Subversion Repositories mkgmap

/*
 * Copyright (C) 2008 Steve Ratcliffe
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  This program 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.
 *
 *
 * Author: Steve Ratcliffe
 * Create date: 03-Nov-2008
 */
package uk.me.parabola.mkgmap.osmstyle.eval;

import uk.me.parabola.mkgmap.reader.osm.Element;

/**
 * Holds a string value; the name of a tag or the value of a tag for example.
 *
 * @author Steve Ratcliffe
 */
public class ValueOp extends AbstractOp {
        private final String value;

        public ValueOp(String value) {
                setType(NodeType.VALUE);
                this.value = value;
        }

        public boolean eval(Element el) {
                return true;
        }

        public int priority() {
                return 0;
        }

        @Override
        public String value(Element el) {
                return value;
        }

        /**
         * Get the saved value.
         * For a base ValueOp this returns the same as {@link #value} but in classes where value is
         * overridden it returns the base value.
         */
        public final String getKeyValue() {
                return value;
        }

        public boolean isValue(String val) {
                return value.equals(val);
        }

        /**
         * Returns true if you can index the rule from this value.
         * This should almost always return false, override in subclasses that are indexable.
         */
        public boolean isIndexable() {
                return false;
        }

        public String toString() {
                StringBuilder sb = new StringBuilder();
                boolean needQuote = false;
                boolean needDouble = false;
                for (char c : value.toCharArray()) {
                        if ( !(Character.isLetterOrDigit(c) || c == '_'))
                                needQuote = true;
                        if (c == '\'') {
                                needQuote = true;
                                needDouble = true;
                        }
                        sb.append(c);
                }
                if (needQuote) {
                        char q = needDouble ? '"' : '\'';
                        sb.insert(0, q);
                        sb.append(q);
                }
                return sb.toString();
        }
}