/// <summary>
/// Updates the chart when the data has been changed. (Optional - The data source is
/// updated automatically when the chart is drawn.)
/// </summary>
public void UpdateDataSource()
{
if (_isDataSourceValid)
return;
Data = null;
Axis xAxis = XAxis;
Axis yAxis = YAxis;
if (xAxis == null || yAxis == null)
{
// Postpone update until axes are set.
return;
}
CultureInfo culture = ChartHelper.GetCulture(this);
IList<TextLabel> xLabels = GetLabels(xAxis);
IList<TextLabel> yLabels = GetLabels(yAxis);
Data = ChartDataHelper.CreateChartDataSource(DataSource, XValuePath, YValuePath, XYValuePath, culture, xLabels, yLabels);
ValidateData();
_isDataSourceValid = true;
if (xAxis.AutoScale)
xAxis.Invalidate();
if (yAxis.AutoScale)
yAxis.Invalidate();
}
/// <summary>
/// Suggests a scale for the base axis (independent values).
/// </summary>
/// <returns>
/// A suitable <see cref="TextScale"/> with ticks between the text labels.
/// </returns>
public AxisScale SuggestBaseScale()
{
if (Data == null || Data.Count == 0)
return null;
CultureInfo culture = ChartHelper.GetCulture(this);
Orientation orientation = EffectiveOrientation;
if (Data.Count == 1)
{
DataPoint data = Data[0];
double value = (orientation == Orientation.Vertical) ? data.X : data.Y;
TextScale textScale = new TextScale(value - 0.5, value + 0.5);
textScale.Labels.Add(new TextLabel(value, value.ToString(culture), null));
textScale.TicksBetweenLabels = true;
return textScale;
}
else
{
DataPoint dataN = Data[0];
DataPoint dataNPlus1 = Data[1];
DataPoint dataNMinus2 = Data[Data.Count - 2];
DataPoint dataNMinus1 = Data[Data.Count - 1];
double valueN;
double valueNPlus1;
double valueNMinus2;
double valueNMinus1;
if (orientation == Orientation.Vertical)
{
valueN = dataN.X;
valueNPlus1 = dataNPlus1.X;
valueNMinus2 = dataNMinus2.X;
valueNMinus1 = dataNMinus1.X;
}
else
{
valueN = dataN.Y;
valueNPlus1 = dataNPlus1.Y;
valueNMinus2 = dataNMinus2.Y;
valueNMinus1 = dataNMinus1.Y;
}
double min = valueN - (valueNPlus1 - valueN) / 2;
double max = valueNMinus1 + (valueNMinus1 - valueNMinus2) / 2;
TextScale textScale = new TextScale(min, max)
{
TicksBetweenLabels = true
};
for (int i = 0; i < Data.Count; i++)
{
DataPoint data = Data[i];
double value = (orientation == Orientation.Vertical) ? data.X : data.Y;
textScale.Labels.Add(new TextLabel(value, value.ToString(culture), null));
}
return textScale;
}
}
