/// <summary>
/// Calculate the <see cref="Legend"/> rectangle (see cref="Rect"/>),
/// taking into account the number of required legend
/// entries, and the legend drawing preferences. Adjust the size of the
/// <see cref="AldysPane.AxisRect"/> for the parent <see cref="AldysPane"/> to accomodate the
/// space required by the legend.
/// </summary>
/// <param name="g">
/// A graphic device object to be drawn into. This is normally e.Graphics from the
/// PaintEventArgs argument to the Paint() method.
/// </param>
/// <param name="pane">
/// A reference to the <see cref="AldysPane"/> object that is the parent or
/// owner of this object.
/// </param>
/// <param name="scaleFactor">
/// The scaling factor to be used for rendering objects. This is calculated and
/// passed down by the parent <see cref="AldysPane"/> object using the
/// <see cref="AldysPane.CalcScaleFactor"/> method, and is used to proportionally adjust
/// font sizes, etc. according to the actual size of the graph.
/// </param>
/// <param name="axisRect">
/// The rectangle that contains the area bounded by the axes, in pixel units.
/// <seealso cref="AldysPane.AxisRect">AxisRect</seealso>
/// </param>
/// <param name="hStack">The number of columns (horizontal stacking) to be used
/// for drawing the legend</param>
/// <param name="legendWidth">The width of each column in the legend (pixels)</param>
public void CalcRect(Graphics g, AldysPane pane, double scaleFactor,
ref RectangleF axisRect, out int hStack,
out float legendWidth)
{
// Start with an empty rectangle
this.rect = Rectangle.Empty;
hStack = 1;
legendWidth = 1;
// If the legend is invisible, don't do anything
if (!this.isVisible)
{
return;
}
int nCurve = 0;
float charHeight = this.FontSpec.GetHeight(scaleFactor),
halfCharHeight = charHeight / 2.0F,
charWidth = this.FontSpec.GetWidth(g, scaleFactor),
gap = pane.ScaledGap(scaleFactor),
maxWidth = 0,
tmpWidth;
// Loop through each curve in the curve list
// Find the maximum width of the legend labels
foreach (CurveItem curve in pane.CurveList)
{
// Calculate the width of the label save the max width
if (curve.Label.ToString() == "")
{
continue;
}
tmpWidth = this.FontSpec.GetWidth(g, curve.Label, scaleFactor);
if (tmpWidth > maxWidth)
{
maxWidth = tmpWidth;
}
nCurve++;
}
float widthAvail;
// Is this legend horizontally stacked?
if (this.isHStack)
{
// Determine the available space for horizontal stacking
switch (this.location)
{
// Never stack if the legend is to the right or left
case LegendLoc.Right:
case LegendLoc.Left:
widthAvail = 0;
break;
// for the top & bottom, the axis frame width is available
case LegendLoc.Top:
case LegendLoc.Bottom:
widthAvail = pane.AxisRect.Width;
break;
// for inside the axis area, use 1/2 of the axis frame width
case LegendLoc.InsideTopRight:
case LegendLoc.InsideTopLeft:
case LegendLoc.InsideBotRight:
case LegendLoc.InsideBotLeft:
widthAvail = pane.AxisRect.Width / 2;
break;
// shouldn't ever happen
default:
widthAvail = 0;
break;
}
// width of one legend entry
legendWidth = 3 * charHeight + maxWidth;
// Calculate the number of columns in the legend
// Normally, the legend is:
// available width / ( max width of any entry + space for line&symbol )
if (maxWidth > 0)
{
hStack = (int)((widthAvail - halfCharHeight) / legendWidth);
}
// You can never have more columns than legend entries
if (hStack > nCurve)
{
hStack = nCurve;
}
// a saftey check
if (hStack == 0)
{
hStack = 1;
}
}
else
{
legendWidth = 3.5F * charHeight + maxWidth;
}
// legend is:
// item: space line space text space
// width: wid 4*wid wid maxWid wid
// The symbol is centered on the line
//
// legend begins 3 * wid to the right of the plot rect
//
// The height of the legend is the actual height of the lines of text
// (nCurve * hite) plus wid on top and wid on the bottom
// total legend width
float totLegWidth = hStack * legendWidth;
// The total legend height
float legHeight = (float)Math.Ceiling((double)nCurve / (double)hStack)
* charHeight;
// Now calculate the legend rect based on the above determined parameters
// Also, adjust the plotArea and axisRect to reflect the space for the legend
if (nCurve > 0)
{
// The switch statement assigns the left and top edges, and adjusts the axisRect
// as required. The right and bottom edges are calculated at the bottom of the switch.
