// Fig. 17.7: CreditInquiry.java
// This program reads a file sequentially and displays the
// contents in a text area based on the type of account the
// user requests (credit balance, debit balance or
// zero balance).
import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.text.DecimalFormat;
import javax.swing.*;
import com.deitel.jhtp3.ch17.BankAccountRecord;

public class CreditInquiry extends JFrame {  
   private JTextArea recordDisplay;
   private JButton open, done, credit, debit, zero;
   private JPanel buttonPanel;         
   private ObjectInputStream input;
   private FileInputStream fileInput;
   private File fileName;
   private String accountType;

   public CreditInquiry()
   {
      super( "Credit Inquiry Program" );

      Container c = getContentPane();
      c.setLayout( new BorderLayout() );      
      buttonPanel = new JPanel();
      
      open = new JButton( "Open File" );
      open.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {
               openFile( true );
            }
         }
      );
      buttonPanel.add( open );

      credit = new JButton( "Credit balances" );
      credit.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {
               accountType = e.getActionCommand();
               readRecords();
            }
         }
      );
      buttonPanel.add( credit );

      debit = new JButton( "Debit balances" );
      debit.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {
               accountType = e.getActionCommand();
               readRecords();
            }
         }
      );
      buttonPanel.add( debit );

      zero = new JButton( "Zero balances" );
      zero.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {
               accountType = e.getActionCommand();
               readRecords();
            }
         }
      );
      buttonPanel.add( zero );

      done = new JButton( "Done" );
      buttonPanel.add( done );
      done.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {
               if ( fileInput != null )     
                  closeFile();

               System.exit( 0 );
            }
         }
      );

      recordDisplay = new JTextArea();
      JScrollPane scroller = new JScrollPane( recordDisplay );      
      c.add( scroller, BorderLayout.CENTER );
      c.add( buttonPanel, BorderLayout.SOUTH );

      credit.setEnabled( false );
      debit.setEnabled( false );
      zero.setEnabled( false );

      pack();
      setSize( 600, 250 );
      show();
   }

   private void openFile( boolean firstTime )
   {
      if ( firstTime ) {
         JFileChooser fileChooser = new JFileChooser();

         fileChooser.setFileSelectionMode(
            JFileChooser.FILES_ONLY );
         int result = fileChooser.showOpenDialog( this );

         // user clicked Cancel button on dialog
         if ( result == JFileChooser.CANCEL_OPTION )
            return;

         fileName = fileChooser.getSelectedFile();
      }

      if ( fileName == null ||
           fileName.getName().equals( "" ) )
         JOptionPane.showMessageDialog( this,
            "Invalid File Name",
            "Invalid File Name",
            JOptionPane.ERROR_MESSAGE );
      else {
         // Open the file
         try {
            // close file from previous operation
            if ( input != null )  
               input.close();   

            fileInput = new FileInputStream( fileName );
            input = new ObjectInputStream( fileInput );
            open.setEnabled( false );
            credit.setEnabled( true );
            debit.setEnabled( true );
            zero.setEnabled( true );
         }
         catch ( IOException e ) {
            JOptionPane.showMessageDialog( this,
               "File does not exist",
               "Invalid File Name",
               JOptionPane.ERROR_MESSAGE );
         }      
      }
   }
  
   private void closeFile()
   {
      try {
         input.close();
      }
      catch ( IOException ioe ) {
         JOptionPane.showMessageDialog( this,
            "Error closing file",
            "Error", JOptionPane.ERROR_MESSAGE );
         System.exit( 1 );
      }
   }

   private void readRecords()
   {      
      BankAccountRecord record;
      DecimalFormat twoDigits = new DecimalFormat( "0.00" );
      openFile( false );

      try {   
         recordDisplay.setText( "The accounts are:\n" );

         // input the values from the file
         while ( true ) {
            record =
               ( BankAccountRecord ) input.readObject();

            if ( shouldDisplay( record.getBalance() ) )
               recordDisplay.append( record.getAccount() +
                  "\t" + record.getFirstName() + "\t" +                  
                  record.getLastName() + "\t" +
                  twoDigits.format( record.getBalance() ) +
                  "\n" );
         }            
      }
      catch ( EOFException eof ) {
         closeFile();
      }
      catch ( ClassNotFoundException cnfex ) {
         JOptionPane.showMessageDialog( this,
            "Unable to create object",
            "Class Not Found", JOptionPane.ERROR_MESSAGE );
      }
      catch ( IOException e ) {
         JOptionPane.showMessageDialog( this,
            "Error reading from file",
            "Error", JOptionPane.ERROR_MESSAGE );
      }
   }

   private boolean shouldDisplay( double balance )
   {
      if ( accountType.equals( "Credit balances" ) &&
           balance < 0 )
         return true;
      else if ( accountType.equals( "Debit balances" ) &&
                balance > 0 )
         return true;
      else if ( accountType.equals( "Zero balances" ) &&
                balance == 0 )
         return true;

      return false;
   }
   
   public static void main( String args[] )
   {
      final CreditInquiry app = new CreditInquiry();

      app.addWindowListener(
         new WindowAdapter() {
            public void windowClosing( WindowEvent e )
            {
               app.closeFile();
               System.exit( 0 );
            }
         }
      );
   }
}

/**************************************************************************
 * (C) Copyright 1999 by Deitel & Associates, Inc. and Prentice Hall.     *
 * All Rights Reserved.                                                   *
 *                                                                        *
 * DISCLAIMER: The authors and publisher of this book have used their     *
 * best efforts in preparing the book. These efforts include the          *
 * development, research, and testing of the theories and programs        *
 * to determine their effectiveness. The authors and publisher make       *
 * no warranty of any kind, expressed or implied, with regard to these    *
 * programs or to the documentation contained in these books. The authors *
 * and publisher shall not be liable in any event for incidental or       *
 * consequential damages in connection with, or arising out of, the       *
 * furnishing, performance, or use of these programs.                     *
 *************************************************************************/