browserframe.java

这是《Java图形用户界面设计与实例》一书配套的源代码

//BrowserFrame.java
//The frame which contains the interface components


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

public class BrowserFrame extends JFrame{
    //各个控件
    private WebWindow ww = new WebWindow(this);
    private MenuBar mb = new MenuBar(this);
    private ToolBar tb = new ToolBar(this);

    private HistoryList hl = new HistoryList();//历史记录

    private String sURL;//替代URL

    public BrowserFrame(){
        //Frame和各个成员的位置
        setTitle("Show");//Frame
        setSize(640, 480);
        setLocation(20, 20);
        getContentPane().setLayout(new BorderLayout());

        setJMenuBar(mb);//MenuBar

        JPanel jpToolMenu = new JPanel();//the toolbar 
        jpToolMenu.setLayout(new FlowLayout(FlowLayout.LEFT, 5, 5));
        jpToolMenu.add(tb);

        getContentPane().add(jpToolMenu, BorderLayout.NORTH);

        getContentPane().add(ww, BorderLayout.CENTER);

        setCurrentURL("http://www.zsu.edu.cn");
    }

    
    public void setToolBarURL(String s) {//将 url 记录在 toolbars text field
        tb.setTextField(s);
    }

//***************************后退按钮*******************************
    public void goBack() {
        try {
            
            sURL = hl.getLast();//得到 previous URL
            ww.setCurrentURL(sURL);//显示 it
            setToolBarURL(sURL);   //更改 toolbar text field

        }

        catch(Exception e) {
            new PopupDialog("错误！", e.getMessage());
        }
    }

//***************************前进按钮*******************************
    public void goForward() {
           //结构同后退按钮
        try {
            sURL = hl.getNext();
            ww.setCurrentURL(sURL);
            setToolBarURL(sURL);
        }
        catch(Exception e) {
            new PopupDialog("错误", e.getMessage());
        }
    }

//***************************刷新按钮*******************************
    public void refreshURL() {
           //结构同后退按钮
        try {
            ww.setCurrentURL(sURL);
            setToolBarURL(sURL);
        }
        catch(Exception e) {
            new PopupDialog("错误！", e.getMessage());
        }
    }


    public String getCurrentURL() {//记录当前的URL
        return sURL;
    }


    public void setCurrentURL(String current) {//设置当前URL

        if (!(current.substring(0, 7)).equals("http://")) {
            if(!(current.substring(0, 3)).equals("www"))
                current = "www."+current;
            current = "http://"+current;//确保URL的格式正确
        }

        sURL = current;//使得URL为current值

        try {
            ww.setCurrentURL(sURL);//转动该网页
            hl.add(sURL);  //加入历史记录
            setToolBarURL(sURL);//更改toolbar text field
        }

        catch(Exception e) {
            new PopupDialog("错误！", e.getMessage());
        }
    }
}