org.simantics.r.scl/src/org/simantics/r/scl/variable/RListItemNode.java

   1 package org.simantics.r.scl.variable;\r
   2 \r
   3 import org.rosuda.REngine.REXP;\r
   4 import org.rosuda.REngine.REXPMismatchException;\r
   5 import org.rosuda.REngine.RList;\r
   6 \r
   7 public class RListItemNode implements RVariableNode {\r
   8 \r
   9         private RVariableNode parent;\r
  10         private int index;\r
  11         \r
  12         public RListItemNode(RVariableNode parent, int index) {\r
  13                 this.index = index;\r
  14                 this.parent = parent;\r
  15         }\r
  16 \r
  17         @Override\r
  18         public REXP getValue() {\r
  19                 REXP parentValue = parent.getValue();\r
  20                 if (parentValue == null || ! parentValue.isList())\r
  21                         return null;\r
  22                 \r
  23                 RList list;\r
  24                 try {\r
  25                         list = parentValue.asList();\r
  26                 } catch (REXPMismatchException e) {\r
  27                         // Should never happen\r
  28                         return null;\r
  29                 }\r
  30                 \r
  31                 return list.at(index);\r
  32         }\r
  33 \r
  34         @Override\r
  35         public String getName() {\r
  36                 return RNodeManager.INDEXED_ITEM_NAME_PREFIX + Integer.toString(index);\r
  37         }\r
  38 \r
  39         @Override\r
  40         public RVariableNode getParent() {\r
  41                 return parent;\r
  42         }\r
  43 }\r