internal ChartDataContext GetDataContext(Point physicalOrigin, ChartPointDistanceCalculationMode pointDistanceMode)
{
// The tool tip location has to be translated because the data points are laid out in a larger layout slot if there is a zoom factor.
// Also, the absolute value of the pan offset is used in the transformation because the pan offset is applied as a negative value to
// the visualization of the plot area in order to simulate pan behavior.
RadRect plotAreaClip = this.PlotAreaClip;
physicalOrigin.X += Math.Abs(plotAreaClip.Width * this.scrollOffsetCache.X);
physicalOrigin.Y += Math.Abs(plotAreaClip.Height * this.scrollOffsetCache.Y);
if (this.lastDataContext != null && this.lastDataContext.TouchLocation == physicalOrigin)
{
return(this.lastDataContext);
}
this.lastDataContext = this.GetDataContextCore(physicalOrigin, pointDistanceMode);
return(this.lastDataContext);
}
internal override double GetDistanceToPoint(DataPoint dataPoint, Point tapLocation, ChartPointDistanceCalculationMode pointDistanceMode)
{
var pieDataPoint = dataPoint as PieDataPoint;
if (pieDataPoint != null && pointDistanceMode == ChartPointDistanceCalculationMode.TwoDimensional)
{
// TODO: Consider whether we will need linear distance.
return(pieDataPoint.GetPolarDistance(tapLocation));
}
return(base.GetDistanceToPoint(dataPoint, tapLocation, pointDistanceMode));
}
internal virtual double GetDistanceToPoint(DataPoint dataPoint, Point tapLocation, ChartPointDistanceCalculationMode pointDistanceMode)
{
var dataPointLocation = dataPoint.Center();
if (pointDistanceMode == ChartPointDistanceCalculationMode.TwoDimensional)
{
////TODO: Math.Sqrt could lead to potential performance issues with lost of points/series.
return(RadMath.GetPointDistance(dataPointLocation.X, tapLocation.X, dataPointLocation.Y, tapLocation.Y));
}
else
{
AxisPlotDirection plotDirection = this.Model.GetTypedValue <AxisPlotDirection>(AxisModel.PlotDirectionPropertyKey, AxisPlotDirection.Vertical);
if (plotDirection == AxisPlotDirection.Vertical)
{
return(Math.Abs(tapLocation.X - dataPointLocation.X));
}
else
{
return(Math.Abs(tapLocation.Y - dataPointLocation.Y));
}
}
}
/// <summary>
/// Gets <see cref="ChartDataContext"/> associated with a gives physical location.
/// </summary>
/// <param name="tapLocation">The relative physical position of the requested data context.</param>
/// <param name="pointDistanceMode">The point distance calculation mode to be used in finding closest point.</param>
/// <returns>Returns <see cref="ChartDataContext"/> object holding information for the requested physical location.</returns>
protected virtual ChartDataContext GetDataContextCore(Point tapLocation, ChartPointDistanceCalculationMode pointDistanceMode)
{
List <DataPointInfo> closestPoints = new List <DataPointInfo>();
double totalMinDistance = double.PositiveInfinity;
DataPointInfo closestPoint = null;
foreach (ChartSeriesModel series in this.chartArea.Series)
{
if (!series.Presenter.IsVisible)
{
continue;
}
DataPointInfo currentClosestDataPoint = null;
double minDistance = double.PositiveInfinity;
ChartSeries visualSeries = series.presenter as ChartSeries;
foreach (DataPoint dataPoint in series.DataPointsInternal)
{
if (dataPoint.isEmpty)
{
continue;
}
double distance;
if (dataPoint.ContainsPosition(tapLocation.X, tapLocation.Y))
{
distance = 0;
}
else
{
distance = visualSeries.GetDistanceToPoint(dataPoint, tapLocation, pointDistanceMode);
}
if (distance < minDistance)
{
minDistance = distance;
if (currentClosestDataPoint == null)
{
currentClosestDataPoint = new DataPointInfo();
}
currentClosestDataPoint.DataPoint = dataPoint;
currentClosestDataPoint.SeriesModel = series;
}
if (distance < totalMinDistance)
{
totalMinDistance = distance;
closestPoint = currentClosestDataPoint;
if (distance == 0)
{
closestPoint.ContainsTouchLocation = true;
}
}
}
if (currentClosestDataPoint != null)
{
closestPoints.Add(currentClosestDataPoint);
}
}
return(new ChartDataContext(closestPoints, closestPoint)
{
TouchLocation = tapLocation
});
}
