/**
* @see <a href="http://en.wikipedia.org/wiki/Sweep_line_algorithm">Sweep line algorithm</a>
*/
private void SweepCleanColumns(CT_Cols cols, CT_Col[] flattenedColsArray, CT_Col overrideColumn)
{
List <CT_Col> flattenedCols = new List <CT_Col>(flattenedColsArray);
TreeSet <CT_Col> currentElements = new TreeSet <CT_Col>(CTColComparator.BY_MAX);
IEnumerator <CT_Col> flIter = flattenedCols.GetEnumerator();
CT_Col haveOverrideColumn = null;
long lastMaxIndex = 0;
long currentMax = 0;
IList <CT_Col> toRemove = new List <CT_Col>();
int pos = -1;
//while (flIter.hasNext())
while ((pos + 1) < flattenedCols.Count)
{
//CTCol col = flIter.next();
pos++;
CT_Col col = flattenedCols[pos];
long currentIndex = col.min;
long colMax = col.max;
long nextIndex = (colMax > currentMax) ? colMax : currentMax;
//if (flIter.hasNext()) {
if ((pos + 1) < flattenedCols.Count)
{
//nextIndex = flIter.next().getMin();
nextIndex = flattenedCols[pos + 1].min;
//flIter.previous();
}
IEnumerator <CT_Col> iter = currentElements.GetEnumerator();
toRemove.Clear();
while (iter.MoveNext())
{
CT_Col elem = iter.Current;
if (currentIndex <= elem.max)
{
break; // all passed elements have been purged
}
toRemove.Add(elem);
}
foreach (CT_Col rc in toRemove)
{
currentElements.Remove(rc);
}
if (!(currentElements.Count == 0) && lastMaxIndex < currentIndex)
{
// we need to process previous elements first
CT_Col[] copyCols = new CT_Col[currentElements.Count];
currentElements.CopyTo(copyCols);
insertCol(cols, lastMaxIndex, currentIndex - 1, copyCols, true, haveOverrideColumn);
}
currentElements.Add(col);
if (colMax > currentMax)
{
currentMax = colMax;
}
if (col.Equals(overrideColumn))
{
haveOverrideColumn = overrideColumn;
}
while (currentIndex <= nextIndex && !(currentElements.Count == 0))
{
NPOI.Util.Collections.HashSet <CT_Col> currentIndexElements = new NPOI.Util.Collections.HashSet <CT_Col>();
long currentElemIndex;
{
// narrow scope of currentElem
CT_Col currentElem = currentElements.First();
currentElemIndex = currentElem.max;
currentIndexElements.Add(currentElem);
while (true)
{
CT_Col higherElem = currentElements.Higher(currentElem);
if (higherElem == null || higherElem.max != currentElemIndex)
{
break;
}
currentElem = higherElem;
currentIndexElements.Add(currentElem);
if (colMax > currentMax)
{
currentMax = colMax;
}
if (col.Equals(overrideColumn))
{
haveOverrideColumn = overrideColumn;
}
}
}
//if (currentElemIndex < nextIndex || !flIter.hasNext()) {
if (currentElemIndex < nextIndex || !((pos + 1) < flattenedCols.Count))
{
CT_Col[] copyCols = new CT_Col[currentElements.Count];
currentElements.CopyTo(copyCols);
insertCol(cols, currentIndex, currentElemIndex, copyCols, true, haveOverrideColumn);
//if (flIter.hasNext()) {
if ((pos + 1) < flattenedCols.Count)
{
if (nextIndex > currentElemIndex)
{
//currentElements.removeAll(currentIndexElements);
foreach (CT_Col rc in currentIndexElements)
{
currentElements.Remove(rc);
}
if (currentIndexElements.Contains(overrideColumn))
{
haveOverrideColumn = null;
}
}
}
else
{
//currentElements.removeAll(currentIndexElements);
foreach (CT_Col rc in currentIndexElements)
{
currentElements.Remove(rc);
}
if (currentIndexElements.Contains(overrideColumn))
{
haveOverrideColumn = null;
}
}
lastMaxIndex = currentIndex = currentElemIndex + 1;
}
else
{
lastMaxIndex = currentIndex;
currentIndex = nextIndex + 1;
}
}
}
SortColumns(cols);
}