switch (this.location)
{
case LegendLoc.Right:
this.rect.X = pane.PaneRect.Right - totLegWidth - gap;
this.rect.Y = axisRect.Top;
axisRect.Width -= totLegWidth + halfCharHeight;
break;
case LegendLoc.Top:
this.rect.X = axisRect.Left;
this.rect.Y = axisRect.Top;
axisRect.Y += legHeight + halfCharHeight;
axisRect.Height -= legHeight + halfCharHeight;
break;
case LegendLoc.Bottom:
this.rect.X = axisRect.Left;
this.rect.Y = pane.PaneRect.Bottom - legHeight - gap;
axisRect.Height -= legHeight + halfCharHeight;
break;
case LegendLoc.Left:
this.rect.X = pane.PaneRect.Left + gap;
this.rect.Y = axisRect.Top;
axisRect.X += totLegWidth + halfCharHeight;
axisRect.Width -= totLegWidth + halfCharHeight;
break;
case LegendLoc.InsideTopRight:
this.rect.X = axisRect.Right - totLegWidth;
this.rect.Y = axisRect.Top;
break;
case LegendLoc.InsideTopLeft:
this.rect.X = axisRect.Left;
this.rect.Y = axisRect.Top;
break;
case LegendLoc.InsideBotRight:
this.rect.X = axisRect.Right - totLegWidth;
this.rect.Y = axisRect.Bottom - legHeight;
break;
case LegendLoc.InsideBotLeft:
this.rect.X = axisRect.Left;
this.rect.Y = axisRect.Bottom - legHeight;
break;
}
// Calculate the Right and Bottom edges of the rect
this.rect.Width = totLegWidth;
this.rect.Height = legHeight;
}
}
/// <summary>
/// Render the <see cref="Legend"/> to the specified <see cref="Graphics"/> device
/// This method is normally only called by the Draw method
/// of the parent <see cref="AldysPane"/> object.
/// </summary>
/// <param name="g">
/// A graphic device object to be drawn into. This is normally e.Graphics from the
/// PaintEventArgs argument to the Paint() method.
/// </param>
/// <param name="pane">
/// A reference to the <see cref="AldysPane"/> object that is the parent or
/// owner of this object.
/// </param>
/// <param name="scaleFactor">
/// The scaling factor to be used for rendering objects. This is calculated and
/// passed down by the parent <see cref="AldysPane"/> object using the
/// <see cref="AldysPane.CalcScaleFactor"/> method, and is used to proportionally adjust
/// font sizes, etc. according to the actual size of the graph.
/// </param>
/// <param name="hStack">The number of columns (horizontal stacking) to be used
/// for drawing the legend</param>
/// <param name="legendWidth">The width of each column in the legend</param>
public void Draw(Graphics g, AldysPane pane, double scaleFactor,
int hStack, float legendWidth)
{
// if the legend is not visible, do nothing
if (!this.isVisible)
{
return;
}
// Fill the background with the specified color if required
if (this.isFilled)
{
SolidBrush brush = new SolidBrush(this.fillColor);
g.FillRectangle(brush, this.rect);
}
// Set up some scaled dimensions for calculating sizes and locations
float charHeight = this.FontSpec.GetHeight(scaleFactor),
halfCharHeight = charHeight / 2.0F;
float charWidth = this.FontSpec.GetWidth(g, scaleFactor);
float gap = pane.ScaledGap(scaleFactor);
int iEntry = 0;
float x, y;
// Get a brush for the legend label text
SolidBrush brushB = new SolidBrush(Color.Black);
// Loop for each curve in the CurveList collection
foreach (CurveItem curve in pane.CurveList)
{
// Calculate the x,y (TopLeft) location of the current
// curve legend label
// assuming:
// charHeight/2 for the left margin, plus legendWidth for each
// horizontal column
// charHeight is the line spacing, with no extra margin above
if (curve.Label.ToString() != "")
{
x = this.rect.Left + halfCharHeight +
(iEntry % hStack) * legendWidth;
y = this.rect.Top + (int)(iEntry / hStack) * charHeight;
// Draw the legend label for the current curve
this.FontSpec.Draw(g, curve.Label, x + 2.5F * charHeight, y,
FontAlignH.Left, FontAlignV.Top, scaleFactor);
// Draw a sample curve to the left of the label text
curve.Line.Draw(g, x, y + charHeight / 2,
x + 2 * charHeight, y + halfCharHeight);
// Draw a sample symbol to the left of the label text
curve.Symbol.Draw(g, x + charHeight, y + halfCharHeight,
scaleFactor);
// maintain a curve count for positioning
iEntry++;
}
}
// Draw a frame around the legend if required
if (iEntry > 0 && this.isFramed)
{
Pen pen = new Pen(this.frameColor, this.frameWidth);
g.DrawRectangle(pen, Rectangle.Round(this.rect));
}
}