/*
    * Copyright 2007 - 2009 JEuclid, http://jeuclid.sf.net
    * 
    * 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.
   */
  
  /* $Id: AbstractTokenWithTextLayout.java,v 923658a2b249 2009/09/11 09:57:31 max $ */
  
  package net.sourceforge.jeuclid.elements.presentation.token;
  
  import java.awt.Color;
  import java.awt.Graphics2D;
  import java.awt.font.TextLayout;
  import java.text.AttributedCharacterIterator;
  import java.text.AttributedString;
  import java.util.Collections;
  import java.util.List;
  
  import net.sourceforge.jeuclid.LayoutContext;
  import net.sourceforge.jeuclid.context.Parameter;
  import net.sourceforge.jeuclid.elements.AbstractJEuclidElement;
  import net.sourceforge.jeuclid.elements.support.text.StringUtil;
  import net.sourceforge.jeuclid.layout.LayoutInfo;
  import net.sourceforge.jeuclid.layout.LayoutStage;
  import net.sourceforge.jeuclid.layout.LayoutView;
  import net.sourceforge.jeuclid.layout.LayoutableNode;
  import net.sourceforge.jeuclid.layout.TextObject;
  
  import org.apache.batik.dom.AbstractDocument;
  import org.w3c.dom.mathml.MathMLPresentationToken;
  
  /**
   * Common functionality for all tokens based on a text layout.
   * 
   * @version $Revision: 923658a2b249 $
   */
  public abstract class AbstractTokenWithTextLayout extends
          AbstractJEuclidElement implements MathMLPresentationToken {
  
      private static final long serialVersionUID = 1L;
  
      /**
       * Default constructor. Sets MathML Namespace.
       * 
       * @param qname
       *            Qualified name.
       * @param odoc
       *            Owner Document.
       */
      public AbstractTokenWithTextLayout(final String qname,
              final AbstractDocument odoc) {
          super(qname, odoc);
      }
  
      /** {@inheritDoc} */
      @Override
      public void layoutStageInvariant(final LayoutView view,
              final LayoutInfo info, final LayoutStage stage,
              final LayoutContext context) {
          final Graphics2D g = view.getGraphics();
          final TextLayout t = this.produceTextLayout(g, context);
          if (t != null) {
              final StringUtil.TextLayoutInfo tli = StringUtil.getTextLayoutInfo(
                      t, false);
              info.setAscentHeight(tli.getAscent(), stage);
              info.setDescentHeight(tli.getDescent(), stage);
              final float width = tli.getWidth();
              info.setHorizontalCenterOffset(width / 2.0f, stage);
              info.setWidth(width, stage);
              info.setGraphicsObject(new TextObject(t, tli.getOffset(),
                      (Color) this.applyLocalAttributesToContext(context)
                              .getParameter(Parameter.MATHCOLOR)));
          }
      }
  
      private TextLayout produceTextLayout(final Graphics2D g2d,
              final LayoutContext context) {
          TextLayout layout;
          final LayoutContext now = this.applyLocalAttributesToContext(context);
  
          final AttributedCharacterIterator aci = StringUtil
                  .textContentAsAttributedCharacterIterator(now, this, this, 1.0f);
  
          if (aci.getBeginIndex() == aci.getEndIndex()) {
              return null;
          } else {
              layout = StringUtil.createTextLayoutFromAttributedString(g2d,
                      new AttributedString(aci), now);
              return layout;
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public List<LayoutableNode> getChildrenToLayout() {
         return Collections.emptyList();
     }
 
     /** {@inheritDoc} */
     @Override
     public List<LayoutableNode> getChildrenToDraw() {
         return Collections.emptyList();
     }
 
 }