michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.message;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.util.CharArrayBuffer;
michael@0: 
michael@0: /**
michael@0:  * This class represents a context of a parsing operation:
michael@0:  * <ul>
michael@0:  *  <li>the current position the parsing operation is expected to start at</li>
michael@0:  *  <li>the bounds limiting the scope of the parsing operation</li>
michael@0:  * </ul>
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public class ParserCursor {
michael@0: 
michael@0:     private final int lowerBound;
michael@0:     private final int upperBound;
michael@0:     private int pos;
michael@0: 
michael@0:     public ParserCursor(int lowerBound, int upperBound) {
michael@0:         super();
michael@0:         if (lowerBound < 0) {
michael@0:             throw new IndexOutOfBoundsException("Lower bound cannot be negative");
michael@0:         }
michael@0:         if (lowerBound > upperBound) {
michael@0:             throw new IndexOutOfBoundsException("Lower bound cannot be greater then upper bound");
michael@0:         }
michael@0:         this.lowerBound = lowerBound;
michael@0:         this.upperBound = upperBound;
michael@0:         this.pos = lowerBound;
michael@0:     }
michael@0: 
michael@0:     public int getLowerBound() {
michael@0:         return this.lowerBound;
michael@0:     }
michael@0: 
michael@0:     public int getUpperBound() {
michael@0:         return this.upperBound;
michael@0:     }
michael@0: 
michael@0:     public int getPos() {
michael@0:         return this.pos;
michael@0:     }
michael@0: 
michael@0:     public void updatePos(int pos) {
michael@0:         if (pos < this.lowerBound) {
michael@0:             throw new IndexOutOfBoundsException("pos: "+pos+" < lowerBound: "+this.lowerBound);
michael@0:         }
michael@0:         if (pos > this.upperBound) {
michael@0:             throw new IndexOutOfBoundsException("pos: "+pos+" > upperBound: "+this.upperBound);
michael@0:         }
michael@0:         this.pos = pos;
michael@0:     }
michael@0: 
michael@0:     public boolean atEnd() {
michael@0:         return this.pos >= this.upperBound;
michael@0:     }
michael@0: 
michael@0:     public String toString() {
michael@0:         CharArrayBuffer buffer = new CharArrayBuffer(16);
michael@0:         buffer.append('[');
michael@0:         buffer.append(Integer.toString(this.lowerBound));
michael@0:         buffer.append('>');
michael@0:         buffer.append(Integer.toString(this.pos));
michael@0:         buffer.append('>');
michael@0:         buffer.append(Integer.toString(this.upperBound));
michael@0:         buffer.append(']');
michael@0:         return buffer.toString();
michael@0:     }
michael@0: 
michael@0: }