# FWDTimer.java

    /*
    ** Module   : FWDTimer.java
    ** Abstract : Interface for Timer FWD extension to 4GL.
    **
    ** Copyright (c) 2017-2018, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- --------------------------------Description-----------------------------------
    ** 001 OM  20170530 First commit.
    ** 002 CA  20180510 Moved ENABLED attribute in its own interface.
    */
    /*
    ** 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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    **     the covered work, without written authorization.
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    **
    **     You may not represent the covered work as solely your work.  All modified
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    **     attribution required in this license.
    */

    package com.goldencode.p2j.extension;

    import com.goldencode.p2j.util.*;

    /**
     * Interface of the FWD TIMER Extension. An {@code FWDTimer} object can be scheduled to run
     * repetitive tasks at fixed intervals. This is not fully compatible with ABL standard language,
     * it is an extension to 4GL specific to FWD.
     */
    @FWDResource
    @LegacyResource(resource = FWDResource.FWD_TIMER)
    public interface FWDTimer
    extends Enabled
    {
       /**
        * Obtain the current {@code interval} between two consecutive events.
        *
        * @return  the current value of {@code interval} property.
        */
       @LegacyAttribute(name = "Interval")
       public integer getInterval();

       /**
        * Sets the current {@code interval} between two consecutive events. If the timer is already
        * {@code enabled}, it will be automatically armed and will fire after {@code interval} millis
        * elapses. Setting it to 0, will stop the timer. Setting to a negative value will lead to
        * an error message to be displayed.
        *
        * @param   interval
        *          The new interval between two timer events, in milliseconds.
        */
       @LegacyAttribute(name = "Interval", setter = true)
       public void setInterval(NumberType interval);

       /**
        * Sets the current {@code interval} between two consecutive events. If the timer is already
        * {@code enabled}, it will be automatically armed and will fire after {@code interval} millis
        * elapses. Setting it to 0, will stop the timer. Setting to a negative value will lead to
        * an error message to be displayed.
        *
        * @param   interval
        *          The new interval between two timer events, in milliseconds.
        */
       @LegacyAttribute(name = "Interval", setter = true)
       public void setInterval(long interval);

       /**
        * Gets the legacy name of the callback procedure to be called at fixed interval when running
        * in FWD extension mode (not as a COM).
        *
        * @return  the legacy name of the callback procedure.
        */
       @LegacyAttribute(name = "Callback")
       public character getCallback();

       /**
        * Sets the legacy name of the callback procedure to be called at fixed interval when running
        * in FWD extension mode (ignored when in COM mode). If set to {@code unknown} the timer will
        * continue 'ticking' but since there is no known peer to call, nothing will happen. This
        * property can be set while the timer is active, without resetting it.
        *
        * @param   callback
        *          the new legacy name of the callback procedure.
        */
       @LegacyAttribute(name = "Callback", setter = true)
       public void setCallback(character callback);

       /**
        * Sets the legacy name of the callback procedure to be called at fixed interval when running
        * in FWD extension mode (ignored when in COM mode). If set to {@code unknown} the timer will
        * continue 'ticking' but since there is no known peer to call, nothing will happen. This
        * property can be set while the timer is active, without resetting it.
        *
        * @param   callback
        *          the new legacy name of the callback procedure.
        */
       @LegacyAttribute(name = "Callback", setter = true)
       public void setCallback(String callback);

       /**
        * Starts the timer. It has the exact effect like setting the {@code enabled} property to
        * {@code true}. Note that timer will not be activated unless the {@code interval} property
        * was set to a strictly positive value.
        */
       @LegacyMethod(name = "Start")
       public void start();

       /**
        * Force the timer to cease firing events. It has the exact effect like setting the
        * {@code enabled} property to {@code false}.
        * <p>
        * The name of the method was selected intentionally for the FWD extension since {@code STOP}
        * would create some syntactic incompatibility with standard ABL attributes.
        */
       @LegacyMethod(name = "Cease")
       public void cease();

       /**
        * Undocumented attribute found by chance. Might as well be either one of:
        * <br> - an attribute of Control Frame COM Object (from {@link ControlFrameComObject});
        * <br> - an attribute of any COM-HANDLE (from {@link comhandle});
        * <br> - id "0" some kind of unknown value for {@code comhandle}-s.
        *
        * @return  Always some kind of "0".
        */
       @LegacyAttribute(name = "COM-HANDLE")
       default public character comHandle()
       {
          return new character("0");
       }
    }