/// <summary>
/// Draw one cell of the header
/// </summary>
/// <param name="g"></param>
/// <param name="columnIndex"></param>
/// <param name="itemState"></param>
protected void CustomDrawHeaderCell(Graphics g, int columnIndex, int itemState)
{
Rectangle r = this.GetItemRect(columnIndex);
OLVColumn column = this.ListView.GetColumn(columnIndex);
const int CDIS_SELECTED = 1;
bool isPressed = ((itemState & CDIS_SELECTED) == CDIS_SELECTED);
// Calculate which style should be used for the header
HeaderStateStyle stateStyle = this.CalculateStyle(column, columnIndex == this.ColumnIndexUnderCursor, isPressed);
// If there is an owner drawn delegate installed, give it a chance to draw the header
if (column.HeaderDrawing != null)
{
if (!column.HeaderDrawing(g, r, columnIndex, column, isPressed, stateStyle))
{
return;
}
}
// Draw the background
if (this.ListView.HeaderUsesThemes &&
VisualStyleRenderer.IsSupported &&
VisualStyleRenderer.IsElementDefined(VisualStyleElement.Header.Item.Normal))
{
this.DrawThemedBackground(g, r, columnIndex, isPressed);
}
else
{
this.DrawUnthemedBackground(g, r, columnIndex, isPressed, stateStyle);
}
// Draw the sort indicator if this column has one
if (this.HasSortIndicator(column))
{
if (this.ListView.HeaderUsesThemes &&
VisualStyleRenderer.IsSupported &&
VisualStyleRenderer.IsElementDefined(VisualStyleElement.Header.SortArrow.SortedUp))
{
this.DrawThemedSortIndicator(g, r);
}
else
{
r = this.DrawUnthemedSortIndicator(g, r);
}
}
if (this.HasFilterIndicator(column))
{
r = this.DrawFilterIndicator(g, r);
}
// Finally draw the text
this.DrawHeaderImageAndText(g, r, column, stateStyle);
}