Name: rk38400 Date: 04/15/98


The following source code contains the problem.
When I press the "Print" button a white sheet of paper is printed.
When I press the "Print all" button an exception whithout message is raised.
The line "Exception caught during printing. Exception = null
" is printed in the java console.

Is it a bug or where I mismatch ?

Thanks.

C. PIGNEROL (###@###.###)


The source code :

/** PrintTree.java.
This file contains the PrintTree's class, which enables users to
see config files.
This class is made with the JFC.
*/

// Gui support :
import java.awt.Frame;
import java.awt.Container;
import java.awt.FileDialog;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import com.sun.java.swing.JApplet;
import com.sun.java.swing.JButton;
import com.sun.java.swing.JLabel;
import com.sun.java.swing.JTree;
import com.sun.java.swing.tree.DefaultMutableTreeNode;
import com.sun.java.swing.tree.TreeNode;
import com.sun.java.swing.JScrollPane;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;

// Printing support :
import java.awt.Toolkit;
import java.awt.Graphics;
import java.awt.PrintJob;


public final class PrintTree extends JApplet implements ActionListener
{
    public PrintTree ( )
    {
super ( );
    }
    
    /** main. For using not in an Applet. */
    public static void main (String args [ ])
    {
Frame frame = new Frame ("Tree Viewer");
PrintTree PrintTree = new PrintTree ( );
frame.add (PrintTree);
PrintTree.init ( );
frame.pack ( );
frame.show ( );
    }
    
    public void init ( )
    {
JButton button = null;
JLabel label = null;
final int colsNum = 6, rowsNum = 6;
GridBagLayout gridbag = new GridBagLayout ( );
GridBagConstraints constraints = new GridBagConstraints ( );
constraints.fill = GridBagConstraints.BOTH;
getContentPane ( ).setLayout (gridbag);

// The tree.
tree = new JTree ( );
JScrollPane scrollPane = new JScrollPane (tree);
buildConstraints (constraints, 0, 0, colsNum, rowsNum - 2, 100, 100);
gridbag.setConstraints (scrollPane, constraints);
getContentPane ( ).add (scrollPane);

// Last row : Print and Exit buttons.
button = new JButton ("Print view");
buildConstraints (constraints, 0, rowsNum - 1, 1, 1, 100, 100);
gridbag.setConstraints (button, constraints);
getContentPane ( ).add (button);
button.setActionCommand (button.getText ( ));
button.addActionListener (this);
button.setToolTipText ("Print the tree view.");
button = new JButton ("Print all");
buildConstraints (constraints, 1, rowsNum - 1, 1, 1, 100, 100);
gridbag.setConstraints (button, constraints);
getContentPane ( ).add (button);
button.setActionCommand (button.getText ( ));
button.addActionListener (this);
button.setToolTipText ("Print all the gui.");
button = new JButton ("Exit");
buildConstraints (constraints, colsNum - 1, rowsNum - 1, 1, 1, 100, 100);
gridbag.setConstraints (button, constraints);
getContentPane ( ).add (button);
button.setActionCommand (button.getText ( ));
button.addActionListener (this);
button.setToolTipText ("Exit from this application.");
    }
    
    private void print (int what) // what = PRINT_VIEW or PRINT_ALL
    {
try
{
//Toolkit tk = Toolkit.getDefaultToolkit ( );

Frame parent = (Frame)getParent ( );
Toolkit tk = getToolkit ( );
PrintJob pjob = tk.getPrintJob (parent, "PrintTree", null);

if (null != pjob)
{
Graphics g = pjob.getGraphics ( );

if (null != g)
{
if (PRINT_VIEW == what)
{
System.out.println ("Printing document ...");
tree.printAll (g);
//tree.paint (g);
}
else
{
System.out.println ("Printing gui ...");
parent.printAll (g);
//parent.paint (g);
}

g.dispose ( ); // Flush page.
pjob.end ( );
System.out.println ("Printing succeeded.");
}
else
System.out.println ("Graphics nul.");
}
else
{
System.out.println ("Printing canceled.");
}
}
catch (Exception e)
{
System.out.println ("Exception caught during printing. Exception = " + e.getMessage ( ));
}
    }
    
    private void exit ( )
    {
System.exit (0);
    }
    
    public void actionPerformed (ActionEvent e)
    {
String action = e.getActionCommand ( );

if (action.equals ("Print view"))
print (PRINT_VIEW);
else if (action.equals ("Print all"))
print (PRINT_ALL);
else if (action.equals ("Exit"))
exit ( );
    }

    /** buildConstraints. Create a constain. cf. Java 1.1 en 21 jours, page 324. */
    private void buildConstraints (GridBagConstraints gbc, int gx, int gy,
                                   int gw, int gh, double wx, double wy)
    {
     gbc.gridx = gx;
     gbc.gridy = gy;
     gbc.gridwidth = gw;
     gbc.gridheight = gh;
     gbc.weightx = wx;
     gbc.weighty = wy;
    }
    
    private final int PRINT_VIEW = 0;
    private final int PRINT_ALL = 1;
    private JTree tree;
}
(Review ID: 27747)
======================================================================