Name: krT82822 Date: 04/29/99


The code for an applet is given at the end of this description.
This applet has a main with a frame and applet stub so that it
can run as an application. I did this to avoid having to sign
the applet. If I run the applet as an application (using javac)
and press the Print button, I get the following exception.
NOTE: I ran it with
   -Djava.compiler=NONE
so that I would get line numbers.
This was compiled and executed using JDK1.2.1.
The full version is JDK-1.2.1-A



Unable to print: java.lang.ClassCastException: sun.java2d.PeekGraphics
java.lang.ClassCastException: sun.java2d.PeekGraphics
at sun.awt.windows.WComponentPeer.print(WComponentPeer.java:92)
at java.awt.Component.printAll(Component.java:1966)
at java.awt.Container.printOneComponent(Container.java:914)
at java.awt.Container.printComponents(Container.java:904)
at PrintMe.print(PrintMe.java:150)
at sun.java2d.RasterPrinterJob.printPage(RasterPrinterJob.java:486)
at sun.java2d.RasterPrinterJob.print(RasterPrinterJob.java:235)
at PrintMe.print(PrintMe.java:119)
at PrintMe.button1_ActionPerformed(PrintMe.java:102)
at PrintMe$SymAction.actionPerformed(PrintMe.java:94)
at java.awt.Button.processActionEvent(Button.java:308)
at java.awt.Button.processEvent(Button.java:281)
at java.awt.Component.dispatchEventImpl(Component.java:2376)
at java.awt.Component.dispatchEvent(Component.java:2289)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:258)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:68)




/*
A basic extension of the java.applet.Applet class
 */

import java.awt.*;
import java.applet.*;
import java.util.Enumeration;
import java.net.URL;

public class PrintMe extends Applet implements java.awt.print.Printable
{
/**
* When printing, the Graphics must be translated to allow for the
* top and left margins. If no translation is done, then part of
* the image will be clipped off because most printers can not print
* to the edge of the paper.
*/
public static final float PRINT_TOP_MARGIN_IN_INCHES = 0.75F;
public static final float PRINT_LEFT_MARGIN_IN_INCHES = 0.75F;


/**
* This constructor is used when running standalone.
* It sets the AppletContext to an instance of the DummyAppletContext
* which is an inner class defined in this file!
*/
public PrintMe(String dummyArgument)
{
setStub(new DummyAppletStub());
}

public void init()
{
// This code is automatically generated by Visual Cafe when you add
// components to the visual environment. It instantiates and initializes
// the components. To modify the code, only use code syntax that matches
// what Visual Cafe can generate, or Visual Cafe may be unable to back
// parse your Java file into its visual environment.
//{{INIT_CONTROLS
setLayout(new GridLayout(0,1,20,20));
setSize(426,298);
list1 = new java.awt.List(0);
list1.add("yellow");
list1.add("red");
list1.add("green");
list1.add("blue");
list1.setBounds(0,0,426,33);
add(list1);
textField1 = new java.awt.TextField();
textField1.setText("I am a text field");
textField1.setBounds(0,53,426,33);
add(textField1);
choice1 = new java.awt.Choice();
choice1.addItem("yellow");
choice1.addItem("red");
choice1.addItem("green");
choice1.addItem("blue");
choice1.setBounds(0,106,426,33);
add(choice1);
label1 = new java.awt.Label("I am a label.");
label1.setBounds(0,159,426,33);
add(label1);
checkbox1 = new java.awt.Checkbox("Check Me");
checkbox1.setBounds(0,212,426,33);
add(checkbox1);
button1 = new java.awt.Button();
button1.setLabel("Print");
button1.setBounds(0,265,426,33);
button1.setBackground(new Color(12632256));
add(button1);
//}}

//{{REGISTER_LISTENERS
SymAction lSymAction = new SymAction();
button1.addActionListener(lSymAction);
//}}
}

//{{DECLARE_CONTROLS
java.awt.List list1;
java.awt.TextField textField1;
java.awt.Choice choice1;
java.awt.Label label1;
java.awt.Checkbox checkbox1;
java.awt.Button button1;
//}}

class SymAction implements java.awt.event.ActionListener
{
public void actionPerformed(java.awt.event.ActionEvent event)
{
Object object = event.getSource();
if (object == button1)
button1_ActionPerformed(event);
}
}

void button1_ActionPerformed(java.awt.event.ActionEvent event)
{
try
{
print();
}
catch (Exception e)
{
System.out.println("Unable to print: " + e);
e.printStackTrace(System.out);
}
}




    void print() throws java.awt.print.PrinterException
      {
      java.awt.print.PrinterJob printerJob = java.awt.print.PrinterJob.getPrinterJob();
      
      printerJob.setPrintable(this);
      printerJob.print();
      }
   
   
   /**
    * This method is called when there is an applet
    * to print which does not use the grid.
    */
   public int print
   (
   Graphics graphics,
   java.awt.print.PageFormat pageFormat,
   int pageIndex
   )
      {
      if (pageIndex > 0)
         {
         return java.awt.print.Printable.NO_SUCH_PAGE;
         }
         
      int myPR = 72;
      float printTopMargin = myPR * PRINT_TOP_MARGIN_IN_INCHES;
      float printLeftMargin = myPR * PRINT_LEFT_MARGIN_IN_INCHES;
      Dimension usableSize = new Dimension(
                                     (int) Math.round(pageFormat.getWidth() - 2*printLeftMargin),
                                     (int) Math.round(pageFormat.getHeight() - 2*printTopMargin));
      
      graphics.translate(
                Math.round(printLeftMargin),
                Math.round(printTopMargin));

      this.printComponents(graphics);
      
      return java.awt.print.Printable.PAGE_EXISTS;
      }

        
   /**
    * This class is used when running standalone.
    * It will supply methods that are called via an
    * AppletContext (such as showDocument) but most of these
    * methods will not do anything!
    */
   public class DummyAppletStub implements AppletStub, AppletContext
      {
      
      //
      // AppletStub methods
      //
      
      public String getParameter(String name)
         {
return null;
}
      
      public boolean isActive() {return true;}
      public URL getDocumentBase() {return null;}
      public AppletContext getAppletContext() {return this; }
      public void appletResize(int width, int height) { }
      
      public URL getCodeBase()
         {
         String currentDirectory = System.getProperty("user.dir", "c:");
         
         try
            {
            return new URL("file:" + currentDirectory);
            }
         catch (Exception e)
            {
            return null;
            }
         }
      
      
      //
      // AppletContext methods
      //
      
      public AudioClip getAudioClip(URL url) {return null;}
      public Image getImage(URL url) {return null;}
      public Applet getApplet(String name) {return null;}
      public Enumeration getApplets() {return null;}
      public void showDocument(URL url) { }
      public void showDocument(URL url, String target) { }
      public void showStatus(String status) { }
      
      }
      
      
      
public static void main(String args[])
{
PrintMe a = new PrintMe("select special constructor");
Frame f = new Frame("I am holding an applet!");

f.setSize(300, 300);
f.add("Center", a);

a.init();
f.show();
a.start();
}
   }
(Review ID: 57331)
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