/* * BioJava development code * * This code may be freely distributed and modified under the * terms of the GNU Lesser General Public Licence. This should * be distributed with the code. If you do not have a copy, * see: * * http://www.gnu.org/copyleft/lesser.html * * Copyright for this code is held jointly by the individual * authors. These should be listed in @author doc comments. * * For more information on the BioJava project and its aims, * or to join the biojava-l mailing list, visit the home page * at: * * http://www.biojava.org/ * */ package org.biojava.bio.program.tagvalue; import java.util.Set; import org.biojava.utils.ParserException; import org.biojava.utils.SmallSet; /** * Silently drop all tags except those specified, and pass the rest onto a * delegate. * * @author Matthew Pocock * @since 1.2 */ public class TagDropper extends SimpleTagValueWrapper { private final Set tags; private boolean retain; private boolean propagate; { tags = new SmallSet(); retain = true; } public TagDropper() { super(); } /** * Create a new TagDropper that will pass on all retained tags and values to * tvl. Initially, no tags will be retained. * * @param tvl the TagValueListener to inform of all surviving events */ public TagDropper(TagValueListener tvl) { super(tvl); } /** * Add a tag to retain. * * @param tag a tag that will be forwarded to the delegate */ public void addTag(Object tag) { tags.add(tag); } /** * Remove a tag so that it will not be retained. * * @param tag a tag that will not be forwarded to the delegate */ public void removeTag(Object tag) { tags.remove(tag); } /** * Get the complete set of tags that are currently recognized. * * @return the Set of known tags */ public Set getTags() { return tags; } /** * Set wether known tags are to be retained or dropped. * *
* If retain is true, then all known tags will be passed on and all other tags * will be discarded. If retain is true, then all known tags will be dropped * and all others passed on. *
* * @param retain true if the tags are to be retained */ public void setRetain(boolean retain) { this.retain = retain; } /** * Find out if known tags are retained or dropped. * * @return true if values are retained */ public boolean doRetain() { return retain; } public void startTag(Object tag) throws ParserException { propagate = retain == tags.contains(tag); if(propagate) { super.startTag(tag); } } public void endTag() throws ParserException { if(propagate) { super.endTag(); } } public void value(TagValueContext ctxt, Object value) throws ParserException { if(propagate) { super.value(ctxt, value); } } }