/*
 * SimplyHTML, a word processor based on Java, HTML and CSS
 * Copyright (C) 2002 Ulrich Hilger
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

package com.lightdev.app.shtm;

import java.awt.event.ActionListener;
import java.awt.AWTEvent;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.WindowEvent;
import java.awt.event.ActionEvent;

import javax.swing.AbstractButton;
import javax.swing.JDialog;
import javax.swing.JButton;
import javax.swing.JPanel;
import java.awt.Frame;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.Container;
import java.awt.Dialog;

/**
 * Base class for other dialogs of application SimplyHTML.
 *
 * @author Ulrich Hilger
 * @author Light Development
 * @author <a href="http://www.lightdev.com">http://www.lightdev.com</a>
 * @author <a href="mailto:info@lightdev.com">info@lightdev.com</a>
 * @author published under the terms and conditions of the
 *      GNU General Public License,
 *      for details see file gpl.txt in the distribution
 *      package of this software
 *
 * 
 */

class DialogShell extends JDialog implements ActionListener {

  /** panel containing dialog buttons */
  protected JPanel buttonPanel;

  /** button to confirm the operation */
  protected AbstractButton okButton;

  /** button to cancel the operation */
  protected AbstractButton cancelButton;

  /** button to display context sensitive help */
  protected AbstractButton helpButton;

  /**
   * the result of the operation, one of RESULT_CANCEL and RESULT_OK
   */
  private int result;

  /** result value for a cancelled operation */
  public static int RESULT_CANCEL = 1;

  /** result value for a confirmed operation */
  public static int RESULT_OK = 0;

  /** id of associated help topic (if any) */
  protected String helpTopicId = null;
  
  /** Listens to enter and cancel. */
  private KeyListener completionKeyListener = null;
  
  /**
   * constructor
   *
   * @param parent  the parent dialog
   * @param title  the title for this dialog
   */
  public DialogShell(Dialog parent, String title) {
    super(parent, title);
    buildDialog();
  }

  /**
   * constructor
   *
   * @param parent  the parent frame
   * @param title  the title for this dialog
   */
  public DialogShell(Frame parent, String title) {
    super(parent, title);
    buildDialog();
  }

  /**
   * constructor
   *
   * @param parent  the parent frame
   * @param title  the title for this dialog
   * @param helpTopicId  the id of the help topic to display for this dialog
   */
  public DialogShell(Frame parent, String title, String helpTopicId) {
    super(parent, title);
    this.helpTopicId = helpTopicId;
    buildDialog();
  }

  /**
   * constructor
   *
   * @param parent  the parent dialog
   * @param title  the title for this dialog
   * @param helpTopicId  the id of the help topic to display for this dialog
   */
  public DialogShell(Dialog parent, String title, String helpTopicId) {
    super(parent, title);
    this.helpTopicId = helpTopicId;
    buildDialog();
  }

  /**
   * create dialog components
   */
  private void buildDialog() {

    enableEvents(AWTEvent.WINDOW_EVENT_MASK);

    // construct dialog buttons
    okButton = new JButton(Util.getResourceString("okBtnName"));
    cancelButton = new JButton(Util.getResourceString("cancelBtnName"));
    cancelButton.addActionListener(this);
    okButton.addActionListener(this);
    
    // construct button panel
    buttonPanel = new JPanel(new FlowLayout());
    buttonPanel.add(okButton);
    buttonPanel.add(cancelButton);
    
    // construct help button
    if(helpTopicId != null) {
        try {
            helpButton = SHTMLHelpBroker.createHelpButton(helpTopicId);
            helpButton.setText(Util.getResourceString("helpLabel"));
            buttonPanel.add(helpButton);
        } catch (NoClassDefFoundError e) {
            helpTopicId = null;
        }
    }

    // add all to content pane of dialog
    Container contentPane = getContentPane();
    contentPane.setLayout(new BorderLayout(5,5));
    contentPane.add(buttonPanel, BorderLayout.SOUTH);
    
  }

  /**
   * dispose the dialog properly in case of window close events
   */
  protected void processWindowEvent(WindowEvent e) {
    if (e.getID() == WindowEvent.WINDOW_CLOSING) {
      cancel();
    }
    super.processWindowEvent(e);
  }

  /**
   * cancel the operation
   */
  protected void cancel() {
    result = RESULT_CANCEL;
    dispose();
  }

  /**
   * confirm the operation
   */
  protected void confirm() {
    result = RESULT_OK;
    dispose();
  }

  /**
   * get the result of the operation performed in this dialog
   *
   * @return the result, one of RESULT_OK and RESULT_CANCEL
   */
  public int getResult() {
    return result;
  }

  /**
   * implements the ActionListener interface to be notified of
   * clicks onto the ok and cancel button.
   */
  public void actionPerformed(ActionEvent e) {
    Object src = e.getSource();
    if(src == cancelButton) {
      cancel();
    }
    else if(src == okButton) {
      confirm();
    }
  }
  
  protected KeyListener getCompletionKeyListener() {
    if (completionKeyListener == null) {
      completionKeyListener =
        new KeyAdapter() {
        public void keyPressed(KeyEvent e) {
          if (e.getKeyCode() == KeyEvent.VK_ESCAPE) {
            e.consume();
            cancel();
          }
          else if (e.getKeyCode() == KeyEvent.VK_ENTER) {
            e.consume();
            confirm();
          }
        }       
      };
    }
    return completionKeyListener;
  }
}