# MultipleSelectWithValidation.java

    /*
    ** Module   : MultipleSelectWithValidation.java
    ** Abstract : Multi selection list box with validation.
    **
    ** Copyright (c) 2017, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- --------------------------------Description-----------------------------------
    ** 001 HC  20170612 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
    **     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
    **     publicity purposes without written authorization.
    **
    **   2. No Misrepresentation of Affiliation.
    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     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.admin.client.widget;

    import com.google.gwt.editor.client.*;
    import com.google.web.bindery.event.shared.*;
    import org.gwtbootstrap3.client.ui.base.mixin.*;
    import org.gwtbootstrap3.client.ui.form.validator.*;
    import org.gwtbootstrap3.extras.select.client.ui.*;

    import java.util.*;

    /**
     * The class implements multi selection list box widget with blank validation. "Blank" is
     * interpreted as no value selected.
     */
    public class MultipleSelectWithValidation
    extends MultipleSelect
    implements HasBlankValidator<List<String>>,
               HasValidators<List<String>>,
               Editor<List<String>>
    {
       /** The error handling implementation */
       private final ErrorHandlerMixin<List<String>> errorHandlerMixin =
          new ErrorHandlerMixin<>(this);

       /** The validation logic */
       private final BlankValidatorMixin<MultipleSelectWithValidation, List<String>> validatorMixin =
          new BlankValidatorMixin<>(this, errorHandlerMixin.getErrorHandler());

       /**
        * Allow-blank flag getter.
        *
        * @return  see above
        */
       @Override
       public boolean getAllowBlank()
       {
          return validatorMixin.getAllowBlank();
       }

       /**
        * The allow-blank flag setter.
        *
        * @param   allowBlank
        *         the new allow blank flag
        */
       @Override
       public void setAllowBlank(boolean allowBlank)
       {
          validatorMixin.setAllowBlank(allowBlank);
       }

       /**
        * Adds the validator.
        *
        * @param   validator
        *          the validator
        */
       @Override
       public void addValidator(Validator<List<String>> validator)
       {
          validatorMixin.addValidator(validator);
       }

       /**
        * Gets the validate on blur.
        *
        * @return  the validate on blur
        */
       @Override
       public boolean getValidateOnBlur()
       {
          return validatorMixin.getValidateOnBlur();
       }

       /**
        * Removes the validator.
        *
        * @param   validator
        *          the validator
        *
        * @return  <code>true</code>, if successful
        */
       @Override
       public boolean removeValidator(Validator<List<String>> validator)
       {
          return validatorMixin.removeValidator(validator);
       }

       /**
        * Reset the form element to blank and clear error messages.
        */
       @Override
       public void reset()
       {
          validatorMixin.reset();
       }

       /**
        * Sets the validate on blur.
        *
        * @param   validateOnBlur
        *          the new validate on blur
        */
       @Override
       public void setValidateOnBlur(boolean validateOnBlur)
       {
          validatorMixin.setValidateOnBlur(true);
       }

       /**
        * The validators used to validate this object.
        *
        * @param   validators
        *          the new validators
        */
       @Override
       public void setValidators(Validator<List<String>>... validators)
       {
          validatorMixin.setValidators(validators);
       }

       /**
        * Validate the field's value using the supplied validators.
        *
        * @return  <code>true</code>, if valid
        */
       @Override
       public boolean validate()
       {
          return validatorMixin.validate();
       }

       /**
        * Validate the field's value using the supplied validators.
        *
        * @param   show
        *          the error to the user.
        *
        * @return  <code>true</code>, if valid
        */
       @Override
       public boolean validate(boolean show)
       {
          return validatorMixin.validate(show);
       }

       /**
        * Adds a validation changed handler.
        *
        * @param   handler
        *          the handler
        * @return  the handler registration
        */
       @Override
       public HandlerRegistration
       addValidationChangedHandler(ValidationChangedEvent.ValidationChangedHandler handler)
       {
          return validatorMixin.addValidationChangedHandler(handler);
       }
    }