scrollborder.java

java程序设计 清华出版社 孙燮华老师编写的程序源代码

//scrollborder.java
    import java.awt.*;
    import java.awt.event.*;

    public class scrollborder extends Frame implements AdjustmentListener{
      Scrollbar hScroll1, hScroll2, vScroll1, vScroll2;
      textPanel Panel1;

      public scrollborder(){
        setLayout(new BorderLayout());
        hScroll1 = new Scrollbar(Scrollbar.HORIZONTAL, 1, 1, 1, 200);
        add("North", hScroll1);
        hScroll1.addAdjustmentListener(this);

        vScroll1 = new Scrollbar(Scrollbar.VERTICAL, 1, 1, 1, 200);
        add("West", vScroll1);
        vScroll1.addAdjustmentListener(this);

        hScroll2 = new Scrollbar(Scrollbar.HORIZONTAL, 1, 1, 1, 200);
        add("South", hScroll2);
        hScroll2.addAdjustmentListener(this);

        vScroll2 = new Scrollbar(Scrollbar.VERTICAL, 1, 1, 1, 200);
        add("East", vScroll2);
        vScroll2.addAdjustmentListener(this);

        Panel1 = new textPanel();
        add("Center", Panel1);
        Panel1.Text1.setLocation(0, 0);
        setSize(200, 200);
        setVisible(true);
      }
    
      public void adjustmentValueChanged(AdjustmentEvent e){
        if(e.getAdjustable() == hScroll1){
          hScroll1.setValue(hScroll1.getValue());
          hScroll2.setValue(hScroll1.getValue());
          Panel1.Text1.setText("Horizontal location: " + 
             hScroll1.getValue());
        }
        if(e.getAdjustable() == vScroll1){
          vScroll1.setValue(vScroll1.getValue());
          vScroll2.setValue(vScroll1.getValue());
          Panel1.Text1.setText("Vertical location: " + 
              vScroll1.getValue());
        }
        if(e.getAdjustable() == hScroll2){
          hScroll2.setValue(hScroll2.getValue());
          hScroll1.setValue(hScroll2.getValue());
          Panel1.Text1.setText("Horizontal location: " + 
             hScroll2.getValue());
        }
        if(e.getAdjustable() == vScroll2){
          vScroll2.setValue(vScroll2.getValue());
          vScroll1.setValue(vScroll2.getValue());
          Panel1.Text1.setText("Vertical location: " + vScroll2.getValue());
        }
      }
      public static void main(String args[]){
        scrollborder scroll=new scrollborder();
      }
    }

    class textPanel extends Panel{
      TextField Text1;
      textPanel(){
        Text1 = new TextField(20);
        add(Text1);
      }
    }