/***
    *  The contents of this file are subject to the Mozilla Public
    *  License Version 1.1 (the "License"); you may not use this file
    *  except in compliance with the License. You may obtain a copy of
    *  the License at http://www.mozilla.org/MPL/
    *
    *  Software distributed under the License is distributed on an "AS
    *  IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
    *  implied. See the License for the specific language governing
   *  rights and limitations under the License.
   *
   *  The Original Code is pow2WebGui library.
   *
   *  The Initial Owner of the Original Code is Power Of Two S.R.L.
   *  Portions created by Power Of Two S.R.L. are Copyright (C) Power Of Two S.R.L.
   *  All Rights Reserved.
   *
   * Contributor(s):
   */
  
  package com.pow2.webgui.tabbedselector;
  
  
  import com.pow2.util.Util;
  import com.pow2.webgui.Widget;
  
  
  /***
   *  Tab class.
   *
   * @author  Luca Fossato
   * @created  22 September 2001
   */
  public class Tab extends Widget
  {
    /*** LEFTUP is the left-most selected tab. */
    public final static int LEFTUP = 0;
  
    /*** LEFTDOWN is the left-most deselected tab. */
    protected final static int LEFTDOWN = 1;
  
    /*** UP is a selected tab, but not a left-most one. */
    protected final static int UP = 2;
  
    /*** DOWN is a deselected tab,  but not a left-most one. */
    protected final static int DOWN = 3;
  
    /*** tabbedSelector key */
    public final static String KEY = "tab";
  
    protected final static String FOLLOWUP_PARAMETER_PREFIX = "webgui.tbdselector.";
    protected final static String FOLLOWUP_PARAMETER        = ".tab";
  
  
    /***
     *  Tab type.
     *  <br>
     *  Its value can be:<br>
     *  <ul>
     *    <li>LEFTUP    the left-most selected tab.</li>
     *    <li>LEFTDOWN  the left-most deselected tab.</li>
     *    <li>UP        a selected tab, but not a left-most one.</li>
     *    <li>DOWN      a deselected tab,  but not a left-most one.</li>
     *  </ul>
     */
    protected int type;
  
  
    /***
     *  Default constructor.
     */
    public Tab()
    {
      type = LEFTUP;
    }
  
  
  
    /***
     *  Sets the type attribute of the Tab object
     *
     * @param  newType The new type value
     */
    public void setType(int newType)
    {
      type = newType;
    }
  
  
    /***
     *  Gets the type attribute of the Tab object
     *
     * @return  The type value
     */
    public int getType()
    {
      return type;
    }
  
 
   /***
    *  Gets the followUp attribute of the Tab object.
    *  <br>
    *  If the Tab followUp attribute value is null, this method
    *  uses the parent TabbedPanel followUp attribute value, adding to it
    *  the new parameter  FOLLOWUP_PARAMETER={tabName}
    *  where<br>
    *  FOLLOWUP_PARAMETER = webGUI.tabbedPanel.tab<br>
    *  {tabName}          = the name of the selected tab
    *
    * @return  The followUp value
    */
   public String getFollowUp()
   {
     if (parentW == null)
       return followUp;    // can be null, but avoid null pointer exceptions;
 
     // Tab followUp parameter value is null ?
     if (Util.isNull(followUp) && Util.isNull(followUp = parentW.getFollowUp()))
     {
       cat.warn("::getFollowUp - followUp is null either for tag [" + name + "] and for its parent");
       return followUp;
     }
 
     // add the the selected tab parameter (if it doesn't exits);
     if (followUp.indexOf(FOLLOWUP_PARAMETER_PREFIX) == -1)
       followUp = Util.addURLParameter(followUp, getSelectedTabParam());
 
     // DbForms (www.dbforms.org) followUp attribute compatibility trick:
     // remove any "/" initial character from
     // the pow2webGui followUp attribute value;
     return (followUp.startsWith("/")) ?
       followUp.substring(1, followUp.length()) : followUp;
   }
 
 
 
 
   /***
    *  PROTECTED METHODS here
    */
 
 
   /***
    *  Sets the type attribute of the Tab object.
    */
   protected void setType()
   {
     if      (isFirst() &&   isSelected())  type = LEFTUP;
     else if (isFirst() &&  !isSelected())  type = LEFTDOWN;
     else if (!isFirst() &&  isSelected())  type = UP;
     else if (!isFirst() && !isSelected())  type = DOWN;
   }
 
 
   /***
    *  Check if this tab is the tabbedPanel selected tab.
    *
    * @return  true if this tab is the tabbedPanel selected tab;
    *          false otherwise.
    */
   protected boolean isSelected()
   {
     if (parentW == null)
     {
       cat.warn("::isSelected - parent is null. Cannot operate.");
       return false;
     }
 
     // is this tag name equal to the TabbedPanel selectedTab attribute ?
     TabbedSelector p = (TabbedSelector) parentW;
     String st = p.getSelectedTab();
 
     return ((st != null) && (name != null) && name.equals(st));
   }
 
 
 
 
   /***
    *  PRIVATE METHODS here
    */
 
 
   /***
    *  Check if this tab is the first tab of the TabbedPanel widget.
    *
    * @return  true if this tab is the first tab of the TabbedPanel widget;
    *          false otherwise.
    */
   private boolean isFirst()
   {
     if (parentW == null)
     {
       cat.warn("::isFirst - parent is null. Cannot operate.");
       return false;
     }
 
     TabbedSelector p = (TabbedSelector) parentW;
 
     return (p.getTabs().size() <= 1);
   }
 
 
   /***
    *  Build the selectedTab parameter
    *
    * @return the selectedTab parameter
    */
   private String getSelectedTabParam()
   {
     return TabbedSelectorUtil.getSelectedTabParam(getParentW().getName(), name);
   }
 }