/**
   * Returns all of the possible subtypes of this type hierarchy. Returns null if they could not be
   * determine.
   */
  private String[] determinePossibleSubTypes(final HashSet localTypes, IProgressMonitor monitor) {

    class PathCollector implements IPathRequestor {
      HashSet paths = new HashSet(10);

      public void acceptPath(String path, boolean containsLocalTypes) {
        this.paths.add(path);
        if (containsLocalTypes) {
          localTypes.add(path);
        }
      }
    }
    PathCollector collector = new PathCollector();

    try {
      if (monitor != null) monitor.beginTask("", MAXTICKS); // $NON-NLS-1$
      searchAllPossibleSubTypes(
          getType(),
          this.scope,
          this.binariesFromIndexMatches,
          collector,
          IJavaSearchConstants.WAIT_UNTIL_READY_TO_SEARCH,
          monitor);
    } finally {
      if (monitor != null) monitor.done();
    }

    HashSet paths = collector.paths;
    int length = paths.size();
    String[] result = new String[length];
    int count = 0;
    for (Iterator iter = paths.iterator(); iter.hasNext(); ) {
      result[count++] = (String) iter.next();
    }
    return result;
  }
  private void buildForProject(
      JavaProject project,
      ArrayList potentialSubtypes,
      org.eclipse.jdt.core.ICompilationUnit[] workingCopies,
      HashSet localTypes,
      IProgressMonitor monitor)
      throws JavaModelException {
    // resolve
    int openablesLength = potentialSubtypes.size();
    if (openablesLength > 0) {
      // copy vectors into arrays
      Openable[] openables = new Openable[openablesLength];
      potentialSubtypes.toArray(openables);

      // sort in the order of roots and in reverse alphabetical order for .class file
      // since requesting top level types in the process of caching an enclosing type is
      // not supported by the lookup environment
      IPackageFragmentRoot[] roots = project.getPackageFragmentRoots();
      int rootsLength = roots.length;
      final HashtableOfObjectToInt indexes = new HashtableOfObjectToInt(openablesLength);
      for (int i = 0; i < openablesLength; i++) {
        IJavaElement root = openables[i].getAncestor(IJavaElement.PACKAGE_FRAGMENT_ROOT);
        int index;
        for (index = 0; index < rootsLength; index++) {
          if (roots[index].equals(root)) break;
        }
        indexes.put(openables[i], index);
      }
      Arrays.sort(
          openables,
          new Comparator() {
            public int compare(Object a, Object b) {
              int aIndex = indexes.get(a);
              int bIndex = indexes.get(b);
              if (aIndex != bIndex) return aIndex - bIndex;
              return ((Openable) b).getElementName().compareTo(((Openable) a).getElementName());
            }
          });

      IType focusType = getType();
      boolean inProjectOfFocusType =
          focusType != null && focusType.getJavaProject().equals(project);
      org.eclipse.jdt.core.ICompilationUnit[] unitsToLookInside = null;
      if (inProjectOfFocusType) {
        org.eclipse.jdt.core.ICompilationUnit unitToLookInside = focusType.getCompilationUnit();
        if (unitToLookInside != null) {
          int wcLength = workingCopies == null ? 0 : workingCopies.length;
          if (wcLength == 0) {
            unitsToLookInside = new org.eclipse.jdt.core.ICompilationUnit[] {unitToLookInside};
          } else {
            unitsToLookInside = new org.eclipse.jdt.core.ICompilationUnit[wcLength + 1];
            unitsToLookInside[0] = unitToLookInside;
            System.arraycopy(workingCopies, 0, unitsToLookInside, 1, wcLength);
          }
        } else {
          unitsToLookInside = workingCopies;
        }
      }

      SearchableEnvironment searchableEnvironment =
          project.newSearchableNameEnvironment(unitsToLookInside);
      this.nameLookup = searchableEnvironment.nameLookup;
      Map options = project.getOptions(true);
      // disable task tags to speed up parsing
      options.put(JavaCore.COMPILER_TASK_TAGS, ""); // $NON-NLS-1$
      this.hierarchyResolver =
          new HierarchyResolver(searchableEnvironment, options, this, new DefaultProblemFactory());
      if (focusType != null) {
        Member declaringMember = ((Member) focusType).getOuterMostLocalContext();
        if (declaringMember == null) {
          // top level or member type
          if (!inProjectOfFocusType) {
            char[] typeQualifiedName = focusType.getTypeQualifiedName('.').toCharArray();
            String[] packageName = ((PackageFragment) focusType.getPackageFragment()).names;
            if (searchableEnvironment.findType(typeQualifiedName, Util.toCharArrays(packageName))
                == null) {
              // focus type is not visible in this project: no need to go further
              return;
            }
          }
        } else {
          // local or anonymous type
          Openable openable;
          if (declaringMember.isBinary()) {
            openable = (Openable) declaringMember.getClassFile();
          } else {
            openable = (Openable) declaringMember.getCompilationUnit();
          }
          localTypes = new HashSet();
          localTypes.add(openable.getPath().toString());
          this.hierarchyResolver.resolve(new Openable[] {openable}, localTypes, monitor);
          return;
        }
      }
      this.hierarchyResolver.resolve(openables, localTypes, monitor);
    }
  }