/*

  * Copyright 2002,2004 The Apache Software Foundation.

  * 

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  * 

  *      http://www.apache.org/licenses/LICENSE-2.0

  * 

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.apache.commons.scaffold.sql;

 import java.util.Collection;

 import org.apache.commons.scaffold.lang.Tokens;

 import org.apache.commons.scaffold.lang.ParameterException;

 import org.apache.commons.scaffold.lang.ResourceException;

 import org.apache.commons.scaffold.util.ProcessResult;

 import org.apache.commons.scaffold.util.ProcessResultBase;

 import org.apache.commons.scaffold.util.ResultList;

 import org.apache.commons.scaffold.util.ResultListBase;

 import org.apache.commons.scaffold.util.Scroller;

 import org.apache.commons.scaffold.util.ScrollerBean;

 /**

  * Base class for scrolling searches.

  *

  * @author Ted Husted

  * @version $Revision: 155464 $ $Date: 2005-02-26 13:26:54 +0000 (Sat, 26 Feb 2005) $

  */

 public class ScrollerBeanBase extends StorageBeanBase implements ScrollerBean {

     /**

      * The entry (or page) from which to scroll [1].

      */

     public Integer scrollFrom = new Integer(1);

      // See interface for Javadoc

     public Integer getScrollFrom() {

         return scrollFrom;

     }

      // See interface for Javadoc

     public void setScrollFrom(Integer scrollFrom) {

         this.scrollFrom = scrollFrom;

     }

      // See interface for Javadoc

     public Integer scrollOffset() {

         int offset = getScrollFrom().intValue();

         return new Integer(--offset);

     }

      // See interface for Javadoc

     public int scrollRows() {

         return Scroller.SCROLL_ROWS;

     }

      // See interface for Javadoc

     public String countKey() {

         return null;

     }

      // See interface for Javadoc

     public boolean hasParameter() {

         return false;

     }

      // See interface for Javadoc

     public Object searchValue() {

         return null;

     }

      // See interface for Javadoc

     public boolean isLike() {

         return false;

     }

      // See interface for Javadoc

     public int entryCount() throws ResourceException {

         if (hasParameter()) {

             if (isLike())

                 return count(countKey(),like(searchValue().toString()));

             else

                 return count(countKey(),searchValue());

         }

        return count(countKey());

     }

      // See interface for Javadoc

     public String commandKey() {

         return null;

     }

      // See interface for Javadoc

     public String searchProperty() {

         return null;

     }

      // See interface for Javadoc

     public String searchLabel() {

         return searchProperty();

     }

      // See interface for Javadoc

     public boolean failsOnEmpty () {

         return false;

     }

      // See interface for Javadoc

     public String tokenEmptyMessage() {

         return Tokens.DATA_ACCESS_EMPTY;

     }

      // See interface for Javadoc

     public String tokenEmptyDispatch() {

         return Tokens.FAILURE;

     }

      // See interface for Javadoc

     public Object[] scrollerParams(String parameter) {

         Object[] parameters = null;

         if (hasParameter()) {

             parameters = new Object[3];

             parameters[0] = parameter;

             parameters[1] = scrollOffset();

             parameters[2] = new Integer(scrollRows());

         }

         else {

             parameters = new Object[2];

             parameters[0] = scrollOffset();

             parameters[1] = new Integer(scrollRows());

         }

         return parameters;

     }

      // See interface for Javadoc

     public Collection result(Object target, Object parameter)

             throws ResourceException {

         String param = null;

         if (null!=parameter) {

             if (isLike()) param = like(parameter.toString());

             else param = parameter.toString();

         }

         return findCollection(

             target,

             commandKey(),

             scrollerParams(param)

         );

     }

      // See interface for Javadoc

     public Scroller newScroller(int entries) throws ResourceException {

         Scroller scroller = new Scroller();

         scroller.calculate(

             entries,

             getScrollFrom().intValue(),

             entryCount(),

             scrollRows()

             );

         if (hasParameter()) {

             java.util.Map map = new java.util.HashMap();

             map.put(searchProperty(),searchValue());

             scroller.setParameters(map);

         }

         return scroller;

     }

      // See interface for Javadoc

     public void listLegend(ResultList list) {

         if (hasParameter())

             list.setLegend(searchLabel(),searchValue().toString());

         else

             list.setLegend(searchLabel());

     }

      // See interface for Javadoc

     public ProcessResult scrollerSearch() throws Exception {

         Object key = null;

         if (hasParameter()) {

             key = searchValue();

             if (null==key) {

                 throw new ParameterException();

             }

         }

         ResultList list = new ResultListBase (result(this,key));

         Scroller scroller = newScroller(list.size());

         list.setScroller(scroller);

         ProcessResult result = new ProcessResultBase(list);

         listLegend(list);

         if (failsOnEmpty() && list.isEmpty()) {

             result.addMessage(tokenEmptyMessage());

             result.setDispatch(tokenEmptyDispatch());

         }

         return result;

    } // end scrollerSearch

 } // end ScrollerBeanBase