package textbender.g.util.prefs; // Copyright 2001-2005, Michael Allan.  Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Textbender Software"), to deal in the Textbender Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicence, and/or sell copies of the Textbender Software, and to permit persons to whom the Textbender Software is furnished to do so, subject to the following conditions: The preceding copyright notice and this permission notice shall be included in all copies or substantial portions of the Textbender Software. THE TEXTBENDER SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE TEXTBENDER SOFTWARE OR THE USE OR OTHER DEALINGS IN THE TEXTBENDER SOFTWARE.

import java.util.prefs.Preferences;


/** Convenience wrapper for preference nodes.
  * Allows you to write code such as <tt>preference.get()</tt>,
  * instead of <tt>preferences.getX('preference',default)</tt>.
  */
public abstract class Preference // Unfortunately, it cannot be done with generics, because java.util.prefs.Preferences does not deal with Objects. So the subclasses handle the typing.
{

    /** Constructs a Preference.
      *
      *     @param preferences per {@linkplain #preferences() preferences}()
      *     @param key per {@linkplain #key() key}()
      */
    public Preference( Preferences preferences, String key )
    {
        this.preferences = preferences;
        this.key = key;
    }



   // ------------------------------------------------------------------------------------


    /** Returns the unique key under which the preference value is stored,
      * per Preferences.put() and get().
      * <p>
      *     It may help to choose keys that are typographically distinct from ordinary names
      *     to guard against inadvertent changes.
      *     So perhaps "USERnAME" instead of "userName".
      *     </p>
      */
    public String key() { return key; }


        protected final String key;



    /** Returns the preference node used for storage.
      */
    public Preferences preferences() { return preferences; }


        protected final Preferences preferences;



    /** Removes this preference. Equivalent to <tt>preferences.remove(key)</tt>
      */
    public void remove() { preferences.remove( key ); }



}