using Gtk;

public class TextFileViewer : Window
{
  private TextView text_view;

  public TextFileViewer()
  {
    this.title = "Просмотр текстового файла";
    this.window_position = WindowPosition.CENTER;
    this.set_default_size( 500, 400 );

    var toolbar = new Toolbar();
    var open_button = new ToolButton.from_stock( Stock.OPEN );
    toolbar.add( open_button );
    open_button.clicked.connect( on_open_clicked );

    this.text_view = new TextView();
    this.text_view.editable = false;
    this.text_view.cursor_visible = false;

    var scroll = new ScrolledWindow( null, null );
    scroll.set_policy( PolicyType.AUTOMATIC, PolicyType.AUTOMATIC );
    scroll.add( this.text_view );

    var vbox = new VBox( false, 0 );
    vbox.pack_start( toolbar, false, true, 0 );
    vbox.pack_start( scroll, true, true, 0 );
    this.add( vbox );
  }

  private void on_open_clicked()
  {
    var file_chooser = new FileChooserDialog( "Открыть файл", this,
                             FileChooserAction.OPEN,
                             Stock.CANCEL, ResponseType.CANCEL,
                             Stock.OPEN, ResponseType.ACCEPT, null );
    if( file_chooser.run() == ResponseType.ACCEPT )
    {
      open_file( file_chooser.get_filename() );
    }
    file_chooser.destroy();
  }

  private void open_file( string filename )
  {
    try
      {
        string text;
        size_t size;
        FileUtils.get_contents( filename, out text, out size );
        this.text_view.buffer.set_text( text, (int) size );
      }
    catch( Error e )
      {
        stderr.printf( "Ошибка: %s\n", e.message );
      }
  }

  public static int main( string[] args )
  {
    Gtk.init( ref args );
    var window = new TextFileViewer();
    window.destroy.connect( Gtk.main_quit );
    window.show_all();
    Gtk.main();
    return 0;
  }
}