EnumRadioGroup.java

/*
** Module   : EnumRadioGroup.java
** Abstract : EnumRadioGroup is a GWT radio group control initialized by enumeration values.
**
** Copyright (c) 2017, Golden Code Development Corporation.
**
** -#- -I- --Date-- ----------------Description----------------------
** 001 SBI 20170601 Created initial version.
*/
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
** 
** Additional terms under GNU Affero GPL version 3 section 7:
** 
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
**   are non-permissive additional terms allowed under Section 7 of the GNU
**   Affero GPL version 3 and may not be removed by you.
** 
**   0. Attribution Requirement.
** 
**     You must preserve all legal notices or author attributions in the covered
**     work or Appropriate Legal Notices displayed by works containing the covered
**     work.  You may not remove from the covered work any author or developer
**     credit already included within the covered work.
** 
**   1. No License To Use Trademarks.
** 
**     This license does not grant any license or rights to use the trademarks
**     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
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**     name Golden Code, FWD, or the names of any author or contributor, for
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*/


package com.goldencode.p2j.admin.client.widget;

import java.text.ParseException;
import java.util.Map;

import org.gwtbootstrap3.client.ui.InlineRadio;
import org.gwtbootstrap3.client.ui.Radio;
import org.gwtbootstrap3.client.ui.base.RadioGroupBase;

import com.google.gwt.text.shared.Parser;
import com.google.gwt.uibinder.client.UiConstructor;
import com.google.gwt.user.client.ui.Widget;

/**
 * GWT radio group control that can be initialized by the target enumeration. It displays
 * radio button labels from a translation map if it is provided or takes its labels from
 * enumeration values.
 *
 * @param    <E>
 *           Enumeration that implements EnumCreator interface.
 */
public class EnumRadioGroup<E extends EnumCreator> extends RadioGroupBase<E>
{
   /**
    * Radio group styles
    */
   public static enum RadioStyles
   {
      /** Vertically stacked radio buttons */
      RADIO,
      
      /** In-line horizontal radio buttons */
      RADIO_INLINE
   }
   
   /**
    * The auto initialization flag that means how radio buttons are created for this widget. If
    * its value is true, then radio buttons are created from the enumeration values, otherwise
    * radio buttons are provided by the UI xml descriptor.
    */
   private boolean init = true;
   
   /** The enumeration creator */
   private final E creator;
   
   /** The layout style used to place radio buttons */
   private final RadioStyles rstyle;
   
   /** The translation map that holds entries of the enumeration name and its presentation value */
   private final Map<String, String> translationMap;
   
   /**
    * Radio Group UI constructor.
    * 
    * @param    name
    *           A radio group common name.
    * @param    creator
    *           A labels/buttons creator
    * @param    rstyle
    *           Radio group style tha can be an in-line style or a vertical style
    * @param    init
    *           If its value is true, then radio buttons are created with the help of
    *           the provided creator. The false value means that the values are provided by
    *           the UI xml descriptor. 
    */
   @UiConstructor
   public EnumRadioGroup(String name, E creator, RadioStyles rstyle, boolean init)
   {
      this(name, creator, rstyle, init, null);
   }

   /**
    * Radio Group UI constructor.
    * 
    * @param    name
    *           A radio group common name.
    * @param    creator
    *           A labels/buttons creator
    * @param    rstyle
    *           Radio group style tha can be an in-line style or a vertical style
    * @param    init
    *           If its value is true, then radio buttons are created with the help of
    *           the provided creator. The false value means that the values are provided by
    *           the UI xml descriptor. 
    * @param    translationMap
    *           The translation map that maps the target enumeration type to its labels. 
    */
   public EnumRadioGroup(String name,
                         E creator,
                         RadioStyles rstyle,
                         boolean init,
                         Map<String, String> translationMap)
   {
      super(name, getParser(creator));
      this.creator = creator;
      this.rstyle = rstyle;
      this.init = init;
      this.translationMap = translationMap;
      
      init();
   }
   
   /**
    * Enable a radio button by its enumeration value.
    * 
    * @param    value
    *           The target value that represents the button that should be enabled or disabled.
    * @param    enabled
    *           The enable state for the target radio button.
    */
   public void setEnabled(Enum value, boolean enabled)
   {
      Widget radio = getWidget(value.ordinal());
      if (radio instanceof Radio)
      {
         ((Radio) radio).setEnabled(enabled);
      }
   }
   
   /**
    * Creates radio buttons from the given enumeration values.
    */
   private void init()
   {
      if (init)
      {
         for(Enum value : creator.getValues())
         {
            String label = null;
            if (translationMap != null)
            {
               label = translationMap.get(value.name());
            }
            Radio radioButton;
            switch(rstyle)
            {
               case RADIO:
                  radioButton = new Radio(getName(), (label != null) ? label : value.toString());
                  break;
               case RADIO_INLINE:
               default:
                  radioButton = new InlineRadio(getName(), (label != null) ? label : value.toString());
            }
            
            radioButton.setFormValue(value.name());
            
            add(radioButton);
         }
         init = false;
      }
   }

   /**
    * Creates the enumeration parser.
    * @param    <E>
    *           The parameter type of EnumCreator
    * @param    creator
    *           The enumeration creator
    * 
    * @return   The object that can parse text and return its enumeration value.
    */
   private static <E extends EnumCreator> Parser<E> getParser(E creator)
   {
      /**
       * An object that can parse text and return its enumeration value.
       */
      return new Parser<E>()
      {
         @Override
         public E parse(CharSequence text) throws ParseException
         {
            if (text == null)
            {
               throw new ParseException("The null input value was encountered.", 0);
            }
            
            return (E) creator.createFrom(text.toString());
         }
      };
   }
}