/// <summary>
/// Draw the NodeCollection instance.
/// </summary>
/// <param name="tc">Reference to owning TreeControl.</param>
/// <param name="nc">Reference to NodeCollection instance.</param>
/// <param name="g">Reference to Graphics instance to draw into.</param>
/// <param name="clipRectangle">Clipping rectangle used when drawing.</param>
/// <param name="preDraw">True when drawing before children and fales for drawing after.</param>
public virtual void Draw(TreeControl tc,
NodeCollection nc,
Graphics g,
Rectangle clipRectangle,
bool preDraw)
{
if (preDraw)
{
// Only draw lines and boxes if there is at least one child node
if (nc.VisibleCount > 0)
{
// Find out if lines and boxes needed drawing
bool showLines = ShowLines(tc, nc);
bool showBoxes = ShowBoxes(tc, nc);
bool showIndicators = (IsRootCollection(tc, nc) && (tc.Indicators != Indicators.None)) ||
(!IsRootCollection(tc, nc) && (tc.Indicators == Indicators.AtGroup));
// Is there any drawing to perform?
if (showLines || showBoxes || showIndicators)
{
Pen lineDashPen = tc.GetCacheLineDashPen();
// Cache the whole rectangle used for drawing
Rectangle ncBounds = nc.Cache.Bounds;
// Find the size of space taken up with indicators
Size indicatorSize = showIndicators ? tc.IndicatorSize : Size.Empty;
// Perform any adjustment for drawing within the bounds
AdjustBeforeDrawing(tc, nc, ref ncBounds);
// Cache the mid and right hand side of the lines column
int xMid = ncBounds.Left + indicatorSize.Width + (tc.ColumnWidth / 2) - 1;
int xRight = ncBounds.Left + indicatorSize.Width + tc.ColumnWidth;
// Need to adjust drawing child connecting lines, so that wider than one
// pixel pens start from left of vertical for top and bottom children, but
// are placed to the right of middle children.
int xMidAdjustL = xMid - (tc.LineWidth / 2);
int xMidAdjustR = xMid + 1;
// Find the first and last visible nodes
int firstVisible = nc.FirstVisibleIndex;
int lastVisible = nc.LastVisibleIndex;
// Find the first and last nodes mid points
int yMidFirst = nc[firstVisible].Cache.Bounds.Top + (nc[firstVisible].Cache.Bounds.Height / 2);
int yMidLast = nc[lastVisible].Cache.Bounds.Top + (nc[lastVisible].Cache.Bounds.Height / 2);
// No point drawing line after end of clipping rectangle
if (yMidLast > clipRectangle.Bottom)
{
yMidLast = clipRectangle.Bottom;
}
// Do we need to draw the long vertical line?
if (showLines)
{
// Draw the long vertical line down the middle
if (IsRootCollection(tc, nc))
{
// No point drawing line before start of clipping rectangle
if (yMidFirst < clipRectangle.Top)
{
yMidFirst = clipRectangle.Top;
// Adjust starting point up so dot/dash lines are consistent
switch (tc.LineDashStyle)
{
case LineDashStyle.Dot:
yMidFirst -= yMidFirst % (2 * tc.LineWidth);
break;
case LineDashStyle.Dash:
yMidFirst -= yMidFirst % (4 * tc.LineWidth);
break;
}
}
// We are root collection, so draw from the first node to the last
g.DrawLine(lineDashPen, xMid, yMidFirst, xMid, yMidLast);
}
else
{
// Not at root, so draw from top of column to the last node
g.DrawLine(lineDashPen, xMid, ncBounds.Top, xMid, yMidLast);
}
}
// Process each child node in turn, drawing horizontal line and any box
for (int i = nc.ChildFromY(clipRectangle.Top); i < nc.Count; i++)
{
if (DrawNode(tc, nc[i], g, clipRectangle, showLines, showBoxes,
showIndicators, (i == 0) || (i == (nc.Count - 1)),
lineDashPen, xMidAdjustL, xMidAdjustR, xMid, xRight,
ncBounds.Left))
{
break;
}
}
}
}
}
}