,500));
        contentPane.add (scrollPane, BorderLayout.SOUTH);
        
        //在工具欄中添加按鈕組件
        toolBar.add(picSave);
        toolBar.addSeparator();
        toolBar.add(picBack);
        toolBar.add(picForward);
        toolBar.addSeparator();
        toolBar.add(picView);
        toolBar.addSeparator();
        toolBar.add(picExit);
        
        contentPane.add (bar,BorderLayout.CENTER); 
        contentPane.add(toolBar,BorderLayout.NORTH);
        
        viewMenu.add (fullscreenItem); 
        viewMenu.add (sourceItem); 
        viewMenu.addSeparator (); 
        viewMenu.add (reloadItem); 
        
        jMenuBar1.add (fileMenu); 
        jMenuBar1.add (editMenu); 
        jMenuBar1.add (viewMenu); 

        setJMenuBar (jMenuBar1); 
    
        adress.add (label); 
        adress.add (jurl); 
        adress.add (button); 
        bar.add (adress); 
        
        //為組件添加事件監聽
        saveAsItem.addActionListener(this);
        picSave.addActionListener(this);
        exitItem.addActionListener(this);
        picExit.addActionListener(this);
        backItem.addActionListener(this);
        picBack.addActionListener(this);
        forwardItem.addActionListener(this);
        picForward.addActionListener(this);
        fullscreenItem.addActionListener(this);
        sourceItem.addActionListener(this);
        picView.addActionListener(this);
        reloadItem.addActionListener(this);
        button.addActionListener(this);
        jurl.addActionListener(this);
    }
    
    /**
    **實現監聽器接口的actionPerformed函數
    */
    public void actionPerformed(ActionEvent e) {
        String url = "";
        //點擊轉向按鈕
        if (e.getSource() == button){
            //獲得地址欄的內容
            url=jurl.getText (); 
            //url不為“”，并且以“http://”開頭
            if(url.length ()>0&&url.startsWith ("http://")){ 
                try { 
                    //JEditorPane組件顯示url的內容鏈接
                    jEditorPane1.setPage (url); 
                    //將url的內容添加到ArrayList對象history中
                    history.add(url); 
                    //historyIndex的數值設為history對象的長度-1
                    historyIndex=history.size()-1;
                    //重新布局
		    jEditorPane1.setEditable(false); //add by copy editor :)
                    jEditorPane1.revalidate (); 
                } 
                catch(Exception ex) { 
                    //如果鏈接顯示失敗，則彈出選擇對話框“無法打開該搜索頁”
                    JOptionPane.showMessageDialog (WebBrowser.this,"無法打開該搜索頁","網頁瀏覽器",JOptionPane.ERROR_MESSAGE);
                } 
            } 
            //url不為“”，并且不以“http://”開頭
            else if(url.length ()>0&&!url.startsWith ("http://")) { 
                //在url前面添加“http://”
                url="http://"+url; 
                try { 
                    jEditorPane1.setPage (url ); 
                    history.add(url); 
                    historyIndex=history.size()-1;
		    jEditorPane1.setEditable(false); //add by copy editor :)
                    jEditorPane1.revalidate (); 
                } 
                catch(Exception ex) {
                    JOptionPane.showMessageDialog (WebBrowser.this,"無法打開該搜索頁","網頁瀏覽器",JOptionPane.ERROR_MESSAGE);
                } 
            }
            //沒有輸入url，即url為空
            else if(url.length ()==0){
                JOptionPane.showMessageDialog (WebBrowser.this,"請輸入鏈接地址","網頁瀏覽器",JOptionPane.ERROR_MESSAGE);
            }
        
        }
        //輸入地址后點擊回車
        else if (e.getSource() == jurl){
            url=jurl.getText (); 
            if(url.length ()>0&&url.startsWith ("http://")) { 
                try { 
                    jEditorPane1.setPage (url); 
                    history.add(url); 
                    historyIndex=history.size()-1;
		    jEditorPane1.setEditable(false); //add by copy editor :)
                    jEditorPane1.revalidate (); 
                    jurl.setMaximumSize (jurl.getPreferredSize ()); 
                } 
                catch(Exception ex) { 
                    JOptionPane.showMessageDialog (WebBrowser.this,"無法打開該搜索頁","網頁瀏覽器",JOptionPane.ERROR_MESSAGE);
                } 
            } 
            else if(url.length ()>0&&!url.startsWith ("http://")) { 
                url="http://"+url; 
                try { 
                    jEditorPane1.setPage (url );
                    history.add(url); 
                    historyIndex=history.size()-1;
		    jEditorPane1.setEditable(false); //add by copy editor :)
                    jEditorPane1.revalidate (); 
                } 
                catch(Exception ex) { 
                    JOptionPane.showMessageDialog (WebBrowser.this,"無法打開該搜索頁","網頁瀏覽器",JOptionPane.ERROR_MESSAGE);
                } 
            }
            else if(url.length ()==0){
                JOptionPane.showMessageDialog (WebBrowser.this,"請輸入鏈接地址","網頁瀏覽器",JOptionPane.ERROR_MESSAGE);