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Diffstat (limited to 'libjava/classpath/gnu/javax/swing/text/html/parser/models/list.java')
-rw-r--r-- | libjava/classpath/gnu/javax/swing/text/html/parser/models/list.java | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/javax/swing/text/html/parser/models/list.java b/libjava/classpath/gnu/javax/swing/text/html/parser/models/list.java new file mode 100644 index 000000000..1ff22f8cd --- /dev/null +++ b/libjava/classpath/gnu/javax/swing/text/html/parser/models/list.java @@ -0,0 +1,384 @@ +/* list.java -- + Copyright (C) 2005 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package gnu.javax.swing.text.html.parser.models; + +import gnu.java.lang.CPStringBuilder; + +import java.io.Serializable; + +/** + * Part of the internal representation of the content model. + * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org) + */ +public class list + extends node + implements Serializable +{ + private static final long serialVersionUID = 1; + + /** + * Setting to true means that the list nodes must always be connected + * by the same operation. This is far safer and clearer, but not + * required by default standard. + */ + public static boolean CLEAR; + + /** + * A list of nodes. + */ + public final node[] nodes; + + /** + * Creates a new model list that is a member of some enclosing list. + * @param binary_operator An operator with that this list is connected + * with other members of the enclosing list. + * @param unary_operator The unary operator for this list. + * @param a_nodes The nodes inside this list. + */ + public list(char binary_operator, char unary_operator, node[] a_nodes) + { + super(binary_operator, unary_operator, a_nodes); + nodes = a_nodes; + } + + /** + * Creates a new model list. Assigns the previous field. + * @param a_nodes The nodes for this list. + * @throws an error if the node elements are connected by the + * different operations. This is not supported, use grouping. + */ + public list(node[] a_nodes) + throws Error + { + this(',', (char) 0, a_nodes); + + int operation = nodes [ 0 ].binary; + + for (int i = 0; i < nodes.length; i++) + { + if (CLEAR && nodes [ i ].binary != operation) + throw new Error("List members can only be connected by " + + "the same operation, use grouping" + ); + + if (i > 0) + nodes [ i ].previous = nodes [ i - 1 ]; + } + } + + /** + * Returns true if all members in the list are closed. + */ + public boolean isClosed() + { + if (super.isClosed()) + return true; + for (int i = 0; i < nodes.length; i++) + { + if (!nodes [ i ].isClosed()) + return false; + } + return true; + } + + /** + * Find the token that could match as the next token in + * the token list. + * + * @return Such token object or null if none is found. + */ + public Object findFreeNode() + { + Object fn; + for (int j = 0; j < nodes.length; j++) + { + if (!nodes [ j ].isClosed()) + { + fn = nodes [ j ].findFreeNode(); + if (fn != null) + return fn; + } + } + return null; + } + + /** + * Tries to match this list agains the given token sequence. + * @param tokens the sequence of the tokens to match. + * @return true if the valid match is found. + */ + public boolean matches(Object[] tokens) + { + reset(); + + Object x; + boolean m; + boolean matched = false; + + for (int i = 0; i < tokens.length; i++) + { + matched = false; + x = tokens [ i ]; + + nodescan: + for (int j = 0; j < nodes.length; j++) + { + if (!nodes [ j ].isClosed()) + { + m = nodes [ j ].performMatch(x); + + if (m) + { + matched = true; + break nodescan; + } + } + } + if (!matched) + return false; + } + + boolean valid = true; + + for (int i = 0; i < nodes.length; i++) + { + if (!nodes [ i ].valid()) + valid = false; + } + + return valid; + } + + /** + * The list never closes, despite it is trated as closed + * if all members in the list are closed. + * @return false. + */ + public boolean mustClose() + { + return false; + } + + /** + * Perform a match operation for the single token + * against this list. + * @param token a token to match. + * @return true if the match is found. + */ + public boolean performMatch(Object token) + { + boolean ok = false; + Matching: + for (int i = 0; i < nodes.length; i++) + { + ok = nodes [ i ].performMatch(token); + + if (ok) + break Matching; + } + + if (ok) + matches(); + + return ok; + } + + /** + * Prepeares the list for the next matching operation. + */ + public void reset() + { + super.reset(); + for (int i = 0; i < nodes.length; i++) + nodes [ i ].reset(); + } + + /** + * Check if the provided token can match as a next token in the + * list. In the case of match, the list state changes, moving + * current position after the matched token. However if this method + * returns a suggested new token to insert before the provided one, + * the state of the list does not change. + * @return Boolean.TRUE if the match is found, + * Boolean.FALSE if the match is not possible and no token can be + * inserted to make the match valid. Otherwise, returns the + * token object that can be inserted before the last token in the + * list, probably (not for sure) making the match valid. + * If the object is an instance of Element or TagElement, + * it is first ensured that the object flag "omit start" is set. + */ + public Object show(Object x) + { + boolean m; + boolean matched = false; + + nodescan: + for (int j = 0; j < nodes.length; j++) + { + if (!nodes [ j ].isClosed()) + { + m = nodes [ j ].performMatch(x); + + if (m) + { + matched = true; + break nodescan; + } + else + { + // For comma operation, only first not closed + // node must be tested for a match. + // unless it allows matching zero times. + if (binary == ',' && + !(nodes [ j ].unary == '?' || nodes [ j ].unary == '*') + ) + break nodescan; + } + } + } + + if (!matched) + { + // Find and return that would be matched. + Object freeNode = findFreeNode(); + if (freeNode == null) + return Boolean.FALSE; + else + return freeNode; + } + + for (int i = 0; i < nodes.length; i++) + if (!nodes [ i ].validPreliminary()) + { + return Boolean.FALSE; + } + + return Boolean.TRUE; + } + + /** + * Returns a string representation of the list. + * @return String representation, similar to BNF expression. + */ + public String toString() + { + CPStringBuilder b = new CPStringBuilder(); + b.append(" ( "); + for (int i = 0; i < nodes.length; i++) + { + if (i > 0) + b.append(" " + (char) nodes [ i ].binary + " "); + b.append(nodes [ i ]); + } + + b.append(" )"); + if (unary != 0) + b.append((char) unary); + else + b.append(' '); + return b.toString(); + } + + /** + * Returns true if all memebers in the list are valid. + */ + public boolean valid() + { + for (int i = 0; i < nodes.length; i++) + { + if (!nodes [ i ].valid()) + return false; + } + return true; + } + + /** + * Returns true if all memebers in the list are either valid + * or unvisited. The unvisited members can become valid after + * more tokens will be shown. + */ + public boolean validPreliminary() + { + if (silenceAllowed()) + { + boolean everVisited = false; + for (int i = 0; i < nodes.length; i++) + { + if (nodes [ i ].visits > 0) + { + everVisited = true; + break; + } + } + if (!everVisited) + return true; + } + + for (int i = 0; i < nodes.length; i++) + { + if (!nodes [ i ].validPreliminary()) + return false; + } + return true; + } + + /** + * Closes all members in the list. + */ + protected void close() + { + super.close(); + for (int i = 0; i < nodes.length; i++) + { + nodes [ i ].close(); + } + } + + /** + * Compare given token with the token of this node. + * If the token represents a <code>list</code>, the call may be + * delegeted to the child subnodes. + * @param a_token A token to compare. + * @return True if the token matches the token of this node. + */ + protected boolean compare(Object a_token) + { + return performMatch(a_token); + } +} |