/*
    * Fsgrep is a simple Java application which allows a user to
    * search all files in a directory structure for lines matching
    * a given pattern.  Its functionality is a combination of the
    * Unix 'find' and 'grep' utilities.
    * Visit [http://fsgrep.sourceforge.net/] for more information.
    * 
    * Copyright (C) 2003-2006 Murali Krishnan [murali_ca_us@users.sourceforge.net]
    * 
   * Fsgrep is free software; you can redistribute it and/or modify
   * it under the terms of version 2 of the GNU General Public
   * License as published by the Free Software Foundation.
   * 
   * Fsgrep is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   * 
   * You should have received a copy of the GNU General Public License
   * along with Fsgrep (see the file named LICENSE.txt); if not, write
   * to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
   * Boston, MA  02111-1307  USA
   */
  
  package mk.fsgrep.gui;
  
  
  import java.awt.*;
  import java.awt.event.ActionEvent;
  import java.awt.event.ActionListener;
  import java.awt.event.WindowAdapter;
  import java.awt.event.WindowEvent;
  import java.io.*;
  import java.util.*;
  
  import javax.swing.*;
  
  
  /***
   * A simple viewer for text files.  It displays the file contents and
   * can be directed to show a particular line.
   * 
   * @author  Murali Krishnan
   *
   */
  public class FileViewer extends JFrame {
  
      //------------------------------------------------------------
      //- Class Variables
  
      private static FileViewer sInstance = null;
  
  
      //------------------------------------------------------------
      //- Class Functions
  
      public static FileViewer getInstance()
      {
          if (sInstance == null) {
              sInstance = new FileViewer();
          }
  
          return sInstance;
      }
  
  
      //------------------------------------------------------------
      //- Instance Variables
  
      private JTextArea _textArea = new JTextArea("", 30, 60);
      private JButton _buttonOk = new JButton("Ok");
      private JTextField _fieldFilename = new JTextField("");
      private String _lastFilename = null;
      private SelectionLocation _selectionLocation = new SelectionLocation();
  
  
      //------------------------------------------------------------
      //- Constructors
  
      public FileViewer() 
      {
          super("FileViewer");
  
          defineActions();
          makeFrame();
      }
  
  
  
      //------------------------------------------------------------
      //- Accessors
  
      protected JTextArea getTextArea() {return _textArea;}
      protected JButton getButtonOk() {return _buttonOk;}
      protected JTextField getFieldFilename() {return _fieldFilename;}
      protected String getLastFilename() {return _lastFilename;}
      protected SelectionLocation getSelectionLocation() {return _selectionLocation;}
  
  
     //------------------------------------------------------------
     //- Settors
 
     protected void setLastFilename(String val) {_lastFilename=val;}
 
 
     //------------------------------------------------------------
     //- Private/Protected Utility Functions
 
     protected void defineActions() {
         getFieldFilename().setEditable(false);
 
         getTextArea().setEditable(false);
         // getTextArea().getCaret().setVisible(true);
 
         getButtonOk().addActionListener(new ActionListener() {
                 public void actionPerformed (ActionEvent aEvent) {
                     setVisible(false);
                 }
             });
 
         addWindowListener(new WindowAdapter() {
                 public void windowActivated(WindowEvent e) {
                     getButtonOk().grabFocus();
                 }
             });
     }
 
 
     protected void makeFrame() {
         getContentPane().setLayout(new BorderLayout());
 
         JScrollPane scrollPane = new JScrollPane();
         scrollPane.setViewportView(getTextArea());
 
         getContentPane().add(scrollPane, BorderLayout.CENTER);
         getContentPane().add(makeBottomPanel(), BorderLayout.SOUTH);
 
         pack();
     }
 
 
     protected JPanel makeBottomPanel() {
         JPanel result = new JPanel(new BorderLayout());
 
         result.add(getFieldFilename(), BorderLayout.CENTER);
         result.add(getButtonOk(), BorderLayout.EAST);
 
         return result;
     }
 
 
     protected void readFile(String filename) {
         StringBuffer buffer = new StringBuffer();
 
         getTextArea().setText("");
         getSelectionLocation().clear();
 
         try {
             FileReader fr = new FileReader(filename);
             LineNumberReader lnr = new LineNumberReader(fr);
 
             String line=lnr.readLine();
             while (line != null) {
                 int position = buffer.length();
                 getSelectionLocation().set(lnr.getLineNumber(), position, (position+line.length()));
                 buffer.append(line).append('\n');
                 line=lnr.readLine();
             }
 
             lnr.close();
             fr.close();
         } catch (IOException ioe) {
             System.err.println("Problem reading [" + filename + "].");
             ioe.printStackTrace();
         }
 
         getTextArea().setText(buffer.toString());
         setLastFilename(filename);
     }
 
 
     protected void show(String pLinenum) {
         int linenum = Integer.parseInt(pLinenum);
 
         Points points = getSelectionLocation().get(linenum);
         getTextArea().getCaret().setDot(points.getEnd());
         getTextArea().getCaret().moveDot(points.getStart());
         getTextArea().getCaret().setSelectionVisible(true);
 
         // System.out.println("Selection [" + getTextArea().getSelectedText() + "]");
     }
 
 
     //------------------------------------------------------------
     //- Public Interface Functions
 
     public void display(String filename, String linenum) {
         // getTextArea().setText("display(" + filename + "," + linenum + ")");
         if (!filename.equals(getLastFilename())) {
             readFile(filename);
         }
 
         show(linenum);
 
         getFieldFilename().setText(filename + "; line " + linenum);
 
         setVisible(true);
     }
 
 
 
     //------------------------------------------------------------
     //- Class Interface Functions
 
 
 
     //------------------------------------------------------------
     //- Inner Classes
 
     protected class Points {
         private int _start = 0;
         private int _end = 0;
 
         protected Points(int pStart, int pEnd) {
             _start = pStart;
             _end = pEnd;
         }
 
         public int getStart() {return _start;}
         public int getEnd() {return _end;}
     }
 
     protected class SelectionLocation extends HashMap<Integer,Points> {
         protected void set(int linenum, int start, int end) {
             put(linenum, new Points(start, end));
         }
     }
 
 
 
     //------------------------------------------------------------
     //- Main
 
 
 
 }