/******************************************************************************* * * * File: Enumerator.java Revision: 1.0 * * * * Purpose: implements an enumeration data type for "Rhino" * * * * Creation: 21.11.2001 Last Modification: 21.11.2001 * * * * Platform: IBM-compatible PC running Windows 98SE * * * * Environment: Java 1.3, Rhino 1.5 * * * * Author: Andreas Rozek Phone: ++49 (711) 6770682 * * Kirschblütenweg 15 Fax: - * * D-70569 Stuttgart EMail: Andreas.Rozek@T-Online.De * * Germany * * * * URL: http://www.Andreas-Rozek.de/ * * * * Copyright: this software is published under the "GNU Lesser General Pub- * * lic License" (see "http://www.fsf.org/copyleft/lesser.html" * * for additional information) * * * * Comments: the specification of this data type combines the "JScript" da- * * ta type "Enumerator" and the "java.util.Enumeration" interface * * * * This version of "Enumerator" has been realized as a Rhino * * "Host Object" with the additional implementation of methods * * from the "Scriptable" interface. * * * *******************************************************************************/ package sunda.rhino.data; import org.mozilla.javascript.*; // Rhino distribution classes import sunda.rhino.*; // basic Rhino extension classes public class Enumerator extends ScriptableObject { /******************************************************************************* * * * Non-Public Class Constants * * * *******************************************************************************/ /**** a shortcut for Rhino's "undefined" object ****/ final static Object undefined = org.mozilla.javascript.Undefined.instance; /**** list of all enumerable ids in this object ****/ final static Object[] SlotNameList = new Object[] { "actualElement", "atEnd", "Count", "equals", "hasMoreElements", "moveFirst", "nextElement", "toString" }; /******************************************************************************* * * * Non-Public Instance Variables * * * *******************************************************************************/ Object[] ItemList; // the sequence of objects within this enumeration int ItemCount; // actual number of elements in "ItemList" int actualIndex; // points to the "current" enumeration item /******************************************************************************* * * * Constructor * * * *******************************************************************************/ public Enumerator () { super(); // just to be complete /**** instantiate an empty enumeration ****/ ItemList = new Object[8]; ItemCount = 0; /**** ...and position it at the beginning ****/ actualIndex = 0; }; public Enumerator (Object[] newItemArray) throws RhinoException { super(); // just to be complete /**** instantiate an enumeration with all elements from "newItemArray" ****/ if ((newItemArray == null) || (newItemArray == undefined)) throw new NullValueException("no \"newItemArray\" given"); ItemCount = newItemArray.length; ItemList = new Object[ItemCount]; java.lang.System.arraycopy(newItemArray,0, ItemList,0, ItemCount); /**** ...and position it at the beginning ****/ actualIndex = 0; }; /******************************************************************************* * * * Public Instance Methods * * * *******************************************************************************/ /******************************************************************************* * * * add adds the given object to this enumeration * * * *******************************************************************************/ public void add (Object newItem) throws RhinoException { add(newItem,false); }; public void add (Object newItem, boolean NullOrUndefinedAllowed) throws RhinoException { if (((newItem == null) || (newItem == undefined)) && !NullOrUndefinedAllowed) throw new NullValueException("no \"newItem\" given"); if (actualIndex > 0) throw new sunda.rhino.IllegalStateException("Enumerator is already within a traversal"); if (ItemCount == ItemList.length) { Object[] newItemList = new Object[ItemCount < 1024 ? ItemCount*2 : ItemCount+1024]; java.lang.System.arraycopy(ItemList,0, newItemList,0, ItemCount); ItemList = newItemList; }; ItemList[ItemCount] = newItem; ItemCount++; }; /******************************************************************************* * * * addContents adds the elements of a given array to this enumeration * * * *******************************************************************************/ public void addContents (Object[] newItemArray) throws RhinoException { addContents(newItemArray,false); }; public void addContents (Object[] newItemArray, boolean NullOrUndefinedAllowed) throws RhinoException { if ((newItemArray == null) || (newItemArray == undefined)) throw new NullValueException("no \"newItemArray\" given"); if (actualIndex > 0) throw new sunda.rhino.IllegalStateException("Enumerator is already within a traversal"); int newItemCount = newItemArray.length; if (ItemCount+newItemCount > ItemList.length) { Object[] newItemList = new Object[ItemCount+newItemCount]; java.lang.System.arraycopy(ItemList,0, newItemList,0, ItemCount); ItemList = newItemList; }; for (int i = 0; i < newItemCount; i++) { if (!NullOrUndefinedAllowed && ((newItemArray[i] == null) || (newItemArray[i] == undefined))) throw new NullValueException("missing element in \"newItemArray\""); }; java.lang.System.arraycopy(newItemArray,0, ItemList,ItemCount, newItemCount); ItemCount+=newItemCount; }; /******************************************************************************* * * * getClassName