/// <summary>
/// We know which labels are overlapping the data points, but we need to make sure the labels that will be
/// displayed can fit in the scale using the Min/MaxGrace properties and adjusting the label fractions if appropriate:
/// TextObjs with CoordType.AxisXYScale coordinates will move proportionally with Min/MaxGrace, but ChartFraction
/// coordinates will not.
/// </summary>
protected void autoScaleForManualLabels(Graphics g)
{
Axis yAxis = YAxis;
bool maxAuto = yAxis.Scale.MaxAuto;
try
{
if (maxAuto)
{
AxisChange(g);
}
double yMaxRequired = 0;
foreach (var kvp in _manualLabels)
{
TextObj text = kvp.Key;
if (text.Location.X < XAxis.Scale.Min || text.Location.X > XAxis.Scale.Max)
{
continue;
}
if (!YAxis.Scale.IsLog && !IsYChartFractionObject(text))
{
double axisHeight = YAxis.Scale.Max - YAxis.Scale.Min;
PointF[] pts = text.FontSpec.GetBox(g, text.Text, 0, 0, text.Location.AlignH, text.Location.AlignV, 1.0f,
new SizeF());
float pixelShift = 0;
var rectPeak = _labelBoundsCache.GetLabelBounds(text, this, g);
foreach (var id in _manualLabels.Keys.Where(IsYChartFractionObject))
{
var rectID = _labelBoundsCache.GetLabelBounds(id, this, g);
// If the rectangles overlap
if (Math.Min(rectID.Right, rectPeak.Right) - Math.Max(rectID.Left, rectPeak.Left) > 0 &&
Math.Min(rectID.Bottom, rectPeak.Bottom) - Math.Max(rectID.Top, rectPeak.Top) > 0)
{
pixelShift = Math.Max(rectID.Height + 7, pixelShift); // 7 pixel gap between labels
}
}
double y2Pos = yAxis.Scale.ReverseTransform(pts[2].Y);
double labelHeight =
Math.Abs(yAxis.Scale.ReverseTransform(pts[0].Y - pixelShift) - y2Pos);
// If separating the labels takes too much space, just revert to showing them aligned
if (labelHeight >= axisHeight / 2)
{
labelHeight = Math.Abs(yAxis.Scale.ReverseTransform(pts[0].Y) - y2Pos);
}
if (labelHeight < axisHeight / 2)
{
// Ensure that the YAxis will have enough space to show the label.
// Only do this if the labelHeight is going to take up less than half the space on the graph, because
// otherwise the graph will be shrunk too much to have any useful information.
// When calculating the scaling required, take into account that the height of the label
// itself will not shrink when we shrink the YAxis.
var labelYMaxRequired = (text.Location.Y - labelHeight * YAxis.Scale.Min / axisHeight) /
(1 - labelHeight / axisHeight);
yMaxRequired = Math.Max(yMaxRequired, labelYMaxRequired);
}
}
if (!GraphObjList.Any(
o =>
(o is TextObj) && ((TextObj)o).Location == text.Location &&
((TextObj)o).Text == text.Text))
{
if (_pointAnnotations.Contains(text))
{
GraphObjList.Add(text);
}
}
}
if (maxAuto && yMaxRequired > 0)
{
yAxis.Scale.Max = Math.Max(yAxis.Scale.Max, yMaxRequired);
}
}
finally
{
// Reset the value of MaxAuto since it may have been changed to false when Scale.Max was changed.
yAxis.Scale.MaxAuto = maxAuto;
}
}
