public static AxisPoint getAxisPoint(Chart xChart, RangeAxis xAxis, Point xPoint)
{
if (xAxis == null) return null;
if (xAxis is LinearAxis)
{
// some redundant basic checks
LinearAxis lAxis = xAxis as LinearAxis;
double? lMin;
double? lMax;
lMin = lAxis.ActualMinimum;
lMax = lAxis.ActualMaximum;
if ((!lMin.HasValue) || (!lMax.HasValue)) return null;
if (lMin.Value >= lMax.Value) return null;
return new AxisPointLinear(xChart, lAxis, xPoint, lMin.Value, lMax.Value);
}
if (xAxis is DateTimeAxis)
{
// some redundant basic checks
DateTimeAxis lAxis = xAxis as DateTimeAxis;
DateTime? lMin;
DateTime? lMax;
lMin = lAxis.ActualMinimum;
lMax = lAxis.ActualMaximum;
if ((!lMin.HasValue) || (!lMax.HasValue)) return null;
if (lMin.Value >= lMax.Value) return null;
return new AxisPointDateTime(xChart, lAxis, xPoint, lMin.Value, lMax.Value);
}
throw new Exception("Axis type not supported yet.");
} //
public readonly double Length; // object pixel display units, larger than zero
public AxisPoint(Chart xChart, RangeAxis xAxis, Point xPoint)
{
if (xAxis.Orientation == AxisOrientation.X) Length = xAxis.ActualWidth;
else Length = xAxis.ActualHeight;
if (Length <= 0) throw new Exception("Chart object length is zero or less.");
MouseAbsoluteLocation = xChart.TranslatePoint(xPoint, xAxis);
if (xAxis.Orientation == AxisOrientation.X) MouseAxisValueRelative = MouseAbsoluteLocation.X / Length;
else MouseAxisValueRelative = 1.0 - (MouseAbsoluteLocation.Y / Length);
if (MouseAxisValueRelative > 1.0) MouseAxisValueRelative = 1.0;
else if (MouseAxisValueRelative < 0.0) MouseAxisValueRelative = 0.0;
} // constructor