protected void OnScroll(float oldPos, float newPos)
{
float delta = newPos - oldPos;
int firstVisibleCellIndex = FirstVisibleCellIndex;
int lastVisibleCellIndex = LastVisibleCellIndex;
if (delta > 0)
{
int rowsCount = RowsCount;
// wipe invisible rows
while (!IsCellVisible(firstVisibleCellIndex, newPos) && VisibleCellsCount > 0)
{
RemoveVisibleCell(FirstVisibleCell);
++firstVisibleCellIndex;
}
if (VisibleCellsCount > 0) // not all rows were wiped: just append more visible cells at the end
{
for (int cellIndex = lastVisibleCellIndex + 1; cellIndex < rowsCount && IsCellVisible(cellIndex, newPos); ++cellIndex)
{
CTableViewCell cell = TableCellForRow(cellIndex);
m_visibleCells.AddLastItem(cell);
}
}
else
{
int rowIndex = FindFirstVisibleRow(newPos, lastVisibleCellIndex + 1, rowsCount - 1);
while (rowIndex < rowsCount && IsCellVisible(rowIndex, newPos))
{
CTableViewCell cell = TableCellForRow(rowIndex);
m_visibleCells.AddLastItem(cell);
++rowIndex;
}
}
}
else if (delta < 0)
{
while (this.VisibleCellsCount > 0 && !IsCellVisible(lastVisibleCellIndex, newPos))
{
RemoveVisibleCell(LastVisibleCell);
--lastVisibleCellIndex;
}
if (VisibleCellsCount > 0) // not all rows were wiped: just prepend more visible cells at the beginning
{
for (int cellIndex = firstVisibleCellIndex - 1; cellIndex >= m_cellsEntries.HeadIndex && IsCellVisible(cellIndex, newPos); --cellIndex)
{
CTableViewCell cell = TableCellForRow(cellIndex);
m_visibleCells.AddFirstItem(cell);
}
}
else
{
int rowIndex = FindLastVisibleRow(newPos, m_cellsEntries.HeadIndex, firstVisibleCellIndex - 1);
while (rowIndex >= m_cellsEntries.HeadIndex && IsCellVisible(rowIndex, newPos))
{
CTableViewCell cell = TableCellForRow(rowIndex);
m_visibleCells.AddFirstItem(cell);
--rowIndex;
}
}
}
if (ScrollDelegate != null)
{
ScrollDelegate.OnTableScroll(this, oldPos);
}
}
