import javax.swing.*;
import au.com.forward.utils.StringUtils;
import java.awt.EventQueue;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

/**
 * the main class of your application
 */ 
public class ExampleShowErrorMessage {

  private static String errMsgTitle = "Application Error";
  
  // set to main frame of the application 
  // used to attach error message dialog boxes to
  private static JFrame frame = null;  
  // set to null so can still show errors if get error initializing JFrame
  
  //.....
  // other application method here
  //......
  
  /**
   *  Show an Error message 
   *
   * @param  window  a class extending from JInternalFrame 
   *                  that implements the displayError(Throwable t) method
   *                  Should be defined as an interface IWindow.
   * @param  t       the Throwable to be displayed 
   */
  public static void showErrorMessage(IWindow window, Throwable t) {
    // need to catch all errors here
    try {   
      // do any special processing here
      // for example
      // if (t instanceof FileTransferStopped) {
      //        ignore these as they are generated by other errors
      //   return;
      // }
      if (window != null) {
        window.displayError(t); // display in the related window
      } else {
        Application.showErrorMessage(t); // no related window just show here
      }
    } catch (Throwable tex) {
      // this should never happen but lets be sure
      System.err.println("Caught exception in showErrorMessaage()\n"+StringUtils.toString(tex));
    }
      
  }

  
  /**
   *  Show an Error message 
   *
   * @param  t  the Throwable Error to be shown 
   */
  public static void showErrorMessage(Throwable t) {
    // need to catch all errors here
    try {   
      // do any special processing here
      // for example
      // if (t instanceof FileTransferStopped) {
      //        ignore these as they are generated by other errors
      //   return;
      // }

      // log the error here if appropriate
      // See "How to set up Java logging" for a better way
      System.err.println(StringUtils.toString(t));
      
      JButton dismiss = new JButton("Continue");
      JButton help = new JButton("Help");    
      JOptionPane messageBox = new JOptionPane("",JOptionPane.INFORMATION_MESSAGE);
      
      String msg =  formatThrowableMessage(t); 
      messageBox.setMessage(msg);
      
      Object[] options = {dismiss,help};
      messageBox.setOptions(options);
      
      final JDialog dialog = messageBox.createDialog(frame,errMsgTitle);
      // if frame is null the messageBox is a top level component.
      
      final String helpID = getHelpContext(t);

      // add action listener for continue button
      dismiss.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
          try {
            dialog.dispose();
          } catch (Throwable tex) {
            // something bad happened
            System.err.println("Caught exception in when trying to close showErrorMessaage()\n"
            +StringUtils.toString(tex));
          }
        }
      });
      
      // add action listener for help button
      help.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
          SwingUtilities.invokeLater(new Runnable() {
            public void run() {
              try {
                  // this class (not shown here) displays this helpID using Java Help.
                  // see "A suggestion for unified error messages" for more details
                  ApplicationHelp.showHelp(helpID);
              } catch (Throwable tex) {
                // something bad happened
                System.err.println("Caught exception in when trying to show help()\n"
                +StringUtils.toString(tex));
              }
            }
          });
        }
      });
  
      // this lets us call this method from any thread
      if (EventQueue.isDispatchThread()) {
        dialog.show();
      } else {
        SwingUtilities.invokeLater(new Runnable() {
          public void run() {
            // need to catch all error here
            try {
              dialog.show();
            } catch (Throwable tex) {
              // something bad happened
              System.err.println("Caught exception in when trying to show showErrorMessaage()\n"
              +StringUtils.toString(tex));
            }
          }
        });
      }
    } catch (Throwable tex) {
      // this should never happen but lets be sure
      System.err.println("Caught exception in showErrorMessaage()\n"+StringUtils.toString(tex));
    }
  }
  
  /**
   * returns the error message to be displayed for this exception
   *
   * could look up international property files etc
   * for now just show the message
   */
  private static String formatThrowableMessage(Throwable t) {
    return t.getMessage();
  }
    
  /**
   * returns the helpID associated with this exception
   *
   * will use the class name as the helpID
   */
  private static String getHelpContext(Throwable t) {
    return t.getClass().getName();
  }
    
  public static void main(String args[]) {
    Throwable t = new OutOfMemoryError("The Application ran out of Memory.\nWill try to recover.");
    showErrorMessage(t);
    // need to kill this sample application manually
    // as Swing thread still running
  }
}