/// <summary>
/// Paints an annotation object on the specified graphics.
/// </summary>
/// <param name="graphics">
/// A <see cref="ChartGraphics"/> object, used to paint an annotation object.
/// </param>
/// <param name="chart">
/// Reference to the <see cref="Chart"/> owner control.
/// </param>
override internal void Paint(Chart chart, ChartGraphics graphics)
{
// Get annotation position in relative coordinates
PointF firstPoint = PointF.Empty;
PointF anchorPoint = PointF.Empty;
SizeF size = SizeF.Empty;
GetRelativePosition(out firstPoint, out size, out anchorPoint);
PointF secondPoint = new PointF(firstPoint.X + size.Width, firstPoint.Y + size.Height);
// Create selection rectangle
RectangleF selectionRect = new RectangleF(firstPoint, new SizeF(secondPoint.X - firstPoint.X, secondPoint.Y - firstPoint.Y));
// Adjust coordinates
AdjustLineCoordinates(ref firstPoint, ref secondPoint, ref selectionRect);
// Check if text position is valid
if (float.IsNaN(firstPoint.X) ||
float.IsNaN(firstPoint.Y) ||
float.IsNaN(secondPoint.X) ||
float.IsNaN(secondPoint.Y))
{
return;
}
// Set line caps
bool capChanged = false;
LineCap oldStartCap = LineCap.Flat;
LineCap oldEndCap = LineCap.Flat;
if (this._startCap != LineAnchorCapStyle.None ||
this._endCap != LineAnchorCapStyle.None)
{
capChanged = true;
oldStartCap = graphics.Pen.StartCap;
oldEndCap = graphics.Pen.EndCap;
// Apply anchor cap settings
if (this._startCap == LineAnchorCapStyle.Arrow)
{
// Adjust arrow size for small line width
if (this.LineWidth < 4)
{
int adjustment = 3 - this.LineWidth;
graphics.Pen.StartCap = LineCap.Custom;
graphics.Pen.CustomStartCap = new AdjustableArrowCap(
this.LineWidth + adjustment,
this.LineWidth + adjustment,
true);
}
else
{
graphics.Pen.StartCap = LineCap.ArrowAnchor;
}
}
else if (this._startCap == LineAnchorCapStyle.Diamond)
{
graphics.Pen.StartCap = LineCap.DiamondAnchor;
}
else if (this._startCap == LineAnchorCapStyle.Round)
{
graphics.Pen.StartCap = LineCap.RoundAnchor;
}
else if (this._startCap == LineAnchorCapStyle.Square)
{
graphics.Pen.StartCap = LineCap.SquareAnchor;
}
if (this._endCap == LineAnchorCapStyle.Arrow)
{
// Adjust arrow size for small line width
if (this.LineWidth < 4)
{
int adjustment = 3 - this.LineWidth;
graphics.Pen.EndCap = LineCap.Custom;
graphics.Pen.CustomEndCap = new AdjustableArrowCap(
this.LineWidth + adjustment,
this.LineWidth + adjustment,
true);
}
else
{
graphics.Pen.EndCap = LineCap.ArrowAnchor;
}
}
else if (this._endCap == LineAnchorCapStyle.Diamond)
{
graphics.Pen.EndCap = LineCap.DiamondAnchor;
}
else if (this._endCap == LineAnchorCapStyle.Round)
{
graphics.Pen.EndCap = LineCap.RoundAnchor;
}
else if (this._endCap == LineAnchorCapStyle.Square)
{
graphics.Pen.EndCap = LineCap.SquareAnchor;
}
}
if (this.Common.ProcessModePaint)
{
// Draw line
graphics.DrawLineRel(
this.LineColor,
this.LineWidth,
this.LineDashStyle,
firstPoint,
secondPoint,
this.ShadowColor,
this.ShadowOffset);
}
if (this.Common.ProcessModeRegions)
{
// Create line graphics path
using (GraphicsPath path = new GraphicsPath())
{
path.AddLine(
graphics.GetAbsolutePoint(firstPoint),
graphics.GetAbsolutePoint(secondPoint));
using (Pen pen = (Pen)graphics.Pen.Clone())
{
// Increase pen size by 2 pixels
pen.DashStyle = DashStyle.Solid;
pen.Width += 2;
try
{
path.Widen(pen);
}
catch (OutOfMemoryException)
{
// GraphicsPath.Widen incorrectly throws OutOfMemoryException
// catching here and reacting by not widening
}
catch (ArgumentException)
{
}
}
// Add hot region
this.Common.HotRegionsList.AddHotRegion(
graphics,
path,
false,
ReplaceKeywords(this.ToolTip),
String.Empty,
String.Empty,
String.Empty,
this,
ChartElementType.Annotation);
}
}
// Restore line caps
if (capChanged)
{
graphics.Pen.StartCap = oldStartCap;
graphics.Pen.EndCap = oldEndCap;
}
// Paint selection handles
PaintSelectionHandles(graphics, selectionRect, null);
}