חזרה

שאלה- כתוב אפליקציה ב Java העונה על ההוראות  

/*File SampProg133.java Copyright 1997, R.G.Baldwin Without viewing the solution that follows, write a Java application that replicates the behavior of the application named Event31.java (discussed in lesson 106) with the  following changes. This is an upgrade to the original version of Event31. In particular, in its original form, there is no visual  indication when the user clicks on the Label object  identified by the Click Me caption. Since this Label object is being used to simulate a Button object, a visual  indication that the Label object has been clicked would be appropriate. In your upgraded version, the white Label object which  originally had the Click Me caption will appear as a  magenta colored rectangle when the program starts and will not display a caption.   When the user clicks the magenta Label object, the caption  "ouch" will momentarily appear and disappear in synchronism with the down stroke and the up stroke of the left mouse  button.  The caption will appear on the down stroke and  will disappear on the upstroke. In addition to the above, make your name appear in the banner at the top of the Frame object. The upgraded version of the program has been tested using JDK 1.1.3 under Win95. */ //========================================================= import java.awt.*; import java.awt.event.*; //========================================================= public class SampProg133 extends Frame{   public static void main(String[] args){     //instantiate obj     SampProg133 displayWindow = new SampProg133();   }//end main   //-------------------------------------------------------   public SampProg133(){//constructor     setTitle("Copyright 1997, R.G.Baldwin");     setLayout(new FlowLayout());     Button clickMeButton = new Button("Click Me");     Label colorMeLabel = new Label("Color Me");     Label clickMeLabel = new Label("      ");     clickMeLabel.setBackground(Color.magenta);       add(clickMeButton);//add components to the Frame object     add(colorMeLabel);     add(clickMeLabel);     setSize(300,100);//set frame size         setVisible(true);//display the frame     //Register listener objects     clickMeLabel.addMouseListener(           new MyMouseListener(clickMeButton,clickMeLabel));     clickMeButton.addActionListener(                        new MyActionListener(colorMeLabel));     //terminate when Frame is closed                            this.addWindowListener(new Terminate());    }//end constructor }//end class SampProg133 //========================================================= /*This MouseListener class is used to monitor for mouse  clicks on a Label object.  Whenever the user clicks on the  label, the code in an object of this class creates a  counterfeit ActionEvent object and posts it to the  SystemEventQueue.  The source of the event is specified to  be a particular Button object that is passed in when an  object of this class is instantiated.  Thus, the Label  object "claims" to be the Button object and posts  ActionEvent objects that are interpreted by the runtime  system as originating at the Button object.  The type of ActionEvents generated are ACTION_PERFORMED events.  The  events are automatically delivered to the actionPerformed() method of an ActionListener object registered on the  button. */ class MyMouseListener extends MouseAdapter{   Button clickMeButton;//reference to the Button   Label clickMeLabel;//reference to the Label   //-------------------------------------------------------   //constructor   MyMouseListener(Button inButton,Label inLabel){     clickMeButton = inButton;//save reference to Button     clickMeLabel = inLabel;//save reference to Label   }//end constructor   //-------------------------------------------------------   //overridden mouseClicked() method   public void mouseClicked(MouseEvent e){     //Note that the following is a single statement     Toolkit.getDefaultToolkit().         getSystemEventQueue().         postEvent(new ActionEvent(clickMeButton,                                   ActionEvent.                                   ACTION_PERFORMED,                                   "counterfeit"));   }//end overridden mouseClicked() method   //------------------------------------------------------   //overridden mousePressed() method   public void mousePressed(MouseEvent e){     clickMeLabel.setText(" ouch ");   }//end overridden mousePressed() method   //------------------------------------------------------   //overridden mouseReleased() method   public void mouseReleased(MouseEvent e){     clickMeLabel.setText("      ");   }//end overridden mousePressed() method }//end MyMouseListener //========================================================= /*This ActionListener class is used to instantiate a  Listener object for the Button object.  Whenever the button is clicked, or a counterfeit ActionEvent is posted with the Button as the specified source object, the code in an  object of this class toggles the background color of a  Label object back and forth between yellow and blue.*/ class MyActionListener implements ActionListener{   int toggle = 0;   Label myLabel;   //-------------------------------------------------------   MyActionListener(Label inLabel){//constructor     myLabel = inLabel;   }//end constructor     //-------------------------------------------------------   public void actionPerformed(ActionEvent e){     if(toggle == 0){       toggle = 1;       myLabel.setBackground(Color.yellow);     }else{       toggle = 0;       myLabel.setBackground(Color.blue);     }//end else   }//end actionPerformed() }//end class myActionListener //========================================================= class Terminate extends WindowAdapter{   public void windowClosing(WindowEvent e){     //terminate the program when the window is closed       System.exit(0);   }//end windowClosing }//end class Terminate //=========================================================