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    1   /*
    2    * Copyright 1999-2004 The Apache Software Foundation
    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  package org.apache.commons.jxpath.ri.axes;
    17
    18  import org.apache.commons.jxpath.ri.EvalContext;
    19  import org.apache.commons.jxpath.ri.compiler.NodeTest;
    20  import org.apache.commons.jxpath.ri.model.NodePointer;
    21
    22  /***
    23   * EvalContext that walks the "parent::" axis.
    24   *
    25   * @author Dmitri Plotnikov
    26   * @version $Revision: 1.15 $ $Date: 2004/03/25 03:49:50 $
    27   */
    28  public class ParentContext extends EvalContext {
    29      private NodeTest nodeTest;
    30      private boolean setStarted = false;
    31      private NodePointer currentNodePointer;
    32
    33      public ParentContext(EvalContext parentContext, NodeTest nodeTest) {
    34          super(parentContext);
    35          this.nodeTest = nodeTest;
    36      }
    37
    38      public NodePointer getCurrentNodePointer() {
    39          return currentNodePointer;
    40      }
    41
    42      public int getCurrentPosition() {
    43          return 1;
    44      }
    45
    46      public int getDocumentOrder() {
    47          return -1;
    48      }
    49
    50      public void reset() {
    51          super.reset();
    52          setStarted = false;
    53      }
    54
    55      public boolean setPosition(int position) {
    56          super.setPosition(position);
    57          return position == 1;
    58      }
    59
    60      public boolean nextNode() {
    61          // Each set contains exactly one node: the parent
    62          if (setStarted) {
    63              return false;
    64          }
    65          setStarted = true;
    66          NodePointer thisLocation = parentContext.getCurrentNodePointer();
    67          currentNodePointer = thisLocation.getImmediateParentPointer();
    68          while (currentNodePointer != null
    69              && currentNodePointer.isContainer()) {
    70              currentNodePointer = currentNodePointer.getImmediateParentPointer();
    71          }
    72          if (currentNodePointer != null
    73              && currentNodePointer.testNode(nodeTest)) {
    74              position++;
    75              return true;
    76          }
    77          return false;
    78      }
    79  }