# 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.
    **
    **     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
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
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    **
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    **
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    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */

    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;
       }
    }