attributetest.java

来自「java learn PPT java learn PPT java learn」· Java 代码 · 共 144 行

     import java.applet.*;
     import java.awt.*;
     import java.awt.event.*;

     // 允许改变属性
     class AttributeButton extends Button
     {
          // 放这个按钮的panel
          private AttributePanel parent;

          public AttributeButton(String label, AttributePanel ap)
          {
               super(label);
               parent = ap;
          }

          // 更新父控件的属性
          public int updatePanel(
               int pointsRemaining  // 还未分配的点值
               )
          {
               // 为 'plus' 按钮分配一个点值
               if(getLabel().equals("+"))
               {
                    // 仅仅在还有点值剩余时分配
                    if(pointsRemaining > 0)
                    {                  
                         parent.allocatePoints(1); 
                         return -1;
                    }
                    else return 0;
               }

               // 否则，不分配
               else
               {
                    // 不允许分配负数
                    if(parent.getPointsAllocated() > 0)
                    {
                         parent.allocatePoints(-1);
                         return 1;
                    }
                    else return 0;
               }
          }

     }    // AttributeButton

     // allows the value for single character Attribute to be adjusted
	 // 允许更改角色的一个属性
     class AttributePanel extends Panel
     {
          // 属性的文本描述
          private String attribute;

          // 显示给这个属性所分配点值的Label
          private Label pointsAllocated;
           
          public AttributePanel(String attr, ActionListener l)
          {
               attribute = attr;

               pointsAllocated = new Label("0", Label.CENTER);

               // 设置panel的布局为 3x1 的网格
               setLayout(new GridLayout(3, 1));

               setBackground(Color.GREEN);
               
               // 添加描述属性的标签
               add(new Label(attr, Label.CENTER));
               add(pointsAllocated);

               // 把 +/- 按钮添加到父 ActionListner 上
               Button incr = new AttributeButton("+", this);
               incr.addActionListener(l);
               Button decr = new AttributeButton("-", this);
               decr.addActionListener(l);

               // 添加另一个有加减按钮的panel
               Panel p = new Panel();
               p.add(incr);  
               p.add(decr);
               add(p);
          }

          // 更新 pointsAllocated label
		  public void allocatePoints(int n)
          {
               int value = getPointsAllocated() + n;
               pointsAllocated.setText("" + value);
          }

          // 返回给这个属性分配的点值
          public int getPointsAllocated()
          {
               return Integer.parseInt(pointsAllocated.getText());
          }

          public String toString()
          {
               // 返回这个属性的详细描述
               return attribute + ": " + getPointsAllocated();
          }

     }    // AttributePanel

     public class AttributeTest extends Applet implements ActionListener
     {          
          // 所有剩余的点值
          Label pointsRemaining;

          // 这个 applet 的属性
          private final String ATTRS[] = { "Strength", "Wisdom", "Agility", "Magic" };

          public void init() 
          {
               pointsRemaining = new Label("Points remaining: 10", Label.CENTER);

               // 设置 applet 的布局为FlowLayout
               setLayout(new FlowLayout(FlowLayout.CENTER, 5, 10));

               // 添加组件
               for(int i = 0; i < ATTRS.length; i++)
               {
                    add(new AttributePanel(ATTRS[i], this));
               }

               add(pointsRemaining);

          }    // init

          // 
          public void actionPerformed(ActionEvent e)
          {
               // 得到剩余的点值
               int n = Integer.parseInt(pointsRemaining.getText().substring(18));

               // 更新按钮panel的标签和主标签
               n += ((AttributeButton)e.getSource()).updatePanel(n);
               pointsRemaining.setText("Points remaining: " + n);
          } 

     }    // AttributeTest