ClipboardManager.java

/*
** Module   : ClipboardManager.java
** Abstract : Implements CLIPBOARD handle.
**
** Copyright (c) 2016-2022, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description---------------------------------------
** 001 SBI 20160601 Created initial version.
** 002 SBI 20180213 Changed java docs.
** 003 CA  20181221 Added MULTIPLE attribute stubs.
** 004 OM  20201203 Fixed handling of READ/ONLY attributes.
** 005 VVT 20221003 CommonHandle.getResourceType() method renamed to resourceType() to prevent conflicts
**                  with namesakes in DMO. See #6694.
*/

/*
** 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.
** 
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**     work or Appropriate Legal Notices displayed by works containing the covered
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*/

package com.goldencode.p2j.util;

import com.goldencode.p2j.security.ContextLocal;
import com.goldencode.p2j.ui.LogicalTerminal;
import com.goldencode.proxy.StaticProxy;

/**
 * Manages clipboard operations from the server.
 */
public class ClipboardManager
{
   /** Saves clipboard resource id. */
   private static final ContextLocal<WorkArea> work = new ContextLocal<WorkArea>()
   {
      /**
       * Initializes the work area, the first time it is requested within a new context.
       *
       * @return   The newly instantiated work area.
       */
      @Override
      protected WorkArea initialValue()
      {
         WorkArea wa = new WorkArea();
         
         return wa;
      }
   };

   /**
    * Gets the system clipboard value invoked by business methods on the server side that use
    * CLIPBOARD:VALUE.
    * 
    * @return   The system clipboard value.
    */
   public static character getClipboardValue()
   {
      return LogicalTerminal.getClient().getClipboardValue();
   }

   /**
    * Sets the system clipboard value invoked by business methods on the server side that set
    * CLIPBOARD:VALUE.
    * 
    * @param    value
    *           The target value to set.
    */
   public static void setClipboardValue(character value)
   {
      // if value is unknown, then value.toJavaType() is null.
      setClipboardValue(value.toJavaType());
   }

   /**
    * Sets the system clipboard value invoked by business methods on the server side that set
    * CLIPBOARD:VALUE.
    * 
    * @param    value
    *           The target value to set.
    */
   public static void setClipboardValue(String value)
   {
      LogicalTerminal.getClient().setClipboardValue(value != null ? value : "");
   }
   /**
    * Getter for the MULTIPLE attribute which specifies whether the user can select multiple
    * rows from the widget or only a single row.
    *
    * @return  value of MULTIPLE attribute.
    */
   public static logical isMultiple()
   {
      UnimplementedFeature.todo("CLIPBOARD:MULTIPLE");
      return new logical();
   }

   /**
    * Set MULTIPLE attribute which specifies whether the user can select multiple rows from the
    * widget or only a single row.
    *
    * @param   multiple
    *          New value for the attribute.
    */
   public static void setMultiple(boolean multiple)
   {
      UnimplementedFeature.todo("CLIPBOARD:MULTIPLE");
   }

   /**
    * Set MULTIPLE attribute which specifies whether the user can select multiple rows from the
    * widget or only a single row.
    *
    * @param   multiple
    *          New value for the attribute.
    */
   public static void setMultiple(logical multiple)
   {
      UnimplementedFeature.todo("CLIPBOARD:MULTIPLE");
   }

   /**
    * Get a the instance for the CLIPBOARD system handle.  Is obtained using
    * a call to the {@link StaticProxy#obtain(Class, Class[])}, using the
    * {@link Clipboard} interface and its methods implemented by these
    * classes: {@link ClipboardManager}, {@link NumberType}.
    * 
    * @return   See above.
    */
   public static handle asHandle()
   {
      WorkArea wa = work.get();

      Class[] classes = 
      {
         ClipboardManager.class,
         NumberType.class
      };

      Clipboard proxy = StaticProxy.obtain(Clipboard.class, classes);

      if (wa.id == null)
      {
         wa.id = handle.resourceId(proxy);
      }

      return new handle(proxy);
   }

   /**
    * Get this resource's ID.
    * 
    * @return   The resource's ID.
    */
   public static Long id()
   {
      WorkArea wa = work.get();
      
      return wa.id;
   }

   /**
    * Set this resource's ID.
    * <p>
    * This is a no-op for system handles.
    *  
    * @param    id
    *           The resource's ID.
    */
   public static void id(long id)
   {
      // no-op
   }

   /**
    * Get the type of its associated handle.
    * 
    * @return   Always return the PSEUDO-WIDGET value.
    */
   public static character resourceType()
   {
      return new character(LegacyResource.PSEUDO_WIDGET);
   }

   /**
    * Implementation for the {@link WrappedResource#valid()} API.
    * 
    * @return   Always true.
    */
   public static boolean valid()
   {
      return true;
   }

   /**
    * Implementation for the {@link WrappedResource#unknown()} API.
    * 
    * @return   Always false.
    */
   public static boolean unknown()
   {
      return false;
   }
   
   /**
    * API needed to implement read-only attribute assignment (a 4GL "feature").
    * 
    * @param    attribute
    *           The attribute's name.
    *           
    * @see      handle#readOnlyError(handle, String)
    */
   public static void readOnlyError(String attribute)
   {
      handle.readOnlyError(asHandle(), attribute);
   }
   
   /**
    * API needed to implement read-only attribute assignment (a 4GL "feature").
    * 
    * @param    attribute
    *           The attribute's name.
    * @param    expr
    *           The value which is attempted to be assigned to the read-only attribute. 
    *
    * @see      handle#readOnlyError(handle, String, Object)
    */
   public static void readOnlyError(String attribute, Object expr)
   {
      handle.readOnlyError(asHandle(), attribute);
   }
   
   /**
    * Stores global data relating to the state of the current context.
    */
   private static class WorkArea
   {
      /** The resource's ID. */
      private Long id = null;
   }
}