AttributedStringIterator(Attribute[] attributes,
    int beginIndex,
    int endIndex) 
{
            if (beginIndex <  0 || beginIndex  > endIndex || endIndex  > length()) {
                throw new IllegalArgumentException("Invalid substring range");
            }
            this.beginIndex = beginIndex;
            this.endIndex = endIndex;
            this.currentIndex = beginIndex;
            updateRunInfo();
            if (attributes != null) {
                relevantAttributes = (Attribute[]) attributes.clone();
            }
}

 public Object clone() 
{
            try {
                AttributedStringIterator other = (AttributedStringIterator) super.clone();
                return other;
            }
            catch (CloneNotSupportedException e) {
                throw new InternalError();
            }
}

 public char current() 
{
            if (currentIndex == endIndex) {
                return DONE;
            } else {
                return charAt(currentIndex);
            }
}

 public boolean equals(Object obj) 
{
            if (this == obj) {
                return true;
            }
            if (!(obj instanceof AttributedStringIterator)) {
                return false;
            }
            AttributedStringIterator that = (AttributedStringIterator) obj;
            if (AttributedString.this != that.getString())
                return false;
            if (currentIndex != that.currentIndex || beginIndex != that.beginIndex || endIndex != that.endIndex)
                return false;
            return true;
}

 public char first() 
{
            return internalSetIndex(beginIndex);
}

 public Set getAllAttributeKeys() 
{
            // ??? This should screen out attribute keys that aren't relevant to the client
            if (runAttributes == null) {
                // ??? would be nice to return null, but current spec doesn't allow it
                // returning HashSet saves us from dealing with emptiness
                return new HashSet();
            }
            synchronized (AttributedString.this) {
                // ??? should try to create this only once, then update if necessary,
                // and give callers read-only view
                Set keys = new HashSet();
                int i = 0;
                while (i <  runCount) {
                    if (runStarts[i] <  endIndex && (i == runCount - 1 || runStarts[i + 1]  > beginIndex)) {
                        Vector currentRunAttributes = runAttributes[i];
                        if (currentRunAttributes != null) {
                            int j = currentRunAttributes.size();
                            while (j--  > 0) {
                                keys.add(currentRunAttributes.get(j));
                            }
                        }
                    }
                    i++;
                }
                return keys;
            }
}

 public Object getAttribute(Attribute attribute) 
{
            int runIndex = currentRunIndex;
            if (runIndex <  0) {
                return null;
            }
            return AttributedString.this.getAttributeCheckRange(attribute, runIndex, beginIndex, endIndex);
}

 public Map getAttributes() 
{
            if (runAttributes == null || currentRunIndex == -1 || runAttributes[currentRunIndex] == null) {
                // ??? would be nice to return null, but current spec doesn't allow it
                // returning Hashtable saves AttributeMap from dealing with emptiness
                return new Hashtable();
            }
            return new AttributeMap(currentRunIndex, beginIndex, endIndex);
}

 public int getBeginIndex() 
{
            return beginIndex;
}

 public int getEndIndex() 
{
            return endIndex;
}

 public int getIndex() 
{
            return currentIndex;
}

 public int getRunLimit() 
{
            return currentRunLimit;
}

 public int getRunLimit(Attribute attribute) 
{
            if (currentRunLimit == endIndex || currentRunIndex == -1) {
                return currentRunLimit;
            } else {
                Object value = getAttribute(attribute);
                int runLimit = currentRunLimit;
                int runIndex = currentRunIndex;
                while (runLimit <  endIndex &&
                        valuesMatch(value, AttributedString.this.getAttribute(attribute, runIndex + 1))) {
                    runIndex++;
                    runLimit = runIndex <  runCount - 1 ? runStarts[runIndex + 1] : endIndex;
                }
                if (runLimit  > endIndex) {
                    runLimit = endIndex;
                }
                return runLimit;
            }
}

 public int getRunLimit(Set attributes) 
{
            if (currentRunLimit == endIndex || currentRunIndex == -1) {
                return currentRunLimit;
            } else {
                int runLimit = currentRunLimit;
                int runIndex = currentRunIndex;
                while (runLimit <  endIndex &&
                        AttributedString.this.attributeValuesMatch(attributes, currentRunIndex, runIndex + 1)) {
                    runIndex++;
                    runLimit = runIndex <  runCount - 1 ? runStarts[runIndex + 1] : endIndex;
                }
                if (runLimit  > endIndex) {
                    runLimit = endIndex;
                }
                return runLimit;
            }
}

 public int getRunStart() 
{
            return currentRunStart;
}

 public int getRunStart(Attribute attribute) 
{
            if (currentRunStart == beginIndex || currentRunIndex == -1) {
                return currentRunStart;
            } else {
                Object value = getAttribute(attribute);
                int runStart = currentRunStart;
                int runIndex = currentRunIndex;
                while (runStart  > beginIndex &&
                        valuesMatch(value, AttributedString.this.getAttribute(attribute, runIndex - 1))) {
                    runIndex--;
                    runStart = runStarts[runIndex];
                }
                if (runStart <  beginIndex) {
                    runStart = beginIndex;
                }
                return runStart;
            }
}

 public int getRunStart(Set attributes) 
{
            if (currentRunStart == beginIndex || currentRunIndex == -1) {
                return currentRunStart;
            } else {
                int runStart = currentRunStart;
                int runIndex = currentRunIndex;
                while (runStart  > beginIndex &&
                        AttributedString.this.attributeValuesMatch(attributes, currentRunIndex, runIndex - 1)) {
                    runIndex--;
                    runStart = runStarts[runIndex];
                }
                if (runStart <  beginIndex) {
                    runStart = beginIndex;
                }
                return runStart;
            }
}

 public int hashCode() 
{
            return text.hashCode() ^ currentIndex ^ beginIndex ^ endIndex;
}

 public char last() 
{
            if (endIndex == beginIndex) {
                return internalSetIndex(endIndex);
            } else {
                return internalSetIndex(endIndex - 1);
            }
}

 public char next() 
{
            if (currentIndex <  endIndex) {
                return internalSetIndex(currentIndex + 1);
            }
            else {
                return DONE;
            }
}

 public char previous() 
{
            if (currentIndex  > beginIndex) {
                return internalSetIndex(currentIndex - 1);
            }
            else {
                return DONE;
            }
}

 public char setIndex(int position) 
{
            if (position <  beginIndex || position  > endIndex)
                throw new IllegalArgumentException("Invalid index");
            return internalSetIndex(position);
}