yields the name of this class under JavaScript * * * *******************************************************************************/ public String getClassName () { return "Enumerator"; }; /******************************************************************************* * * * getIds yields a list of all enumerable slot indices in this object * * * *******************************************************************************/ public Object[] getIds () { return SlotNameList; }; /******************************************************************************* * * * jsConstructor initializes a recently created "Enumerator" instance * * * *******************************************************************************/ public void jsConstructor (Object RhinoArray) throws RhinoException { if ((RhinoArray == null) || (RhinoArray == undefined)) return; /**** check proper argument type ****/ if (!(RhinoArray instanceof NativeArray)) throw new sunda.rhino.IllegalArgumentException("an Enumerator can only be constructed from an array of elements"); /**** copy any array items into the enumeration ****/ ItemCount = (int) ((NativeArray) RhinoArray).jsGet_length(); // "long" would be better... ItemList = new Object[ItemCount]; for (int i = 0; i < ItemCount; i++) { ItemList[i] = ((NativeArray) RhinoArray).get(i,null); }; /**** ...and position it at the beginning ****/ actualIndex = 0; }; /******************************************************************************* * * * jsFunction_atEnd does the "item pointer" point beyond the last element? * * * *******************************************************************************/ public boolean jsFunction_atEnd () { return (actualIndex >= ItemCount); }; /******************************************************************************* * * * jsFunction_equals compares this enumeration with a given object * * * *******************************************************************************/ public boolean jsFunction_equals (Object Candidate) { if (this == Candidate) return true; // check identity first if (!(Candidate instanceof Enumerator)) return false; // incorrect type /**** now compare the two enumeration's contents ****/ if (this.ItemCount != ((Enumerator) Candidate).ItemCount) return false; for (int i = 0; i < ItemCount; i++) { if (!(this.ItemList[i].equals(((Enumerator) Candidate).ItemList[i]))) return false; }; /**** ok - both enumerations seem to be equal ****/ return true; }; /******************************************************************************* * * * jsFunction_hasMoreElements does this enumeration contain further elements? * * * *******************************************************************************/ public boolean jsFunction_hasMoreElements () { return (actualIndex < ItemCount-1); }; /******************************************************************************* * * * jsFunction_moveFirst resets the "item pointer" to the first element * * * *******************************************************************************/ public void jsFunction_moveFirst () { actualIndex = 0; }; /******************************************************************************* * * * jsFunction_moveNext moves "item pointer" to next item of this enumeration * * * *******************************************************************************/ public void jsFunction_moveNext () { if (actualIndex < ItemCount) actualIndex += 1; }; /******************************************************************************* * * * jsFunction_nextElement yields the next element & moves "item pointer" to it * * * *******************************************************************************/ public Object jsFunction_nextElement () { if (actualIndex < ItemCount) actualIndex += 1; return (actualIndex < ItemCount ? ItemList[actualIndex] : undefined); }; /******************************************************************************* * * * jsFunction_toString yields a literal representation of this enumeration * * * *******************************************************************************/ public String jsFunction_toString () { return this.toString(); }; /******************************************************************************* * * * jsGet_actualElement yields the "actual" element of this enumeration * * * *******************************************************************************/ public Object jsGet_actualElement () { return (actualIndex < ItemCount ? ItemList[actualIndex] : undefined); }; /******************************************************************************* * * * jsGet_Count yields the actual number of elements in this enumeration * * * *******************************************************************************/ public int jsGet_Count () { return ItemCount; }; /******************************************************************************* * * * toString yields a literal representation of this enumeration * * * *******************************************************************************/ public String toString () { switch (ItemCount) { case 0: return ""; case 1: return (ItemList[0] == null ? "(null)" : ItemList[0].toString()); default: StringBuffer Result = new StringBuffer("("); Result.append(ItemList[0] == null ? "null" : ItemList[0].toString()); for (int i = 1; i < ItemCount; i++) { Result.append(','); Result.append(ItemList[i] == null ? "null" : ItemList[i].toString()); }; Result.append(')'); return Result.toString(); } }; };