com/intendico/gorite/SequenceGoal.java

   1 /*********************************************************************
   2 Copyright 2012, Ralph Ronnquist.
   3
   4 This file is part of GORITE.
   5
   6 GORITE is free software: you can redistribute it and/or modify it
   7 under the terms of the Lesser GNU General Public License as published
   8 by the Free Software Foundation, either version 3 of the License, or
   9 (at your option) any later version.
  10
  11 GORITE is distributed in the hope that it will be useful, but WITHOUT
  12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  14 License for more details.
  15
  16 You should have received a copy of the Lesser GNU General Public
  17 License along with GORITE.  If not, see <http://www.gnu.org/licenses/>.
  18 **********************************************************************/
  19
  20 package com.intendico.gorite;
  21
  22 import com.intendico.data.Query;
  23 import com.intendico.data.Ref;
  24
  25 import java.util.HashSet;
  26 import java.util.Iterator;
  27 import java.util.Vector;
  28
  29 /**
  30  * A SequenceGoal is achieved by means of achieving its sub goals in
  31  * order. The goal fails when and if any sub goal fails.
  32  */
  33 public class SequenceGoal extends Goal {
  34
  35     /**
  36      * Constructor.
  37      */
  38     public SequenceGoal(String n,Goal [] sg) {
  39         super( n, sg );
  40     }
  41
  42     /**
  43      * Convenience constructor without sub goals.
  44      */
  45     public SequenceGoal(String n) {
  46         this( n, null );
  47     }
  48
  49     /**
  50      * Creates and returns an instance object for achieving
  51      * a SequenceGoal.
  52      */
  53     public Instance instantiate(String head,Data d) {
  54         return new SequenceInstance( head );
  55     }
  56
  57     /**
  58      * Implements sequential goal execution.
  59      */
  60     public class SequenceInstance extends Instance {
  61
  62         /**
  63          * Constructor.
  64          */
  65         public SequenceInstance(String h) {
  66             super( h );
  67         }
  68
  69         /**
  70          * Keeps the currently ongoing subgoal instance
  71          */
  72         public Instance ongoing = null;
  73
  74         /**
  75          * Index of the currently ongoing sub goal.
  76          */
  77         public int index = 0;
  78
  79         /**
  80          * Cancels execution.
  81          */
  82         public void cancel() {
  83             super.cancel();
  84             if ( ongoing != null )
  85                 ongoing.cancel();
  86         }
  87
  88         /**
  89          * Instantiates and performs sub goals in sequence.
  90          */
  91         public States action(String head,Data d)
  92             throws LoopEndException, ParallelEndException {
  93             Goal [] subgoals = getGoalSubgoals();
  94             if ( subgoals == null )
  95                 return super.action( head, d );
  96             while ( index < subgoals.length ) {
  97                 if ( ongoing == null ) {
  98                     ongoing = subgoals[ index ].instantiate(
  99                         head + "." + index, d );
 100                 }
 101                 States s = ongoing.perform( d );
 102                 if ( s != States.PASSED )
 103                     return s;
 104                 index += 1;
 105                 ongoing = null;
 106             }
 107             return States.PASSED;
 108         }
 109     }
 110
 111 }