/*

  * Copyright 2007 - 2007 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: AbstractRoot.java,v bc1d5fde7b73 2009/06/01 14:40:54 maxberger $ */

 package net.sourceforge.jeuclid.elements.presentation.general;

 import java.awt.Color;

 import java.awt.FontMetrics;

 import java.awt.Graphics2D;

 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.GraphicsSupport;

 import net.sourceforge.jeuclid.elements.support.attributes.AttributesHelper;

 import net.sourceforge.jeuclid.layout.GraphicsObject;

 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.LineObject;

 import org.apache.batik.dom.AbstractDocument;

 import org.w3c.dom.mathml.MathMLRadicalElement;

 /**

  * common superclass for root like elements (root, sqrt).

  * 

  * @version $Revision: bc1d5fde7b73 $

  */

 public abstract class AbstractRoot extends AbstractJEuclidElement implements

         MathMLRadicalElement {

     private static final String EXTRA_SPACE = "0.1ex";

     private static final String ROOT_WIDTH = "0.5em";

     /**

      * Default constructor. Sets MathML Namespace.

      * 

      * @param qname

      *            Qualified name.

      * @param odoc

      *            Owner Document.

      */

     public AbstractRoot(final String qname, final AbstractDocument odoc) {

         super(qname, odoc);

     }

     /**

      * retrieve the content of this radical element.

      * 

      * @return A List<MathElement> with the contents for this element.

      */

     protected abstract List<LayoutableNode> getContent();

     /** {@inheritDoc} */

     // CHECKSTYLE:OFF

     // This function is too long, but it depends on too many parameters.

     @Override

     protected void layoutStageInvariant(final LayoutView view,

             final LayoutInfo info, final LayoutStage stage,

             final LayoutContext context) {

         // CHECKSTYLE:ON

         // Basic Calculations

         final Graphics2D g = view.getGraphics();

         final LayoutContext now = this.applyLocalAttributesToContext(context);

         final float middleShift = this.getMiddleShift(g, context);

         final float linethickness = GraphicsSupport.lineWidth(now);

         final float extraSpace = AttributesHelper.convertSizeToPt(

                 AbstractRoot.EXTRA_SPACE, now, "");

         final float rootwidth = AttributesHelper.convertSizeToPt(

                 AbstractRoot.ROOT_WIDTH, context, "");

         final Color color = (Color) now.getParameter(Parameter.MATHCOLOR);

         float xPos = linethickness;

         final LayoutableNode index = (LayoutableNode) this.getIndex();

         final List<GraphicsObject> graphicObjects = info.getGraphicObjects();

         graphicObjects.clear();

         // Draw Index

         float indexAscent;

         if (index == null) {

             indexAscent = 0.0f;

         } else {

             final LayoutInfo indexInfo = view.getInfo(index);

             final float indexPos = middleShift + linethickness / 2.0f

                     + extraSpace + indexInfo.getDescentHeight(stage);

             indexInfo.moveTo(xPos, -indexPos, stage);

             xPos += indexInfo.getWidth(stage);

             graphicObjects.add(new LineObject(linethickness, -middleShift,

                     xPos, -middleShift, linethickness, color));

             indexAscent = indexPos + indexInfo.getAscentHeight(stage);

         }

         // Skip Root Space

         xPos += rootwidth;

         // Draw Content below Root

         final float contentStartX = xPos;

         final FontMetrics metrics = this

                 .getFontMetrics(view.getGraphics(), now);

         float maxAscent = metrics.getAscent();

         float maxDescent = metrics.getDescent();

         for (final LayoutableNode child : this.getContent()) {

             final LayoutInfo childInfo = view.getInfo(child);

             childInfo.moveTo(xPos, 0, stage);

             maxAscent = Math.max(maxAscent, childInfo.getAscentHeight(stage));

             maxDescent = Math

                     .max(maxDescent, childInfo.getDescentHeight(stage));

             xPos += childInfo.getWidth(stage);

         }

         xPos += 2 * extraSpace;

         final float topLinePos = maxAscent + 2 * extraSpace + linethickness

                 / 2.0f;

         // Fill in Info

         info.setAscentHeight(Math.max(topLinePos + linethickness / 2.0f,

                 indexAscent), stage);

         info.setDescentHeight(maxDescent + linethickness / 2.0f, stage);

         info.setHorizontalCenterOffset(xPos / 2.0f, stage);

         info.setWidth(xPos + linethickness, stage);

         info.setStretchAscent(maxAscent);

         info.setStretchDescent(maxDescent);

         // Add Root Glyph

         graphicObjects.add(new LineObject(contentStartX - rootwidth,

                 -middleShift, contentStartX - rootwidth / 2.0f, maxDescent,

                 linethickness, color));

         graphicObjects.add(new LineObject(contentStartX - rootwidth / 2.0f,

                 maxDescent, contentStartX, -topLinePos, linethickness, color));

         graphicObjects.add(new LineObject(contentStartX, -topLinePos, xPos,

                 -topLinePos, linethickness, color));

     }

 }