1 /* 2 * Copyright 2002 - 2007 JEuclid, http://jeuclid.sf.net 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /* $Id: AbstractElementWithDelegates.java,v bc1d5fde7b73 2009/06/01 14:40:54 maxberger $ */ 18 19 package net.sourceforge.jeuclid.elements; 20 21 import java.util.List; 22 23 import net.sourceforge.jeuclid.elements.presentation.AbstractContainer; 24 import net.sourceforge.jeuclid.layout.LayoutableNode; 25 26 import org.apache.batik.dom.AbstractDocument; 27 28 /** 29 * Generic class for all mathobjects that can be represented using other Math 30 * objects. These math objects use a delegates for the actual display and 31 * calculations. 32 * <p> 33 * To use this class, overwrite {@link #createDelegates()} to create the 34 * delegate objects. 35 * 36 * @version $Revision: bc1d5fde7b73 $ 37 */ 38 public abstract class AbstractElementWithDelegates extends AbstractContainer { 39 40 // TODO: Re-Enable resetting delegates on changeHook! 41 private List<LayoutableNode> delegates; 42 43 /** 44 * Default constructor. Sets MathML Namespace. 45 * 46 * @param qname 47 * Qualified name. 48 * @param odoc 49 * Owner Document. 50 */ 51 public AbstractElementWithDelegates(final String qname, 52 final AbstractDocument odoc) { 53 super(qname, odoc); 54 } 55 56 /** 57 * Overwrite this function in your implementation. 58 * 59 * @return a MathObject representing the real contents. 60 */ 61 protected abstract List<LayoutableNode> createDelegates(); 62 63 private void prepareDelegates() { 64 if (this.delegates == null) { 65 this.delegates = this.createDelegates(); 66 for (final LayoutableNode element : this.delegates) { 67 ((JEuclidElement) element).setFakeParent(this); 68 } 69 } 70 } 71 72 /** {@inheritDoc} */ 73 @Override 74 public List<LayoutableNode> getChildrenToLayout() { 75 this.prepareDelegates(); 76 return this.delegates; 77 } 78 79 /** {@inheritDoc} */ 80 @Override 81 public List<LayoutableNode> getChildrenToDraw() { 82 this.prepareDelegates(); 83 return this.delegates; 84 } 85 86 }