/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* 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 Lesser General Public License for more details.
*
* Copyright (c) 2006 - 2013 Pentaho Corporation and Contributors.  All rights reserved.
*/

package org.pentaho.reporting.libraries.css.resolver.values.computed;

import org.pentaho.reporting.libraries.base.util.DebugLog;
import org.pentaho.reporting.libraries.css.dom.DocumentContext;
import org.pentaho.reporting.libraries.css.dom.LayoutElement;
import org.pentaho.reporting.libraries.css.model.StyleKey;
import org.pentaho.reporting.libraries.css.values.CSSConstant;
import org.pentaho.reporting.libraries.css.values.CSSValue;
import org.pentaho.reporting.libraries.css.values.CSSValueList;


/**
 * Creation-Date: 14.12.2005, 23:08:14
 *
 * @author Thomas Morgner
 */
public abstract class ListOfConstantsResolveHandler extends ConstantsResolveHandler {
  public ListOfConstantsResolveHandler() {
  }

  /**
   * Resolves a single property.
   *
   * @param currentNode
   * @param style
   */
  public void resolve( final DocumentContext process,
                       final LayoutElement currentNode,
                       final StyleKey key ) {
    final CSSValue value = currentNode.getLayoutStyle().getValue( key );
    if ( value == null ) {
      return;
    }
    if ( value instanceof CSSValueList == false ) {
      return;
    }

    final CSSValueList list = (CSSValueList) value;
    final int length = list.getLength();
    if ( length == 0 ) {
      return;
    }

    for ( int i = 0; i < length; i++ ) {
      final CSSValue item = list.getItem( i );
      if ( item instanceof CSSConstant == false ) {
        resolveInvalidItem( process, currentNode, key, i );
      } else {
        resolveItem( process, currentNode, key, i, (CSSConstant) item );
      }
    }
  }

  protected void resolveInvalidItem( final DocumentContext process,
                                     final LayoutElement currentNode,
                                     final StyleKey key,
                                     final int index ) {
    DebugLog.log( "Encountered invalid item in Style " + key + " at index " + index );
  }

  protected abstract boolean resolveItem( final DocumentContext process,
                                          LayoutElement currentNode,
                                          StyleKey key,
                                          int index,
                                          CSSConstant item );
}